Page 19 - Journal of Special Operations Medicine - Fall 2015

Table 1 Symptoms of Androgen Deficiency man does not have hypogonadism and the evaluation for

More-specific symptoms and signs another cause for the symptoms should be pursued.How-
Reduced libido or sexual activity ever, some Operators may believe they need higher than
normal levels of testosterone and will ask for treatment or
Decreased spontaneous erections
Breast discomfort repeated testing. One small study of healthy men aged 21
Low or zero sperm count to 35 years found a mean testosterone level of 524ng/dL
Bone fracture from low-energy trauma with a 25% to 75% confidence interval of 420 to 619ng/
Low bone density dL, but the study did not specify a lower limit of normal.
5
Hot flushes or sweats Most clinicians will follow the Endocrine Society’s 2010
Other, less-specific symptoms and signs guidelines that state the lower limit of normal for young
2
Decreased energy and or motivation men is 300ng/dL. The US Food and Drug Association also
Feeling sad or depressed mood uses that same level, 300ng/dL, as their cut-off as normal
Poor concentration testosterone levels in approving clinical trials, which re-
Sleep disturbance or increased sleepiness sults in most US clinical trials using 300ng/dL as the lower
Reduced muscle bulk and strength 5
Increased body fat limit of normal. Additionally, many insurance companies
Diminished physical or work performance will only approve payments for testosterone treatments if
the total testosterone level is less than 300ng/dL. 5
hypogonadism, evaluate and treat that condition before
proceeding down the evaluation. When a testosterone level is below 300ng/dL, providers
must evaluate further to meet a standard of “unequivo-
The differential diagnosis should include, but not be cally low testosterone levels.” Many factors can tem-
limited to, the following : porarily depress the testosterone levels and up to 30%
1
of men with a low testosterone level on initial evalua-
• Stress or anxiety tion can have normal levels on repeated testing. The
2
• Depression USASOC guideline suggests repeating the total testoster-
• Posttraumatic stress disorder one level test in 2 to 4 weeks, again ensuring an early
• Hypothyroidism morning laboratory draw. The interval between the first
• Anemia abnormal laboratory draw and the repeated laboratory
• Vitamin D deficiency draw allows any illness, supplement, or other temporary
• Sleep deprivation influencing factors to possibly resolve before recheck-
• Obstructive sleep apnea ing of the testosterone level. If this repeated testosterone
level is still below 300ng/dL, then the provider should
In addition to evaluating for other conditions that can initiate a more advanced evaluation. 1
have similar presentations, providers must be aware of
several factors that can affect laboratory results. Testos- If a man has two total testosterone levels below 300ng/
terone levels fluctuate significantly throughout the day dL, then he should have a third blood draw to confirm
and are prone to alterations due to a number of factors. the diagnosis of hypogonadism. At this stage in the eval-
In younger men, testosterone is released in a diurnal uation, it is sometimes necessary to consider the three
pattern, which peaks early in the morning and fluctu- subcomponents that make up a total testosterone (TT)
ates during the day. A low testosterone level based on a level. 1–3,5 Free testosterone is easily used by the body
blood draw in the afternoon does not necessarily mean but comprises only 1% to 3% of the TT. Testosterone
a man has hypogonadism; it may simply be a result of bound to albumin is only loosely bound and also is eas-
the normal variations seen throughout the day. As such, ily used and comprises about 48% of the TT. Finally,
testosterone should be checked as close to 0800 hours about 50% of the TT is bound in the serum to a pro-
as possible. 1,2,4,5 tein called sex hormone–binding globulin (SHBG). The
free testosterone and the albumin-bound testosterone are
sometimes referred to as the bioavailable testosterone.
Laboratory Testing
The TT may be below 300ng/dL, but if the man has a
The USASOC CPG recommends that the initial evaluation normal free testosterone level or a normal bioavailable
include an early morning total testosterone. In addition, testosterone level, then he does not have hypogonadism.
providers should also order thyroid-stimulating hormone For example, obesity and diabetes can both lower SHBG
(TSH), complete blood cell count (CBC), and 25-hydro- levels. 1–3,5 When this happens, the body has less SHGB-
xyvitamin D levels to evaluate for other possible causes bound testosterone and thus more bioavailable testos-
for the patients’ symptoms. If there are any correctable terone. The combination can result is a low TT level but
1
abnormalities, they should be addressed at this stage. If normal free and bioavailable testosterone levels. On the
the total testosterone level is above 300ng/dL, then the other hand, some disorders, such as hepatitis, cirrhosis,

Evaluation for Testosterone Deficiency 7