Acanthosis Nigricans as a Clinical Predictor of Insulin Resistance in Obese Children

PURPOSE This study aimed to evaluate the utility of acanthosis nigricans (AN) severity as an index for predicting insulin resistance in obese children. METHODS The subjects comprised 74 obese pediatric patients who attended the Department of Pediatrics at Chosun University Hospital between January 2013 and March 2016. Waist circumference; body mass index; blood pressure; fasting glucose and fasting insulin levels; lipid profile; aspartate transaminase, alanine transaminase, glycated hemoglobin, C-peptide, and uric acid levels; and homeostatic model assessment insulin resistance (HOMA-IR) and quantitative insulin check sensitivity index (QUICKI) scores were compared between subjects with AN and those without AN. Receiver operating characteristic curves were used to investigate the utility of the AN score in predicting insulin resistance. HOMA-IR and QUICKI were compared according to AN severity. RESULTS The With AN group had higher fasting insulin levels (24.1±21.0 mU/L vs. 9.8±3.6 mU/L, p<0.001) and HOMA-IR score (5.74±4.71 vs. 2.14±0.86, p<0.001) than the Without AN group. The AN score used to predict insulin resistance was 3 points or more (sensitivity 56.8%, specificity 83.9%). HOMA-IR scores increased with AN severity, from the Without AN group (mean, 2.15; 95% confidence interval [CI], 1.72-2.57) to the Mild AN (mean, 4.15; 95% CI, 3.04-5.25) and Severe AN groups (mean, 7.22; 95% CI, 5.08-9.35; p<0.001). CONCLUSION Insulin resistance worsens with increasing AN severity, and patients with Severe AN (AN score ≥3) are at increased risk of insulin resistance.