Skin disorders in overweight and obese patients and their relationship with insulin

Introduction: The prevalence of obesity has increased worldwide in recent years. Some authors have described skin conditions associated with obesity, but there is little evidence on the association between insulin levels and such disorders.

Objective: To describe the skin disorders present in overweight and obese patients and analyze their association with insulin levels.

Material and methods: The study included nondiabetic male and female patients over 6 years of age who were seen at our hospital between January and April 2011. All the patients were evaluated by a dermatologist, who performed a physical examination, including anthropometry, and reviewed their medical history and medication record; fasting blood glucose and insulin were also measured. The patients were grouped according to degree of overweight or obesity and the data were compared using analysis of variance or the χ(2) test depending on the type of variable. The independence of the associations was assessed using regression analysis.

Results: In total, 109 patients (95 adults and 13 children, 83.5% female) were studied. The mean (SD) age was 38 (14) years and the mean body mass index was 39.6±8 kg/m(2). The skin conditions observed were acanthosis nigricans (AN) (in 97% of patients), skin tags (77%), keratosis pilaris (42%), and plantar hyperkeratosis (38%). Statistically significant associations were found between degree of obesity and AN (P=.003), skin tags (P=.001), and plantar hyperkeratosis. Number of skin tags, AN neck severity score, and AN distribution were significantly and independently associated with insulin levels.

Conclusions: AN and skin tags should be considered clinical markers of hyperinsulinemia in nondiabetic, obese patients.