Infertile men are more likely to develop metabolic diseases as they grow older, scientists have warned. Their study, presented at the European Association of Urology conference in Munich, suggests that up to a third of men with fertility issues face increased risks of developing illnesses such as diabetes or osteoporosis. They also have lower sex hormone levels, highlighting a potential link between hypogonadism and metabolic disorders.
The research, carried out by a Swedish team, examined 192 men with low sperm count, at a reproductive medicine centre in the city of Malmo. A control group was made up of 199 fertile men for the study.
The scientists ran some tests to compare various biological markers. They examined in particular bone mineral density as well as levels of protein HbA1c, used to measure average levels of glucose present in the blood. It acts therefore as a biomarker for diabetes. The researchers also assessed levels of sex hormones, such as testosterone.
Infertility and hypogonadism
About one-third of the infertile study subjects, all aged under 50, were seven-times more likely than men in the control group to show signs of hypogonadism, or low sex hormone levels. Hypogonadism can in fact lead to infertility, so this result did not entirely come as a surprise for scientists.
However, they discovered that this infertility and low levels of hormones was very clearly linked to a risk of developing metabolic diseases. The group of infertile men with hypogonadism had lower bone mineral density, leaving them more at risks of fractures. As they age, this bone fragility increases the probability of developing osteoporosis, a condition which causes bones to break more easily and regularly.
The study also points out that, for this third of infertile man, diabetes was also more likely to occur. Indeed, they also displayed unusually high levels of HbA1c in the blood, and therefore of glucose. This indicates a tendency towards diabetes, which can lead to developing the disease when men grow older.
The study's authors believe that although hypogonadism can be the cause of the men's infertility, it can also be an opportunity to predict the development of metabolic diseases, and to offer a closer follow-up to the patients.
"We would recommend that levels of reproductive hormones should be checked in all men seeking advice for fertility problems. Those at risk of serious disease should be followed after the completion of fertility treatment", says lead author Dr Aleksander Giwercman.
In the UK, three million people suffer from osteoporosis while approximately 3.2m are diagnosed with diabetes.