Objective assessment of facial skin aging and the associated environmental factors in Japanese monozygotic twins

Abstract

Twin studies, especially those involving monozygotic (MZ) twins, facilitate the analysis of factors affecting skin aging while controlling for age, gender, and genetic susceptibility. The purpose of this study was to objectively assess various features of facial skin and analyze the effects of environmental factors on these features in MZ twins. At the Osaka Twin Research Center, 67 pairs of MZ twins underwent medical interviews and photographic assessments, using the VISIA® Complexion Analysis System. First, the average scores of the right and left cheek skin spots, wrinkles, pores, texture, and erythema were calculated; the differences between the scores were then compared in each pair of twins. Next, using the results of medical interviews and VISIA data, we investigated the effects of environmental factors on skin aging. The data were analyzed using Pearson's correlation coefficient test and the Wilcoxon signed-rank test. The intrapair differences in facial texture scores significantly increased as the age of the twins increased (P = 0.03). Among the twin pairs who provided answers to the questions regarding history differences in medical interviews, the twins who smoked or did not use skin protection showed significantly higher facial texture or wrinkle scores compared with the twins not exposed to cigarettes or protectants (P = 0.04 and 0.03, respectively). The study demonstrated that skin aging among Japanese MZ twins, especially in terms of facial texture, was significantly influenced by environmental factors. In addition, smoking and skin protectant use were important environmental factors influencing skin aging.

Oxidization of squalene, a human skin lipid: a new and reliable marker of environmental pollution studies

“…Such factor, although of different natures and origins, comprise common elements. As example, cigarette smokes contain seven Polycyclic Aromatic Hydrocarbons (PAH's) in common to those present as air pollutants [43][44][45] and smoking habit is increasingly viewed as an important amplifying factor of the skin ageing process [46]. Various protocols can be set up to assess the influence of combined pollutants upon squalene oxidization.…”

Clinical impacts of sun exposures on the faces and hands of Japanese women of different ages

“…In the latter, pigmentary disorders (dyschromia) are however of a much lower incidence. These results drove us to extend such approach to 1011 Japanese women (aged 18-83 years) since the related literature on UV exposure(s) and lifestyle's impact on Japanese facial skin ageing is scarce [13][14][15][16]. A similar protocol was adopted, using the same differentiation (i.e.…”

Age estimation based on visual parameters of the skin of cadavers

“…Erythema is a skin tone-related parameter and is reported to increase with aging. 4,25 This increase is speculated to be due to sunlight exposure time, which increases almost proportionally with age, 31 although individual differences in the level of exposure arise due to lifestyle and occupation. 32 This individual variation produces variation within age groups and is speculated to reduce the strength of correlation.…”

“…In the fields of dermatology and cosmetology, a variety of methods are used to evaluate aging of the skin. [1][2][3][4][5][6] One of these methods involves examination of images of skin to determine visual parameters.…”