The relative contributions of aging, health, and lifestyle factors to serum testosterone decline in men

J Clin Endocrinol Metab. 2007 Feb;92(2):549-55. doi: 10.1210/jc.2006-1859. Epub 2006 Dec 5.


Context: Although it is known that serum testosterone (T) concentrations decline with age, the relative contributions of changes in health and lifestyle to that decline have not been adequately assessed.

Objective: The objective of this study was to establish the relative importance of aging, health, and lifestyle in contributing to male T decline.

Design: A prospective cohort study of health and endocrine functioning in randomly selected men with a baseline visit (T1, 1987-1989) and two follow-up visits (T2, 1995-1997; T3, 2002-2004) was conducted.

Setting: An observational study of men residing in greater Boston, Massachusetts, was conducted.

Participants: Participants included 1667 men aged 40 to 70 at baseline; follow-up was conducted on 947 (57%) and 584 (35%) at T2 and T3, respectively.

Main outcome measures: Main outcome measures included total serum T, calculated free T (FT), and SHBG.

Results: There were substantial declines in total serum T and FT levels associated with aging alone. However, many health and lifestyle changes were associated with accelerated decline. A 4- to 5-kg/m2 increase in body mass index or loss of spouse was associated with declines in total serum T comparable to that associated with approximately 10 yr of aging. Results were similar for FT, but fewer factors were associated with SHBG after age was taken into account.

Conclusions: Both chronological aging and changes in health and lifestyle factors are associated with declines in serum T. Comorbidities and lifestyle influences may be as strongly associated with declining T levels as is aging itself over the short- to midterm. These results suggest the possibility that age-related hormone decline may be decelerated through the management of health and lifestyle factors.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Aging / blood*
  • Boston / epidemiology
  • Cohort Studies
  • Endocrine System / physiology
  • Health Status
  • Humans
  • Hypogonadism / epidemiology*
  • Hypogonadism / metabolism*
  • Life Style*
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Prospective Studies
  • Sex Hormone-Binding Globulin / metabolism
  • Testosterone / blood
  • Testosterone / deficiency*


  • Sex Hormone-Binding Globulin
  • Testosterone