Association between long working hours and poor cardiovascular health assessed by the American Heart Association’s “Life’s essential 8”: findings from a nationally representative sample of Korean workers (2014–2021)

Abstract Background Long working hours represent a major public health concern. We explored the association between working hours and the American Heart Association’s “Life’s Essential 8 (LE8).” Methods A nationwide sample comprising 21 062 Korean workers was analyzed. The LE8 scores (range 0–100) were calculated based on the following cardiovascular disease risk factors: diet, physical activity, nicotine exposure, sleep health, body mass index, blood lipid levels, blood glucose levels, and blood pressure. Cardiovascular health (CVH) was categorized as low (LE8: 0–49), intermediate (LE8: 50–59), and high (LE8: 80–100). Linear regression and multinomial logistic regression models were used for statistical analyses. Results The means of the LE8 scores for those working <35 h, 35–40 h, 41–48 h, 49–54 h, and ≥ 55 h per week were 69.4, 68.2, 66.8, 64.7, and 61.9, respectively. Among men, working 49–54 h per week [β: –1.43; 95% confidence interval (CI): −2.40, −0.45] and ≥55 h per week (β: –3.23; 95% CI: −4.11, −2.35) were associated with lower LE8 scores. Similarly, among women, working 49–54 h per week (β: –1.62; 95% CI: −2.72, −0.52) and ≥55 h per week (β: –2.88; 95% CI: −3.88, −1.88) had negative associations with LE8 scores. Working ≥55 h per week was associated with a 2.03-fold increase (95% CI: 1.53, 2.68) in the odds of low CVH among men and a 2.02-fold increase (95% CI: 1.37, 2.98) among women. Conclusion Long working hours are associated with poor CVH, emphasizing the necessity of mitigating excessive working hours. Key message What is already known on this topic—The American Heart Association recently introduced “Life Essential 8 (LE8),” a metric assessing cardiovascular health. This study explored the association between long working hours and poor cardiovascular health among Korean adult workers. What this study adds—This study demonstrates that compared with working 35–40 h per week, working ˃48 h per week is associated with a reduced LE8 score. Specifically, working 49–54 h and ≥55 h per week are associated with increased odds of having poor cardiovascular health in both men and women, compared with working 35–40 h per week. Notably, long working hours showed a strong association with the health behavior factors of LE8. How this study might affect research, practice, or policy—This study suggests that promoting cardiovascular health based on the LE8 framework can be beneficial in mitigating the health burdens of long working hours.