Another diabetes effect

May 4, 2007 21:11 GMT  ·  By

"You're sweet" cannot have sexual connotations. Cause when sugar from your blood cannot be stored in the tissues, that's diabetes. Besides the vast amount of general health problems induced by diabetes, including hearing and kidney disease, nerve damage and blindness, there is also impotence in men (due to circulation problems) and decreased semen quantities. The number of diabetes patients will nearly double by 2025, exceeding 300 million, fueled by the increasing rates of obesity, inactivity and aged population. Type 1 diabetes typically installs in childhood or young adulthood, while Type 2 appears in adults over 30.

But a team at Queen's University in Belfast, U.K., shows that sex-related problems induced by diabetes are even worse: infertility. Diabetic men have been found to present much more sperm cells with damaged DNA than healthy ones. The researchers investigated semen samples from two small pools of young men assigned to a local fertility clinic, both of similar ages: one of 27 patients with Type 1 diabetes, and another of 29 nondiabetics. There was no variation in the sperm concentration, appearance, or mobility amongst diabetics and healthy patients.

But DNA analyses revealed that 52% of sperm from diabetic males presented mutations under the form of fragmented DNA molecules, which could impede egg fertilization or induce abnormalities/malformations. Amongst healthy men, just 32% of sperm presented DNA errors. The researchers blame this on the destructive free radicals, a result of high glucose concentration in the blood of the diabetics. "We know that sperm is very susceptible to free radical damage," said co-author Sheena Lewis, reproductive biologist. "Because the DNA in sperm has no repair mechanisms, the damage is permanent. The team's unpublished results show the same effect in men with Type 2 diabetes." said Lewis.

"Researchers should also track whether birth defects are more prevalent in children of diabetic fathers," she said. "The study represents "a good start," but much more needs to be learned", said reproductive endocrinologist Pasquale Patrizio of the Yale Fertility Center in New Haven, Connecticut.

"In particular, it's important to know how long the individual subjects have been afflicted with diabetes because that could impact the amount of damage to sperm DNA. Likewise, the blood sugar of the diabetic men in the study was not controlled, so it raises the question of whether fertility could be improved by better disease management." added Patrizio.