Current guidelines from the National Institute for Clinical Excellence1 advise doctors to warn infertile men about the dangers of smoking, alcohol consumption and recreational drug use, as well as the risks of being overweight and wearing tight underwear.
However, a team of scientists from the Universities of Manchester and Sheffield have found that many common lifestyle choices make little difference to male fertility, based on how many swimming sperm men produce.
The study, published in the medical journal Human Reproduction, recruited 2,249 men from 14 fertility clinics around the UK2 and asked them to fill out detailed questionnaires about their lifestyle. The information was then compared between 939 men who ejaculated low numbers of swimming sperm and a control group of 1,310 men who produced higher numbers.
The research found that men who ejaculated low numbers of swimming sperm were 2.5 times more likely to have had testicular surgery, twice as likely to be of black ethnicity, and 1.3 times more likely to be in manual work, not wear boxer shorts, or not had a previous conception. Surprisingly, men’s use of recreational drugs, tobacco and alcohol, as well as their weight measured by their body mass index (BMI), had little effect3.
Up to now the impact of damaged nerves in the peripheral nervous system on ED has been underestimated” says lead author Dr Consuelo Valles-Antuña, from the Department of Neurophysiology at the Hospital Universitario Central de Asturias in Oviedo.
“However our study of 90 patients shows that men with more severe symptoms of peripheral neuropathy, which can be caused by disease, trauma or illness, had greater self-reported ED and required more aggressive treatment.
“Our findings underline the importance of clinicians carrying out neurophysiological tests on patients with ED, particularly in the pelvic area.”
The research team, which included experts on both neurophysiology and urology, studied 90 consecutive patients with sexual problems recruited from the hospital’s Department of Andrology.
ED was diagnosed using the five-item version of the International Index of Erectile Dysfunction (IIEF-5) and the occurrence of peripheral neuropathy was predicted using the Neuropathy Symptom Score.
A range of neurophysiology tests were carried out to assess the presence of large and small fibreperipheral neuropathy.
Metabolic syndrome comprises a cluster of complications that can increase the risk of heart and blood-vessel disease as well as type 2 diabetes. These complications include excess body weight, especially around the waist and torso, and abnormal concentrations of fat in the blood, known as lipids. In particular, patients with metabolic syndrome have high blood levels of the so-called bad fats, or triglycerides and low-density lipoproteins, and insufficient amounts of the healthy fats known as high-density lipoproteins. In addition, they often have high blood pressure and sugar, or glucose, levels.
Previous research has linked metabolic syndrome to testosterone deficiency, which can cause decreased muscle and bone mass, depression, low energy, and decreased sex drive and ability. In addition, testosterone deficiency is also associated with the individual symptoms of metabolic syndrome, even when they are present without the other complications.
“When indicated, testosterone treatment is both essential and safe in elderly patients with symptomatic late onset hypogonadism, or testosterone deficiency,” said study lead author Aksam A. Yassin, M.D., Ph.D., Ed.D., chairman of the Institute of Urology & Andrology in Norderstedt-Hamburg, Germany. “Further analysis is needed to confirm if our findings are due to a direct effect of restoring physiologic testosterone levels.”