From the Guidelines
For a 60-year-old male with symptomatic low testosterone on transdermal testosterone therapy, hematocrit or hemoglobin level should be monitored in addition to PSA levels. This recommendation is based on the study by 1, which emphasizes the importance of monitoring hematocrit or hemoglobin levels to assess blood levels during testosterone-replacement therapy.
Key Laboratory Values to Monitor
- Hematocrit or hemoglobin level: to measure blood levels and assess for potential polycythemia, a condition that can occur due to increased red blood cell production stimulated by testosterone therapy.
- PSA level: to monitor for signs of prostate cancer, as recommended by 1.
- Serum testosterone level: to assess the efficacy of treatment and ensure levels are within the therapeutic range, although the exact target levels may vary according to clinical response and physician preference, as noted in the study by 1.
Monitoring Schedule
Monitoring visits should be performed at one to two months after initiating therapy to assess efficacy and potential side effects, with subsequent visits at three-to-six-month intervals for the first year and yearly thereafter, as recommended by 1. At each visit, an assessment of symptomatic response, voiding symptoms, and sleep apnea should be conducted, along with a physical examination including a digital rectal examination and blood tests for serum testosterone, PSA, and hematocrit or hemoglobin levels.
Additional Considerations
While lipid evaluation is considered optional by 1, it may be prudent to monitor lipid profiles periodically, especially if the patient has a history of lipid disorders, as testosterone therapy can affect cholesterol levels. Similarly, monitoring for signs of sleep apnea and voiding symptoms is important, as these can be exacerbated by testosterone therapy. However, the primary focus for laboratory monitoring, in addition to PSA, should be on hematocrit or hemoglobin levels to ensure patient safety and adjust therapy as necessary to prevent adverse effects.
From the FDA Drug Label
Monitor serum testosterone, prostate specific antigen (PSA), hemoglobin, hematocrit, liver function tests and lipid concentrations periodically (5.1,5.3,5.9,5.13) The laboratory values that should be monitored in a 60-year-old male with symptomatic low testosterone on transdermal testosterone therapy, aside from Prostate-Specific Antigen (PSA) levels, are:
- Serum testosterone
- Hemoglobin
- Hematocrit
- Liver function tests
- Lipid concentrations 2
From the Research
Laboratory Values to be Monitored
In addition to Prostate-Specific Antigen (PSA) levels, the following laboratory values should be monitored in a 60-year-old male with symptomatic low testosterone on transdermal testosterone therapy:
- Hematocrit levels: to assess the risk of polycythemia, a known side effect of testosterone therapy that can increase the risk of thromboembolic events 3, 4, 5, 6, 7
- Hemoglobin levels: to monitor for potential increases in hemoglobin concentration, which can be a sign of polycythemia 3, 4
Rationale for Monitoring
Monitoring hematocrit and hemoglobin levels is crucial because:
- Polycythemia can occur in individuals on testosterone therapy, with a higher risk in those with certain factors such as tobacco use, long-acting undecanoate injections, age at initiation of hormone therapy, body mass index (BMI), and pulmonary conditions 4
- Developing polycythemia while on testosterone therapy is an independent risk factor for major adverse cardiovascular events (MACE) and venous thromboembolic events (VTE) in the first year of therapy 5
- Regular monitoring of hematocrit can help identify individuals at risk of polycythemia and inform treatment choices 6
- Changes in hematocrit can affect blood flow characteristics, viscosity, and oxygen delivery, which may have harmful effects on different vascular beds 7