Does work-family conflict predict allostatic load? A 4-year longitudinal study.

Objective: A growing number of studies have reported that occupational psychosocial factors increase the risk of cardiovascular disease. Allostatic load (AL) is a main biological mechanism that explains the pathway from stress to disease. This study examined whether work-to-family conflict (WFC) and family-to-work conflict (FWC) at baseline would be associated with changes in the AL index (ALI) across four years.

Methods: We used the Midlife in Japan survey, Wave I, and the biomarker projects, Waves I and II. This study included 152 participants with paid jobs and variables of interest at baseline and target biomarkers at baseline and follow-up. We examined the four-year longitudinal changes in the ALI using two methods: comparing ALI scores at baseline and follow-up, named "Two ALI approach," and creating one ALI score considering changes at baseline and follow-up, named "One ALI approach." Negative binomial regression analysis and generalized estimating equations were used for analyses. The results were reported by count ratios (CRs) and 95% confidence intervals (CIs).

Results: In the final model, our results demonstrated that WFC at baseline was significantly associated with increased ALI using the "Two ALI approach" (CR 1.15, 95% CIs: 1.03, 1.28) and "One ALI approach" (CR 1.15, 95% CIs: 1.01, 1.32), whereas FWC did not show statistical significance in both methods.

Conclusions: WFC was longitudinally associated with increased ALI. It is crucial to mitigate the effects of work-to-family conflict.