Late-onset hypogonadism (LOH) or testosterone deficiency syndrome (TDS) is a condition in older men characterized by measurably low testosterone levels and clinical symptoms mostly of a sexual nature, including decreased desire for mating, fewer spontaneous erections, and erectile dysfunction. It is the result of a gradual drop in testosterone; a steady decline in testosterone levels of about 1% per year can happen and is well documented in both men and women.
Signs and symptoms
Some men present with symptoms, but they have normal testosterone levels, while others with low testosterone levels have no symptoms. The reasons for this phenomenon are currently unknown.
Men aged 40–70 years, total serum testosterone decreases at a rate of 0.4% per year, while free testosterone shows a greater decline of 1.3% annually. In males over 35 years old, there are alterations in the hypothalamic–pituitary–gonadal axis, particularly a decrease in gonadotropin-releasing hormone secretion and reduced leydig cell responsiveness to luteinizing hormone stimulation partly due to mitochondrial dysfuction and SASP from senescent cells. defined the condition by the presence of at least three sexual symptoms (e.g. reduced libido, reduced spontaneous erections, and erectile dysfunction) and total testosterone concentrations less than 11 nmol/L (3.2 ng/mL) and free testosterone concentrations less than 220 pmol/L (64 pg/mL).
Screening
Due to difficulty and expense of testing, and the ambiguity of the results, screening is not recommended. While some clinical instruments (standard surveys) had been developed as of 2016, their specificity was too low to be useful clinically.
Testosterone replacement therapy should only be started if low levels have been confirmed;
Exogenous testosterone may also cause suppression of spermatogenesis, leading to, in some cases, infertility. This reduced secretion of testosterone can be caused by old age which usually results in primary hypogonadism. The dysfunction of this system is due to degradation of Leydig cells which causes testosterone levels to drop. There have been a number of cellular changes identified that affect the production of testosterone as age increases. Some of these include luteinizing hormone and cAMP production. Though it is seen that when secondary hypogonadism occurs it can be linked to obesity and other risk factors rather than old age.
History
The impact of low levels of testosterone has been previously reported. In 1944, Heller and Myers identified symptoms of what they labeled the "male climacteric" including loss of libido and potency, nervousness, depression, impaired memory, the inability to concentrate, fatigue, insomnia, hot flushes, and sweating. Heller and Myers found that their subjects had lower than normal levels of testosterone, and that symptoms decreased dramatically when patients were given replacement doses of testosterone.
Society and culture
The 1997 book Male Menopause by Jed Diamond, a psychologist with a PhD in international health,
fueled popular interest in the concept of "andropause".
Diamond regards andropause as a change of life in middle-aged men which has hormonal, physical, psychological, interpersonal, social, sexual, and spiritual aspects. Diamond claims that this change occurs in all men, that it may occur as early as age 45 to 50 and more dramatically after the age of 70 in some men, and that women's and men's experiences are somewhat similar phenomena. The medical community has rejected the term "andropause" and its supposed parallels with menopause.
Thomas Perls and David J. Handelsman, in a 2015 editorial in the Journal of the American Geriatrics Society, say that between the ill-defined nature of the diagnosis and the pressure and advertising from drug companies selling testosterone and human-growth hormone, as well as dietary supplement companies selling all kinds of "boosters" for aging men, the condition is overdiagnosed and overtreated.
Perls and Handelsman note that in the US, "sales of testosterone increased from $324 million in 2002 to $2 billion in 2012, and the number of testosterone doses prescribed climbed from 100 million in 2007 to half a billion in 2012, not including the additional contributions from compounding pharmacies, Internet, and direct-to-patient clinic sales." A decrease in libido in men as a result of age is sometimes colloquially referred to as penopause.
Research directions
As of 2016, research was necessary to find better ways to measure testosterone and to be better able to understand the measurements in any given person, and to understand why some people with low testosterone do not present with symptoms and some with seemingly adequate levels do present with symptoms.
See also
- Androgen deficiency
- Menopause
- European Menopause and Andropause Society