According to British researchers, diabetes is fast becoming a common reason for male infertility.
The researchers from the Reproductive Medicine Research Group at Queen's University, Belfast, based their study results on semen samples of 57 men who were diagnosed with Diabetes Type 1. In this disorder, which occurs from birth, the body does not produce the hormone insulin needed for various metabolic activities. In such samples it was seen that diabetes brought about a damage of the sperms.
Defective sperm DNA that was observed by the scientists in these men, is one of the leading causes of male infertility. Here an average of 52 percent of the sperm were found to be fragmented as against 32 percent in normal men. The study also found a higher rate of deletions of DNA in the mitochondria.
Though semen volume was significantly less in diabetic men, there were no significant differences in sperm concentration, structure of the sperm or their ability to move, within the two groups.
Defective sperm DNA is one cause of male infertility, pregnancy failure and miscarriage yet the implications for sperm affected by diabetes are unknown.
Writing in the journal Human Reproduction, the researchers said that though the study samples had Type 1 diabetes, the same sperm damage was found in Type 2 Diabetes. This is bound to worry health professionals as rates of Diabetes Type 2 are soaring like never before.
Says study author Dr Ishola Agbaje: "Diabetes will affect many more men prior to and during their reproductive years."
He added that up to one in six couples needs specialist help to conceive.
Co-author Professor Sheena Lewis stressed it was not possible to say whether the DNA damage caused by diabetes would have the same effect on fertility as DNA damage caused by other factors such as smoking.
"There are three things we need to look at - the number of men with diabetes and fertility problems, we need to look at children of diabetic fathers to see if there is an impact on their health and we need to find the exact nature of the DNA damage", she said. She added that high levels of glucose in men with diabetes might be a cause.
According to Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield, quality of sperm DNA is important.
"Although there is no significant evidence that men with diabetes are less fertile, or their children less healthy, it is of some concern that more of their sperm DNA may be damaged.
"It would be important to understand the mechanism by which this damage occurs so that if it can be avoided we can work out how to do this", he opined.
Matt Hunt, science information manager at Diabetes UK, was of the opinion that although the study was small the findings were somewhat alarming.
"This is the first research to suggest DNA damage maybe occurring at a cellular level and that is cause for great concern. We would welcome further investigation", he was quoted.