Source: Heart  |  Posted 8 years ago

Metformin therapy may improve metabolic control in adolescents with poorly controlled type I diabetes, according to new research.

Children with type I diabetes frequently experience a substantial decrease in insulin sensitivity during puberty, which often leads to a decline in metabolic control despite increased insulin dosages.

"Thus, there is a great need for alternative therapeutic strategies in adolescents with type I diabetes," writes Stefan Sarnblad of the University Hospital, Orebro, Sweden. Dr. Sarnblad and colleagues performed a study to determine whether the addition of metformin therapy could improve glycaemic control and insulin sensitivity in adolescents with poorly controlled type I diabetes.

Twenty-six adolescents (mean age, 16.9 ? 1.6 years; 18 females) were randomised to receive either oral metformin or placebo for 3 months. Participants receiving metformin started with 500 mg daily for 1 week, followed by 500 mg twice daily for 3 weeks, and then 1000 mg twice daily for the rest of the study.

Mean glycated haemoglobin significantly decreased in the metformin group during the study period (9.6% to 8.7%; []P[] < .05), but remained unchanged in the placebo group (9.5% vs. 9.2%; ns). Participants receiving metformin also experienced a significant increase in peripheral insulin sensitivity ([]P[] < .05), which was estimated by euglycaemic hyperinsulinaemic clamp.

In addition, the researcher noted that patients with a higher level of insulin-resistance showed greater improvements in both glycated haemoglobin and peripheral insulin sensitivity. They suggest that, "the main effect of metformin in adolescents with type I diabetes is associated with improved peripheral insulin sensitivity." This mechanism is in contrast to patients with type 2 diabetes, where the effect is predominately mediated by a decrease in hepatic glucose output.

No changes in weight or blood lipid levels occurred for either group, and no serious adverse effects were detected. Although previous studies have reported a reduced need for insulin in type I diabetes patients receiving metformin, a similar effect was not observed in the present study.

"Adjunctive therapy with metformin in adolescents with type I diabetes is efficacious and safe, " the researchers conclude. However, they add that "further, larger studies carried out over longer time periods, are recommended."