Your childhood may be doing more to shape your future health than you think — especially if you're male.
A new study from the University of Nottingham finds that boys who were overweight in early childhood or who had infections like chickenpox as infants may have a higher risk of developing chronic diseases as adults — all due to a little-known hormone that reflects how well the testicles can produce testosterone.
The hormone, called INSL3 (insulin-like peptide 3), plays a key role in male reproductive development and overall hormonal health. It’s produced by the same cells that make testosterone and remains stable over time, making it a promising early marker of men’s long-term health outlook.
In the new study, published in the journal Andrology, scientists analyzed hormone levels in young men around age 24 and compared them with data collected throughout their childhood as part of the long-running Children of the Nineties study in the UK. They found that boys who had been overweight or had infections like chickenpox in infancy had 10–15% lower levels of INSL3 as young adults — a reduction linked in past studies to increased risk of type 2 diabetes, cardiovascular disease, bone weakness and sexual dysfunction as men age.
“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 study author Dr. Ravinder Anand-Ivell. “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 findings suggest that factors as early as infancy could influence how a man’s hormones develop and how vulnerable he may be to chronic diseases later. The results also add weight to early childhood nutrition, healthy weight and routine vaccination, especially as infections like chickenpox were strongly associated with lower INSL3 levels.
Researchers hope to one day include INSL3 testing in routine men’s health screenings, offering a new way to flag long-term health risks before disease sets in.
This research was supported by the UK Medical Research Council, the Wellcome Trust and the University of Bristol, which provide core funding for the Children of the Nineties study (ALSPAC).