Hypogonadism is diagnosed based on clinical symptoms and testosterone measurements. One common approach to evaluating symptoms is use of a questionnaire such as the Androgen Deficiency in Aging Men (ADAM) questionnaire.3,4 This questionnaire has a reported sensitivity of 88% and specificity of 60%.4 Thus, eight of nine men with hypogonadism will be identified with ADAM. However, four of ten men will be falsely identified as having hypogonadism. If the hypogonadism prevalence is 10%, then 20% of those positively identified by ADAM will really have hypogonadism (true positives). On the other hand, 98% of those who are negative by ADAM will not have hypogonadism (true negatives).
The components of the ADAM questionnaire include:
- Changes in mood (fatigue, depression, anger)
- Decreased body hair (feminization)
- Decreased bone mineral density and possible resulting osteoporosis
- Decreased lean body mass and muscle strength
- Decreased libido and erectile quality
- Increased visceral fat
- Oligospermia or azoospermia
There is no consensus on the degree of these signs or symptoms required for diagnosis.
An alternative questionnaire is the Massachusetts Male Aging Survey (MMAS) questionnaire.5 This survey has far better sensitivity than specificity.
Scores derived from these questionnaires do not predict or correlate well with measured total testosterone.6 Specimens for testosterone measurement should be collected between 7 and 10 a.m., because levels show a circadian rhythm; peak levels occur in the morning, especially among younger men. Also, because levels can fluctuate day-to-day, repeat testing is recommended by the Endocrine Society prior to the initiation of treatment.1
Free and bioavailable testosterone measurements may be helpful when the total testosterone concentration is near the decision level or when perturbations in sex hormone binding globulin (SHBG) are likely. Longitudinal studies such as the Massachusetts Male Aging Study suggest that total testosterone decreases at a rate of about
1.6% annually, with a concomitant 1.3% annual increase in SHBG after age 40 years.7 An estimated 30% of men aged 70–79 years have low serum total testosterone, and approximately 70% have low bioavailable testosterone levels.2 Free and bioavailable testosterone can be measured or calculated based on the total testosterone, SHBG, and albumin concentrations.
Luteinizing hormone (LH) testing may be useful in determining if a patient’s hypogonadism is primary (elevated LH) or secondary (LH within range or low). Prolactin testing is used to rule out hyperprolactinemia.