The Study
8039 Role Of Genetics In The Age-Related Testosterone Decline In Men: A UK Biobank Study
This study looked at how testosterone changes in men over time and checked if their genes could predict how fast it drops. It found that genes don’t seem to affect how fast it drops — but that doesn’t mean genes don’t matter at all. It just means something else, like health or lifestyle, might be the main reason it goes down.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
This study looked at whether your genes decide how fast your testosterone drops as you get older.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 555 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Even though genes affect your starting testosterone level, they don't control how fast it falls — lifestyle and health conditions like obesity matter more.
- 2On average, testosterone dropped 1.6% over 4.3 years, but some men dropped much more.
- 3Men who started with higher testosterone levels lost it slower.
- 4Genes didn't predict how fast it dropped.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of the Endocrine Society
Year
2024
Authors
L. Ogoniak, S. Sandmann, J. Varghese, A. S. Busch
Related Content
Claims (5)
Higher levels of sex hormone-binding globulin at the start of aging are linked to a slower decrease in total testosterone over time, with each 1 nmol/L increase in SHBG associated with a 0.4% reduction in the rate of testosterone decline per year.
Age-related testosterone decline is linked to rising rates of obesity, type 2 diabetes, and cardiovascular disease, not to genetic differences, which affect starting testosterone levels but not how quickly they drop over time.
In men around age 58, those with higher initial levels of certain hormones tend to experience a slower decrease in those hormone levels over 4.3 years, and each 1 nmol/L increase in baseline bioavailable testosterone corresponds to a 7.8% slower rate of decline.
Genetic scores based on common variants that affect testosterone levels at a single point in time do not predict how quickly those levels decrease over time in men around age 58.
In middle-aged men, bioavailable testosterone levels decrease by an average of 1.6% over 4.3 years, but individual changes vary widely, with some men experiencing much larger drops.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.