The use of metformin in pediatric patients with type 1 diabetes may improve vascular smooth muscle function and may lower HbA1c levels and required insulin dose, according to a study published in the Journal of Clinical Endocrinology and Metabolism.
Researchers identified 90 children ages 8 to 18 years diagnosed with type 1 diabetes who were above the 50th percentile for body mass index (BMI) and randomly assigned them to receive either metformin (up to 1 g twice daily) or placebo in a 12-month double blind, randomized, placebo-controlled trial at a tertiary pediatric diabetes clinic in South Australia. The primary purpose of this study was to “determine the effect of metformin on vascular health in children with type 1 diabetes and above average weight.”
Study results showed that patients who received metformin twice daily had improved glyceryl trinitrate-mediated dilation independent of HbA1c level by 3.3 percentage units compared with placebo, a finding that was obtained by ultrasound to determine vascular function in the brachial artery (95% CI, 0.3-6.3, P =.03). In addition, over the course of 12 months, patients treated with metformin experienced a total reduction in insulin dose by 0.2 units/kg/day, with results observed as soon as 3 months after initiation of therapy (95% CI, 0.1, 0.3, P =.001). Differences in adjusted levels of HbA1c of 1.0% were observed between groups over 12 months; 95% CI, 0.4-1.5 (10.9 mmol/mol; 95% CI, 4.4-16.4, P =.001), with beneficial effects observed after 3 months of treatment (P =.001). No effects on carotid/aortic intima media thickness, BMI, lipid levels, blood pressure, or other cardiovascular risk factors were observed in this study.
Researchers concluded that the use of metformin over the course of 12 months improved vascular function, reduced HbA1c levels, and decreased the required insulin dose and sensitivity in patients with type 1 diabetes with an above average weight. Based on these findings and the good safety profile, clinicians should consider the use of metformin in this patient population.
Anderson JJA, Couper JJ, Giles LC, et al. Effect of metformin on vascular function in children with type 1 diabetes: a 12 month randomized controlled trial [published online October 9, 2017]. J Clin Endocrinol Metab. doi: 10.1210/jc.2017-00781