Comparison of Insulin resistance in obese women with and without Acanthosis Nigricans

Background and aim: Acanthosis nigricans (AN) is characterized by hyperpigmented velvety plaques of body folds and neck. Insulin can have a role in the pathogenesis of this disease and hyperinsulinemia as a consequence of insulin resistance may stimulate the formation of the characteristic plaques of AN. In this study insulin resistance was compared in obese women with and without AN.Materials and Methods: Glucose tolerance test (GTT) and fasting blood insulin were measured in two groups of obese women (BMI>30 kg/m2) with AN (32 cases) and without AN (34 cases) and insulin resistance was determined using HOMA formula.Results: The mean fasting blood insulin in two groups with and without AN were 15.5±8.5 and 12.2±4.1 IU/mL; respectively (P<0.05). The mean of insulin resistance in two groups with and without AN were 3.5±1.9 and 2.6±0.9; respectively (P<0.05). The results of GTT showed that the mean fasting blood sugar was 89.5±12 mg/dl and following using glucose were 144±7 mg/dl after 30 minutes, 132±45 mg/dl after 60 minutes, 107±30 mg/dl after 120 minutes in persons with AN and in the other group were 87±8, 130±3, 122±26 and 100±26 mg/dl; respectively. The difference between two groups was only significant after 60 minutes.Conclusion: Acanthosis nigricans maybe a marker of insulin resistance in obese women.