Continuous glucose monitoring systems for type 1 diabetes mellitus

Real-time continuous glucose monitoring (CGM) may be more effective in improving HbA1c-levels in patients with poorly controlled type 1 diabetes compared to conventional self-monitoring. The effect appears to be larger in patients who also start insulin pump therapy.

The quality of evidence is downgraded by study limitations (lack of/unclear allocation concealment and failure to adhere to the intention-to-treat principle).

The recommendation is weak because of questionable cost-effectiveness.

Summary

A Cochrane review included 22 RCTs with a total of 2883 patients to assess the effects of continuous glucose monitoring (CGM) systems compared to conventional self-monitoring of blood glucose (SMBG) in patients with diabetes mellitus type 1. All age groups were included.

After six months there was a significant larger decline in HbA1c level for real-time CGM users who started insulin pump therapy compared to patients using multiple daily injections (MDI) and SMBG (MD in change in HbA1c level -0.7%, 95% CI -0.8% to -0.5%, 2 RCTs, n = 562, I²=84%).

For patients starting with CGM only (on MDI), the average decline in HbA1c level six months after baseline was also statistically significantly larger for CGM users compared to SMBG users, but much smaller than for patients starting using an insulin pump and CGM at the same time (MD change in HbA1c level -0.2%, 95% CI -0.4% to -0.1%, 6 RCTs, n = 963, I2=55%). On average, there was no significant difference in risk of severe hypoglycaemia or ketoacidosis between CGM and SMBG users (table 1).

Clinical comments

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Ədəbiyyat

1. Langendam M, Luijf YM, Hooft L et al. Continuous glucose monitoring systems for type 1 diabetes mellitus. Cochrane Database Syst Rev 2012;1:CD008101.