Abstract:

Objective To determine whether skin friction coefficient （SFC） is associated with gender and age in a normal Chinese Han population. Methods A total of 414 Chinese Han subjects including 187 males and 227 females, who were aged from 0.15 to 79 years （mean age: 35.80 ± 1.33 years）, were enrolled in this study. According to human development stages, subjects were divided into pre-puberty group （aged 0 - 12 years）, young group （aged 20 - 40 years） and old group （aged 60 - 80 years）. SFC and stratum corneum capacitance were measured with A Frictiometer?誖FR 770 and Corneometer?誖CM 825 （C&K MPA 5）, respectively, on the dorsal hand, forehead, as well as canthus. Results SFC was higher on the dorsal hand than on the forehead in old males （P < 0.05）, and higher on the dorsal hand and canthus than on the forehead in young females （both P < 0.001）, while no significant difference was observed between the three measured sites in other groups of females or males （all P > 0.05）. In males, SFC on each measured site was similar among the three groups. In contrast, SFC was significantly higher on the forehead of females in aged than in young and pre-puberty groups （both P < 0.01）, and on the canthus and dorsal hand of females in young than in pre-puberty and aged groups （all P < 0.01）. The SFC on the canthus and dorsal hands of young females was higher than that of age-matched males （P < 0.0001 and 0.05, respectively）. A positive correlation was found between SFC and stratum corneum hydration in young males （foreahead: r = 0.6342, P < 0.0001; canthus: r = 0.4501, P < 0.001; dorsal hands: r = 0.3627, P < 0.01）. Moreover, SFC on the forehead （r = 0.2797, P < 0.05） and canthus （r = 0.486, P < 0.001） was also positively correlated with stratum corneum hydration in old females. Conclusion Skin friction coefficient varies with age, gender, body sites and stratum corneum hydration in normal Han populations.

Key words: Age, gender, stratum corneum hydration, skin friction coefficient