LOS ANGELES – On the male fertility front, obesity seems to hurt semen quality. So does weight-loss surgery reverse the trend? A new review of existing research suggests that there may be an effect, but the findings aren’t conclusive.
Dr. Sikarin Upala
“We found something,” said Sikarin Upala, MD, a second-year endocrinology fellow at the University of Chicago, who pointed out that three of the four reports he and his colleagues reviewed suggested improvement in semen motility. “But we still need to study more about whether bariatric surgery will affect infertility,” he continued.
Dr. Upala, who led the systematic review and meta-analysis of research into bariatric surgery and semen quality, spoke in an interview after his presentation at the annual scientific and clinical congress of the American Association of Clinical Endocrinologists.
As researchers explained in a 2018 report, “conflicting results have been observed in studies evaluating the correlation between [body mass index] and sperm parameters, such as sperm concentration and total sperm count.” However, they noted that it is “generally accepted” that men with obesity seem to be at higher risk of having a low sperm count or having azoospermia, which is the total lack of sperm in semen.
It’s also not clear whether weight loss directly improves male fertility. “We do know that androgen levels improve after weight-loss surgery, and that might be one factor among several that may contribute to improved male fertility,” Edward Lin, DO, MBA, FACS, professor of surgery and chief of gastrointestinal and general surgery at Emory University, Atlanta, said in an interview.
In their review, Dr. Upala and his colleagues analyzed four studies published between 2012 and 2018 that evaluated the effect of bariatric surgery on semen quality. All of the studies examined semen volume and sperm morphology and motility, and three examined sperm concentration.
A meta-analysis found that motility and volume improved after surgery; however, some of the studies (two for volume, one for motility) failed to show a statistically significant change.
There was no statistically significant difference in sperm morphology or concentration overall, although one study showed a statistically significant improvement in both categories.
Overall, “there might be a little bit of positive effect, but we couldn’t reach a good conclusion because there were too few studies,” Dr. Upala said.
Dr. Lin, director of the Emory Bariatrics Center, agreed that the review findings are limited. He said that although the findings hint at a positive effect on semen quality, “the jury is still out” when it comes to a link between bariatric surgery and male infertility.
“Multiple factors contribute to semen quality,” he added, pointing to vitamin deficiencies, micronutrient levels in the body, enzyme signaling pathways, and sperm chromatin integrity. “In fact, surgically or diet-induced weight loss may be associated with permissive malnutrition, which further exacerbates these deficiencies. Deficiencies in these areas can sometimes take months, if not years, to correct by taking vitamin D or copper or zinc, for example.”
Dr. Lin referred to a small study in which reporters observed semen abnormalities and subfertility after weight-loss surgery despite improvements in androgenic and quality of life levels.
Dr. Upala reported having no relevant disclosures.