Table 1_Association between sunlight exposure and risk of rheumatic diseases: a prospective cohort study in the UK.docx

Objective<p>To investigate the relationships between sunlight exposure and the risk of three major rheumatic diseases (systemic lupus erythematosus [SLE], rheumatoid arthritis [RA], and gout) in a large-scale prospective cohort.</p>Methods<p>Data were derived from the UK Biobank (a nationwide prospective cohort in the United Kingdom), including 363,873 participants followed up from 2006 to 2022. Sunlight exposure was assessed by self-reported average daily outdoor time in summer and winter.

Incident SLE, RA, and gout were identified using International Classification of Diseases, Tenth Revision (ICD-10) codes from linked hospital records. Multivariate Cox proportional hazards models, restricted cubic splines, subgroup analyses, and sensitivity analyses were performed to evaluate associations.</p>Results<p>During the 13-year follow-up, 335 SLE, 5,591 RA, and 7,485 gout cases were ascertained. Compared with sunlight exposure of 2.5 h/day, both lower and higher sunlight exposure were associated with increased risks of SLE (< 2.5 h/day: HR = 1.71, 95% CI:1.13, 2.59; >2.5 h/day: HR = 1.75, 95% CI:1.17, 2.63).