Age trends in the level of serum testosterone and other hormones in middle-aged men: longitudinal results from the Massachusetts male aging study.
Level 3 - non-randomized controlled study
Prospective longitudinal cohort study with repeated measures over 7-10 years
PubMed 11836290 · doi:10.1210/jcem.87.2.8201
What was done
Longitudinal data from the Massachusetts Male Aging Study, a population-based random-sample cohort of men aged 40-70 years at baseline (1987-1989), were analyzed to determine normative age-related hormone trends. Of 1,709 men enrolled at baseline, 1,156 were followed up 7-10 years later. Repeated-measures statistical modeling was used to estimate and compare cross-sectional age trends at baseline, cross-sectional trends at follow-up, and longitudinal within-subject trends, while assessing the modifying effect of general health status (absence of chronic illness, prescription medications, obesity, or excessive drinking).
What was found
Cross-sectionally at follow-up, total testosterone (T) declined by 0.8%/yr of age, free and albumin-bound T declined by approximately 2%/yr, and sex hormone-binding globulin (SHBG) increased by 1.6%/yr. Longitudinally within subjects, the rate of decline was steeper: total T fell by 1.6%/yr and bioavailable T fell by 2-3%/yr. Dehydroepiandrosterone, dehydroepiandrosterone sulfate, cortisol, and estrone also declined longitudinally, whereas dihydrotestosterone, pituitary gonadotropins, and prolactin increased. Apparent good health was associated with 10-15% higher levels of several androgens and attenuated cross-sectional trends in T and luteinizing hormone, but did not substantially alter longitudinal rates of decline.
Why it matters
Cross-sectional studies underestimate the rate of age-related androgen decline in middle-aged men compared to longitudinal within-subject tracking. The steeper longitudinal decline suggests that incident health deterioration over time accelerates hormonal decreases beyond normal chronological aging.
Limits
Follow-up was completed in 1,156 of 1,709 original participants (32.4% attrition rate), introducing potential survivor or retention bias. The abstract does not report specific hormone assays, precision metrics, or confidence intervals for the percentage declines.
Cited by
- supports Starting at age 30, testosterone levels in men decline by roughly 1% per year.