The following year (2003), two double-blind placebo-controlled trials, one carried out in Canada [20] and the other in Sweden [21], each randomising 30 adolescent individuals with type 1 diabetes, reported improvements in HbA1c after 3 months of metformin use (by 0.6% [6.6 mmol/mol] and 0.9% [9.9 mmol/mol], respectively); only the Canadian study demonstrated a significant reduction in insulin dose requirement and fasting glucose [20] and neither detected a difference in weight or in insulin sensitivity [20, 21]. Here, INS is linked to type 1 diabetes mellitus.