| Literature DB >> 28359097 |
Mathis Grossmann1,2, Alvin M Matsumoto3,4.
Abstract
Context: Middle-aged and older men (≥50 years), especially those who are obese and suffer from comorbidities, not uncommonly present with clinical features consistent with androgen deficiency and modestly reduced testosterone levels. Commonly, such men do not demonstrate anatomical hypothalamic-pituitary-testicular axis pathology but have functional hypogonadism that is potentially reversible. Evidence Acquisition: Literature review from 1970 to October 2016. Evidence Synthesis: Although definitive randomized controlled trials are lacking, evidence suggests that in such men, lifestyle measures to achieve weight loss and optimization of comorbidities, including discontinuation of offending medications, lead to clinical improvement and a modest increase in testosterone. Also, androgen deficiency-like symptoms and end-organ deficits respond to targeted treatments (such as phosphodiesterase-5 inhibitors for erectile dysfunction) without evidence that hypogonadal men are refractory. Unfortunately, lifestyle interventions remain difficult and may be insufficient even if successful. Testosterone therapy should be considered primarily for men who have significant clinical features of androgen deficiency and unequivocally low testosterone levels. Testosterone should be initiated either concomitantly with a trial of lifestyle measures, or after such a trial fails, after a tailored diagnostic work-up, exclusion of contraindications, and appropriate counseling. Conclusions: There is modest evidence that functional hypogonadism responds to lifestyle measures and optimization of comorbidities. If achievable, these interventions may have demonstrable health benefits beyond the potential for increasing testosterone levels. Therefore, treatment of underlying causes of functional hypogonadism and of symptoms should be used either as an initial or adjunctive approach to testosterone therapy.Entities:
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Year: 2017 PMID: 28359097 PMCID: PMC5477803 DOI: 10.1210/jc.2016-3580
Source DB: PubMed Journal: J Clin Endocrinol Metab ISSN: 0021-972X Impact factor: 5.958
Figure 1.Causes of hypogonadism. (a) Causes of secondary hypogonadism. (b) Causes of primary hypogonadism. In middle-aged and older men, functional (late-onset, age-related onset, or adult onset) hypogonadism is usually associated with low or normal gonadotropin levels. In contrast to organic secondary hypogonadism due to structural, destructive, or congenital pathology, functional hypogonadism is due to functional HPT axis suppression. Whereas organic hypogonadism typically presents with clinically and biochemically severe androgen deficiency and is not usually reversible, functional hypogonadism often presents with less severe androgen deficiency, is potentially reversible, and is more common than organic hypogonadism. IHH, idiopathic hypogondadotropic hypogonadism; GnRH, gonadotropin-releasing hormone; FSH, follicle-stimulating hormone; T, testosterone; T2DM, type 2 diabetes mellitus. Adapted from Matsumoto (12).
Organic Hypogonadism Versus Functional Hypogonadism in Middle-Aged and Older Men
| Organic Hypogonadism | Functional Hypogonadism | |
|---|---|---|
| Condition | Proven HPT axis pathology (structural, destructive, or congenital disease) | No recognizable structural intrinsic HPT axis pathology. No specific pathologic etiologies of functional hypogonadism (diagnosis of exclusion) |
| Reversibility | Established disease state, organic and generally irreversible HPT axis pathology | HPT axis suppression is functional and may be reversible |
| Symptoms/signs | Specific: eunuchoidism. More specific/objective: low libido, small testes, loss of male hair, gynecomastia | Less specific: erectile dysfunction, low energy and mood |
| Testosterone levels | Unequivocally, consistently, and severely low | Borderline low, fluctuating around the lower limit of assay range, occasionally severely low |
| Gonadotropin levels | Elevated (primary hypogonadism) or low/inappropriately normal (secondary hypogonadism) | Usually in the normal range, occasionally low (secondary hypogonadism) |
| Association of low T with symptoms | Causal | Uncertain, symptoms may be predominantly or partially due to comorbid illness |
| Testosterone therapy | Replacement | Replacement? |
| Benefits of therapy | Marked symptomatic and somatic response (except fertility) | Symptomatic and somatic response less well established |
| Risks of therapy | Considered low relative to benefits | Unknown |
Adapted in part from Basaria (7).
Figure 2.Effect of weight loss on testosterone levels. Each datum point refers to an individual study, and the size of the datum point is proportional to the size of the study, ranging from 10 to 293 men. Open circles represent studies where weight loss was achieved by diet and exercise, and filled circles by bariatric surgery. Updated from Grossmann (20). For individual studies, refer to Supplemental Table 1.