A case control study of association of Acanthosis nigricans, Insulin resistance and Type 2 diabetes mellitus in a tertiary care centre in South India

Introduction: Acanthosis Nigricans is a dermatosis characterized by velvety, papillomatous, brownish black, hyperkeratotic plaques typically on the intertriginous surfaces and neck. Acanthosis Nigricans is commonly associated with disorders associated with insulin resistance, including obesity, type 2 diabetes mellitus and Polycystic ovarian syndrome. Hyperinsulinaemia is thought to play a pivotal role. Aims: To find the association of Acanthosis Nigricans with insulin resistance and type 2 diabetes mellitus and its correlation with anthropometric measurements such as waist circumference, waist hip ratio and BMI.Settings and Design: This is a hospital based cross sectional analytical study including 30 cases with acanthosis nigricans and 30 controls. Materials and Methods: All cases and controls underwent clinical examination, relevant anthropometric measurements, fasting sugar and fasting insulin levels. Statistical analysis used: Collective data was analysed by frequency, percentage, mean, Standard Deviation, Karl-Pierson correlation, Chi-square test and t-test. Results: In our study AN was significantly associated with increase in BMI, WC, WHR, skin tags, low physical activity, family history of DM, fasting glucose, and fasting insulin levels (p=0.000) as compared to controls. There was no significant association of AN with age, gender, comorbid conditions and blood pressure. Grade of AN, number of sites also were significantly associated with hyperinsulinemia. Therefore screening for AN would provide a simple and noninvasive method for identifying people who may have hyperinsulinemia and high risk for diabetes mellitus. Conclusions: AN was significantly associated with increase in BMI, WC, WHR, skin tags, low physical activity, family history of DM, fasting glucose, and fasting insulin levels.