Association of specific symptoms and metabolic risks with serum testosterone in older men
Zitzmann, Faber and Nieschlag at the Institute of Reproductive Medicine in Münster examined how specific symptoms and metabolic risks map onto serum testosterone in ageing men. They widen the threshold further than Scovell: the first symptoms appeared around 15 nmol/L, but the authors note there was no clear-cut boundary — some men experience symptoms earlier than others. Their cluster analysis is the reason low testosterone should not be read as one syndrome: it presents as three largely independent pictures.
Focus
Symptom clusters & metabolic risk
Published finding
Symptom clusters & metabolic risk
Source
10.1210/jc.2006-0401
Record
Ref 10
Structured abstract
Method
Zitzmann, Faber and Nieschlag at the Institute of Reproductive Medicine in Münster examined how specific symptoms and metabolic risks map onto serum testosterone in ageing men. They widen the threshold further than Scovell: the first symptoms appeared around 15 nmol/L, but the authors note there was no clear-cut boundary — some men experience symptoms earlier than others. Their cluster analysis is the reason low testosterone should not be read as one syndrome: it presents as three largely independent pictures.
Result
Psychosomatic symptoms and metabolic risk factors accumulated progressively as testosterone fell. Loss of libido or vigour increased significantly below 15 nmol/L (P < 0.001). Depression and type 2 diabetes — also in non-obese men — were significantly more present below 10 nmol/L. Cluster analysis revealed three independent groups: psychosomatic complaints, metabolic disorders, and sexual health problems.
What to take with you
Libido and vigour rose below 15 nmol/L. Depression and type 2 diabetes were clearly more common below 10 nmol/L. The thresholds describe where symptoms gathered.
Why it matters
Libido and vigour rose below 15 nmol/L; depression and type 2 diabetes were clearly more common below 10 nmol/L — a map of where symptoms gather.
Study frame
Symptom clusters & metabolic risk
Zitzmann, Faber and Nieschlag at the Institute of Reproductive Medicine in Münster examined how specific symptoms and metabolic risks map onto serum testosterone in ageing men. They widen the threshold further than Scovell: the first symptoms appeared around 15 nmol/L, but the authors note there was no clear-cut boundary — some men experience symptoms earlier than others. Their cluster analysis is the reason low testosterone should not be read as one syndrome: it presents as three largely independent pictures.
Finding
Psychosomatic symptoms and metabolic risk factors accumulated progressively as testosterone fell.
Contrast
Loss of libido or vigour increased significantly below 15 nmol/L (P < 0.001).
Context
Depression and type 2 diabetes — also in non-obese men — were significantly more present below 10 nmol/L.
DOI
10.1210/jc.2006-0401
Category
Symptom clusters & metabolic risk
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
1
Psychosomatic symptoms and metabolic risk factors accumulated progressively as testosterone fell.
Reported finding
15 nmol/L
Loss of libido or vigour increased significantly below 15 nmol/L (P < 0.001).
Reported finding
2
Depression and type 2 diabetes — also in non-obese men — were significantly more present below 10 nmol/L.
Cross-sectional associations describe how prevalence changes with level; they do not by themselves prove that raising the level removes the symptom.
Why it matters when reading your own result
Pulled from the study's own findings.
Psychosomatic symptoms and metabolic risk factors accumulated progressively as testosterone fell.
Symptom clusters & metabolic risk
Loss of libido or vigour increased significantly below 15 nmol/L (P < 0.001).
Symptom clusters & metabolic risk
Depression and type 2 diabetes — also in non-obese men — were significantly more present below 10 nmol/L.
Symptom clusters & metabolic risk
Clinical reading
How to use this page
Zitzmann, Faber and Nieschlag at the Institute of Reproductive Medicine in Münster examined how specific symptoms and metabolic risks map onto serum testosterone in ageing men. They widen the threshold further than Scovell: the first symptoms appeared around 15 nmol/L, but the authors note there was no clear-cut boundary — some men experience symptoms earlier than others. Their cluster analysis is the reason low testosterone should not be read as one syndrome: it presents as three largely independent pictures.
Related studies in this library
New England Journal of Medicine · 2010
Identification of late-onset hypogonadism in middle-aged and elderly men
BJU International · 2015
Hypogonadal symptoms in young men are associated with a serum total testosterone threshold of 400 ng/dL
Journal of Clinical Endocrinology & Metabolism 96: 2430–2439 · 2011
Reference ranges for testosterone in men generated using LC–MS/MS in healthy non-obese young men (Framingham Heart Study)
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