In the "largest-ever study in the United States to examine the relationship between fatherhood and cardiovascular disease," Michael Eisenberg, MD, has found that childless men are at greater risk for cardiovascular disease than fathers.
Eisenberg, an assistant professor of urology at Stanford University, first became interested in the topic when doing his urologic residency at the University of California-San Francisco. Over a 10-year period, he "tracked 135,000 male members of the American Association of Retired Persons" in order to determine if the number of a man's offspring and his long-term health could be positively correlated.
All of the studies participants were all over the age of 50 when they study began, and they were either married or had once been married. Researchers excluded men with any previous history of various health conditions that might prevent them from successfully reproducing.
Naturally, since some participating in the study were older, there was an expected mortality rate, and 10 percent of the men died while the study was being conducted. The researchers "tallied mortality from between 60 and 70 different causes," and took into consideration many variables, including but not limited to body-mass index, tobacco and alcohol use, race, age, education and household income. They also assesed their deaths using various methods through through Social Security Administration, other national databases and questionnaire responses mailed in by surviving relatives.
Afterwards, the men, both living and dead, were divided into groups based on how many children they had fathered. Researchers found that "one in every five of those deaths was attributable to cardiovascular disease and that represented a 17-percent increase in the likelihood of a childless man's dying of a condition related to cardiovascular disease, compared with fathers." It made no difference if the man had fathered a boy or a girl.
However, though researchers found that parental status and cardiovascular risk were positively correlated, this study may not indicate direct cause and effect. Eisenberg himself noted that it is impossible to directly assess a man's "reproductive intent, but eliminating unmarried men from his team's analysis brought childlessness a step closer to being a proxy for infertility." Other studies have also suggested that low testosterone levels and living alone prolong a man's life.According to the Centers For Disease Control and Prevention, heart disease is the leading cause of death among men and women in the United States, and 70-89% of sudden cardiac events occur in men. The CDC also reported that in 2006, 315,706 men died from heart disease and half of the men who die suddenly of coronary heart disease show no previous symptoms.
"Is there a real biological cause behind both? Maybe we should look closer at the childless group," Eisenberg said. "Since fertility issues can surface well before any obvious outward symptoms of cardiovascular disease, such a link could help flag cardiovascular risk sooner, leading to earlier and more effective intervention."
What do you think about this study? Do you think there could be a direct link between heart disease and childlessness, or that the positive correlation is incidental?
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