A cohort effect on serum testosterone levels in Finnish men
Finnish researchers analysed serum from three population surveys carried out in 1972, 1977 and 2002, covering 3,271 men aged 25–74. Because different birth cohorts could be compared at the same age, the design shows whether each generation starts from a lower baseline than the one before it.
Focus
Generational decline
Published finding
60–69
Source
10.1530/EJE-12-0288
Record
Ref 12
Structured abstract
Method
Finnish researchers analysed serum from three population surveys carried out in 1972, 1977 and 2002, covering 3,271 men aged 25–74. Because different birth cohorts could be compared at the same age, the design shows whether each generation starts from a lower baseline than the one before it.
Result
Men aged 60–69 had 21.9 nmol/L when born 1913–1922, but 13.8 nmol/L when born 1942–1951. The cohort effect covered total testosterone, free testosterone, SHBG and gonadotrophins. The decline remained significant after adjustment for BMI. Gonadotrophin levels were also lower, so the pituitary is not compensating for the fall.
What to take with you
Men aged 60–69 born 1913–22 measured 21.9 nmol/L. The same age born 1942–51 measured 13.8. Gonadotrophins did not rise to compensate.
Why it matters
Same age, different birth years: 60–69-year-olds born 1913–22 measured 21.9 nmol/L; those born 1942–51 measured 13.8.
Study frame
Generational decline
Finnish researchers analysed serum from three population surveys carried out in 1972, 1977 and 2002, covering 3,271 men aged 25–74. Because different birth cohorts could be compared at the same age, the design shows whether each generation starts from a lower baseline than the one before it.
Finding
Men aged 60–69 had 21.9 nmol/L when born 1913–1922, but 13.8 nmol/L when born 1942–1951.
Contrast
The cohort effect covered total testosterone, free testosterone, SHBG and gonadotrophins.
Context
The decline remained significant after adjustment for BMI.
DOI
10.1530/EJE-12-0288
Category
Generational decline
Findings listed
4
Type
As published
What to take from the numbers
Boxes below use only wording already in the published summary for this study.
Reported finding
60–69
Men aged 60–69 had 21.9 nmol/L when born 1913–1922, but 13.8 nmol/L when born 1942–1951.
Reported finding
2
The cohort effect covered total testosterone, free testosterone, SHBG and gonadotrophins.
Reported finding
3
The decline remained significant after adjustment for BMI.
The study documents the trend but, as the authors state plainly, offers no explanation for why it is happening.
Why it matters when reading your own result
Pulled from the study's own findings.
Men aged 60–69 had 21.9 nmol/L when born 1913–1922, but 13.8 nmol/L when born 1942–1951.
Generational decline
The cohort effect covered total testosterone, free testosterone, SHBG and gonadotrophins.
Generational decline
The decline remained significant after adjustment for BMI.
Generational decline
Clinical reading
How to use this page
Finnish researchers analysed serum from three population surveys carried out in 1972, 1977 and 2002, covering 3,271 men aged 25–74. Because different birth cohorts could be compared at the same age, the design shows whether each generation starts from a lower baseline than the one before it.
Related studies in this library
Journal of Clinical Endocrinology & Metabolism · 2007
A population-level decline in serum testosterone levels in American men
Journal of Clinical Endocrinology & Metabolism 86: 724–731 · 2001
Longitudinal effects of aging on serum total and free testosterone levels in healthy men
Journal of Clinical Endocrinology & Metabolism 92: 4696–4705 · 2007
Secular decline in male testosterone and SHBG serum levels in Danish population surveys
Your own numbers
Measure before you decide what this page means for you.
The figures here describe men who were actually measured.
- Total testosterone and SHBG
- Symptoms written down
- Haematocrit as a safety baseline
- Repeat labs before any protocol change