Abstract Background Acne is a multifactorial inflammatory disorder which is influenced by lifestyle and psychosocial factors. Comprehensive evidence is lacking on modifiable behavioural risks and the mediating role of psychological distress. Objective This population‐based cross‐sectional study investigated the associations between sedentary behaviour, physical exercise, sleep and acne in adults living in Southern China, and quantified the mediating effects of depressive and anxiety symptoms. Methods Participants were recruited from 10 districts in Shenzhen who completed investigator‐administered questionnaires. Acne was diagnosed by dermatologists and further evaluated in relation to their severity. Binary and ordinal logistic regression models were used to estimate the factors associated with acne and acne severity. A restricted cubic spline was used to describe the dose–response association. The contribution of depressive and anxiety symptoms was estimated by mediation analyses. Results A total of 11,922 participants were included, and the overall prevalence of acne was 14.79% (1763/11,922), with females outnumbering males (15.91% vs. 13.50%). Severe sedentary behaviour adjusted OR (aOR)= 1.19, 95% CI: 1.06–1.34 and late sleep (aOR = 1.17, 95% CI: 1.03–1.33) were associated with acne risk, while regular exercise demonstrated protective effects (aOR = 0.86, 95% CI: 0.75–0.99). A restricted cubic spline indicated that prolonged sedentary behaviour was associated with a higher risk of acne, especially when total sedentary time exceeded 4 h/day. Depressive and anxiety symptoms partially mediated the sedentary‐acne and late sleep‐acne associations. Conclusions This large‐scale study identified sedentary lifestyles and circadian misalignment as modifiable risk factors for acne, while highlighting exercise as a potential protective behaviour. Psychological distress mediates a partial proportion of these relationships, suggesting the need for integrated biopsychosocial approaches for acne management.
He et al. (2026) studied this question.