The presence of acanthosis nigricans (AN) may predict hyperinsulinemia and insulin resistance in adolescents who are overweight. The skin condition is likely sensitive to changes in insulin level and duration of insulin resistance, according to study results published in Annals of Pediatric Endocrinology & Metabolism.1
Although AN — a dermatologic condition consisting of symmetrical hyperpigmentation and thickened skin — is typically asymptomatic, it can sometimes be pruritic. The pathogenesis of AN is not clear, but it is associated with high insulin levels.
The goal of this study was to assess and score AN using 2 versions of a previously defined scale2 and to explore the predictive power of using either version for estimation of insulin resistance. The short version considered AN scores at the neck and axilla, while the extended version considered AN scores at the neck, axilla, elbows, knuckles, and knees.
The cross-sectional study included data from 139 overweight adolescents aged 12 to 18 years (body mass index ≥85th percentile; 45.3% girls; mean age, 14.4±1.8 years) followed at a pediatric obesity clinic. Of these, 67 participants had evidence of AN and 72 did not.
Adolescents with AN had higher insulin levels (P =.003) and higher scores in the homeostatic model assessment for insulin resistance (HOMA-IR; P =.003), as well as a higher prevalence of hyperinsulinemia (insulin levels ≥90th percentile; 70.2% vs 47.2%, respectively; P =.008) and insulin resistance (HOMA-IR values ≥90th percentile; 62.7% vs 38.9%, respectively; P =.008) compared with participants without AN.
No severity scores for AN were able to predict hyperinsulinemia or insulin resistance. However, the presence of AN alone predicted hyperinsulinemia in 7.3% of adolescents and insulin resistance in 7.1% of adolescents. Participants with AN had more than double the risk of having hyperinsulinemia (odds ratio, 2.59; P =.009) and insulin resistance (odds ratio, 2.68; P =.008) compared with those without AN.
The study had several limitations, including the cross-sectional design and possible bias from the use of retrospective data for 60 adolescents without AN.
“[T]he neck and axilla should be routinely assessed for the presence of AN, since it is a noninvasive and cost-effective way to identify asymptomatic overweight adolescents who have or are at risk of developing [insulin resistance],” concluded the researchers.
1. Videira-Silva A, Albuquerque C, Fonseca H. Acanthosis nigricans as a clinical marker of insulin resistance among overweight adolescents. Ann Pediatr Endocrinol Metab. 2019;24(2):99-103.
2. Burke JP, Hale DE, Hazuda HP, Stern MP. A quantitative scale of acanthosis nigricans. Diabetes Care. 1999;22(10):1655-1659.