P07 Biomechanical ageing of human skin: ethnic and site-specific differences in Chinese and White Northern European skin
Dafydd Thomas, Poonam Halai, Lindsay Cotterell, Anne Chandidzura, Clare O’Connor, Mike Bell, Mark Farrar, Abigail LangtonAbstract
Introduction and aims
Skin colour, quantified using individual typology angle (ITA), can appear similar across ancestries. While age-related biomechanical decline is well characterized in White Northern European (WNE) skin, trajectories in people of Chinese ancestry – who display similar ITA values – remain poorly defined. It is unclear whether these ancestrally distinct groups experience comparable patterns of ageing. This study compared biomechanical ageing in healthy Chinese and WNE adults and examined the influence of pigmentation and photoexposure.
Methods
Healthy Chinese (n = 26) and WNE (n = 98) adults aged 18–50 years were assessed at photoprotected buttock (BU) and photoexposed forearm (FA) sites. Pigmentation (constitutive and facultative) was measured using spectrophotometry. Skin biomechanics were evaluated using cutometry including F3 (overall biomechanical performance) elasticity (R1, R2, R7) and viscoelasticity (R6) parameters. Multiple linear regression models evaluated age and ethnicity effects for each site.
Results
BU pigmentation was similar between groups (ITA ‘Light’), whereas FA pigmentation diverged: Chinese remained ‘Light’, while WNE showed facultative tanning (‘Intermediate’). The FA–BU ITA difference was small in Chinese (–2.1°) but pronounced in WNE (–15.1°) skin, suggesting greater habitual photoexposure. At BU, age-related decline in F3 was significant (P < 0.01) without ethnic differences in slope or elevation. At FA, both groups showed similar age-related decline (P < 0.001), but Chinese participants consistently exhibited higher F3 values across ages (∼10.36 mm2; P < 0.001). Additional cutometry parameters (R1, R2, R6, R7) showed parallel age-related slopes but significantly higher elevations in Chinese FA skin (P < 0.001).
Conclusions
Intrinsic biomechanical ageing appears comparable between ancestrally distinct, lightly pigmented individuals at photoprotected sites. However, at photoexposed sites, Chinese adults maintain superior biomechanical performance despite similar age-related decline. These findings suggest a prolonged skin healthspan in Chinese skin owing to lower early-life photodamage and reinforce the importance of photoprotection in preserving biomechanical skin health.