Night shift work, accelerated biological aging and reduced life expectancy: a prospective cohort study

Summary Background Aging is a lifelong process that initiates at birth and is associated with age-related diseases and death. Night shift work has drawn increasing attention due to its negative health effects. This study aims to explore the association between night shift work, biological aging, and life expectancy using data from the UK Biobank. Methods A total of 192,764 participants (age : 52.69 ± 7.08 years, 51.39% male) from the UK Biobank cohort were included in the analysis. Biological aging was measured by Klemera-Doubal method biological age (KDM-BA) and PhenoAge, derived from anthropometric and blood biomarkers. Polygenic risk scores (PRS) for biological aging were calculated for participants of European descent. Multiple linear regression models were applied, and mediation analysis was used to identify potential mediators. Results Compared to day workers, usual night shift workers showed accelerated biological aging, with β coefficients (95% CI) of 0.09 (0.05–0.13) for KDM-BA acceleration and 0.48 (0.36–0.60) for PhenoAge acceleration. At age 45, life expectancy was reduced by 0.94 years among usual night shift workers. Participants working night shifts exhibited gradually accelerated biological aging as the frequency and duration increased (P for trend <0.05). This association remained robust in a series of sensitivity analyses and across different subgroups. Further mediation analysis showed that BMI mediated 28.88%–42.76% of this association. Conclusions Night shift work is associated with accelerated biological aging and reduced life expectancy. Minimizing night shifts and maintaining a healthy weight may help mitigate these effects.