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.