Increased level of tumour necrosis factor-alpha (TNF-α) on the skin of Japanese obese males: measured by quantitative skin blotting

Objective: A state of chronic inflammation, characterized by an increased level of tumour necrosis factor-alpha (TNF-α), is often found in the obese population. The negative effects of elevated TNF-α are not limited to systemic metabolism. It also reportedly affects skin integrity. Recently, the relationship between obesity and skin fragility was reported; however, there has been little insight into how the level of TNF-α in the skin in situ is related to the severity of obesity. In this study, we aimed to measure the level of TNF-α on the skin and to find the relationship between obesity and the level of TNF-α detected on the skin. Methods: We used a novel, non-invasive method called quantitative skin blotting. Fifty-nine healthy (but some were classified as being overweight or obese) Japanese males were enrolled as subjects. The levels of TNF-α detected on the abdominal and thigh skin along with the body composition were measured, followed by a correlation analysis. Results: Significant positive correlations were found between the levels of TNF-α detected on the skin and the severity of obesity such as body mass index (BMI), body fat weight and visceral fat rating. Conclusion: We found that high levels of TNF-α were detected on the skin of Japanese obese males, which implied the higher TNF-α in the skin. The elevation of skin TNF-α may be one factor related to skin fragility that is often found in obese individuals.