Defining skin aging and its risk factors: a systematic review and meta-analysis

Abstract

Skin aging has been defined to encompass both intrinsic and extrinsic aging, with extrinsic aging effected by environmental influences and overlaying the effects of chronological aging. The risk factors of skin aging have been studied previously, using methods of quantifying skin aging. However, these studies have yet to be reviewed. To better understand skin aging risk factors and collate the available data, we aimed to conduct a systematic review and meta-analysis. We conducted our systematic review in compliance with Preferred Reporting Item for Systematic Review and Meta-Analyses (PRISMA) guidelines. Embase, PubMed and Web of Science databases were searched in October 2020 using specific search strategies. Where odds ratios were reported, meta-analyses were conducted using the random effects model. Otherwise, significant factors were reported in this review. We identified seven notable risk factors for various skin aging phenotypes: age, gender, ethnicity, air pollution, nutrition, smoking, sun exposure. This review’s results will guide future works, such as those aiming to examine the interaction between genetic and environmental influences.

A systematic review of skin ageing genes reveals a pleiotropic landscape where skin colour genes and chromosomal band 16q24.3 genes may drive skin ageing

“…Skin ageing is therefore a superimposition of benign skin phenotypes indicative of histological and morphological changes which are both continuous and inevitable, caused by both intrinsic and extrinsic factors, wherein genetic and chronological in uences constitute the former, and environmental in uences constitute the latter. Building on a previous work by Wong & Chew (2021) 1 , in this review, we focus on the intrinsic factors driving skin ageing.…”

Lipid Nanomaterials for Targeted Delivery of Dermocosmetic Ingredients: Advances in Photoprotection and Skin Anti-Aging

“…However, it is from the second half of the fourth decade that the signs of aging intensify, when estrogen levels drop abruptly at menopause and when the renewal of skin cells begins to slow down. Consequently, the epidermis becomes looser and the grooves begin to organize [ 7 ]. In addition to these factors, actinic elastosis determined by prolonged exposure to the sun (photoaging), and bone resorption, which occurs mainly after the age of 50, further accelerate this process, which can lead to wrinkles and folds [ 8 ].…”

“…The folds are the lines of expression that appear even at rest, marked in the deep dermis. Skin folds occur when the deep folds are covered by a redundant skin from the neighborhood, as shown in Figure 2 [ 7 ].…”

Comparison of Fatty Acid Contents and MMP-1 Inhibitory Effects of the Two Antarctic Fish, Notothenia rossii and Champsocephalus gunnari

“…Skin is the largest external barrier in human body that protects against physical, chemical, and biological insults [ 1 , 2 ]. The skin is composed of the epidermis and dermis, where collagen is the major component of the dermis and is associated with other molecules to stabilize the organization of the extracellular matrix.…”