Laboratory Testing for Erectile Dysfunction

Core Laboratory Testing

The American Urological Association recommends measuring HbA1c and fasting blood glucose to screen for diabetes, as erectile dysfunction is commonly associated with diabetes and may be the first presenting symptom 1, 2, 4
Lipid profile, including total cholesterol, HDL, LDL, and triglycerides, should be obtained to assess cardiovascular risk factors 2, 4
Morning serum total testosterone is essential to evaluate for testosterone deficiency, defined as less than 300 ng/dL with symptoms 3, 5
If hypogonadism is suspected based on history or examination, free testosterone or bioavailable testosterone is preferred over total testosterone 6, 7

The British Medical Journal recommends prostate-specific antigen and digital rectal examination as baseline measurements in patients who may receive testosterone replacement therapy 6, 8

For patients who do not respond to first-line therapies, additional testing may include bulbo-cavernosus reflex testing 4, dorsal sensory nerve conduction studies 1, and pudendal nerve somatosensory evoked potentials 1

Erectile dysfunction is a risk marker for underlying cardiovascular disease and other health conditions that warrant evaluation 3, 5
Laboratory testing should be interpreted in conjunction with a thorough medical, sexual, and psychosocial history 5
Validated questionnaires such as the International Index of Erectile Function should be used alongside laboratory testing to assess erectile dysfunction severity 3, 5

Testosterone levels should be measured in the morning due to diurnal variation 3
Laboratory testing should be interpreted in the context of the patient's psychological and relationship factors 6