Much attention has focused in recent years on how excess weight affects female fertility—and now it's the guys' turn to hear the not-so-good news about obesity and fertility. According to a new study published March 3, 2010, in an advanced issue of the journal Diabetes Care, obese men— especially those who also have Type II diabetes—are more likely than others to have low levels of testosterone, a key component in sperm production.
In the study, researchers took blood samples from over 2,000 men, age 45 years or older, and checked for testosterone concentrations. Forty percent of obese participants in the study had lower-than-normal testosterone readings. And when obese men also had diabetes, that percent rose to 50 percent.
"In view of the fact that almost one-third of the US is obese, these observations have profound … health implications," says Dr. Sandeep Dhindsa, an endocrinology specialist in the UB Department of Medicine and lead author on the study.
Not only is testosterone a major player in sperm production, it is very active in the sexual activity of men. As researchers note, men struggling with low testosterone levels may also suffer from decreased sex drive, another potential roadblock to conception. Impotence or erectile dysfunction (ED) may also happen more frequently when testosterone levels are below normal.
What's a guy to do? The Endocrine Society now recommends that all men with type 2 diabetes have their testosterone levels measured. And now, researchers assert, it seems like a good idea for obese men, even younger men, to undergo screening for low testosterone. And if testosterone levels are low, losing weight may be all that is needed to boost production. Researchers cited another study that found obese men who lost significant weight reported better sexual function.