Being overweight in childhood or having chickenpox or another infectious disease in infancy may raise the risk of chronic illness in adult men, new research suggests.
Scientists found that these early-life health factors can lower levels of a key reproductive hormone by 10 to 15 per cent in young men, potentially increasing their risk of conditions such as diabetes, heart disease, osteoporosis or sexual dysfunction later in life.
The findings are based on levels of insulin-like peptide 3 (INSL3), a hormone made by the testes that reflects long-term testicular function and overall male health.
Researchers measured INSL3 in men aged 24 and examined how their levels related to childhood health records.
Dr Ravinder Anand-Ivell, associate professor in endocrinology and reproductive physiology at University of Nottingham’s School of Biosciences, led the research.
The researcher said: “We know that INSL3 hormone levels in boys and men are a robust biomarker of the testicular capacity to produce the steroid hormone testosterone that is essential not only for reproduction but also for overall healthy well-being,” said
“In this new study we have found that there is a clear link between certain health factors in childhood at a time before puberty when the testes are still developing and later men’s health as they age.”
The study used data from the “Children of the Nineties” cohort – officially known as the Avon Longitudinal Study of Parents And Children – created by the University of Bristol. Participants have been tracked since birth and are now in their twenties.
While most early-life factors had little or no impact, the team found that childhood overweight and infections in infancy – including chickenpox and other diseases – were linked with reduced INSL3 levels in early adulthood.
This is the first study to explore the long-term impact of childhood infections, health and nutrition on men’s health in adulthood.
Previous research by the team found that INSL3 levels in younger men could predict their risk of developing chronic disease later in life, and that reduced levels in older men often originate in early adulthood.
By comparing INSL3 with a wide range of clinical and lifestyle data gathered throughout childhood and adolescence, researchers identified which early-life factors might influence testicular function in adulthood.
Importantly, they also identified many other factors which appeared to have little impact. The results highlight the importance of maintaining a healthy weight in childhood and ensuring timely vaccination against infection.
Dr Anand-Ivell said: “By using this new biomarker INSL3 as well as having this childhood health information allows us now to be able to predict those men at risk and thus consider appropriate preventative measures before disease sets in.
“The next stage of this research is the development of a specialist high-throughput assay which would allow the measurement of INSL3 to be introduced as part of the routine clinical assessment for male healthy ageing.”
