Editing Testosterone Deficiency (2018) (section)

==== Prior to initiating treatment ====
* '''<span style="color:#ff0000">Hemoglobin and hematocrit</span>''' 
**'''<span style="color:#ff0000">Should be measured planning on initiating treatment and patients should be informed regarding the increased risk of polycythemia</span>'''
*** '''<span style="color:#ff0000">Elevation of Hb/Hct is the most frequent adverse event related to testosterone therapy.</span>'''
**** '''Androgens have a stimulating effect on erythropoiesis'''
**** '''<span style="color:#ff0000">Polycythemia,</span>''' sometimes called erythrocytosis, '''<span style="color:#ff0000">is defined as a hematocrit (Hct) >52%</span>'''
**** Trials have indicated that '''<span style="color:#ff0000">injectable testosterone is associated with the greatest treatment-induced increases in Hb/Hct</span>'''
*** '''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'''.
*** '''<span style="color:#ff0000">While on testosterone therapy, a Hct ≥54% warrants intervention:</span>'''
**** '''<span style="color:#ff0000">In males with elevated Hct and</span>'''
***** '''<span style="color:#ff0000">High on-treatment testosterone levels, dose adjustment should be attempted as first-line management</span>'''
***** 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.
* '''<span style="color:#ff0000">Serum estradiol</span>''' 
**'''<span style="color:#ff0000">Should be measured in patients who present with breast symptoms or gynecomastia</span>'''
*** 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'''
* '''<span style="color:#ff0000">Reproductive health evaluation (testicular exam and serum FSH)</span>''' 
**'''<span style="color:#ff0000">Should be evaluated in men who are interested in fertility</span>'''
*** '''<span style="color:#ff0000">Testicular exam</span>'''
**** 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.
*** '''<span style="color:#ff0000">Serum FSH'''
**** '''<span style="color:#ff0000">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'''
***** '''<span style="color:#ff0000">Patients who have elevated FSH with azoospermia or severe oligospermia (sperm concentration <5 million sperm per mL) should be offered reproductive genetics testing consisting of karyotype testing and Y-chromosome analysis for microdeletions'''
****** 2015 CUA Azoospermia Guidelines recommend karyotype and Y-chromosome microdeletion in patients with testicular failure.
* '''<span style="color:#ff0000">PSA</span>''' 
**'''<span style="color:#ff0000">Should be measured in men (3):</span>'''
**# '''<span style="color:#ff0000">Age > 40</span>'''
**# '''<span style="color:#ff0000">Younger males with risk factors for prostate cancer</span>'''
**# '''<span style="color:#ff0000">History of prostate cancer</span>'''
*** '''The rise of PSA levels in patients on testosterone therapy is primarily dependent upon baseline total testosterone levels; <span style="color:#ff0000">males 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.
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