Unemployment associated with higher risk of MI

People older than 51 years of age who lose their jobs have a significantly higher risk of suffering acute MI (AMI) after that event, according to a study published online Nov. 19 in Annals of Internal Medicine. Even brief periods of unemployment significantly raised the risk of acute cardiac events in this population, researchers found.

Matthew E. Dupree, PhD, of Duke Clinical Research Center in Durham, N.C., and colleagues examined data from the Health and Retirement Study (HRS) to determine the temporal effect of job loss on the risk of having AMI. National unemployment reached 10 percent in October 2010 and two years later hovered at 7.9 percent. The study’s authors noted the increasing instability of the U.S. employment climate, lending urgency to the search for ways to ease the physical damage that employment uncertainty can cause.

Participants in the HRS enrolled between the ages of 51 and 61, and were interviewed biennially on a range of health and lifestyle issues between 1992 and 2010. The cohort for the current study was comprised of 13,451 people who were born between 1931-1941 (first interviewed in 1992), 1942-1947 (first interviewed in 1998), and 1948-1953 (first interviewed in 2004), and who reported having held a job at some point in their lives. There was a total of 165,169 person years of reporting.

The researchers reconstructed work histories for the participants based on historical events the participants reported at their entry interview and changes in employment status reported at subsequent interviews. Retirement was not counted as a job loss; persons who were not retired but not employed were counted as unemployed.

By extracting dates of job loss, age at time of job loss and duration of unemployment and comparing this information to dates of reported AMI (there were 1,061 reported AMI among participants during the study period), researchers were able to conclude that unemployment raises the risk of AMI.

“Rates of AMI were significantly higher in study participants who were unemployed and retired compared with employed participants, “ the authors wrote. They noted that cumulative job losses did not significantly affect the risk of AMI until there were four or more job losses. The risk of AMI rose in the first year after job loss but declined as duration of unemployment extended beyond one year.

Specifically, when adjusted for age, sex, race/ethnicity, marital status and geographic region, the AMI hazard ratio among the unemployed was 1.74; among the retired, it was 1.2. The hazard ratio for people who lost employment once was 1.19, for two job losses the ratio was 1.24, after three job losses the ratio increased to 1.47, and after four or more job losses the hazard ratio was 1.62. During the first 12 months of unemployment, the hazard ratio was 1.35, which decreased to 1.08 after two years, and further decreased to 1.05 after five years of unemployment.  

In an accompanying editorial, William T. Gallo, PhD, of the health policy and management and economics department at City University of New York, lauded the study for its clarity in focusing on an outcome that can be ensured to have occurred after job loss, enabling the researchers to draw a causal inference. He also applauded the size of the cohort and the study’s success in identifying “a dose response to the job loss exposure.”

Gallo wrote that with this study, there is now an abundance of compelling evidence that job loss has an impact on physical health. He suggested that future studies look more closely into the mechanism of stressors’ impacts on physical health, in order to design effective interventions. He postulated that the psychological impact of job loss may cause people to “discount” the price current activities will have on the future, leading to poor decision making, riskier choices and less care for their health. Gallo also pointed out the need to identify the population that is particularly vulnerable to manifesting physical illness as a result of psychological stressors, again to develop effective therapies.