Is it wise to check testosterone levels to determine if I have hypogonadism (low testosterone) or hyperandrogenism (high testosterone)?

Testosterone Testing for Hypogonadism and Hyperandrogenism

Yes, checking testosterone levels is essential for diagnosing both hypogonadism (low testosterone) and hyperandrogenism (high testosterone), but this must be done with proper methodology and interpretation of results. 1

Proper Testing Protocol for Testosterone Levels

For Suspected Hypogonadism (Low Testosterone)

1. Morning testing is critical

   • Testosterone levels should be measured in the early morning (between 7am-12pm) when levels are highest 1
   • Unfortunately, compliance with this timing requirement is poor (only 9% of tests are properly timed) 2

2. Confirmation testing required

   • Diagnosis requires at least two separate morning measurements showing consistently low levels 1
   • Use the same laboratory with the same testing method for both measurements 1
   • The threshold for low testosterone is defined as <300 ng/dL 1

3. Additional testing when testosterone is low

   • Measure luteinizing hormone (LH) levels to determine if hypogonadism is primary (testicular) or secondary (pituitary/hypothalamic) 1
   • If LH is low or low-normal, check prolactin levels 1
   • Consider free testosterone measurement in certain cases (obesity, altered binding proteins) 3

For Suspected Hyperandrogenism (High Testosterone)

1. Initial testing
   • Total testosterone is recommended as first-line testing 4
   • If testosterone is twice the upper limit of normal, DHEAS assay should be performed 4
   • High DHEAS (>600 mg/dl) suggests androgen-secreting adrenal tumor 4
   • Normal DHEAS with high testosterone suggests ovarian hyperthecosis or androgen-secreting ovarian tumor 4

When to Test Testosterone Levels

Strong Indications for Testing

• Erectile dysfunction, especially when PDE5 inhibitors fail 1
• Decreased libido (one of few symptoms actually correlated with low testosterone) 5
• Unexplained anemia 1
• Bone density loss 1
• Diabetes (elevated fasting glucose ≥100 mg/dL or HbA1c >6% correlate with low testosterone) 1, 5
• History of chemotherapy or testicular radiation exposure 1
• HIV infection with symptoms of fatigue, weight loss, erectile dysfunction, or depression 1
• Male infertility 1
• Pituitary dysfunction 1
• Chronic corticosteroid use 1

Common Pitfalls in Testosterone Testing

1. Relying solely on symptoms

   • Many symptoms attributed to low testosterone (fatigue, depression, erectile dysfunction) do not reliably correlate with testosterone levels 5
   • Screening questionnaires are not recommended for diagnosis 1

2. Single measurements

   • A single testosterone measurement is insufficient for diagnosis 1
   • Levels can vary significantly day-to-day and throughout the day

3. Ignoring free testosterone

   • In men with borderline total testosterone, only about 25% will have low free testosterone 3
   • Free testosterone correlates better with clinical parameters of androgen deficiency than total testosterone 3

4. Incorrect timing

   • Non-morning testing can lead to falsely low results due to diurnal variation 2

Interpretation of Results

• Low testosterone (<300 ng/dL) with symptoms suggests hypogonadism requiring further evaluation 1
• Normal testosterone with symptoms requires careful interpretation:
  • Consider measuring free testosterone, especially in overweight patients 4, 3
  • SHBG is reduced in overweight individuals, metabolic syndrome, or family history of diabetes 4
• High testosterone requires evaluation for potential adrenal or ovarian pathology 4

Remember that testosterone testing should be part of a comprehensive evaluation that includes assessment of symptoms and signs, not performed in isolation. The diagnosis of testosterone deficiency requires both laboratory confirmation of low testosterone AND the presence of relevant symptoms or signs 1.