R. Meer*, I. Afkir, B.J. Berntzen, N.Z. Siddiqui, M.T. Blom, P.J.M. Elders, J.W.J. Beulens*
* Department of Epidemiology & Data Science, Amsterdam UMC location VUmc, Amsterdam, the Netherlands.
Background: The prevalence of psychological stress is continuously increasing worldwide. One common approach to measure psychological stress is by assessing the number of stressful life events someone has experienced. Stressful life events have been linked to various chronic diseases; however, its relationship with multimorbidity remains underexplored. This study aimed to understand the impact of stressful life events on the onset of chronic diseases over time.
Methods: Data from the New Hoorn study, a population-based cohort set in the city Hoorn in The Netherlands, have been used for this study. Data on stressful life events were collected at baseline using a self-administered questionnaire. This study investigated type 2 diabetes, cardiovascular disease, obesity, cancer, anxiety disorder, and depression as disease outcomes and these were quantified into a count variable. A Poisson regression analysis was performed with the number of chronic diseases as outcome. Three models were used to correct for confounding factors such as demographic factors, lifestyle factors, and pre-existing chronic disease.
Results: Data from 1564 participants (54 [49-59] years, 51% female) were obtained from the cohort. Participants had experienced either zero (16%), one (24%), two (24%) or three or more (36%) stressful live events at baseline. After seven years of follow-up, 54% remained disease free, while 29%, 13%, 4% and 1% had one, two, three or four chronic diseases. The number of stressful life events at baseline was significantly associated with chronic multimorbidity after correction for demographics and lifestyle factors ((IRR= 1.14, 95% CI [1.10-1.17], p<0.001). This effect decreased after additionally correcting for pre-existing chronic disease (IRR= 1.04, 95% CI [1.00-1.07], p= 0.030). We did not find effect modification by sex, education or baseline disease count.
Conclusion: A higher number of stressful life events was associated with a higher number of chronic diseases after seven years of follow-up. These findings suggest that psychological stress may play an important role in the development of multimorbidity and highlight the importance of stress in multimorbidity prevention strategies.