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AUA GUIDELINE: TESTOSTERONE DEFICIENCY 2018

See Original Guideline

Includes parts of Chapter 23 from 11th edition of Campell's

Androgen deficiency (AD)
Pathophysiology
Diagnosis and Evaluation
  • Adjunctive Testing in Patients with Testosterone Deficiency
    • UrologySchool.com summary:

      • Recommended in all patients (1):
        1. LH (helps determine etiology of testosterone deficiency)
          • Prolactin if LH low (screen for hyperprolactinemia)
      • Recommended prior to initiating treatment (4):
        1. Hematocrit (all patients, risk of polycythemia)
        2. Estradiol (in patients who present with breast symptoms or gynecomastia)
        3. Testicular exam and FSH (in patients interested in fertility)
        4. PSA (if history of prostate cancer, men >40 years, or younger with risk factor)

 

    • All patients

      • Serum luteinizing hormone (LH) levels should be measured in patients with low testosterone

        • A low or low/normal LH level points to a secondary (central) hypothalamic-pituitary defect, (hypogonadotropic hypogonadism), while an elevated LH level indicates a primary testicular defect (hypergonadotropic hypogonadism)

          • In some cases, the etiology is obvious (e.g. iatrogenic causes), in others, a karyotype may be warranted to establish a diagnosis of Klinefelter syndrome (47, XXY). In other cases, it may not be possible to establish a definitive etiology

            • Klinefelter syndrome
              • Relatively common condition that affects ≈1:500 males
              • Characterized by hypergonadotropic hypogonadism (very high LH and FSH, low testosterone).
              • Often prescribed exogenous testosterone to treat signs and symptoms associated with low testosterone
        • Age-related changes
          • LH does not decline as men age, suggesting that reduced testosterone results from testicular hypofunction rather than changes at the hypothalamic-pituitary levels.
          • The number of Leydig cells per testis has been shown to remain unchanged, suggesting that changes in the steroidogenic machinery of the individual cells and not their reduced number are responsible for the declining serum testosterone concentrations.
      • Serum prolactin should be measured in patients with low testosterone levels AND low or low/normal luteinizing hormone levels (hypogonadotropic hypogonadism) to screen for hyperprolactinemia.
        • Hyperprolactinemia is a cause of secondary (central) testosterone deficiency and can lead to (4):
          1. Infertility
          2. Decreased libido
          3. Sexual dysfunction
          4. Gynecomastia
        • The mechanism of action of prolactin may be through inhibition of dopaminergic activity in the medial preoptic area and decreased testosterone. In addition, prolactin may have a direct effect on the penis through its contractile effect on the cavernous smooth muscle
        • Causes:
          1. Medications (7):
            1. Dopamine antagonists (most commonly)
            2. Anti-psychotics
            3. Selective serotonin reuptake inhibitors
            4. Proton pump inhibitors
            5. Calcium channel blockers
            6. Anti-emetics
            7. Opiates
          2. Chronic medical conditions (3):
            1. Hypothyroidism
            2. Renal failure
            3. Cirrhosis
          3. Pituitary tumour
            • Persistently elevated prolactin levels can indicate the presence of pituitary tumors such as prolactinomas. Pituitary prolactinomas are benign tumors that can be effectively managed using medications, such as bromocriptine or carbergoline
        • Prolactin is a labile assay; if a patient has elevated prolactin levels, prolactin measurement should be repeated to ensure that the initial elevation was not spurious
          • False positive elevated prolactin levels can occur with a stressful blood draw. Consider this if it is only slightly elevated
        • Men with total testosterone levels of <150 ng/dL in combination with a low or low/normal LH should undergo a pituitary MRI regardless of prolactin levels, as non-secreting adenomas may be identified.
        • Patients should be referred to an endocrinologist for further evaluation if the etiology for hyperprolactinemia cannot be established.
    • Prior to initiating treatment
      • Hemoglobin and hematocrit should be measured planning on initiating treatment and patients should be informed regarding the increased risk of polycythemia
        • Elevation of Hb/Hct is the most frequent adverse event related to testosterone therapy.
          • Androgens have a stimulating effect on erythropoiesis
          • Polycythemia, sometimes called erythrocytosis, is defined as a hematocrit (Hct) >52%
          • Trials have indicated that injectable testosterone is associated with the greatest treatment-induced increases in Hb/Hct
        • Increased blood viscosity can aggravate vascular disease in the coronary, cerebrovascular, or peripheral vascular circulation, particularly in the elderly with pre-existing conditions
        • If the baseline Hct exceeds 50%, clinicians should consider withholding testosterone therapy until the etiology of the high Hct is explained
        • During testosterone therapy, levels of Hb/Hct generally rise for the first 6 months, and then tend to plateau.
        • While on testosterone therapy, a Hct ≥54% warrants intervention:
          • In men with elevated Hct and
            • High on-treatment testosterone levels, dose adjustment should be attempted as first-line management
            • Low/normal on-treatment testosterone levels, measuring a SHBG level and a free testosterone level using a reliable assay is suggested.
              • Low/normal on-treatment testosterone levels with high free testosterone and low SHBG [i.e. low proportion of tightly-bound testosterone]: dose adjustment of the testosterone therapy should be considered.
              • Low/normal on-treatment testosterone levels with low/normal free testosterone: refer to a hematologist for further evaluation and possible coordination of phlebotomy.
      • Serum estradiol should be measured in patients who present with breast symptoms or gynecomastia
        • Given the enzymatic conversion of testosterone to E2 by aromatase, it is not uncommon for E2 levels to increase while patients are on testosterone therapy.
        • Men who present with breast symptoms should have their E2 measured and those with elevated E2 measurements (>40 pg/mL), should be referred to an endocrinologist.
        • Symptomatic gynecomastia or other breast symptoms are an uncommon side effect of testosterone therapy
      • Reproductive health evaluation (testicular exam and serum FSH) should be evaluated in men who are interested in fertility
        • Testicular exam
          • Evaluate testicular size, consistency, and descent; most of the testis is composed of reproductive tissue, such as germ cells and Sertoli cells, and it is common for men with reduced testicular volume to also have impaired sperm production.
        • Serum FSH
          • Elevated FSH levels in the setting of testosterone deficiency (hypergonadatropic hypogonadism) is typically indicative of impaired spermatogenesis, and in such patients, clinicians should consider fertility testing, such as semen analysis.
            • FSH, a pituitary gonadotropin, targets the Sertoli cells within the testes and is a key regulator of spermatogenesis. Normal spermatogenesis is typically associated with an FSH level in the low/normal range
            • Patients who have severe oligospermia (sperm concentration <5 million sperm per mL) or non-obstructive azoospermia should be offered reproductive genetics testing consisting of karyotype testing and Y-chromosome analysis for microdeletions
      • PSA should be measured in men (3):
        1. Age > 40
        2. Younger men with risk factors for prostate cancer
        3. History of prostate cancer
        • The rise of PSA levels in patients on testosterone therapy is primarily dependent upon baseline total testosterone levels; men with lower baseline testosterone levels are more likely to experience PSA level increases.
        • For patients who have an elevated PSA at baseline, a second PSA test is recommended to rule out a spurious elevation. In patients who have two PSA levels at baseline that raise suspicion for the presence of prostate cancer, a more formal evaluation to rule out prostate cancer (4K, phi, prostate biopsy with/without MRI, etc.) should be considered before initiating testosterone therapy.
Counseling Regarding Treatment of Androgen Deficiency
Management
Follow-up of Men on Testosterone Therapy
Questions
  1. List systemic illnesses associated with testosterone deficiency
  2. List causes of primary and secondary androgen deficiency
  3. What are the recommended initial investigations in someone suspected of having AD
  4. Describe your history and physical exam
  5. What is required for a diagnosis of AD?
  6. After confirming diagnosis of AD, what tests are required? What tests are required prior to initiating treatment?
  7. What are the signs and symptoms of hyperprolactinemia? What are causes of hyperprolactinemia?
  8. What are the treatment options for AD in patients who want to preserve fertility?
Answers