The Cumulative Impact of Chronic Stressors on Risks of Myocardial Infarction in US Older Adults

Objective This study aimed to investigate the association between cumulative exposure to chronic stressors and the incidence of myocardial infarction (MI) in US older adults. Methods Nationally representative prospective cohort data of adults 45 years and older (n = 15,109) were used to investigate the association between the cumulative number of chronic stressors and the incidence of MI in US older adults. Proportional hazards models adjusted for confounding risk factors and differences by sex, race/ethnicity, and history of MI were assessed. Results The median age of participants was 65 years, 714 (4.7%) had a prior MI, and 557 (3.7%) had an MI during follow-up. Approximately 84% of participants reported at least one chronic stressor at baseline, and more than half reported two or more stressors. Multivariable models showed that risks of MI increased incrementally from one chronic stressor (hazard ratio [HR] = 1.28, 95% confidence interval [CI] = 1.20-1.37) to four or more chronic stressors (HR = 2.71, 95% CI = 2.08-3.53) compared with those who reported no stressors. These risks were only partly reduced after adjustments for multiple demographic, socioeconomic, psychosocial, behavioral, and clinical risk factors. In adults who had a prior MI (p value for interaction =.038), we found that risks of a recurrent event increased substantially from one chronic stressor (HR = 1.30, 95% CI = 1.09-1.54) to four or more chronic stressors (HR = 2.85, 95% CI = 1.43-5.69). Conclusions Chronic life stressors are significant independent risk factors for cardiovascular events in US older adults. The risks associated with multiple chronic stressors were especially high in adults with a previous MI.