Type 1 diabetes: treatment
EBM Klinik protokolları
31.08.2018 • Sonuncu dəyişiklik 31.08.2018
PirjoIlanne-Parikka
Essentials
The lack of insulin production by the pancreas is compensated by individual administration of different insulin preparations into the subcutaneous fat by injection or using an insulin pump.- In a patient with insulin deficiency, the administration of basal insulin must not be discontinued in any circumstances although it may be necessary to reduce the dose in certain situations.
- Multiple daily injections mimicking normal insulin secretion, with administration at night and between mealtimes (basal insulin) as well as during mealtimes (mealtime insulin), and pump therapy are the primary forms of treatment in patients with type 1 diabetes.
- Meal-specific assessment of carbohydrates is needed for the dosing of mealtime insulin but the principles of healthy eating to prevent arterial disease form an important part of dietary advice.
- Despite careful treatment, plasma glucose (blood sugar) concentrations vary. This may be due to variation in insulin absorption, food composition and gastric emptying, as well as stress, sickness, exercise or menstrual cycle, for instance. Temporary high concentrations are corrected with additional doses of rapid-acting insulin (corrective insulin) administered in association with meals.
- Patients are taught to adjust the insulin dosage themselves according to their daily rhythms, eating patterns, exercise and self-monitoring or sensoring of blood glucose continuous tissue glucose monitoring.
- Good treatment results are based on
- the patient’s acceptance of diabetes as a part of their life;
- recurrent, professionally skilled guidance of treatment according to individual needs;
- continuity of care, i.e. not constantly changing doctors/nurses;
- sufficient and reasonable self-monitoring and/or sensoring of blood glucose, and action taken according to the results;
- the patient becoming the expert in the daily treatment of the disease;
- shared, neutral and empowering problem solving.
- The individual aims and modes of treatment should be decided together with the patient, taking into account their current life situation, proneness to hypoglycaemia and ability to carry out the treatment themselves.
- Hypoglycaemias and fear thereof may pose a substantial obstacle to good control of diabetes.
- If good glycaemic control is not achieved with an appropriate multiple injection regimen and adequate self-monitoring and/or sensoring of blood glucose (i.e. if HbA1c exceeds the individual target, there are episodes of severe hypoglycaemia or wide daily variations in blood glucose concentrations) the suitability of insulin pump therapy is jointly evaluated or the patient is referred to an appropriate insulin pump therapy unit for this purpose.
- Insulin pump therapy is the best way to adjust insulin dosing to correspond to the varying requirements.
- A pump delivers a constant infusion of rapid-acting insulin into the subcutaneous fatty tissue to achieve a basal insulin effect. At mealtimes, a mealtime insulin dose (bolus) is administered, calculated according to carbohydrate intake, exercise or other activity.
- In type 1 diabetes, blood pressure and blood lipids must also be in good control.The missing insulin production of the pancreas is replaced by individual administration of different insulin preparations into the subcutaneous fat through injections or an insulin pump.In a patient with insulin deficiency, the administration of basal insulin must not be discontinued in any circumstances even if it may be necessary to reduce the dose in certain situations.A regime based on multiple daily insulin injections is the primary treatment mode in a patient with type 1 diabetes. It mimics normal insulin secretion at night and between mealtimes (basal insulin) as well as during mealtimes (mealtime insulin).Even in good diabetes control the blood glucose concentrations vary (due to, e.g., variation in insulin absorption, food composition and gastric emptying as well as stress, sickness, exercise, menstrual cycle). Temporary high concentrations are corrected with additional doses of rapid-acting insulin (corrective insulin) administered at meals.The patient is taught to adjust the insulin dosage him-/herself according to the daily rhythms, eating patterns, exercise and self-monitoring of blood glucose (plasma glucose concentration).
Good treatment results are based on
sufficient guidance as well as continuity of carethe patient’s acceptance of the disease as a part of one’s own lifesufficient and reasonable self-monitoring of blood glucose and actions taken according to the measurement results
the ability of the patient to master the daily care of his illness
shared, neutral and empowering problem solving.
The individual aims and modes of treatment should be decided with the patient, taking into account the current life situation, the patient’s proneness to hypoglycaemia and the ability of the patient to carry out the treatment himself/herself.Hypoglycaemias and the fear of them may pose an essential obstacle to good control of diabetes. If good glycaemic control is not achieved (HbA1c exceeds the individually set target, episodes of severe hypoglycaemia or wide daily variations in blood glucose concentration occur) with an appropriate multiple injection regime consisting of rapid-acting and long-acting insulin derivatives, the patient is referred for glucose sensor monitoring and for consideration of an insulin pump.
In type 1 diabetes, blood pressure and blood lipids must also be in good control.
Targets for glycaemic control
The general target for the glycation of erythrocytes, i.e. the blood level of glycohaemoglobin (B-HbA1c), is less than 53 mmol/mol (7%), without episodes of significant hypoglycaemia.- On individual grounds (e.g. patients with recently diagnosed diabetes, successful pump therapy and continuous glucose monitoring, proneness to hypoglycaemia), the target may be more or less strict, e.g. below 50–60 mmol/mol.
- In self-monitoring, the common target values for blood glucose concentrations are:
- before breakfast and other meals and during the night usually 4–7 mmol/l
- after meals usually below 8–10 mmol/l.
- If recurrent significant episodes of hypoglycaemia do occur, the target level should be relaxed. The target before meals may then be 5–8 mmol/l, for example.
- Repeated wide fluctuation of blood glucose concentrations compromising daily life and causing uncomfortable sensations should be avoided.The general target HbA1c level is less than 7% (53 mmol/mol), without episodes of significant hypoglycaemia.For conversion between HbA1c concentration units, see .On individual grounds (e.g. proneness to hypoglycaemia) the target may be less strict, and in some patients a HbA1c concentration below 7.5–8 % (58–64 mmol/mol) may be considered as a realistic target.
The usual target values for plasma glucose concentrations in self-monitoring are:
before breakfast and other meals and during the night as a rule 4–7 mmol/l
approximately 12 hours after meals as a rule below 8–10 mmol/l.
If recurrent shocks do occur, the target level should be relaxed. The target in such a case may be e.g. 5–8 mmol/l before meals.
Repeated wide fluctuations of blood glucose concentration impairing the daily life and causing uncomfortable sensations are avoided. These are often induced by too large proportion of basal insulin and (symptomless) hypoglycaemias as well as subsequent reactive rises in blood glucose concentrations.
Assessing appropriate insulin dose
Add up the total of all daily insulin doses, i.e. the mean total insulin dose in units/kg/day. The total daily insulin requirement of a normal weight patient with type 1 diabetes is usually 0.5–0.8 units/kg. - The requirement may be lower (0.2–0.6 units/kg/day) during the first years after diagnosis (when there is still some residual insulin production) or in highly insulin-sensitive patients.
- The insulin requirement is increased by insulin resistance related to obesity, stress, sickness or puberty.
- If the total daily insulin dose exceeds 1 unit/kg, try to find the reason for this. Are the injection sites too confined, is there oedema or induration or are there other injection site reactions? Is the insulin product well absorbed? Is there some inflammation or stress increasing the need for insulin?
- Check the ratio of basal to mealtime insulin. In patients on an ordinary diet, usually about half or slightly less (30–50%) of the total daily insulin should be derived from basal insulin and the rest from mealtime insulin boluses.
- Paired evening/morning blood glucose tests, i.e. tests performed at bedtime after the evening snack and again in the morning before breakfast, as well as tests before meals and during the night, as necessary, are used to determine the appropriate dose of basal insulin. Continuous tissue glucose monitoring facilitates the assessment of the need for basal insulin.
- The timing and dose of rapid-acting insulin in association with meals depends on blood glucose levels before the meal, the meal composition (carbohydrate intake in particular) and exercising after the meal. An adult of normal weight requires about 0.8–1.2 units of rapid-acting insulin per 10 g of carbohydrates; however, the requirement is lower in patients with significant insulin sensitivity and higher in patients with insulin resistance.
- With the aid of pre-meal and post-meal (about 2 hours after a meal) blood glucose tests, the patient should be taught how to estimate the relationship between the mealtime bolus dose and carbohydrate intake.
- If the insulin-carbohydrate ratio and the timing of the injection are correct, blood glucose will not increase more than 2–3 mmol/l from the pre-meal value.
- At different meals (at different times of the day) the relative need for mealtime insulin may vary slightly.The daily total insulin requirement of a patient of normal weight with type 1 diabetes is usually approximately 0.5–0.8(–1.0) units/kg.
The requirement may be significantly lower (0.2–0.6 units/kg) during the first years after diagnosis (when some residual insulin production still remains) or in highly insulin-sensitive patients.
Insulin requirement is increased by insulin resistance related to overweight, stress, sickness or puberty.
Of the total daily insulin, about half (40–50%) should be derived from basal insulin and the rest from mealtime insulin boluses.
Paired evening/morning blood glucose measurements, i.e. measurements taken at bedtime after evening snack and again in the morning before breakfast, as well as measurements before meals and, if necessary, during the night are used to determine the dose for basal insulin.
The dose of mealtime boluses is determined according to the carbohydrate intake. An adult of normal weight requires about 0.8–1.2 units of mealtime insulin per 10 g of carbohydrates; the requirement is lower in patients with significant insulin sensitivity and higher in patients with insulin resistance. With the aid of both pre-meal and post-meal (about 2 hours after a meal) blood glucose measurements, the patient should be taught how to estimate the relationship between the mealtime bolus dose and carbohydrate intake. If the bolus dose and the timing of the injection are correct, blood glucose will not increase more than 2–3 mmol/l from the pre-meal value.At different meals (at different times of the day) the relative need of mealtime insulin may slightly vary.
Rules of thumb for insulin therapy
An average person weighs 70 kg and his daily insulin dose is 40–50 units- In an average person:
- 10 grams of carbohydrates increase blood glucose by about 2 mmol/l
- 10 grams of carbohydrates require about 1 unit of rapid-acting insulin, or, expressed the other way round, 1 unit of rapid-acting insulin will cover 10 grams of carbohydrates
- 1 unit of rapid-acting insulin lowers the blood glucose concentration by about 2 mmol/l.
- Dividing the number 500 with the total number of insulin units per 24 hours provides a rough estimate of the amount of carbohydrates covered by one unit of rapid-acting insulin in an individual patient. This is known as the insulin carbohydrate ratio.
- Dividing the number 100 with the total number of insulin units per 24 hours provides a rough estimate of the blood glucose lowering effect of one unit of rapid-acting insulin in an individual patient. This is known as the insulin sensitivity.
- For example, if a patient's total amount of insulin per 24 hours is 30 units, one unit of rapid-acting insulin will cover about 15 grams of carbohydrates and lower the blood glucose concentration by about 3 mmol/l.
- Respectively, if the total insulin amount is 60 units / 24 hours, one unit of rapid-acting insulin will cover roughly 8 grams of carbohydrates and lower the blood glucose concentration by about 1.5 mmol/l.
An average person weighs 70 kg and his daily insulin dose is 40–50 units.
In an average person:
10 grams of carbohydrates increase blood glucose about 2 mmol/l
About 1 unit of mealtime insulin is required to cover each 10 grams of carbohydrates 1 unit of insulin decreases blood glucose by about 2 mmol/l.
Dividing the number 100 with the total number of insulin units per 24 hours provides a guiding estimate for the blood sugar lowering effect of one unit of rapid-acting insulin.
For example, if the total amount of insulin per 24 hours is 30 units, one unit of rapid-acting insulin lowers the blood glucose concentration by an estimated 3 mmol/l. Respectively, if the total insulin amount is 60 units/24 hours, the effect of one unit of rapid-acting insulin is an estimated 1.7 mmol/l.
Principles of insulin administration
Basal insulin in a multiple injection regimen
The duration of action of 100 units/ml of insulin glargine (Abasaglar® and Lantus®) is approximately 20–30 hours. Once daily administration, usually in the evening, is sufficient for two out of three patients with insulin deficiency. In one in three patients, a more even and sufficiently long duration of action can be achieved by dividing the dose into two, i.e. morning and evening injections. - The duration of action of 300 units/ml of insulin glargine (Toujeo®) is longer, and the product is given once daily.
- The duration of action of insulin detemir (Levemir®) varies from about 12 to 24 hours, depending on the dose. In type 1 diabetes, it is usually given twice daily, in the morning/midmorning and evening.
- The duration of action of insulin degludec (Tresiba®) is more than 33–42 hours. There are two strengths, 100 and 200 units/ml. Degludec is given once daily.
- The duration of action of NPH insulin (Humulin NPH®, Insuman basal®, Protaphane®) is approximately 12–20 hours, depending on the dose.
- NPH insulin is no longer recommended for the treatment of type 1 diabetes. It involves a higher risk of hypoglycaemia than insulin derivatives.
- NPH insulin has a peak effect about 4–12 hours after the injection. If NPH was injected in the morning, a delayed lunch can easily lead to hypoglycaemia and a snack will be necessary in the afternoon. Correspondingly, NPH insulin injected in the evening may lead to nocturnal hypoglycaemia and the blood glucose concentration must therefore be higher at bedtime than when insulin degludec, detemir or glargine is used.
- The lowest possible dose of basal insulin is injected to obtain the target levels for pre-meal and night-time blood glucose. Blood glucose values will thus not decrease excessively even if a meal is missed or delayed.
- In an adult in the early hours of the night, less basal insulin is usually needed, whereas about 4 hours before and after awakening the need is increased (dawn phenomenon and awakening stress).
- It is advisable to agree on the range of variation in the dose of basal insulin together with the patient.
- Encourage and advise the patient to use less basal insulin on days with a lot of exercise and the following nights, and to increase the dose of basal insulin on days of sickness.
- Advise the patient to correct transient variation in blood glucose with rapid-acting insulin, not long-acting insulin.
- If NPH insulin is changed to insulin detemir or glargine, the dose of basal insulin should initially be reduced by 10–30%, depending on the level of HbA1c. At the same time, the mealtime insulin requirement will increase, particularly at breakfast and the evening snack, and mealtime insulin injections must be given to cover all snacks (unless the snack is taken in order to prepare for exercise).
- If 100 units/ml basal insulin (Abasaglar®, Lantus®, Levemir®) is replaced by 300 units/ml insulin glargine (Toujeo®) or 100 or 200 units/ml insulin degludec, the dose of basal insulin should initially be reduced by 10–20%, depending on the HbA1c level.
- The blood glucose lowering effects of one unit of various basal insulin products are not necessarily quite equivalent.
- The daily dose of basal insulin should be decreased if the patient repeatedly has readings below 4 mmol/l before meals or if the blood glucose concentration decreases by more than 3 mmol/l overnight due to basal insulin.
- The daily dose of basal insulin should be increased if the patient repeatedly has too high readings in the morning when waking up or before meals and they are not caused by a post-hypoglycaemic reaction.
- Initially, blood glucose should also be measured 2 hours after the preceding meal to verify that the high blood glucose level is not due to the preceding mealtime bolus dose being too low.
The duration of action for insulin glargine is approximately 20–30 hours and once daily administration, usually in the evening, is sufficient for most patients.
The duration of action for insulin detemir varies from 12 to 24 hours, depending on the dose. In type 1 diabetes, it is usually administered twice daily; in the morning/midmorning and evening.
The duration of action for NPH insulin is approximately 12–20 hours, depending on the dose, and it is usually administered at least twice daily; in the morning/midday and evening.
NPH insulin has a peak effect about 4–12 hours after the injection. If NPH was injected in the morning, a delayed lunch will easily lead to hypoglycaemia and a snack will be necessary in the afternoon. Correspondingly, NPH insulin injected in the evening may lead to nocturnal hypoglycaemia and the blood glucose level must therefore be higher at bedtime than when insulin detemir or glargine is used.There is more daily fluctuation in the absorption of NPH insulin than in the absorption of insulin detemir or glargine.
The lowest possible dose of basal insulin is chosen to obtain the target levels for pre-meal and night-time blood glucose values. The blood glucose values will thus not decrease excessively even if a meal and mealtime insulin are missed or delayed.In the early hours of the night, less basal insulin is usually needed, whereas about 4 hours before and after awakening the need is increased (the dawn phenomenon and the awakening stress).It is advisable to agree upon the range of variation in the dose of basal insulin together with the patient.
If NPH insulin is changed to insulin detemir or glargine, the dose of basal insulin should initially be reduced by 10–30%, according to HbA1c. At the same time, the mealtime insulin requirement will increase, particularly at breakfast and the evening snack. If rapid-acting insulin is used as the mealtime insulin, a bolus injection must also be given to cover all snacks (unless the carbohydrates are taken in order to prepare for exercise). The daily dose of basal insulin should be decreased if the patient repeatedly has readings below 4 mmol/l before meals or if the blood glucose concentration decreases more than 3 mmol/l overnight due to basal insulin.
The daily dose of basal insulin should be increased if the patient repeatedly has too high readings before meals and they are not caused by a post-hypoglycaemic reaction. Initially, blood glucose measurements should first be measured about 2 hours after the meal to verify that the high blood glucose level is not due to the preceding mealtime bolus dose being too low.
Basal insulin in pump therapy
- In pump therapy, the effect of basal insulin is achieved by continuous infusion of rapid-acting insulin into subcutaneous fatty tissue.
- The pump is programmed with the infusion rate of basal insulin per hour (units/h).
- When changing from a multiple injection regimen to pump therapy, the basal insulin requirement decreases by about 20–30% depending on the HbA1c level.
- For example, a daily requirement of basal long-acting insulin of 24 units would correspond to about 20 units per 24 hours in pump therapy. Divided into equal doses, this would correspond to about 0.8 units/h.
- Based on continuous tissue glucose monitoring or frequent self-monitoring of blood glucose, the administration rate is set to correspond to the varying needs at various times of the day. E.g. at 00–03: 0.6 units/h; at 03–09: 1.0 units/h; at 09–21: 0.9 units/h; at 21–24: 0.6 units/h.
- It is easy to increase or decrease the basal insulin dosage on the pump depending on the needs at any given time (temporary changes to basal rate).
- The pump can be programmed with different basal profiles for different needs, such as for days with exercising or for weekends.
Mealtime insulin
For type 1 diabetes, rapid-acting insulin derivatives are used as mealtime insulin: insulin aspart (Fiasp® and NovoRapid®), insulin glulis (Apidra®) and insulin lispro (Humalog®®). Their effect begins in 10–20 minutes. The peak effect is achieved at 1–2 hours, and the effect continues for 3–5 hours, depending on the dose, the injection site circulation, temperature and physical strain. Fiasp is faster-acting insulin aspart than NovoRapid®.- For a multiple injection regimen, it is also possible to use a short-acting mealtime insulin (Actrapid®, Insuman Rapid®).
- It has a longer duration of action (about 5–8 hours), and it also covers/requires a snack about 2–3 hours after a meal.
- Increasing the dose of short-acting mealtime insulin prolongs the duration of action and predisposes the patient to hypoglycaemia.
- The dose of mealtime rapid-acting insulin is calculated according to the carbohydrate intake from food and drink, blood glucose before the meal and physical or other activity after the meal.
- Any patient on insulin must be instructed in basic calculation of carbohydrate intake,
- for example, using package labels, visual estimation of servings and comparison to a carbohydrate manual.
- When learning to do this, food weighing may also be useful.
- When the insulin-carbohydrate ratio is known, the correct dose of rapid-acting insulin can be given according to the calculated carbohydrate intake.
- The dose of mealtime insulin needed in relation to carbohydrate intake is often higher in the morning due to morning-related insulin resistance and possibly insufficient efficacy of basal insulin.
- Even if breakfast is skipped, a small dose of rapid-acting insulin may be necessary to avoid rising blood glucose levels.
- The dose of mealtime insulin required for an evening snack might be lower than that required for other meals, particularly if the patient has exercised during the evening.
- For example, if 1 unit of insulin is sufficient to cover 10 grams of carbohydrates at other meals, 2 units may be needed at breakfast (i.e. 1 unit per 5 g carbohydrates), particularly if no exercise is included in the morning activities. Correspondingly, the requirement at the evening snack may only be 0.5–1 units per 10 grams of carbohydrates (equivalent to 1 unit per 20 grams of carbohydrates).
- Depending on preprandial blood glucose levels, rapid-acting insulin should be administered 0–20 minutes before a meal or, exceptionally, immediately after the meal. Fiasp® is recommended to be administered 0–2 minutes before a meal.
- If there is a strong increase in blood glucose after breakfast, for example, it is advisable to administer rapid-acting insulin 10–20 minutes before eating.
- Should a meal be prolonged (at a buffet, for example) rapid-acting insulin should be injected in a couple of divided doses during the meal.
- If the patient does not know in advance how much carbohydrates they are going to eat, they can administer a dose of mealtime insulin equivalent to 30 grams of carbohydrates, for example, before the meal and the rest of the mealtime insulin after the meal when they know how much they ate. This is easiest to do when pump therapy is used.
- Pumps and some blood-glucose meters are equipped with bolus calculators which suggest appropriate doses of mealtime and corrective insulin according to the settings made (insulin-carbohydrate ratio, insulin sensitivity, duration of action of the insulin and blood glucose target).
- A pump can be used to administer a normal, extended or combination bolus depending on the composition of the meal.The dose of the mealtime bolus is calculated according to the carbohydrate intake from food and drink.
The proportion of mealtime insulin needed in relation to the carbohydrates consumed is often higher at breakfast than at other mealtimes. This is due to morning-related insulin resistance and the possibility of low concentrations of circulating basal insulin. Even if breakfast were skipped, a small dose of rapid-acting insulin without eating may individually be required because of insulin resistance.
The bolus dose required at the evening snack might be lower than at other mealtimes, particularly if the patient has exercised during the evening.
For example, if 1 unit of insulin is sufficient to cover 10 grams of carbohydrates at other meals, 2 units may be needed at breakfast, particularly if no exercise is included in the morning's activities. Correspondingly, the requirement at the evening snack may only be 0.5–1 units per 10 grams of carbohydrates. The patient must be instructed how to count the amount of carbohydrates.
Package labels, visual estimation of a serving followed by verification with the aid of a carbohydrate counter
Initially, food weighing may also be of benefit.
The correct dose of rapid-acting insulin is administered according to the calculated amount of carbohydrates.Rapid-acting insulin is preferably administered before a meal, but in exceptional cases it may also be administered after a meal.If there is a large increase in blood glucose concentration e.g. after breakfast it is advisable to administer rapid-acting insulin 10–20 minutes before eating.
Also short-acting mealtime insulin can be used if needed.
It has a longer duration of action and it also covers (or requires) a meantime snack.
Increasing the dose of short-acting mealtime insulin prolongs the duration of action and predisposes to hypoglycaemia.If the same bolus dose is injected at each meal, no variation must occur in the amount of carbohydrates consumed and pre-meal blood glucose levels – this sort of standardised dosing is usually not feasible.Should the meal be particularly prolonged (for example a buffet) rapid-acting insulin should be injected in a couple of divided doses during the meal.
Corrective insulin
Variation in the need for basal insulin due to stress, for instance, as well as variation in the absorption of insulin cause unpredictable variation in blood glucose concentrations.- If the pre-meal blood glucose concentration is higher than the target level, a small correction dose of rapid-acting insulin should be administered in addition to the mealtime insulin corresponding to the carbohydrate content of the meal.
- Patients should be given written instructions stating roughly how much 1 unit of rapid-acting insulin will lower their blood glucose level.
- Adjustments should not normally be made between mealtimes, except in special circumstances, as it is difficult to estimate how much of the previous mealtime insulin is still active.
- When correcting high blood glucose concentrations, the pump dose calculator will take into consideration any insulin remaining from the preceding dose.
- Excessive correction of high blood glucose between meals can easily send blood glucose values on ”a rollercoaster ride”.
- Patients should be advised in advance what to do in case of sickness or other abnormal situations.
- Insulin resistance or otherwise notably high blood glucose concentrations on sickness days often increase the need for corrective insulin.Variation in the need of basal insulin due to e.g. stress, as well as variation in the absorption of insulin cause unpredictable variation in blood glucose concentrations.If the pre-meal blood glucose concentration is higher than the target level, a small correction dose of rapid-acting insulin is administered in addition to the mealtime insulin that corresponds to the carbohydrate content of the meal. Adjustments are usually not made between mealtimes, except in special circumstances, as it is difficult to estimate how much of the previous mealtime insulin is still active.Excessive correction of blood glucose concentrations between meals easily leads to a ”rollercoaster” effect.
Management of exceptional situations, e.g. when the patient falls ill, should be agreed upon in advance.
Issues to be considered at meals
What is the pre-meal glucose reading? - If the blood glucose is too low (< 4 mmol/l), it should be immediately corrected by eating rapidly absorbed carbohydrates.
- If it exceeds the target level, the dose of corrective insulin required should be assessed.
- What is the carbohydrate content of the meal or drinks?
- How much rapid-acting insulin will be needed to cover this?
- What am I planning to do after the meal?
- If physical exercise will be taken within 1–2 hours, the dose of rapid-acting insulin may need to be reduced by 20–50%.
- How did blood glucose previously react in similar situations?
the pre-meal blood glucose reading
If blood glucose is significantly higher than the target level, an additional bolus injection must be given.
If blood glucose is too low, the insulin dose must be decreased or the patient should consume an extra amount of rapidly absorbed carbohydrates.
whether rapid-acting insulin (covers the meal) or short-acting insulin (covers the meal and a later snack) is used as mealtime insulin.
A rapid-acting insulin bolus is injected during the meal (or immediately after the meal).
A short-acting insulin bolus is injected about 30 minutes before the meal.
the time elapsed since the last mealtime insulin bolus (is the previous insulin dose still acting)
the carbohydrate content of the meal or snack (how much insulin is required for each 10 grams of carbohydrates)
what the patient is planning to do after the meal (if the patient plans to do some exercise, should the bolus dose be reduced or should a snack be eaten without a bolus injection)
previous blood glucose readings in similar situations.
Insulin pump therapy
Insulin pump therapy is the best way to adjust the administration of insulin to correspond to the body's requirements.
Pump therapy is of particular benefit in (1) patients who are prone to hypoglycaemia, (2) the prevention of nocturnal hypoglycaemia and (3) the management of dawn phenomenon (an increased requirement of insulin early in the morning).
A pump delivers a preset amount (units/hour) of rapid-acting insulin via a catheter inserted into the subcutaneous fat tissue. The catheter needs to be replaced every 2 or 3 days.
For example, a daily basal insulin requirement of 20 units corresponds to about 0.8 units per hour. As the requirement of basal insulin varies during the 24 hour period, it is possible to set a ”daily profile” into the pump, based on blood glucose measurements. For example, from midnight until 3 a.m. a rate of 0.5 units/hour, from 3 a.m. until 8 a.m. a rate of 1.0 unit/hour, from 8 a.m. until 4 p.m. a rate of 0.8 units/hour, from 4 p.m. until 10 p.m. a rate of 1.0 unit/hour and from 10 p.m. until midnight a rate of 0.5 units/hour.
At mealtimes, a bolus dose is given via the pump according to carbohydrate intake.A bolus calculator may be used to assist in the dosage.
Each patient using an insulin pump must also have equipment to inject insulin and a supply of insulin, complete with information leaflets, in case of pump malfunction and to allow for some ”pump free” periods.
Utilization of self-monitoring of blood glucose
Self-monitoring of blood or tissue glucose is recommended in the morning and before meals, as well as before bedtime according to the individual need. See also .- Testing after meals is also required in association with changes to the treatment and when correcting the glucose balance.
- Before an appointment with a doctor or diabetes nurse specialist, intensified monitoring of tissue or blood glucose is advisable with a 24 h profile of glucose concentrations. Carbohydrate intake, the amount of exercise taken and injected insulin doses should also be registered.
- If self-monitoring shows blood glucose readings within the target range, the total daily dose should not be increased.
- Blood glucose reflects the amount of active insulin in the body at the time of measurement.
- Increase doses after which blood glucose readings (taken during the active period of the insulin) are repeatedly increased.
- Correspondingly, decrease doses after which blood glucose readings (taken during the active period of the insulin) are repeatedly decreased.
- Start with correcting the readings that are repeatedly too low.
- Then correct the highest increase in the blood glucose reading and try to bring the morning glucose concentration into the target range (including readings taken during the night and at bedtime). Blinded continuous glucose monitoring, with results disclosed afterwards, may be useful for defining appropriate insulin doses. If this is used, it is important to record all factors affecting blood glucose concentrations, such as physical exercise, carbohydrate intake and insulin doses.
- Glucose sensoring e.g. in periods of 2–4 weeks will also help to define appropriate insulin doses.It is advisable to measure blood glucose concentration in the mornings and before meals, as well as before bedtime (at least in patients prone to hypoglycaemia). See also .Measurements between the meals are also required in association with changes in the treatment and when correcting the glycaemic control.
Before an appointed visit to the doctor or the diabetes nurse specialist, intensified monitoring is advisable: 24 h profile of the blood glucose concentration is registered on at least 3 days by measurements before meals and 2 hours after meals.
At the same time the consumed carbohydrates, the amount of exercise as well as the injected insulin doses are registered.
If self-monitoring shows blood glucose readings within the target range, the daily dose should not be increased.
A blood glucose reading is a reflection of the amount of active insulin in the body at the time of measurement.
The dose/s that repeatedly increase/s the blood glucose concentration should be increased.
Correspondingly, the dose/s that repeatedly decrease/s the blood glucose concentration should be decreased.
Start with correcting the readings that are repeatedly too low.
Otherwise, start with correcting the dose that causes the largest increase in the blood glucose readings. The aim is to bring the morning glucose concentration to the target range (readings taken also during the night and at bedtime).Glucose sensor monitoring is useful in the assessment of diabetes control.
Injection of insulin
Raise a skin fold gently to ensure that the insulin is injected into the subcutaneous fatty tissue (and not into a muscle or too near the skin surface). - Insert the needle at an angle of 90°–45° (adults) depending on the length of the needle (4–8 mm).
- Be careful to ensure that the insulin does not leak out of the injection site.
- Do not inject into hardened or swollen areas of skin or through clothing.
- Use sufficiently extensive skin areas for the injections.
- Long-acting basal insulin is usually injected either into the thigh or the buttock.
- Avoid injecting into the upper arms where the tissue is dense and raising the skin to a fold is difficult.
- Inject mealtime insulin in the abdominal area, short-acting insulin 20–30 minutes before a meal, rapid-acting insulin 0–20 minutes before a meal (depending on the blood glucose value) or, in exceptional cases, immediately after the meal.
- Explain to the patient that exercise and heat increase the absorption of insulin and cold slows it down.
- The needle should preferably be removed after every injection, especially when long-acting insulin is used.Raise the skin fold gently to ensure that the injection goes into the subcutaneous tissue (and not into a muscle or too near the skin surface).
Insert the needle at an angle of 90°–45°– (adults) depending on the length of the needle (4–8 mm). Be careful so that the insulin does not leak out of the injection site.
Do not inject into hardened or swollen areas of skin or through clothing.
Sufficiently extensive skin areas should be employed for the injections.
Long-acting insulin is as a rule injected either into the thigh or buttock. Do not preferably inject into the upper arms where the tissue is dense and raising the skin to a fold is difficult.
Inject mealtime insulin around the abdominal area, short-acting insulin 20–30 minutes before a meal, rapid-acting insulin 0–10 minutes before a meal (depending on the blood glucose value) or, in an exceptional case, immediately after a meal.
It should be explained to the patient that exercise and heat increase the absorption of insulin and cold slows it down.
The needle is preferably removed after every injection, especially when long-acting insulin is used.
The patient may also use a syringe to inject insulin, should he/she prefer to do so.
A patient who uses pen cartridges must also be taught how to, if necessary, draw insulin from the cartridge and inject it with a syringe.
Dietary principles
The diet recommended for patients with type 1 diabetes does not differ from what is recommended for the general public, i.e. a healthy diet ensuring a balanced intake of energy, nutrients, trace elements and minerals.- Energy intake is adjusted according to the patient’s individual needs, avoiding the development of overweight.
- Modern regimes involving multiple daily injections of long- and rapid-acting insulin and insulin pumps allow great flexibility for the timing and size of meals, provided that the mealtime insulin dose corresponds to the size of the meal and particularly to the carbohydrate intake. Special meal planning is not required but the aim is to teach the patient how to adjust meals and insulin doses with the aid of blood glucose tests and the assessment of carbohydrate intake.
- The risk of cardiovascular disease is increased in patients with type 1 diabetes. In addition to carbohydrate intake, the overall healthiness of the diet should be considered with a view to the prevention and treatment of cardiovascular risk factors, i.e. hypertension and disorders of lipid metabolism.
- Several practical guides are available to assist meal planning, such as the plate model.
- Patients with coeliac or renal disease, severe dyslipidaemia or gastroparesis should be referred to a therapeutic dietitian.
Physical exercise and insulin treatment
Blood glucose concentrations may fall excessively either during exercise or immediately or several hours after exercise.- By measuring their blood glucose patients will learn how to adjust the dosage of insulin and carbohydrate intake in association with physical activity.
- In association with strenuous or prolonged exercise, the insulin dose effective during exercise should be reduced (by 20–30% or even 50%) and/or the carbohydrate intake increased.
- In association with strenuous or prolonged exercise, especially if it takes place in the evening, the insulin dose effective during the night should also be reduced (by about 10–20%).
- In addition to after an excessive increase in carbohydrate intake (carb up), blood glucose concentrations will also increase during exercise if the amount of insulin is too low or the stress hormones generated through the physical activity outweigh the effect of insulin.
- Interval-type exercise may elevate blood glucose concentrations during the exercise or immediately thereafter.
- Changes in blood glucose concentrations depend on
- blood insulin levels
- the duration and intensity of exercise
- the type of exercise: endurance exercise, muscle conditioning exercise, interval training
- training experience and muscle fitness
- the food consumed before and during exercise.
- General advice to patients for preparing for exercise
- Avoid exercise if blood glucose is higher than 15 mmol/l or there are ketones.
- If your pre-exercise blood glucose is less than 5–6 mmol/l, take some carbohydrates, such as a banana or 2 dl of fruit juice = 20 g of carbohydrates.
- Learn how exercise affects your blood glucose by measuring your pre- and post-exercise blood glucose concentrations.
- If necessary, take 20–40 g/h of extra carbohydrates in order to prevent hypoglycaemia during exercise.
- For example, fresh juice diluted with mineral water in a ratio of 1:1, a sports drink with about 5% carbohydrates or a banana
- If exercise is to take place during the peak effect of rapid-acting insulin (1–2 h), reduce the dose by 20–50%, as necessary.
- After lengthy exercise, continue to monitor your blood glucose. If your blood glucose level falls later on, correct it by taking carbohydrates, as necessary.
- Based on your own experience and blood glucose tests, you may find it necessary to reduce the insulin dose effective during the night after the exercise by 10–20%.
Hypoglycaemia
The aim of insulin therapy is to avoid blood glucose values below 4 mmol/l. In practice, however, this may prove to be difficult. See also .- Symptoms generally occur at blood glucose values below 3.0 mmol/l. The symptoms may change or be attenuated if the illness is of a long duration, the patient suffers from frequent episodes of hypoglycaemia or low-blood-glucose homeostasis.
- Hypoglycaemia is often followed by reactive hyperglycaemia. Due to excessive secretion of counteracting hormones, insulin resistance may last up to 24 hours after a hypoglycaemic episode.
- The most common causes of hypoglycaemia are
- excessive amount of basal insulin acting during night-time
- too large mealtime bolus in relation to carbohydrate intake
- occasional administration error
- delayed or missed meal with a high concentration of circulating basal insulin
- unexpected physical exertion with no reduction in the insulin dose and no increase in carbohydrate intake
- physical exercise not covered by dose reduction or extra carbohydrates during the maximum effect of the insulin dose
- enhanced insulin absorption associated with changing the injection technique or site
- inadvertent intramuscular or intravenous injection
- excessive alcohol intake and hangover (hepatic glucose production inhibited)
- decreased insulin requirement during remission or due to weight loss, renal insufficiency, hypothyroidism or adrenocortical insufficiency.
- Good patient education and the ability to anticipate forthcoming events by adjusting insulin doses and amounts eaten are essential in the prevention of hypoglycaemia.
- Treatment of hypoglycaemia: see .The aim of insulin therapy is to avoid blood glucose values below 4 mmol/l. In practice, this may prove to be difficult. See also .
Symptoms generally occur at plasma blood glucose values below 3.0 mmol/l. The symptoms may be altered or weakened if the illness is of long duration, the patient suffers from frequent episodes of hypoglycaemia or the glycaemic control is poor.
Hypoglycaemia is often followed by reactive hyperglycaemia. Due to an excessive secretion of counteracting hormones, insulin resistance may last up to 24 hours after the hypoglycaemic episode.
The most common causes of hypoglycaemia are
excessive amount of basal insulin is acting during night-time the mealtime bolus is too large in relation to carbohydrates consumed
occasional administration error
delayed or missed meal with a high concentration of circulating basal insulin
unexpected physical exertion with no reduction in the insulin dose or increase in carbohydrate intake
physical exercise (not covered by dose reduction or extra carbohydrates) during the maximum effect of the insulin dose
enhanced insulin absorption associated with changing the injection technique or site
inadvertent intramuscular or intravenous injection
excessive alcohol intake and hangover (hepatic glucose production inhibited)
decreased insulin requirement during a remission period or due to weight loss, renal insufficiency or endocrine disorders such as hypothyroidism or adrenal insufficiency.
Prevention of hypoglycaemia is based on patient education and ability to anticipate forthcoming events by adjusting insulin doses and carbohydrate intake.
Daily physical exercise should be taken into account, particularly during tight glycaemic control, by reducing the evening insulin dose by 10–20%, according to blood glucose measurements.
Treatment of hypoglycaemia: see .
Hyperglycaemia
Inflammation and stress hormones increase the need for insulin.- In patients with acute illness, blood glucose readings should initially be checked every (1–)2 hours.
- Additional doses of rapid-acting insulin should be administered every 2–4 hours.
- If there are ketones in the urine/blood, the need for insulin is increased.
- Ensure adequate insulin administration as well as adequate carbohydrate and fluid intake.
- If the illness is prolonged, the dose of basal insulin should also be increased, as necessary.
- Nausea and vomiting may be symptoms of ketoacidosis: blood glucose and ketones should always be checked in diabetic patients with abdominal symptoms .
Glucocorticoid treatment
- A glucocorticoid injection may increase blood glucose concentrations for several days.
- During a course of oral glucocorticoids, an additional dose of long-acting (NPH) insulin is required in the morning and often also an increased amount of mealtime insulin during the daytime because of the glucocorticoid-induced insulin resistance.
- If the basal insulin is a long-acting insulin analogue, its dose should not be increased during temporary glucocorticoid treatment taken in the morning because this could easily lead to nocturnal hypoglycaemia.
- It is advisable to divide the daily glucocorticoid dose into two (2/3 in the morning and 1/3 in the afternoon between 4 and 6 p.m.).
- All daytime insulin doses should be increased when such glucocorticoid treatment is begun, morning and day doses more than evening doses.
Morning hyperglycaemia
- Morning hyperglycaemia is usually due to lack of insulin, which may be due to:
- the effect of insulin administered during the previous day not lasting until the morning
- an insufficient effect of circulating insulin due to an increased early morning insulin requirement (dawn phenomenon)
- blood glucose being too high at bedtime after the evening snack
- eating just in case in the evening before going to bed without taking rapid-acting insulin.
- It is fairly common to take excessive amounts of carbohydrates at bedtime due to past episodes of or fear of nocturnal hypoglycaemia.
- Nocturnal hypoglycaemic episodes, due to too high a dose of basal insulin, may lead to reactive hyperglycaemia in the morning.
- The appropriate basal insulin dose should be defined by self-monitoring.
- Blood glucose should be measured before and 2 h after the evening snack, at bedtime (about 4 h from the last dose of rapid-acting insulin), at about 3 a.m. (about 4 hours before waking-up time) and in the morning when waking up.
- The difference between blood glucose values measured at bedtime and when waking up should be no more than ± 2–3 mmol/l.
- It is important to establish whether blood glucose is low or high in the middle of the night and whether the patient is hyperglycaemic at bedtime, already.
- If necessary, continuous glucose monitoring should be performed.
Causes of increased insulin requirement
Weight gain. If weight gain is caused by excessive insulin dosage, both the insulin dose and the amount of carbohydrates and calories should be reduced.
Infections increase the insulin requirement.
In an acute situation, blood glucose readings are initially checked every 1–2 hours.Additional doses of rapid-acting insulin are administered every 2–4 hours. If the patient has ketones in the urine/blood, the additional dose of rapid-acting insulin should be increased.
Nausea and vomiting are not, as such, indications for insulin dose reduction. They may be indicative of increased insulin requirement.
Ketoacidosis may present with symptoms suggestive of gastroenteritis, and the blood glucose, as well as blood/urine ketones, must always be checked in a diabetic patient with abdominal signs and symptoms.
Ensure adequate insulin administration as well as carbohydrate and fluid intake.If the illness is prolonged, also the dose of basal insulin is increased as needed.
HyperthyroidismPremenstrual phase of the menstrual cycle
Acute systemic illness and traumaCorticosteroid treatment
A corticosteroid injection may increase blood glucose concentrations for several days.
During an oral course of corticosteroids, an additional dose of long-acting (NPH) insulin is required in the mornings and often also an increased amount of mealtime insulin during the daytime because of the corticosteroid-induced insulin resistance.It is advisable to divide the daily corticosteroid dose into two in order to attenuate the increase of blood glucose concentration.
Morning hyperglycaemia
Morning hyperglycaemia is usually due to an insufficient amount of insulin which may be due to:
the effect of insulin administered during the previous day or evening does not last until the following morning an insufficient effect of circulating insulin due to an increased early morning insulin requirement (dawn phenomenon)
blood glucose too high at bedtime after the evening snack
eating just in case in the evening before going to bed without a bolus injection of rapid-acting insulin.Consumption of excessive amounts of carbohydrates at bedtime due to past episodes, or fear, of nocturnal hypoglycaemia is fairly common.
Nocturnal hypoglycaemic episodes, due to too high a dose of evening insulin, may lead to reactive hyperglycaemia in the morning.
The cause of morning hyperglycaemia must be identified.
Several blood glucose readings should be taken; i.e. in the evening before the evening snack, at bedtime, in the middle of the night about 4 hours before waking-up time and in the morning when waking up.
It is important to establish whether blood glucose is low or high in the middle of the night and is the patient hyperglycaemic at bedtime.If necessary, the patient is referred for glucose sensor monitoring.
Reasons for variation in blood glucose concentration
Hypoglycaemias (often asymptomatic) induced by an excessive dose of basal insulin, particularly at night and followed by reactive hyperglycaemia of varying degree and duration
Missed insulin injections The patient’s inability to calculate carbohydrates or to understand the importance of such calculations No bolus injections at snack times
Lack of knowledge and skills, as well as poor understanding of the results of blood glucose self-monitoring
The mealtime bolus is injected too late, i.e. blood glucose has time to increase excessively only to be followed by excessive fall as the injected insulin takes effect.
Basal insulin is changed too frequently.
Several factors are changed simultaneously
For example, a high blood glucose value prompts the patient to increase both the insulin dose and amount of exercise.
Irregular, strenuous exercise that is difficult to anticipate
Hypoglycaemia after excessive correction of high blood glucose and subsequent reactive hyperglycaemia will easily send blood glucose values on ”a rollercoaster ride”.
Menstrual cycle affects insulin requirements.
Insulin requirement usually increases at the premenstrual phase and during ovulation.
Treatment weariness and loss of motivation particularly if, despite the patient’s efforts, blood glucose measurements continue to show great variabilitySevere comorbidities (renal failure, GI tract dysfunction, gastroparesis)
Endocrine disorders
Eating disorders (anorexia or bulimia) Omission of insulin injections or too small doses in an attempt to lose weight
Insulin antibodies may cause unexpected episodes of hypoglycaemia. Insulin antibodies should be determined if no other cause for hypoglycaemia is evident.
Systemic illness, trauma and physical stress
Investigating high-blood-glucose homeostasis and variation of blood glucose concentrations
Listen to the patient’s own assessment of glucose control and its variations- How often is blood glucose measured?
- Check the injection sites and the injection technique
- Assess the occurrence of hypoglycaemic episodes
- Assess the patient's usual daily routine during weekdays and weekends
- Work and associated physical and mental stress
- Usual mealtimes, diet and carbohydrate intake
- Exercise: timing, duration, level of intensity and preparation
- Alcohol use
- Is carbohydrate intake calculated?
- Is the insulin-carbohydrate ratio appropriate at various times of the day?
- Are corrective doses used?
- Are the corrective doses appropriate?
- Are corrective doses also administered between meals?
- Does the patient’s psychosocial situation involve stress factors affecting blood glucose levels or the ability to take care of the treatment?
- Ensure that the insulin being used works properly (has not been frozen or overheated at any point).
- The reliability of the blood glucose meter and the testing procedure should be checked at a visit to the diabetes nurse specialist by using a control solution or a parallel test.
- Ensure proper functioning of the glucose meter (and strips).
- Perform intensified monitoring for at least 3 days asking the patient to record the following in a patient diary:
- the dose of basal insulin and time of injection
- tissue glucose sensoring, or if it is not available, 24-h blood glucose profile
- paired morning/evening blood glucose tests
- paired pre-meal and post-meal blood glucose tests (before and 2 hours after breakfast, lunch, supper, and evening snack
- blood glucose at night approximately 4 hours before waking-up time
- carbohydrate intake and insulin dose at all meals and snacks
- any occasional corrective doses
- exercise (timing, intensity [+, ++ or +++] and duration).
- Continuous glucose monitoring can be used to obtain more information to support decisions, more easily and simply.
- Sufficient time should be reserved to discuss the findings from intensified and continuous glucose monitoring with the patient (diabetes nurse specialist and/or doctor).
- If the HbA1c is high and self-measured blood glucose concentrations vary, the first step is to correct any hypoglycaemia.
- If the HBA1c is high and the self-measured blood glucose concentrations are consistently high, the daily dose of insulin should be increased.
- The next aim is to correct the blood glucose concentrations to the target level at wake-up and during the morning.
- After this, other pre-meal blood glucose concentrations should be corrected to the target level.
- The possibility of other disorders should be considered (testing TSH, potassium, sodium, cortisol, creatinine, coeliac disease-associated antibodies).The patient’s own assessment of glucose control and its variations
Checking the injection sites and the injection technique
Assessing the occurrence of hypoglycaemic episodes
Assessing the patient's usual daily routine during weekdays and at the weekend
Work and associated physical and mental stress
Usual mealtimes, diet and the carbohydrate amounts
Exercise: timing, duration, level of intensity and preparation
Alcohol use
Does the patient calculate the carbohydrates consumed?
Does the patient’s psychosocial situation contain stress factors that affect the blood glucose levels or the ability to take care of the treatment? Ensuring that the insulin in current use works properly (has not been frozen or overheated at any point)
Checking the reliability of the glucose meter and the measurement procedure at a visit to the diabetes nurse specialist by using a control solution or a parallel measurement
Ensuring the proper functioning of the glucose meter (and strips)Intensified monitoring in at least 3 days. The following should be recorded in a patient diary:
the dose of basal insulin and time of injection24 h profile of blood glucosePaired morning/evening measurement of blood glucose Paired pre-meal and post-meal (2 hours after a meal) blood glucose measurements at different mealtimes (breakfast, lunch, supper, evening snack)Blood glucose at night approximately 4 hours before waking-up time
carbohydrate intake and insulin bolus dose at all meals and snacks
any occasional additional doses
exercise (timing, intensity and duration).
After the intensified monitoring period, sufficient time must be allocated to discuss the findings with the patient (diabetes nurse specialist and/or doctor). The results can be sent beforehand to the reception.If the HbA1c is high and the self-measured blood glucose concentrations are variable, hypoglycaemias are the first to be corrected. If the HBA1c is high and the self-measured blood glucose concentrations are consistently high, the daily dose of insulin should be increased.The next aim is to correct the blood glucose concentrations to the target level at wake-up and during the morning.
Thereafter, other pre-meal blood glucose concentrations are corrected to the target level.
The possibility of physical or endocrine disturbance should also be borne in mind (serum TSH, plasma potassium, sodium, cortisol, creatinine, coeliac disease-associated antibodies).
If the reasons for poor glycaemic control remain unresolved, the patient should be referred to a specialist physician for continuous glucose monitoring studies.
Multiple injection regime and travel across time zones
A written plan should be drawn up including the departure and destination countries with their corresponding times, the duration of the flight and the envisaged adjustments to insulin administration.
Westward travel
When travelling westward, the length of the day increases. A time difference of more than 2 hours can be covered by adding basal insulin. The additional dose is calculated according to the usual dose of basal insulin per hour.- For example, the daily requirement is 20 units of basal insulin corresponding to about 0.8 units per hour. If the time difference is 6 hours, the additional dose of basal insulin is about 6 × 0.8 units, i.e. 5 units.
- Because of overlapping insulin action, the calculated dose should preferably be rounded slightly downwards.
- During short visits, insulin glargine may be injected at the injection time of the departure country.
- Glargine 100 units/ml (Abasaglar®, Lantus®) ± 2 h and glargine 300 units/ml (Toujeo®) ± 3 h
- If insulin degludec is used, the injection time of basal insulin can be even more flexible.
- Meals are covered in the usual manner by mealtime insulin according to carbohydrate intake.
- On arrival in the destination country, the normal injection regime should be followed according to the time of the destination country. Doses may be adjusted as necessary based on self-monitoring.When travelling westward, the length of the day increases. A time difference of more than two hours is covered with an extra dose of basal insulin. During short visits, insulin glargine may be injected at the injection times of the departure country (every 24 hours). The additional dose is calculated according to the usual dose of basal insulin per hour.
For example, if the daily requirement is 20 units of basal insulin, it corresponds to about 0.8 units per hour. If the time difference is 6 hours, the additional dose of basal insulin is about 6 × 0.8 units, i.e. 5 units.
Because of overlapping insulin action the calculated dose is preferably rounded downwards.
Meals are covered in the usual manner by injecting a bolus dose of mealtime insulin according to carbohydrate intake.
On arrival at the destination country, the normal injection regime should be followed using the time of the destination country. Doses may be adjusted as necessary, according to blood glucose readings.
Eastward travel
- When travelling eastward, the length of the day decreases.
- The dose of basal insulin should be decreased according to how many hours shorter the day will be.
- For example, if the daily requirement is 20 units basal insulin and the time difference is 6 hours, the dose of basal insulin should be decreased by 5 units.
- Meals are covered in the usual manner according to the carbohydrate intake. On arrival in the destination country, the normal injection regime should be followed. Doses may be adjusted as necessary, according to self-monitoring.
Related resources
- Cochrane reviews
- Other evidence summaries
- Literature
Ədəbiyyat
- ADA (American Diabetes Association). Standards of medical care in diabetes 2017. Diabetes Care 2017;40, Suppl 1 January 2017, 40 (Supplement 1)
- McGibbon A, Richardson C, Hernandez C, Dornan J. Pharmacotheray in type 1 diabetes. Clinical Practice Guidelines. Canadian Diabetes Association 2013.
- NICE: Type 1 diabetes in adults. Diagnosis and management
- Wolpert H (Ed.). Intensive Diabetes Management. 6. edition. Alexandria, VA: American Diabetes Association; 2016.
- Scheiner G. Think like a pancreas. A practical guide to managing diabetes with insulin. Lifelong Books 2011.