Association between occupational working time and cardiovascular morbidity: a cross-sectional study of NHANES database

BACKGROUND: Long working hours are recognized as an occupational hazard that may increase the risk of cardiovascular diseases. However, limited contemporary evidence exists from nationally representative US populations. AIMS: This study aimed to examine the association between occupational working time and cardiovascular morbidity using the recent National Health and Nutrition Examination Survey (NHANES) data. METHODS: A cross-sectional analysis including 4502 adults from the 2021-23 NHANES dataset was conducted. Working hours were categorized into 1-34, 35-40, 41-54, and ≥55 h per week. Cardiovascular outcomes included self-reported heart failure, coronary heart disease, angina, myocardial infarction, stroke and hypertension. RESULTS: Participants working 35-40 h last week had significantly lower odds of having coronary heart disease (odds ratio [OR] = 0.524; 95% confidence interval [CI] 0.275-0.998), and angina (OR = 0.411; 95% CI 0.191-0.887) compared to those working 1-34 h. Those working 41-54 h also had reduced odds of angina (OR = 0.125; 95% CI 0.029-0.550). Conversely, working ≥55 h last week was significantly associated with increased odds of hypertension (OR = 1.496; 95% CI 1.135-1.971). No significant association was found between working days per week and CV morbidity. CONCLUSIONS: Standard full-time work (35-40 h/week) may be protective against certain cardiovascular conditions, while long working hours (≥55 h/week) may elevate hypertension risk. These findings support international calls to regulate excessive work hours and highlight the importance of balanced employment for better cardiovascular health.