Relation of acanthosis nigricans to hyperinsulinemia and insulin sensitivity in overweight African American and white children

Objectives: Acanthosis nigricans (AN) has been proposed as a reliable marke r of hyperinsulinemia but its utility for predicting hyperinsulinism has no t been systematically evaluated in overweight children. We examined the rel ationship of AN to hyperinsulinemia and body adiposity. Study design: One hundred thirty-nine children underwent physical examinati on for AN, body composition studies, an oral glucose tolerance test, and a hyperglycemic clamp. Results: Thirty-five children (25%) had AN. AN was more prevalent in Africa n Americans (50.1%) than in white subjects (8.2%, P < .001). Independent of race, children with AN had greater body weight and body fat mass (P < .001 ); greater basal and glucose-stimulated insulin levels during oral glucose tolerance test (P < .001); greater first-phase, second-phase, and steady-st ate insulin levels (P < .001); and lower insulin sensitivity (P < .001) dur ing the hyperglycemic clamp. After adjusting for body fat mass and age. non e of these differences remained significant. When categorized by fasting in sulin, 35% with fasting insulin levels >20 muU/mL and 50% with fasting insu lin levels >15 muU/mL did not have AN. Eighty-eight percent of children wit h fasting insulin levels greater than or equal to 15 muU/mL had a body mass index SE score greater than or equal to3.0. Conclusions: AN is not a reliable marker for hyperinsulinemia in over-weigh t children. Children with a race-, sex-, and age-specific body mass index S D scores greater than or equal to3.0 should be screened for hyperinsulinemi a, whether or not they have AN.