A new study is providing more evidence that a man’s general health can affect his sperm quality. The study, published in BJU International, found that infertile men with prediabetes have altered hormone levels and increased sperm DNA fragmentation compared to infertile men without prediabetes.
Researchers from the University Vita Salute San Raffaele in Milan, Italy, examined 744 men with primary infertility. Of those men, approximately 15 percent met the criteria for having prediabetes, defined as a fasting glucose level of 100-125 mg/dL, a 2-hour, 75 gram oral glucose tolerance test of 140-199 mg/dL, or a HgbA1C level of 5.7-6.4 percent. In this cohort, the men with prediabetes had elevated follicle stimulating hormone and estradiol levels compared to men without prediabetes. Men with prediabetes also showed significantly lower total testosterone, sex hormone binding globulin, and Inhibin B levels compared to men without prediabetes.
In addition, although the men in both groups had similar sperm concentrations and semen volumes, significantly more men with prediabetes had sperm DNA fragmentation levels greater than 30 percent (58.4 percent of men with prediabetes versus 41.8 percent of men without prediabetes).
This is the first study to examine the relationship between prediabetes and male infertility. The results are not surprising given our prior knowledge of how diabetes mellitus is associated with impaired semen parameters, nuclear DNA fragmentation rates, and chromatin quality. It is interesting to see though that even less severe glucose alterations, such as in prediabetes, can affect a man’s reproductive hormones and sperm quality.
The results are also in line with one that I wrote about on our website several months ago, which showed that low sperm counts may be a marker of general health for men. That study showed that low sperm counts were associated with metabolic alterations, cardiovascular risk, and low bone mass. Given all of these findings, I would recommend that men who are struggling with male infertility have an evaluation with their primary care physicians to optimize their general health. This may help improve their chances of conceiving a pregnancy.