Several epidemiological studies confirm age-related decreases in serum total testosterone concentrations.[9]Thirumalai A, Anawalt BD. Epidemiology of male hypogonadism. Endocrinol Metab Clin North Am. 2022 Mar;51(1):1-27.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9136962
http://www.ncbi.nlm.nih.gov/pubmed/35216709?tool=bestpractice.com
In one US study, the prevalence of symptomatic androgen deficiency was 5.6% in men aged between 30 and 79 years.[10]Araujo AB, Esche GR, Kupelian V, et al. Prevalence of symptomatic androgen deficiency in men. J Clin Endocrinol Metab. 2007 Nov;92(11):4241-7.
https://academic.oup.com/jcem/article/92/11/4241/2598366
http://www.ncbi.nlm.nih.gov/pubmed/17698901?tool=bestpractice.com
Prevalence was low (3% to 7%) in men aged under 70 years and increased markedly to 18.4% among men 70 years and older.[10]Araujo AB, Esche GR, Kupelian V, et al. Prevalence of symptomatic androgen deficiency in men. J Clin Endocrinol Metab. 2007 Nov;92(11):4241-7.
https://academic.oup.com/jcem/article/92/11/4241/2598366
http://www.ncbi.nlm.nih.gov/pubmed/17698901?tool=bestpractice.com
The European Male Ageing Study (EMAS) reported late-onset hypogonadism (defined as decreased sexual interest, decreased morning erections, and erectile dysfunction, in combination with testosterone deficiency) prevalence of 2.1% in men aged 40 to 79 years.[5]Tajar A, Forti G, O'Neill TW, et al; EMAS Group. Characteristics of secondary, primary, and compensated hypogonadism in aging men: evidence from the European male ageing study. J Clin Endocrinol Metab. 2010 Apr;95(4):1810-8.
http://www.ncbi.nlm.nih.gov/pubmed/20173018?tool=bestpractice.com
[6]Wu FC, Tajar A, Beynon JM, et al. Identification of late-onset hypogonadism in middle-aged and elderly men. N Engl J Med. 2010 Jul 8;363(2):123-35.
https://www.nejm.org/doi/10.1056/NEJMoa0911101
http://www.ncbi.nlm.nih.gov/pubmed/20554979?tool=bestpractice.com
[11]Lee DM, Pye SR, Tajar A, et al. Cohort profile: the European Male Ageing Study. Int J Epidemiol. 2013 Apr;42(2):391-401.
https://academic.oup.com/ije/article/42/2/391/733095
http://www.ncbi.nlm.nih.gov/pubmed/22314965?tool=bestpractice.com
The age-related accumulation of non-gonadal co-morbidities causing gonadotrophin suppression (e.g., obesity) was a greater risk factor for falling testosterone levels than chronological age.[5]Tajar A, Forti G, O'Neill TW, et al; EMAS Group. Characteristics of secondary, primary, and compensated hypogonadism in aging men: evidence from the European male ageing study. J Clin Endocrinol Metab. 2010 Apr;95(4):1810-8.
http://www.ncbi.nlm.nih.gov/pubmed/20173018?tool=bestpractice.com
[12]Wu FC, Tajar A, Pye SR, et al. Hypothalamic-pituitary-testicular axis disruptions in older men are differentially linked to age and modifiable risk factors: the European Male Aging Study. J Clin Endocrinol Metab. 2008 Jul;93(7):2737-45.
https://academic.oup.com/jcem/article/93/7/2737/2598963
http://www.ncbi.nlm.nih.gov/pubmed/18270261?tool=bestpractice.com
Men with late-onset hypogonadism were at increased risk for diabetes and cardiovascular disease compared with eugonadal men.[13]Tajar A, Huhtaniemi IT, O'Neill TW, et al. Characteristics of androgen deficiency in late-onset hypogonadism: results from the European Male Aging Study (EMAS). J Clin Endocrinol Metab. 2012 May;97(5):1508-16.
https://academic.oup.com/jcem/article/97/5/1508/2536362
http://www.ncbi.nlm.nih.gov/pubmed/22419720?tool=bestpractice.com
Broadly similar findings were reported in the Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China) study.[14]Cheng J, Han B, Li Q, et al. Testosterone: relationships with metabolic disorders in men-an observational study from SPECT-China. Int J Endocrinol. 2017;2017:4547658.
https://www.hindawi.com/journals/ije/2017/4547658
http://www.ncbi.nlm.nih.gov/pubmed/29333158?tool=bestpractice.com
Estimation of hypogonadism prevalence based on large population database surveys of testosterone replacement therapy prescriptions is not recommended; studies have found that testosterone therapy is often initiated in the absence of a diagnosis of hypogonadism as specified by guideline recommendations.[7]Matsumoto AM. Diagnosis and evaluation of hypogonadism. Endocrinol Metab Clin North Am. 2022 Mar;51(1):47-62.
http://www.ncbi.nlm.nih.gov/pubmed/35216720?tool=bestpractice.com