Stratum corneum hydration inversely correlates with certain serum cytokine levels in the elderly, possibly contributing to inflammaging

Background Chronic, low-grade inflammation, also termed ‘inflammaging’, has been linked to the development of some aging-associated disorders. Recent studies suggest that inflammaging is attributable to aging-associated epidermal dysfunction. However, abnormality in which epidermal function contributes to inflammaging is not clear. Objective We delineated the correlation of epidermal functions with circulating levels of proinflammatory cytokines in the elderly. Methods Blood sample was collected from a total of 255 participants aged ≥ 65 years. Epidermal biophysical properties were measured on the left forearm and the right shin. Serum cytokine levels were measured by Multiplex Luminex Assays. Results Neither skin surface pH nor transepidermal water loss rates (TEWL) correlated with serum cytokine levels except TEWL on the right shin for TNFa ( p < 0.05). In contrast, stratum corneum hydration levels on both the forearm and the shin correlated negatively with serum cytokine levels ( p < 0.05). Conclusion Reduced stratum corneum hydration likely contributes to inflammaging.