Diabetes Can Affect Men’s Fertility: QUB Team

By LISA SMYTH

DIABETES may affect men’s fertility by disrupting DNA in sperm, scientists at Queen’s University in Belfast have found.

High levels of blood sugar caused by the condition appear to affect genetic repair mechanisms that keep DNA stable, according to the team led by Dr Con Mallidis, a lecturer in the Department of Obstetrics and Gynaecology in the School of Medicine and Dentistry.

The team presented its evidence at this month’s conference of the European Society of Human Reproduction and Embryology in Barcelona.

Previously, with Professors Sheena Lewis of Queen’s University and Brew Atkinson of the Royal Victoria Hospital in Belfast, the group identified that there was an increased level of DNA damage in sperm in diabetics.

Damaged sperm DNA is known to reduce embryo quality, make it more difficult for an embryo to implant in the womb and, ultimately, leads to higher miscarriage rates. It is also associated with some serious childhood diseases, including cancers.

In the latest study, scientists studied semen samples from eight men with insulin dependent, or type 1, diabetes. Under the microscope, their sperm looked completely normal. But genetic analysis told a very different story.

Dr Mallidis explained: “The Belfast team has shown that diabetes adversely influences male fertility at a molecular level. Now we know that there are significant changes to biological mechanisms that translate the genetic code.

“In a process known as ‘transcription’, a molecule called messenger RNA carries genetic instructions from gene DNA to protein- making machinery in the cells.”

He continued: “Sperm RNA was significantly altered, and many of the changes we observed are in RNA transcripts involved in DNA repair.

“Diabetics have a significant decrease in their ability to repair sperm DNA, and once this is damaged it cannot be restored.

“We have found a class of compounds known as advanced glycation end products (AGEs) in the male reproductive tract.”

Neil McClure, Professor of Obstetrics and Gynaecology at Queen’s University, also a member of the team, said “For too long the role of general health in male fertility has been ignored.”

Originally published by LISA SMYTH lsmyth@belfasttelegraph.co.uk.

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