Correlation of Body Mass Index with Epidermal Biophysical Properties Varies with Gender in Chinese

Background: Epidermal function is associated with diabetes and renal disease. Whether obesity can reflect the changes in epidermal function is not clear yet. Objective: We assessed here the correlation of epidermal functions with body mass index (BMI) in a large Chinese cohort. Methods and Subjects: A total of 1,405 Chinese aged 21–98 years old were enrolled in this study. Epidermal functions, including transepidermal water loss (TEWL), stratum corneum hydration, and skin surface pH, were measured on the flexor forearm and the shin. Subjects’ height and body weight were also measured. Results: Age positively correlated with both TEWL and skin surface pH, while it negatively correlated with stratum corneum hydration on both the forearm and the shin of females. Similarly, age positively correlated with skin surface pH, while negatively correlating with stratum corneum hydration on both the forearm and the shin of males. In females, BMI positively correlated with skin surface pH, while it negatively correlated with stratum corneum hydration on both the forearm and the shin. However, BMI correlated neither with skin surface pH on both the forearm and the shin nor with stratum corneum hydration on the shin of males. Conclusion: These results demonstrate that correlations of BMI with age and epidermal functions vary with gender.