Extrinsic skin ageing in German, Chinese and Japanese women manifests differently in all three groups depending on ethnic background, age and anatomical site

Abstract

Background: It has been suggested that extrinsic skin ageing manifests differently in Caucasians versus East Asians. In particular, from previous studies it was concluded that Caucasians are more prone to develop wrinkles, whereas pigment spot formation is the hallmark of extrinsic skin ageing in East Asians. However, these assumptions are based on a very limited number of studies which did not include different East Asian populations.

Objective: We here compare the manifestation of extrinsic skin ageing signs in German, Japanese and Chinese women by specifically elucidating the age and anatomical site dependence of any potential ethnic difference.

Methods: In the present study, we assessed skin ageing in N=902 German, N=165 Japanese and N=1260 Chinese women ranging from 30 to 90 years by means of SCINEXA™. Linear regression analysis was used to test for ethnic differences and their age and site dependence adjusted for educational level, sun exposure, smoking and sun protection behaviours.

Results: Pigment spots and wrinkles on the face were present among all three ethnic groups and differences were influenced by age and anatomical sites independently of further influencing factors. Pigment spots on the forehead were most pronounced over the whole age range in Chinese and German women and least developed in Japanese. Pigment spots on cheeks were a typical extrinsic skin an ageing sign in the two East Asian populations in all age groups. However, in older German women they reach the same level as observed in the two East Asian populations. In contrast, pigment spots on arms and hands were significantly more pronounced in German women ≥45years of age. Wrinkles were not exclusively a skin an ageing sign of German women, but were also very pronounced in Chinese women on forehead, between the eyebrows and in the crow's feet area.

Conclusion: These results corroborate the previous notion that the occurrence of pigments spots and wrinkles is different between Caucasians and East Asians. In addition, this study shows that this difference depends on age and anatomical site and that it also differs between different ethnic groups from East Asia.

Keywords: Age dependence; Anatomical site dependence; Ethnic populations; Extrinsic skin ageing.