Welcome to part 5 of the ODX Andropause & Low T Syndrome Series. The clinical determination of andropause must take into consideration the patient’s symptomology and lab values of Total and Free testosterone. As you’ll read in this post, the Functional determination of low T syndrome takes a slightly different approach.
Clinical Andropause is likely if these minimum criteria are met, corroborated by EMAS: [i] [ii] [iii] [iv]
Research suggests that certain thresholds of serum T may be associated with a specific set of symptoms. Results of a cross-sectional cohort study of 434 males aged 50-86 years old identified associations between symptoms and total serum T levels. Results were similar when calculated free T was applied:[v] [vi]
Total testosterone |
|
Symptoms |
Below 432 ng/dL |
< 15 nmol/L |
Loss of libido or vigor (in 41% of subjects) |
Below 346 ng/dL |
< 12 nmol/L |
Obesity, BMI greater than 30 |
Below 288 ng/dL |
< 10 nmol/L |
Depression, disturbed sleep, difficulty concentrating, type 2 diabetes |
Below 230 ng/dL |
< 8 nmol/L |
Erectile dysfunction, hot flushes |
Below 225 ng/dL |
< 7.8 nmol/L |
Loss of libido in 90% of subjects |
Below 170 ng/dL |
< 5.9 nmol/L |
Loss of libido in 96% of subjects |
Total testosterone levels of 175 ng/dL (6 nmol/L) or less should be further evaluated using MRI and advanced pituitary hormone assessments to rule out the possibility of organic versus functional hypogonadism.[vii]
Although symptomatology can be significant, the European Male Ageing Study reserves the diagnosis of LOH for sexually-associated symptoms (i.e., decreased libido, poor morning erection, and erectile dysfunction) associated with a TT below 320 ng/dL (11 nmol/L) and a free T below 64 pg/mL (220 pmol/L).
Data from the same study suggests that sexual and physical symptoms may be present when TT is within normal range, but free T was low.
Conversely, when free T was normal and TT was low (presuming low SHBG), sexual and physical symptoms were not present.
Researchers suggest measuring free testosterone in men with conditions associated with altered SHBG and/or TT in the lower 200-400 ng/dL (7-14 nmol/L) range:[viii]
According to the International Society for Sexual Medicine (ISSM) [ix]
In general, free or bioavailable testosterone should be measured when:[x]
Decreased SHBG associated with: [xi] [xii] [xiii] |
Increased SHBG associated with: |
Acromegaly Androgen excess Diabetes mellitus Growth hormone excess Hypothyroidism Insulin resistance Liver disease Nephrotic syndrome Obesity SHBG gene polymorphisms Use of glucocorticoids, some progestins, and androgenic steroids |
Aging Borderline total T 200-400 ng/dL (6.9-13.9 nmol/L) Cirrhosis, hepatitis Estrogen use, elevated estrogen HIV disease Hyperthyroidism SHBG gene polymorphisms Use of some anticonvulsants |
An epidemiological study of 2,588 men 40-80 years found an association between symptomatic LOH and levels of BAT and SHBG.[xiv]
Mean Values |
TT nmol/L |
LH IU/L |
FT nmol/L |
SHBG nmol/L |
BAT |
Case |
13.99 |
8.28 |
0.45 |
52.01 |
4.85 |
Control |
14.29 |
5.8 |
0.61 |
37.67 |
7.53 |
A population-based cross-sectional study of 965 men 40-80 years of age with AMS scores of 27 or greater found those with symptomatic LOH had lower levels of calculated free T, BAT, total cholesterol, and triglycerides, Levels of SHBG were significantly higher with a suggested 4.99 ug/mL (44.4 nmol/L) cutoff for diagnosing LOH in symptomatic individuals:[xv]
The Hypogonadism in Males (HIM) study found that 38.7% of men 45 years or older had a TT of less than 300 mg/dL. Results indicated significant differences in SHGB, total, free, and bioavailable T in those with TT less than 300 ng/dL (hypogonadal) and those with TT of 300 ng/dL (10.4 nmol/L) or greater. Risk of hypogonadism increased 17% for every 10-year increase in age:[xvi]
Mean |
Total T |
Free T |
Bioavailable T |
SHBG |
Hypogonadal |
245.6 ng/dL 8.52 nmol/L |
47.9 pg/mL 166 pmol/L |
86.1 ng/dL 3 nmol/L |
4.9 ug/mL 43.7 nmol/L |
Eugonadal |
439.9 ng/dL 15.3 nmol/L |
63.9 pg/mL 222 pmol/L |
108.8 ng/dL 3.8 nmol/L |
7.7 ug/mL 68.3 nmol/L |
Different societies have proposed various cutoffs for the diagnosis of LOH[xvii]
Total T |
Free T |
Source |
190 ng/dL in men over 70 216 ng/dL in younger men |
- |
European Society of Australia 2016 |
264 ng/dL |
- |
Endocrine Society 2018 |
300 ng/dL |
- |
American Urological Association 2018 |
346 ng/dL |
65 pg/mL |
British Society for Sexual Medicine 2017 |
350 ng/dL |
- |
European Academy of Andrology 2020 |
350 ng/dL |
65 pg/mL |
European Association of Urology 2020 |
350 ng/dL |
65-100 pg/mL |
International Consultation for Sexual Medicine 2019 |
350 ng/dL |
65-70 pg/mL |
International Society of the Study of Aging Male 2015 |
NEXT UP: Andropause Part 6 – Lab Reference Ranges
[i] Wu, Frederick C W et al. “Identification of late-onset hypogonadism in middle-aged and elderly men.” The New England journal of medicine vol. 363,2 (2010): 123-35. doi:10.1056/NEJMoa0911101
[ii] Bhasin, Shalender et al. “Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline.” The Journal of clinical endocrinology and metabolism vol. 103,5 (2018): 1715-1744. doi:10.1210/jc.2018-00229
[iii] Singh, Parminder. “Andropause: Current concepts.” Indian journal of endocrinology and metabolism vol. 17,Suppl 3 (2013): S621-9. doi:10.4103/2230-8210.123552.
[iv] Swee, Du Soon, and Earn H Gan. “Late-Onset Hypogonadism as Primary Testicular Failure.” Frontiers in endocrinology vol. 10 372. 12 Jun. 2019, doi:10.3389/fendo.2019.00372
[v] Zitzmann, Michael et al. “Association of specific symptoms and metabolic risks with serum testosterone in older men.” The Journal of clinical endocrinology and metabolism vol. 91,11 (2006): 4335-43. doi:10.1210/jc.2006-0401
[vi] Nieschlag, E. “Late-onset hypogonadism: a concept comes of age.” Andrology vol. 8,6 (2020): 1506-1511. doi:10.1111/andr.12719
[vii] Giagulli, Vito Angelo et al. “Critical evaluation of different available guidelines for late-onset hypogonadism.” Andrology vol. 8,6 (2020): 1628-1641. doi:10.1111/andr.12850
[viii] Bhasin, Shalender et al. “Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline.” The Journal of clinical endocrinology and metabolism vol. 103,5 (2018): 1715-1744. doi:10.1210/jc.2018-00229
[ix] Lawrence, Kristi L et al. “Approaches to male hypogonadism in primary care.” The Nurse practitioner vol. 42,2 (2017): 32-37. doi:10.1097/01.NPR.0000511774.51873.da
[x] Karakas, Sidika E, and Prasanth Surampudi. “New Biomarkers to Evaluate Hyperandrogenemic Women and Hypogonadal Men.” Advances in clinical chemistry vol. 86 (2018): 71-125. doi:10.1016/bs.acc.2018.06.001
[xi] Bhasin, Shalender et al. “Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline.” The Journal of clinical endocrinology and metabolism vol. 103,5 (2018): 1715-1744. doi:10.1210/jc.2018-00229
[xii] Karakas, Sidika E, and Prasanth Surampudi. “New Biomarkers to Evaluate Hyperandrogenemic Women and Hypogonadal Men.” Advances in clinical chemistry vol. 86 (2018): 71-125. doi:10.1016/bs.acc.2018.06.001
[xiii] Giagulli, Vito Angelo et al. “Critical evaluation of different available guidelines for late-onset hypogonadism.” Andrology vol. 8,6 (2020): 1628-1641. doi:10.1111/andr.12850
[xiv] Liang, GuoQing, et al. "Serum sex hormone-binding globulin and bioavailable testosterone are associated with symptomatic late-onset hypogonadism complicated with erectile dysfunction in aging males: a community-based study." American Journal of Translational Medicine 2018.
[xv] Liang, Guoqing et al. “Serum sex hormone-binding globulin is associated with symptomatic late-onset hypogonadism in aging rural males: a community-based study.” Sexual health, 10.1071/SH20201. 15 Mar. 2021, doi:10.1071/SH20201
[xvi] Mulligan, T et al. “Prevalence of hypogonadism in males aged at least 45 years: the HIM study.” International journal of clinical practice vol. 60,7 (2006): 762-9. doi:10.1111/j.1742-1241.2006.00992.x
[xvii] Giagulli, Vito Angelo et al. “Critical evaluation of different available guidelines for late-onset hypogonadism.” Andrology vol. 8,6 (2020): 1628-1641. doi:10.1111/andr.12850