Metformin in PCOS in type 1 diabetes

• there are no studies regarding medical treatment of ovarian function in PCOS patients with type 1 diabetes mellitus; however, metformin is reported to be helpful for reducing daily insulin doses and body weight, leading to improved insulin resistance and hyperinsulinemia (1,2,3):
  
  
  • in a twelve month study comparing addition of metformin to placebo for type 1 diabetics (3):
    • total daily insulin dose was reduced in the metformin group > -5.7 U/day (-8.6; -2.9), p<0.001;
    • body weight was reduced in the metformin group -1.74 kg (-3.32; -0.17), p = 0.030

Reference:

• Miyoshi A et al. Ovarian morphology and prevalence of polycystic ovary syndrome in Japanese women with type 1 diabetes mellitus. J Diabetes Investig. 2013 May 6;4(3):326-9.
• Vella S, Buetow L, Royle P, et al Metformin in type 1 diabetes reduces insulin requirements without significantly improving glycaemic control. Reply to Schatz H [letter]. Diabetologia 2011; 54: 203-204
• Jacobsen IB, Henriksen JE, Beck-Nielsen H. The effect of metformin in overweight patients with type 1 diabetes and poor metabolic control. Basic Clin Pharmacol Toxicol 2009; 105: 145-149