This dataset is the primary data source for a manuscript submitted for publication.

Manuscript abstract:

Context: The cardiovascular effect of adjunctive metformin therapy in overweight/obese youth with type 1 diabetes (T1D) is unknown.

Objective: To compare the effect of prolonged, adjunctive metformin vs. placebo therapy on markers of cardiovascular risk in overweight/obese youth with T1D based on differences in total cholesterol (TC)/ high-density lipoprotein (HDL) ratio, triglycerides (TG)/HDL ratio, Atherogenic Index of Plasma (AIP) log [TG/HDL] ratio, adiponectin/leptin ratio, and 25-hydroxyvitamin D [25(OH)D] concentration.

Hypothesis: Adjunctive metformin therapy will improve markers of cardiovascular health in overweight/obese youth with T1D.

Setting: University outpatient facility.

Design and Participants: A 9-mo randomized, double-blind, placebo-controlled trial of metformin (1000 mg daily) and placebo in 28 subjects (13m/15f) of ages 10-20years (y), with HbA1c >8%, BMI >85%, and T1D > 12 months. The metformin group consisted of 15 subjects (8 m/7f), of age 15.0±2.5 y; while the control group consisted of 13 subjects (5m/8f), of age 14.5±3.1y. Participants employed a self-directed treat-to-target insulin regimen based on a titration algorithm of (-2)-0-(+2) units to adjust long-acting insulin dose every 3rd day from -3 mo through +9 mo to maintain fasting plasma glucose between 90-120 mg/dL.

Results: After adjusting for age, gender, BMI, and baseline values, the metformin group had a clinically significant reduction in TC/HDL of 0.5 unit: 3.5[3.0-4.1] vs. 4.0 [3.3-4.4] (p=0.578); and TG/HDL of 1.0 unit, 2.6 [1.1-4.3] vs. 3.6 [2.0-5.2] (p=0.476); and AIP of 0.44 unit: -0.23 ± 0.9 vs. 0.21 ± 0.8 (p=0.251). Conversely, the metformin group had a clinically significant elevation in adiponectin/leptin ratio of 0.8 unit: 2.0[0.84-3.2] vs. 1.2[0.11-2.3], (p=0.057); and a mean serum 25(OH)D in the vitamin D sufficiency range, 31.3 ng/mL [22.3-40.4] compared to the placebo group's lower mean 25(OH)D of 25.8 ng/mL [14.1-35.9], (p=0.337).

Conclusions: Prolonged adjunctive metformin therapy may be cardio-protective in overweight/obese youth with T1D.