EVIDENCE FOR DISSOCIATION OF INSULIN-REDUCING AND WEIGHT-REDUCING EFFECTS OF METFORMIN IN NONDIABETIC MALE-PATIENTS WITH CORONARY HEART-DISEASE

Metformin effects on insulin resistance and insulin/glucose relationsh ips during an oral glucose tolerance test (OGTT) were investigated in 60 non-diabetic male patients previously treated with coronary artery bypass surgery or angioplasty in an open, 12 week prospective study. D uring a 4 week run-in period, all patients were treated with diet and lifestyle advice and lovastatin 40 mg daily. Lovastatin treatment was continued in all the patients throughout the study. After randomizatio n, the metformin group got additional treatment with metformin up to 2 000 mg/day. Fasting plasma glucose levels and glucose area during OGTT remained unaffected by metformin treatment. Insulin resistance, asses sed as the insulin area/glucose area ratio during OGTT decreased by 24 % (P = 0.028) in the whole group and by 30% in obese subjects (P = 0.0 49). Notably, the reduction in body weight by metformin treatment did not correlate with amelioration of insulin resistance or changes in li pid levels. However, changes in insulin resistance correlated with cha nges in lipid levels. Hence, metformin effects on insulin resistance a nd body weight appear to be mediated, at least partly, by different me chanisms, while metformin effects on insulin resistance and lipid meta bolism are associated in non-diabetic subjects. (C) 1998 Elsevier Scie nce Ireland Ltd. All rights reserved.