WASHINGTON • Men who are infertile are more likely than those who are fertile to develop other general health ailments, including diabetes and heart disease, says a new study.
The study's lead author, Assistant Professor Michael Eisenberg of Stanford University, said he hoped the findings would encourage more men diagnosed with infertility to seek follow-up care.
"I think it's important to know that sperm counts and fertility may tell a little more than just about reproductive potential," said Prof Eisenberg in a statement.
"There may be some other aspects that men could be alerted to about overall health."
For the study, researchers in the United States examined records filed between 2001 and 2009 of more than 115,000 reproductive- age men from an insurance claims database.
The men's medical visits before and after fertility testing were analysed to determine what health complications they developed in the years after fertility evaluations.
The researchers then compared general health conditions of men with infertility diagnoses to those of men without the diagnoses, and to those who had had a vasectomy.
A vasectomy involves severing the tubes that transport sperm.
Of the three groups, infertile men had higher rates of most diseases the researchers were screening for in the study, including heart disease and diabetes. This holds true even when the results were adjusted for obesity, smoking and healthcare utilisation.
In addition, men with the most severe form of infertility had the highest risk of renal disease and alcohol abuse.
The findings were published online last week in the journal Fertility And Sterility. "It was surprising," said Prof Eisenberg. "These were really young men. The average was in the 30s."
As to why infertility is associated with higher rates of certain diseases, one possibility is that infertile men have lower levels of circulating testosterone than fertile men, a characteristic that has been linked to a higher risk of mortality and cardiovascular disease.
Another possibility is that exposure to harmful environmental influences during foetal development could lead to reproductive and general health challenges later in life.
"Exposures that occur in utero can have lasting effects on the rest of your life," he said.
"Maybe some of these same exposures that set men up later in life for things like heart disease could also set them up for things like lower sperm count."
Regardless of the reason, Prof Eisenberg said, his research suggested that whatever is causing reproductive problems is likely to be influencing physiological systems. He encouraged men - particularly those experiencing reproductive difficulties - to go for a check-up.