Testosterone Therapy Considerations

Introduction to Testosterone Therapy

Testosterone therapy alters body composition, affecting muscle mass and fat distribution, which can influence creatinine generation and potentially complicate kidney function assessment, and consider using cystatin C for estimating glomerular filtration rate as it is less dependent on muscle mass 1
For patients on testosterone therapy, interpret laboratory values based on their affirmed gender and duration of therapy, with values potentially changing over time, especially for those on therapy <1 year 1

Monitor electrolyte levels (sodium, potassium) and blood urea nitrogen, which may fluctuate, particularly in patients receiving spironolactone as part of hormone therapy, and consider the effects of testosterone therapy on kidney function 1
Testosterone therapy can increase blood pressure, particularly with oral formulations, and requires careful monitoring in patients with or at risk for hypertension, as noted by the American College of Physicians, the FDA, and the American Gastroenterological Association 2, 3
The choice of testosterone formulation (oral, injectable, transdermal) can impact blood pressure, with oral formulations associated with increased blood pressure, and transdermal preparations generally having minimal effects, as recommended by the Endocrine Society and the FDA 2, 4

The American Urological Association recommends targeting testosterone levels in the middle tertile of the normal reference range, using the minimal effective dose, and considering lifestyle modifications to mitigate risks, with regular monitoring of blood pressure and hematocrit essential during testosterone replacement therapy (TRT) 5, 3, 4
Ambulatory blood pressure monitoring may be considered in high-risk patients, such as those with pre-existing hypertension or cardiovascular disease, as recommended by the European Society of Hypertension, and patients with pre-existing hypertension, obesity, or higher baseline hematocrit values may be at increased risk of blood pressure elevation with TRT 4
The current evidence is inconclusive regarding whether testosterone therapy increases or decreases the risk of cardiovascular events, but existing evidence suggests a neutral or possible beneficial effect of testosterone therapy on cardiovascular disease, as noted by the American Urological Association and the American College of Physicians 5, 4

Injectable testosterone formulations may be associated with a greater risk of erythrocytosis, which can indirectly affect blood pressure, as noted by the American Heart Association, and physiologic replacement doses of testosterone typically show minimal to no significant changes in blood pressure, with minimal effects on blood pressure in most men 4
The effect of testosterone on blood pressure appears to be influenced by dosage and formulation, with careful consideration of these factors necessary to minimize risks, as cautioned by the American College of Cardiology 4