Differences in Clinical Indicators of Diabetes, Hypertension, and Dyslipidemia Among Workers Who Worked Long Hours and Shift Work

Many studies have reported an association between overwork, shift work, and chronic disease. However, there is little research on the influence of working hours and shift work and management of chronic diseases. The objective of this retrospective study was to examine the association between working hours, shift work type in workers with hypertension, diabetes, and dyslipidemia.Among 18,513 hourly wageworkers from the Korea National Health and Nutrition Examination Survey, 4,313 with hypertension, diabetes, and hyperlipidemia were selected. An analysis of covariance with general linear modeling was used to estimate group differences in clinical indices of chronic diseases according to weekly working hours and types of shift work, both unadjusted and adjusted for gender, age, education, marital status, household income, and medication usage.Clinical indicators were worse in workers with diabetes (differences in HbA1c = 0.15%; fasting blood glucose = 4.84 mg/dL), hypertension (differences in diastolic blood pressure = 1.2 mmHg), or dyslipidemia (differences in total cholesterol = 3.3 mg/dL) who worked for more than 40 hours/week compared with workers who worked less than 40 hours per week. Clinical indicators in workers with diabetes and hypertension were worse in shift workers, including evening and night shifts, relative to those who did not work shiftwork.Working more than 40 hours per week and shift work were negatively associated with adverse clinical indicators among workers with chronic diseases. To improve the health of workers with chronic diseases, these findings suggest that adjustment of working hours and shift work may be warranted.