Therapeutic approach in insulin resistance with acanthosis nigricans

The aim of the present study was to evaluate the effect of metformin in very obese subjects with acanthosis nigricans. Five patients (two obese children, mean age 14.4 +/- 0.6 yr, mean BMI 35.2 +/- 1.9 kg/m2 and normal glucose tolerance, and three newly diagnosed obese type 2 diabetic patients, mean age 37.7 +/- 3.2 yr, mean BMI 37.7 +/- 2.9 kg/m2) were enrolled in the study Insulin secretion was measured during oral glucose tolerance (OGT) and intravenous glucose tolerance (IVGT) tests. Insulin resistance was assessed by the homoeostasis model assessment (HOMA) index. All the patients were treated with metformin at a mean daily dose of 2.23 +/- 0.45 g. Six months after initiation of therapy we found a significant reduction in AUC for insulin secretion during OGTT (p < 0.05), due to reduction in both basal and stimulated insulin secretion (p<0.05). Body weight was reduced by mean 4.7 +/- 1.9% and body fat mass by 8.95 +/- 3.7%. We have demonstrated a significant decrease of 36.3% in insulin resistance (p < 0.01). Our results demonstrate that metformin reduces hyperinsulinaemia, body weight and fat mass and improves insulin sensitivity in patients with insulin resistance and acanthosis nigricans.