Association of acanthosis Nigricans and insulin resistance in indian children and youth – A HOMA2-IR based cross-sectional study

Introduction: The American Diabetes Association includes acanthosis nigricans (AN) as an indicator of diabetes mellitus risk in overweight youth entering puberty. Some argue that AN is not an independent predictor of insulin resistance (IR), when body mass index (BMI) is controlled for. There is a paucity of studies on the association of AN and IR among children and young adults from India. Homeostatic model assessment-IR (HOMA2-IR), a computerized updated model, which is supposed to be superior to HOMA1-IR, has rarely been used for quantification of IR. Methods: Sixty cases (irrespective of BMI), aged 2–24 years with AN, and 30 age- and sex-matched normal weight controls were included. A thorough clinical examination and grading of AN was done. BMI, fasting glucose levels, and fasting insulin levels were measured for all. HOMA-IR calculator V.2.2.3 was used to calculate IR. Those with HOMA 2-IR >1.8 were considered insulin-resistant. Lifestyle modifications were advised for patients with IR. Results: The mean HOMA2-IR value in cases and controls was 2.422 and 1.322, respectively, which was statistically significant. Overweight and obese cases had 2.5 and 11.25 times higher risk of having IR, respectively, by logistic regression. The association of AN with IR was found to be statistically significant in normal weight cases when compared with controls (P = 0.045). Grade 4 of neck severity (P = 0.007), Grade 3 of neck texture (P = 0.001), and Grade 4 of axillary severity (P = 0.001) of AN were found to be significantly associated with IR. Limitations: The relatively small sample size may not reflect the accuracy of AN as a marker of IR. Conclusion: Acanthosis nigricans is associated with IR in both normal and obese. We propose that all children, adolescents, and youth with AN be screened for IR irrespective of BMI. Early identification and prompt lifestyle interventions may prevent or delay the onset of diabetes later.