Principal component analysis of seven skin-ageing features identifies three main types of skin ageing

Longitudinal Assessment of the Prevalence of Actinic Keratosis and Extensive Risk Factor Evaluation: An Update from the Rotterdam Study

Population-based studies available to analyze the prevalence, risk factors, and longitudinal outlook of actinic keratoses (AKs) are limited. These features mentioned earlier were assessed using Rotterdam study participants aged ≥40 years who underwent a full-body skin examination by a dermatology-trained physician. ORs with 95% confidence intervals were calculated for the associations between risk factors and the presence of AK. Among 8,239 eligible participants, the prevalence of one or more AKs was 21.1% (95% confidence interval = 20.2-22.0) and was higher in men. Male sex, age, lighter hair and eye color, baldness, genetic risk score, and digital photoaging measures (digitally assessed pigmented spots, telangiectasias, and global facial wrinkling) had a positive association with AK. Cigarette smokers had reduced odds of having AK, with current smokers having the lowest risk. Among patients with two AK assessments, there was no difference in the presence of AK during follow-up between treated and untreated participants. In conclusion, genetic risk score and digital photoaging measures showed associations with increased lesion count. At the individual level, patients were most likely to decrease in AK severity group over time, possibly regardless of whether or not participants were treated.

Modeling of global skin aging indices among Caucasian and Asian women

BACKGROUND

The skin aging process is defined as the gradual degradation of several skin properties such as firmness, color, or the appearance of wrinkles. These properties can be assessed by trained experts, who perform an overall evaluation of the entire face.

OBJECTIVE

The objective of this paper is the construction of two Global Skin Aging Indices specifically designed to model the overall skin aging process of Caucasian and Asian women.

METHODS

Two hundred forty Asian women and 129 Caucasian women aged between 20 and 60 years old are recruited. Parameters related to wrinkles, sagging, elasticity, and skin tone are measured (clinically or instrumentally). The global skin aging index is defined as the normalized projection on the first principal component of a principal component analysis of the skin measurements. Then, linear regressions are performed between the indices and age of both panels.

RESULTS

The first principal component carries around 50% of the initial variance for both indices. Both Global Skin Aging Indices statistically correlate with age (R2 ≥ 0.7, p-value < 0.05). An equation linking the indices with age is computed.

CONCLUSION

The proposed indices are good indicators of the overall aging process for Caucasian and Asian women. They offer new approaches to assess antiaging product efficacy.

Differences between perceived age and chronological age in women: A multi-ethnic and multi-centre study

Objective

Accuracy in assessing age from facial cues is important in social perception given reports of strong negative correlations between perceived age and assessments of health and attractiveness. In a multi‐ethnic and multi‐centre study, we previously documented similar patterns of female facial age assessments across ethnicities, influenced by gender and ethnicity of assessors.

Methods

Here we extend these findings by examining differences between estimated age from digital portraits and chronological age (Δ age) for 180 women from three age groups (20–34, 35–49, 50–66 years) and five ethnicities (36 images of each ethnicity, assessed for age on a continuous scale by 120 female and male raters of each ethnicity).

Results

Across ethnicities, Δ age was smallest in French assessors and largest in South African assessors. Numerically, French women were judged oldest and Chinese women youngest relative to chronological age. In younger women, Δ age was larger than in middle‐aged and older women. This effect was particularly evident when considering the interaction of women's age with assessor gender and ethnicity, independently and together, on Δ age.

Conclusion

Collectively, our findings suggest that accuracy in assessments of female age from digital portraits depends on the chronological age and ethnicity of the photographed women and the ethnicity and gender of the assessor. We discuss the findings concerning ethnic variation in skin pigmentation and visible signs of ageing and comment on implications for cosmetic science.

Genetics of facial telangiectasia in the Rotterdam Study: a genome-wide association study and candidate gene approach

BACKGROUND

The severity of facial telangiectasia or red veins is associated with many lifestyle factors. However, the genetic predisposition remains unclear.

OBJECTIVES

We performed a genome-wide association study (GWAS) on facial telangiectasia in the Rotterdam Study (RS) and tested for replication in two independent cohorts. Additionally, a candidate gene approach with known pigmentation genes was performed.

METHODS

Facial telangiectasia were extracted from standardized facial photographs (collected from 2010-2013) of 2842 northwestern European participants (median age 66.9, 56.8% female) from the RS. Our GWAS top hits (P-value <10^-6 ) were tested for replication in 460 elderly women of the SALIA cohort and in 576 additional men and women of the RS. Associations of top single nucleotide polymorphisms (SNPs) with expression quantitative trait loci (eQTL) in various tissues were reviewed (GTEx database) alongside phenotype associations in the UK biobank database. SNP-based associations between known pigmentation genes and facial telangiectasia were tested. Conditional analysis on skin colour was additionally performed.

RESULTS

Our most significant GWAS signal was rs4417318 (P-value 5.38*10^-7 ), an intergenic SNP on chromosome 12 mapping to the SLC16A7 gene. Other suggestive SNPs tagged genes ZNF211, ZSCAN4, ICOS and KCNN3; SNP eQTLs and phenotype associations tagged links to the vascular system. However, the top signals did not pass significance in the two replication cohorts. The pigmentation genes KIAA0930, SLCA45A2 and MC1R, were significantly associated with telangiectasia in a candidate gene approach but not independently of skin colour.

CONCLUSION

In this GWAS on telangiectasia in a northwestern European population, no genome-wide significant SNPs were found, although suggestive signals indicate genes involved in the vascular system might be involved in telangiectasia. Significantly associated pigmentation genes underline the link between skin colour and telangiectasia.

Objectives, design and main findings until 2020 from the Rotterdam Study

The Rotterdam Study is an ongoing prospective cohort study that started in 1990 in the city of Rotterdam, The Netherlands. The study aims to unravel etiology, preclinical course, natural history and potential targets for intervention for chronic diseases in mid-life and late-life. The study focuses on cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1700 research articles and reports. This article provides an update on the rationale and design of the study. It also presents a summary of the major findings from the preceding 3 years and outlines developments for the coming period.