Comparison of insulin resistance in obese women with and without acanthosis nigricans

ABSTRACT

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. Glucose tolerance test [GTT] and fasting blood insulin were measured in two groups of obese women [BMI>30 kg/m[2]] with AN [32 cases] and without AN [34 cases] and insulin resistance was determined using HOMA formula. The mean fasting blood insulin in two groups with and without AN were 15.5 +/- 8.5 and 12.2 +/- 4.1 micro 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. Acanthosis nigricans maybe a marker of insulin resistance in obese women