The Cumulative Impact of Chronic Stressors on Risks for Myocardial Infarction in U.S. Older Adults.

OBJECTIVE To investigate the association between cumulative exposure to chronic stressors and the incidence of myocardial infarction (MI) in U.S. older adults. METHODS Nationally-representative prospective cohort data of adults aged 45 and older (n = 15,109) were used to investigate the association between the cumulative number of chronic stressors and incidence of MI in U.S. 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 2 or more stressors. Multivariable models showed that risks for MI increased incrementally from 1 chronic stressor (HR = 1.28; 95% CI, 1.20-1.37) to 4 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 for a recurrent event increased substantially from 1 chronic stressor (HR = 1.30; 95% CI, 1.09-1.54) to 4 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 U.S. older adults. The risks associated with multiple chronic stressors were especially high in adults with a previous MI.