Early Infections and Obesity in Boys May Reduce Key Male Hormone: Study Suggests - Video

Early childhood obesity and common infections like chickenpox may increase the risk of chronic diseases later in life, according to new research published in the journal Andrology. Scientists from the University of Nottingham’s School of Biosciences have found that such early-life health factors are linked to reduced levels of the testis hormone biomarker, insulin-like peptide 3 (INSL3), in men by their mid-twenties, a change that could forecast future health complications.

The study builds on previous work demonstrating that INSL3 is a powerful predictor of long-term male health. INSL3 levels are stable in adulthood and reflect the testes' ability to produce testosterone a hormone vital not only for reproductive function but also for maintaining general health, including bone strength, cardiovascular function, and metabolic health.

In the new study, researchers examined data from the “Children of the Nineties” (Avon Longitudinal Study of Parents and Children), a large UK birth cohort initiated by the University of Bristol. The team measured INSL3 levels in 24-year-old men and matched them against a wide array of clinical and lifestyle data collected since birth.

They discovered that while most early-life factors had little or no influence on adult INSL3 levels, being overweight as a child or experiencing certain infections in infancy — such as chickenpox — were associated with a 10–15% reduction in INSL3. This decline potentially increases the risk of adult-onset conditions such as diabetes, cardiovascular disease, and even sexual dysfunction.

Dr. Ravinder Anand-Ivell, lead author of the study, said: “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.”

“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,” Dr. Anand-Ivell concluded.

Reference: Ivell R, Tilumcu B, Alhujaili W, Anand-Ivell R. Maternal, childhood and adolescent influences on Leydig cell functional capacity and circulating INSL3 concentration in young adults: Importance of childhood infections and body mass index. Andrology. 2025; 1-11. https://doi.org/10.1111/andr.70091