Association and interaction effect of shift work and the risk for obstructive sleep apnea on diabetes mellitus in middle-aged Korean workers

Purpose To investigate the association of shift work and the risk for obstructive sleep apnea (OSA) with diabetes mellitus (DM), and the interaction effect of shift work and the risk for OSA on DM. Methods Data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2019–2021 were used. The participants were 3012 employees aged 40 to 59 years. Shift work was assessed using self-reporting questionnaires. The risk for OSA was assessed by STOP-BANG score. The distribution of demographic factors was calculated using the chi-square test. Adjusted odds ratios (AORs) and 95% confidence intervals (CIs) were calculated using multivariable logistic regression. An interaction effect between shift work and the risk for OSA on DM was evaluated using relative excess risk owing to interaction (RERI) and attributable proportion (AP) with 95% CIs. The synergic index (SI) was also calculated. Results Shift work and the risk for OSA were each significantly associated with DM. There was also a significant interaction effect between shift work and the risk for OSA on DM. The RERI was 0.543 (95% CI 0.205–1.361) and the AP was 0.230 (95% CI 0.145–0.342). The SI was 1.662 (95% CI 1.481–1.843). Conclusions There was an association and a significant interaction effect of shift work and the risk for OSA on DM. The management of OSA in shift workers should be implemented to prevent DM.