Abstract P118: Longitudinal Work Hour Patterns Associated With Hypertension Risk

Abstract

Introduction: Evidence shows a positive correlation between work hour (WH) duration and incident hypertension (HTN). However, little is known about the association between longitudinal WH patterns and the risk of incident HTN. Hypothesis: We hypothesized that the greatest risk of HTN would be observed in consistently long WH patterns and that age, sex, and ethnicity would modify the relationship between WH patterns and incident HTN. Methods: We utilized a representative sample of 10,338 U.S. adults from the Panel Study of Income Dynamics who reported weekly WH for a minimum of five years between 1985-2017 and did not have a history of HTN prior to reporting five years of WH data. Latent class linear mixed modeling was used to identify distinct longitudinal WH trajectory patterns. Weighted Cox proportional hazards model was used to examine the association between WH patterns and incident HTN, adjusting for age, sex, ethnicity, education, number of children, BMI, and smoking status after backwards step-down selection. We also tested for statistical interactions between WH patterns and baseline age, sex, and ethnicity. Results: Over a mean follow-up of 18.6 years, four WH trends were identified: steady (66.1%), increasing (12.1%), quickly decreasing (8.7%), and gradually decreasing (13.0%). Only age (p<0.001) modified the association between WH patterns and incident HTN. In age-stratified analyses, adults aged 18-29 showed no significant association between WH patterns and HTN. In adults aged 30-39, a gradually decreasing WH trend showed lower HTN risk compared to those working steady hours (HR=0.51; 95% CI: 0.39-0.66). Among those ≥40 years, increasing (HR=0.59; 95% CI: 0.39-0.89), quickly decreasing (HR=0.49; 95% CI: 0.41-0.59) and gradually decreasing (HR=0.30; 95% CI: 0.23-0.40) WH patterns were associated with lower risk of HTN compared to those working steady hours. Conclusion: Compared to individuals working steady WH over many years, non-constant WH patterns were associated with a lower risk of incident HTN.