Shift work and arteriosclerosis risk in professional bus drivers.

PURPOSE Professional bus drivers are at increased risk for cardiovascular disease, but the underlying causes are unclear. Professional bus drivers often follow shift schedules. Especially, an association between shift work and early manifestations of cardiovascular disease has not been elucidated. Thus we investigated the links between shift work and arteriosclerosis risk in professional bus drivers. METHODS Questionnaires were administered to 184 bus drivers on demographic characteristics, lifestyle, and occupational history from 5 transportation companies in Taiwan. Brachial-ankle pulse wave velocity (baPWV) was measured using a volume-plethysmographic apparatus. Body mass index, waist circumference, biochemical variables, and blood pressure were also measured. RESULTS Arteriosclerotic risk factors (age, weekly driving hours, systolic blood pressure, diastolic blood pressure, and insulin level) differed in part among different groups of drivers. Long-term shift drivers had higher baPWV compared to regular drivers and short-term shift drivers (1594 cm/s vs. 1497 and 1432, p<0.01). Our multiple regression model showed that age (p<0.01) and diastolic blood pressure (p<0.01) were positively associated with baPWV in our professional drivers. After adjusting for all covariates, we observed that baPWV increased by 3.6 cm/s for per 1-year increment in years of shift driving. CONCLUSIONS Long-term shift work could increase the risk of arteriosclerosis in professional bus drivers. Larger studies would be necessary to provide further evidence regarding this finding.