Tuesday, April 3, 2007

Metformin and Glimepiride: Safe and Effective short-term in paediatric type 2 diabetes

Metformin and Glimepiride: Safe and Effective short-term in paediatric type 2 diabetes

Metformin and Glimepiride have similar efficacy and safety over six months in children with type 2 diabetes, according to a controlled trial.

The authors of the study comment that the incidence of type 2 diabetes in children is increasing rapidly, and that as the course of the condition may be more aggressive in this patient group early control is important. There is therefore a need for data on the safety and efficacy of oral hypoglycaemic agents in children.

Metformin is licensed in the US for this age group, however there are no sulphonylureas so licensed; this study aimed to compare the safety and efficacy of the two drugs in a paediatric population. It involved children with type 2 diabetes who were not adequately controlled on their existing treatment. After two weeks stabilisation, participants were grouped by age (<12> 12 years) and randomised to either metformin or glimepiride for the 24 weeks study period (12 weeks titration, 12 weeks maintenance). Primary outcome was mean change in haemoglobin A1c (A1C) from baseline to week 24.

A total of 285 children were randomised, with a mean age of 13.8 (range 8 to 17) at randomisation; they were significantly obese, with a mean BMI of about 31.7kg/m2. Of these, 284 received at least one dose of study drug and were evaluated for safety: 283 took at least one dose and had at least one A1C measurement to allow assessment of efficacy, thus becoming the intention to treat population.

Significant reduction of A1C:
Both drug groups (Metformin and Glimepiride) had a significant reduction of A1C from baseline by week 24: for glimepiride the reduction was 0.54% and for METFORMIN 0.71% (both differences statistically significant from baseline). Values taken at week 12 were similar. One patient in each group had a severe hypoglycaemic episode; adverse event rates in the two groups were similar, and adverse event rates considered possibly due to the drug were 7.7% in the glimepiride group and 13.4% in the metformin group.

Weight gain with Glimepiride:
Patients in the glimepiride group gained body weight (increase in BMI 0.26 kg/m2) whereas those in the Metformin group lost weight (decrease in BMI 0.33 kg/m2).

Comparative effectiveness:
The authors conclude that glimepiride was as effective as metformin in controlling A1C levels and similarly tolerated, although it was associated with a greater degree of weight gain.

[Editor's comment: six months is a relatively short-term study of a therapy for type 2 diabetes. While glimepiride does control blood glucose over this period, the increase in weight in what was already an obese population would raise some concern.]

Diabetes Care 2007; 30: 790-4 (link to abstract)

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