Disease Profile
A slow and steady decline leads patients to clinical manifestations of decreased libido, erectile dysfunction, muscle atrophy and muscle strength, abdominal fat accumulation, easy fatigue, decreased labor endurance, osteoporosis, increased body fat, decreased cognitive function and memory, and poor self-perception. Laboratory results suggest significantly lower blood testosterone levels, often below 250ng/dl.
If there are no contraindications to testosterone supplementation, such as prostate enlargement, prostate tumors, sleep apnea or erythrocytosis, testosterone supplementation therapy may be attempted. Significant improvement in the above symptoms after medication, such as improved libido, better mood and increased muscle volume, suggests that the treatment is effective, and long-term testosterone supplementation therapy can be administered while monitoring for adverse effects of testosterone.
Causes of morbidity
Testosterone levels in older men gradually decline with age. testosterone levels in 75-year-old men are about 2/3 of those in young men. this may be related to the natural aging of the organism’s organs, including the function of the hypothalamus-pituitary-testes. The androgens in middle-aged and elderly people are only partially deficient, unlike middle-aged and elderly women, whose estrogen drops from normal levels to near-zero levels very quickly after just 1-3 years of menopause. Therefore, this disease is also known as “partial androgen deficiency in middle-aged and elderly men”.
It is important to note that these symptoms are the result of a combination of aging and other factors. In addition to a decrease in androgen levels from the testes and adrenal glands, there is also a decrease in growth hormone, melanotropin, and dehydroepiandrosterone sulfate levels. Growth hormone deficiency may also produce similar clinical manifestations as described above.
Pathogenesis
Erectile dysfunction increases significantly with increasing age. Androgens act centrally and peripherally to enhance libido, promote nitric oxide synthesis and penile corpus cavernosum filling. Low androgen levels can affect erectile function, but this is not the main cause of erectile dysfunction in older men. There is evidence that erection of the penis at night and in the early morning is closely related to androgen levels, while erection induced by sensory stimulation such as visual stimulation is not closely related to androgens.
There is a strong relationship between testosterone levels and cognitive ability, especially spatial judgment and mathematical reasoning. Testosterone levels are also associated with depressed mood and depression in older men. Studies have shown a negative correlation between testosterone levels and depression scores in older men, meaning that those who are in a good mood tend to have higher testosterone levels. Bone density decreases with age, and the incidence of fractures in the elderly increases, which may also be related to a decrease in androgen levels.
In conclusion, many signs of frailty in older men seem to be related to androgens, but in fact, the correlation between androgen levels and clinical symptoms is very weak. Furthermore, we should be aware that many of the clinical manifestations associated with aging are the result of multiple factors, such as decreased growth hormone, which can also lead to decreased muscle mass, abdominal fat accumulation, slower response and decreased activity.
Clinical manifestations
Middle-aged and older men, typically after the age of 50, experience clinical manifestations such as muscle atrophy and loss of muscle strength, increased skin wrinkles, decreased work capacity, easy fatigue, decreased libido, osteoporosis, increased body fat, decreased cognitive function and memory, and poor self-perception as they age.
Most people treat these clinical manifestations as natural signs of aging and neglect the diagnosis of “male delayed hypogonadism”. Objective indicators of androgen deficiency include decreased muscle volume and strength, decreased bone mass and osteoporosis, and accumulation of abdominal fat; subjective indicators include decreased libido, decreased memory, difficulty concentrating, insomnia, and poor self-perception.
Diagnosis
There is no uniform understanding about the diagnostic criteria of this disease. In foreign countries, the average testosterone level of -2.5 SD in normal men is generally used as the lower limit, and when the blood testosterone level is less than 11 nmol/l, it can be used as a reference value for androgen deficiency. However, in China, the androgen level in men is generally low, and the normal population level is between 300-700ng/dl. Therefore, a testosterone level below 250ng/dl can be chosen as the criteria for disease diagnosis.
It should be noted that the patient must also have the above mentioned clinical manifestations of decreased libido, erectile dysfunction, decreased work endurance and increased fat content to be considered for the diagnosis of “male late-onset hypogonadism”. Since LH (luteinizing hormone, derived from the pituitary gland) levels may not be elevated in older men, LH levels are not required for the diagnosis of the disease.
It should be noted that the above clinical symptoms may be the result of a combination of factors or the aging of the body, so this so-called diagnostic criterion is not very precise and has its limitations. Before testosterone supplementation therapy, a comprehensive physical examination of the organism should be conducted, and after basically excluding systemic diseases such as tuberculosis, diabetes or tumors, androgen supplementation therapy can be considered.
Treatment
Treatment aim: By raising the patient’s androgen level, the patient can maintain or regain a higher quality of life, reduce and delay the development of diseases of old age, and ultimately obtain a prolongation of quality life.
Androgen supplementation therapy is only used in patients who have both clear clinical manifestations and low testosterone levels. Before starting testosterone replacement therapy, other possible causes of low testosterone levels must be adequately searched for.
With androgen supplementation, there may be an increase in muscle mass and muscle strength, a decrease in fat mass, and a significant increase in libido and quality of sexual life. Decrease the number of falls, increase bone density, and reduce the incidence of fractures. Testosterone supplementation therapy in excess of physiological amounts does not further improve sexual function. Androgen therapy also improves depression and dysphoria. However, in older men with normal testosterone levels, androgen replacement therapy does not further improve mood.
During drug therapy, close attention needs to be paid to the possible adverse effects of testosterone: increased red blood cell pressure and increased blood viscosity may worsen the clinical manifestations of prostate enlargement and the incidence of prostate cancer. For patients over 60 years of age, prostate ultrasound and PSA should be performed prior to androgen replacement therapy and reviewed annually. Oral preparations of testosterone undecanoate, with stable blood levels and little liver damage with long-term use, are available.