Researchers at the School of Medicine found in a recent study that childless men suffer a higher mortality rate due to greater risk of cardiovascular disease. Childless men in the study were at a 17 percent greater risk of developing cardiovascular disease than men who had fathered children.
“Here we are seeing a real health impact from childlessness,” said Michael Eisenberg, assistant professor of urology and lead author of the study. “The reason is unclear, but if it is biologic . . .we may have a chance to save lives.”
Eisenberg, a male infertility specialist, initiated the study in 2009 during his urology residency at the University of California, San Francisco. He designed the study in response to growing data indicating infertility as a warning sign of other long-term health issues. Eisenberg added that, based on the study’s findings, recommended medical treatment for achieving a good sperm count — such as maintaining a healthy diet and exercising — may also help in maintaining cardiovascular health.
“Cardiovascular disease is one of the largest [healthcare expenditures],” he said. “Last year almost half a trillion dollars was spent on it. If we can somehow cut down on risk factors earlier, we can cut down morbidity and mortality.”
The study, which was published Sept. 26 online in the journal Human Reproduction, tracked 137,903 male American Association of Retired Persons (AARP) members from the ages of 50 to 71 for a 10-year period. The study was part of a larger National Institutes of Health (NIH)/AARP diet and health study that has collected health data from more than 550,000 subjects since the mid-1990s. Participants in the study respond to detailed questionnaires distributed by the AARP.
The larger NIH/AARP diet and health study has contributed to approximately 250 scientific papers.
“It’s the largest epidemiological study of its type ever done,” AARP Senior Research Advisor Albert R. Hollenbeck said.
In order to ensure that the men in the study intended to reproduce, researchers only included subjects who were married or had been formerly married. Researchers also focused solely on men who were over the age of 50 at the start of the study. Due to the long-term nature of the study, researchers excluded men with serious pre-existing health conditions that had already affected their long-term health outlook.
“Obviously there are lots of reasons to be childless,” Eisenberg said. “Certainly some men don’t want to have children, but in the general population as a whole that’s a minority.”
Another recent study found that men with high levels of testosterone were more likely to find mates and father children that those with lower levels of testosterone. Eisenberg drew a connection to his study on fatherhood, saying that men with low sperm counts also tend to have lower levels of testosterone, which could potentially indicate broader underlying health issues.
Eisenberg stressed that external factors must be considered when evaluating the study, including the role of socioeconomic status in determining family size and the change in lifestyle associated with having a child.
“The other important thing to think about is that fathers do have their children and their children take care of them,” Eisenberg said. “Having a child that is involved certainly can help. We do know that being married, living with a spouse and happiness all lead to longevity.”