Sun-Induced Changes in Stratum Corneum Function Are Gender and Dose Dependent in a Chinese Population

Abstract

Previous studies have demonstrated that UVB radiation changes the epidermal permeability barrier and stratum corneum (SC) hydration. It is well known that sun exposure causes erythema, sunburn and melanoma. However, whether daily sun exposure alters SC integrity and epidermal permeability barrier function is largely unknown, especially in Chinese subjects. In the present study, we assess the SC integrity, SC hydration and epidermal permeability barrier function following various doses of sun exposure. A total of 258 subjects (124 males and 134 females) aged 18–50 years were enrolled. A multifunctional skin physiology monitor (Courage & Khazaka MPA5) was used to measure SC hydration and transepidermal water loss (TEWL) on the forearms. In males, basal TEWL was higher with higher doses of sun exposure than with lower doses and control, whereas in females, basal TEWL was higher with lower doses of sun exposure than with higher doses and control. In the group with higher doses of sun exposure, TEWL in females was significantly lower than that in males. The barrier recovery was faster in females than in males in both control and lower-dose groups. In both males and females, barrier recovery was delayed with higher doses of sun exposure. In males, sun exposure did not alter SC hydration, while in females SC hydration was lower with lower doses of sun exposure as compared with control and higher doses of sun exposure. These results demonstrated that sun-induced changes in SC function and SC hydration vary with gender and the extent of sun exposure.

Facial skin pigmentation is not related to stratum corneum cohesion, basal transepidermal water loss, barrier integrity and barrier repair

“…This is consistent with the body site comparison work of photoprotected and photoexposed forearms of subjects living in the U.S.A. . Photoexposed Chinese subjects, however, have been reported to have elevated basal TEWL levels on their volar forearms . In both of these reported studies, it is expected that the body sites will be more melanised, but there was no reported increase in skin barrier function.…”

Sun‐induced changes of stratum corneum hydration vary with age and gender in a normal Chinese population

“…Measurements were taken on the left dorsal hand, left canthus and forehead with a Corneometer CM825 attached to a Courage‐Khazaka MPA5 system (CK electronic GmbH, Koeln, Germany) (2, 32). For the SC rehydration study, a moisturizer containing petrolatum, glycerol and propylene glycol was applied to the measured sites immediately after the initial hydration measurement.…”

“…UB radiation‐caused immunosuppression is greater in males than in females (30) and the number of UVB‐induced skin tumors is more in males than in females (31). Similarly, following lower doses of sun exposure, barrier recovery is faster in females than in males (32). Although previous studies demonstrated some gender difference in sun exposure‐induced changes in SC hydration, its association with age and gender is not well delineated as yet.…”

Research Techniques Made Simple: Transepidermal Water Loss Measurement as a Research Tool

“…Skin surface temperature and sweating additionally alter TEWL (Pinnagoda et al, 1990). Studies have also shown seasonal variation in TEWL and that TEWL is affected by circadian rhythm and sun exposure (Le Fur et al, 2001;Liu et al, 2010).…”