Job Loss Raises Cardiovascular Risk

Results from a large cohort study using multivariate models showed that unemployment status, multiple job losses, and short-term periods without work are all significant risk factors for acute myocardial infarction (AMI) during the nearly 20-year follow-up period, according to a study published in the Archives of Internal Medicine [2012;172(22):1731-1737].

Unemployment has been linked to various risk factors and deficient resources that may add to increased rates of cardiovascular disease. However, to date, the evidence has been based entirely on cross-sectional associations that do not factor lifetime variability in employment, with its immediate consequences for cardiovascular health. Recent research has demonstrated that job loss at older ages substantially increases the risks of AMI. However, the longitudinal evidence connecting unemployment to cardiovascular events has been limited and inconclusive. In the current study, the researchers set out to extend these findings and provide the first prospective investigation of the short- and long-term effects of multiple dimensions on the risks for AMI.

The study included 13,451 US adults 51 to 75 years of age who participated in the Health and Retirement Study (HRS). The study population included the original HRS cohort (1931-1941), the war baby cohort (1942-1947), and early baby-boomer cohort (1948-1953) who were interviewed every 2 years from 1992 to 2010. On average, HRS participants contributed nearly 8 person-years of exposure during the 18-year study period. Of the 13,451 participants, 1061 (7.9%) reported AMI events during the 165,169 person-years of observation. The median age of the cohort was 62 years. Among the participants, 14% were unemployed at baseline, 69.7% had ≥1 cumulative job losses, and 35.1% had spent time unemployed.

Adults who experienced an AMI were more likely to be older, male, and living in the South compared with the non-AMI group. Furthermore, participants who had low levels of education and income, no health insurance, smoked, failed to exercise, were overweight or obese, and had been diagnosed with hypertension or diabetes also had higher levels of AMI than their counterparts.

The primary end point was occurrence of AMI. Unadjusted rates for age-specific AMI were used to demonstrate the differences by employment status, cumulative number of job losses, and total amount of time unemployed. The researchers also used Cox proportional models to assess the multivariate effects of cumulative work histories on AMI while adjusting for sociodemographic background and confounding risk factors.

The results showed that AMI risks were considerably greater among the unemployed (hazard ratio [HR], 1.35; 95% confidence interval [CI], 1.10-1.66) and that risks increased from 1 (HR, 1.22; 95% CI, 1.04-1.42), 2 (HR, 1.27; 95% CI, 1.05-1.54), 3 (HR, 1.52; 95% CI, 1.22-1.90), and 4 or more cumulative job losses (HR, 1.63; 95% CI, 1.29-2.07). Chronic job loss did not appear to be a factor—only joblessness lasting a year or less (HR, 1.27; 95% CI, 1.01-1.60).

The multivariate findings were significant and comparable to other major risk factors in the model, such as smoking (HR, 1.44; 95% CI, 1.24-1.68), diabetes (HR, 1.51; 95% CI, 1.30-1.75), and hypertension (HR, 1.62; 95% CI, 1.42-1.86).

The researchers cited study limitations. Data on certain clinical factors such as treatment and control of hypertension, diabetes, and hyperlipidemia before AMI or other prophylactic measures to reduce the likelihood of infarction were lacking.

“Results from our large prospective cohort study demonstrate the powerful effect of one’s lifetime employment history and cumulative job losses on risks for a major cardiovascular event,” concluded the researchers. “Additional studies are needed to assess how such information can be used to target and aggressively treat vulnerable segments of the population.”