Job Strain and Nonstandard Work Schedules as Drivers of Accelerated Biological Aging

Objective: To evaluate associations between occupational characteristics and accelerated phenotypic aging among working-age U.S. adults. Methods: This cross-sectional study used National Health and Nutrition Examination Survey (NHANES) 1999-2010 data from 12,090 working adults aged 20-65 years. Occupations were categorized as high, moderate, or low strain based on job strain and control. Work schedule was classified as day, evening/night, or other nonstandard shift. Phenotypic age acceleration was assessed using PhenoAge residuals. Results: High strain (β = 0.44 years, 95% Confidence Interval [CI] 0.14-0.74) and moderate strain occupations (β = 0.49 years, 95% CI 0.12-0.85) were associated with higher PhenoAge residuals compared with those in low strain occupations. Evening/night shifts work was also associated with accelerated aging (β = 0.66 years, 95% CI 0.13-1.19). Conclusions: Occupational strain and evening/night shift work may contribute to accelerated phenotypic aging.