In my previous entry, I mentioned a study indicating that obesity adversely affects men's sperm quality. Aside from obesity, diabetes also seem to reduce a man's chances of conceiving a baby. Although obesity and diabetes are commonly linked to each other, this one is an entirely separate study showing that chronic diseases do affect a man's fertility. Apparently, the fact that increase in the numbers of diabetics diagnosed at a young age has coincided with worldwide concerns over male fertility is not mere coincidence.

The scientists studied semen samples from men with diabetes who were receiving insulin therapy. On initial routine microscopic examination the semen samples appeared normal, apart from a slight decrease in volume.

"But when we looked for DNA damage, we saw a very different picture," said Dr. Mallidis, adding that this is not part of a routine semen analysis. "Sperm RNA was significantly altered, and many of the changes we observed are in RNA transcripts involved in DNA repair. And comparison with a database of men of proven fertility confirmed our findings. Diabetics have a significant decrease in their ability to repair sperm DNA, and once this is damaged it cannot be restored."

If you want to know in detail how diabetes affects sperm DNA, read the report here.