Acanthosis nigricans (AN) is increasing in its prevalence and is the most prevalent cutaneous manifestation in individuals with obesity. Insulin resistance or hyperinsulinemia is the main pathophysiological mechanism of obesity-related AN. However, the effect of laparoscopic sleeve gastrectomy (LSG) on insulin secretion pattern in Chinese morbidly obese patients with AN is unknown. In these study, the investigators aimed to explore the insulin secretion patterns in Chinese morbidly obese patients with Acanthosis nigricans (AN) and their alterations after LSG.