Background Unhealthy lifestyles may constitute significant risk factors for dyslipidemia. However, limited studies focus on the association mentioned above among railway workers undertaking frequent shift work.
Objective To understand the status of dyslipidemia and lifestyles among railway workers, and to investigate the association between the lifestyles of workers involved in different shift work schedules and dyslipidemia, aiming to provide a reference for the development of targeted intervention strategies against dyslipidemia in this occupational group.
Methods The participants were selected from the in-service staff of a railway unit in 2021. A quota sampling approach was used to ensure the participation of at least 50% of employees from each department. Demographic and lifestyle information of the railway workers in 2021 was collected through self-administered questionnaires, while physiological and biochemical indicators were obtained through health examinations. Chi-square tests were employed to analyze the distribution of dyslipidemia among railway workers with different characteristics. Binary logistic regression was utilized to examine the associations between selected variables and dyslipidemia, and additive model was used to investigate the interaction between lifestyle and different shift work schedules on dyslipidemia.
Results A total of 17392 railway workers were included in the study, and the total prevalence of dyslipidemia was 31.3%, with a higher prevalence reported among workers undertaking rotating night shifts (33.5%) and permanent night shifts (34.3%) than those with regular day work. The main adverse lifestyles among the railway workers were physical inactivity (59.6%), alcohol consumption (40.0%), and smoking (35.7%), and only 13.6% reported a healthy lifestyle. Furthermore, significant statistical differences in the prevalence of dyslipidemia were reported among workers with different lifestyles (P<0.01). After adjusting for confounding factors, smoking was a risk factor for dyslipidemia (OR=1.61, 95%CI: 1.48, 1.75), while highly active physical activity served as a protective factor against dyslipidemia (OR=0.79, 95%CI: 0.71, 0.88). In general, adopting a healthy lifestyle was associated with a decreased risk of dyslipidemia (OR=0.86, 95%CI: 0.77, 0.95). The stratified analyses based on different shift work schedules revealed a statistically significant association between smoking and dyslipidemia across various shift work occupational groups (P<0.001): regular day work, OR=1.62, 95%CI: 1.42, 1.84; rotating night shifts, OR=1.54, 95%CI: 1.35, 1.76; and permanent night shifts, OR=1.75, 95%CI: 1.40, 2.18. In regular day workers, highly active physical activity was associated with a reduced risk of dyslipidemia (OR=0.81, 95%CI: 0.69, 0.95). A similar association was observed among workers undertaking rotating night shifts (OR=0.78, 95%CI: 0.65, 0.94); furthermore, moderately active physical activity was also associated with a reduced risk of dyslipidemia in this occupational group (OR=0.85, 95%CI: 0.74, 0.97). There was no additive interaction between rotating night shifts and lifestyle with relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (S) of 0.18 (95%CI: −0.04, 0.41), 0.15 (95%CI: −0.04, 0.33), and 3.19 (95%CI: 0.09~110.44), respectively. There was also no additive interaction between permanent night shifts and lifestyle, with RERI, AP and S of −0.03 (95%CI: −0.43~0.37), −0.02 (95%CI: −0.35~0.31) and 0.90 (95%CI: 0.18~4.46). Further stratification of populations according to shift work schedules and lifestyles revealed that those who worked rotating night shifts and reported unhealthy lifestyles were more likely to present dyslipidemia than those who undertook regular day work and had healthy lifestyles (OR=1.27, 95%CI: 1.09, 1.48).
Conclusion Railway workers present less optimistic lipid health status, and unhealthy lifestyles are prevalent among them. Those engaged in night shift work report a higher prevalence of dyslipidemia. Among workers with different shift schedules, smoking and physical inactivity are identified as the primary risk factors for dyslipidemia, and particular attention should be paid to the lipid health status of rotating night shift workers with poor lifestyles.