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Combining Behavioral Endocrinology and Experimental Economics: Testosterone and Social Decision Making
Published on: March 2, 2011
Longitudinal changes in testosterone over five years in community-dwelling men
Zumin Shi1, Andre B Araujo, Sean Martin
1Discipline of Medicine, University of Adelaide, 122 Frome Street, Adelaide, South Australia 5000, Australia. zumin.shi@adelaide.edu.au
The Journal of Clinical Endocrinology and Metabolism
|June 19, 2013
Summary
Testosterone levels in men are not inevitably tied to aging. Lifestyle factors like smoking, obesity, and depression significantly impact testosterone and SHBG levels over time.
Area of Science:
- Endocrinology
- Men's Health
- Longitudinal Studies
Background:
- Limited population-based data exists on longitudinal changes in testosterone (T), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and sex hormone-binding globulin (SHBG).
- Risk factors influencing these hormonal changes in men are not well understood.
Purpose of the Study:
- To investigate 5-year changes in serum T, LH, FSH, and SHBG levels within a cohort of Australian men.
- To identify factors associated with these hormonal fluctuations.
Main Methods:
- A randomly selected, community-based cohort of 1588 Australian men aged 35+ was recruited.
- Exclusion criteria included medications or conditions affecting the hypothalamo-pituitary gonadal axis, leaving 1382 men for analysis.
- Serum hormone levels were assessed at baseline and follow-up over 5 years.
Main Results:
- Mean T levels decreased by -0.13 nmol/L/year.
- Annualized T changes were linked to obesity, being unmarried, and smoking.
- Persistent depression or developing chronic disease correlated with T decline; marriage was associated with increased T compared to being unmarried.
- Smoking cessation, central obesity, or generalized obesity significantly decreased T levels.
- Smoking cessation, developing obesity, and persistent depression were inversely related to SHBG changes.
Conclusions:
- Age-related decline in testosterone is not inevitable.
- Smoking behavior and changes in health status, particularly obesity and depression, are key determinants of testosterone levels.
- These findings highlight modifiable lifestyle and health factors influencing male hormone levels over time.
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