Diabetes - DNA Damage in Men
Diabetic Men Show Damaged DNA
Dr. Ishola Agbaje, a research fellow in the Reproductive Medicine Research Group at Queen's University, Belfast, Ireland and co-author Professor Sheena Lewis, have completed a study indicating that DNA in sperm from diabetic men had more signs of damage than in men without diabetes. In their writings, appearing in Human Reproduction, the team said that the findings were worrying given the rapidly rising rates of diabetes and that more research was needed.
Defective sperm DNA is a cause of male infertility, pregnancy failure and miscarriage, although the implications for sperm affected by diabetes are unknown.
The Effects of Diabetes on Sperm
In the study, 52 percent of the DNA in the sperm cells of diabetic men was fragmented as compared to 32 percent in men without diabetes. There was also a higher rate of deletions of DNA in the mitochondria which are the energy generating compartments found within cells. There was also a significant decrease in the volume of semen in diabetic men; however, no differences in sperm concentration, motility and structure were noted.
Even though the men in the original study were classified Type 1 diabetes, researchers found the same DNA damage in men with Type 2 diabetes as well. Type 2 diabetes normally begins in adulthood and both diet and obesity are known factors in the disease. Type 1 diabetes, which usually begins in childhood or early adolescence, has been increasing at the rate of three percent per year.
Diabetic Men Will Be Affected in Their Reproductive Years
Dr. Agbaje said: "Diabetes will affect many more men prior to and during their reproductive years." He added that up to one in six couples will require the help of a specialist to conceive. Professor Lewis has strongly indicated that it was not possible to say definitively whether DNA damage resulting from diabetes would affect fertility in the same manner as DNA damage caused by other factors such as smoking.
Professor Lewis said: "There are many 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 also indicated that high levels of glucose in men with diabetes may be a cause.
More Investigation is Needed, but the Concern is Real
According to Dr. Allan Percy, senior lecturer in andrology at the University of Sheffield, quality of sperm 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," he said. Further, "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." Dr. Percy indicated that men should consult with their physicians if they have any concerns.
Matt Hunt, science information manager at Diabetes UK, said that although the study was not large, the findings created some alarm. Mr. Hunt said: "This is the first research to suggest DNA damage may be occurring at a cellular level and that is cause for great concern. We would welcome further investigation."