endocrinology

Male Hypogonadism

Generality

Male hypogonadism is the condition by which a man's gonads - or testicles - no longer produce physiological amounts of testosterone.

Testosterone is the main male sex hormone.

The presence of male hypogonadism can depend on a problem inherent in the testicles (in this case we speak of primary male hypogonadism) or from a problem at the level of the hypothalamic-pituitary axis, an axis that controls the activity of the testicles (secondary male hypogonadism) .

The symptoms of male hypogonadism consist essentially in the failure to develop secondary sexual characteristics, a process which depends on testosterone.

The treatment of male hypogonadism varies depending on whether the hypogonadism is primary or secondary.

Brief review of hypogonadism and gonad function

Hypogonadism is the medical term that indicates a more or less marked reduction in the functional activity of the gonads .

Human testes and ovaries in women, the gonads are the reproductive organs responsible for the production of sex cells or gametes and sex hormones

Therefore, a reduction in the functional activity of the gonads involves a decrease in the secretion of the sex hormones, necessary for the development of secondary sexual characteristics and the control of the reproductive apparatus.

WHAT DOES THE GONADI ACTIVITY DEPEND ON?

The activity of the gonads depends on the hypothalamus, a particular organ of the brain, and on the hypophysis, a gland located at the base of the skull.

In fact, through the secretion of the so-called GnRH, the hypothalamus stimulates the pituitary gland to produce FSH and LH, two hormones that have, among their various roles, the task of regulating the production of sex hormones by the gonads.

What is male hypogonadism?

Male hypogonadism is the condition that a man's gonads (testicles) no longer produce adequate amounts of testosterone, the main male sex hormone.

ROLE OF SEXUAL MALE HORMONES

The male sex hormones - testosterone in the head - control the development of the secondary sexual characteristics of man, namely the growth of the penis and testicles, the appearance of pubic, cutaneous and beard hair, the strengthening of the musculature, the enlargement of the shoulders and prostate enlargement.

Types

Experts distinguish two types of male hypogonadism: primary male hypogonadism and secondary (or central) male hypogonadism .

  • Male hypogonadism is defined as primary when it results from a defect or problem in the testicles.

    This means that the signals coming from the hypothalamus and pituitary gland are correct; what does not work properly are the reproductive organs secreting sex hormones.

  • Male hypogonadism is called secondary when it is the result of defects in the hypothalamus or pituitary gland.

    This means that the testicles are healthy and would function properly, if there were not a problem upstream, at the level of the hypothalamic gland and the pituitary gland.

Causes

The possible causes of primary male hypogonadism include:

  • Klinefelter's syndrome ;
  • Cryptorchidism, when it is not cured in childhood;
  • Some forms of post-mumps orchitis ;
  • Strong testicular traumas
  • Radiotherapy and / or chemotherapy treatment for a or testicular cancer.

Among the possible causes of secondary male hypogonadism, however, are:

  • Kallmann's syndrome ;
  • Pituitary diseases (eg, pituitary tumors);
  • Some inflammatory diseases, such as sarcoidosis, tuberculosis or histiocytosis, which affect the hypothalamus or pituitary gland, altering its activity;
  • AIDS
  • Prolonged intake of opiate pain medications (eg: codeine, morphine, oxycodone, methadone, fentanyl, hydromorphine and didrocodeine);
  • Obesity ;
  • Aging ;
  • Hemochromatosis ;
  • Nutritional deficiencies due to malnutrition;
  • Brain surgery, from which a more or less serious lesion of the hypothalamus arises;
  • Brain tumors involving the hypothalamus;
  • Head trauma that specifically affects the hypothalamus or pituitary gland.

Symptoms and Complications

To learn more: Symptoms of Male Hypogonadism

The symptoms and signs of male hypogonadism are numerous and vary with age.

During fetal life, the symptomatic picture depends on how severe the lack of testosterone is. From the most severe to the least severe, clinical manifestations can range from: presence at birth of female genital organs → presence at birth of ambiguous genital organs → presence at birth of underdeveloped male genital organs.

In puberty, male hypogonadism is responsible for:

  • Reduced development of muscle mass
  • Failure to lower the tone of the voice
  • Lack of body hair growth
  • Reduced development of penis and testicles
  • Excessive growth of the arms and legs, compared to the trunk
  • Abnormal breast development (gynecomastia)

Finally, in adulthood, hypogonadism is a reason for:

  • Erectile dysfunction
  • Infertility
  • Reduced or absent growth of the beard, which is associated with the lack of hair on the rest of the body
  • Decrease in muscle mass
  • Gynecomastia
  • Tendency to osteopenia or osteoporosis
  • Sense of recurrent fatigue
  • Low libido
  • Hot flashes
  • Decline in concentration

WHEN TO REFER TO THE DOCTOR?

A man should contact his treating physician or an expert in male genital tract problems at the onset of any minimal symptom attributable to male hypogonadism.

An early diagnosis of the disorder has positive implications for treatment.

Diagnosis

For a correct diagnosis of male hypogonadism, the following are essential: physical examination, medical history and hormone dosage tests on a blood sample.

If they suspect a disease of the hypothalamus or pituitary gland, doctors may also consider the use of a CT scan or a nuclear magnetic resonance (NMR) of the head indispensable.

EXAMS OF HORMONAL DOSAGE

Typically, hormone dosing tests on a blood sample include:

  • Measurement of FSH (or follicle-stimulating hormone) and LH (or luteinizing hormone) levels;
  • Measurement of testosterone levels.

Treatment

The treatment of male hypogonadism varies depending on whether the hypogonadism is primary or secondary.

In the case of primary male hypogonadism, the planning of adequate testosterone replacement therapy (or TRT ) is essential. TRT consists, essentially, in the exogenous administration of the main male sex hormone and is, in fact, a hormonal therapy.

In the case of secondary male hypogonadism, on the other hand, it is important to first treat or, at least, try to limit the disorder at the hypothalamic-pituitary axis level. However, in these situations, hormone therapy with testosterone is useful, but it is not the first line treatment, as is the case in primary male hypogonadism.

SUBSTITUTE THERAPY WITH TESTOSTERONE: SOME DETAILS

  • The administration of exogenous testosterone can take place: via a patch or gel that can be applied to the skin (via the transdermal route), by injection (via parenteral route) or by ingestible tablets (orally).
  • Prolonged TRT increases the risk of cardiovascular disease, including heart attack and stroke. In this regard, in 2015, the FDA, that is the US government agency for the regulation of food and pharmaceutical products, required pharmaceutical companies that trade exogenous testosterone to report, in the illustrative leaflets (under the heading undesirable effects) the increased risk of cardiovascular disease events.
  • Sometimes, in addition to TRT, doctors could combine the exogenous administration of GnRH (ie the hypothalamic hormone that stimulates the pituitary gland to secrete FSH and LH). GnRH is useful in case of prepubertal patients (to promote puberty) and in case of reduced sperm production.

EXAMPLE OF TREATMENT OF SECONDARY MALE HYPOGONADISM

When the cause of secondary male hypogonadism is a tumor of the hypothalamus or pituitary gland, the treatment envisaged may consist of: surgery to remove the tumor mass, radiotherapy and / or chemotherapy.

Prognosis

The Urology Care Foundation - an American Foundation specializing in the field of urology - argues that hypogonadism is a mostly chronic condition that requires life-long treatment.

The cases of secondary hypogonadism, whose causes are sometimes treatable even with good results, represent exceptions to what has just been said.