What type of workup is needed for a patient with suspected hormonal imbalance and erectile dysfunction?

Workup for Suspected Hormonal Imbalance and Erectile Dysfunction

A comprehensive hormonal and erectile dysfunction workup should include laboratory testing for testosterone levels, other hormonal parameters, metabolic factors, and cardiovascular risk assessment, along with specific diagnostic tests for erectile function when indicated.

Initial Laboratory Assessment

• Morning total testosterone measurement is essential as the first step in evaluating suspected hormonal imbalance and erectile dysfunction 1
• Free testosterone level by equilibrium dialysis should be measured, especially in obese patients, as obesity can lower sex hormone-binding globulin levels 1
• Sex hormone-binding globulin (SHBG) should be measured to properly interpret total testosterone levels in obese patients 1
• Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) to distinguish between primary (testicular) and secondary (pituitary-hypothalamic) hypogonadism 1
• Prolactin measurement is indicated in patients with low testosterone and low/normal LH to screen for hyperprolactinemia 1, 2
• Thyroid function tests (TSH, free T4) as thyroid disorders can contribute to erectile dysfunction 1, 3
• Glucose-lipid profile to assess for diabetes and dyslipidemia, which are common comorbidities 1, 3

Additional Hormonal Evaluation

• Serum estradiol should be measured in patients presenting with breast symptoms or gynecomastia prior to testosterone therapy 1
• Morning cortisol may be considered if adrenal insufficiency is suspected 1, 2
• Repeat hormone measurements should be performed to confirm abnormal results, particularly for testosterone levels 1

Imaging Studies

• Pituitary MRI is indicated for patients with total testosterone <150 ng/dL combined with low/normal LH, regardless of prolactin levels 1
• MRI of the brain with pituitary cuts should be considered for patients with multiple hormonal deficiencies or visual symptoms suggesting pituitary dysfunction 1

Cardiovascular Assessment

• Assessment of cardiovascular risk factors including blood pressure measurement, BMI calculation, and waist circumference measurement 1, 4
• ECG may be indicated in patients with multiple cardiovascular risk factors before initiating treatment 1

Specific Erectile Function Assessment

• International Index of Erectile Function (IIEF) questionnaire to objectively assess erectile function 1
• Nocturnal penile tumescence and rigidity testing may be considered in specific cases to differentiate psychogenic from organic causes 1
• Vascular studies including intracavernous injection tests may be indicated in selected patients, particularly younger men with history of pelvic trauma 1

Special Considerations

• Prostate-specific antigen (PSA) should be measured in men over 40 years before initiating testosterone therapy 1
• Hemoglobin/hematocrit should be measured before testosterone therapy to establish baseline values 1
• Semen analysis should be performed in men interested in fertility before initiating testosterone therapy 1

Diagnostic Algorithm

1. First visit: Complete medical and sexual history, physical examination, and basic laboratory tests (morning total testosterone, glucose-lipid profile)
2. If testosterone is low: Repeat morning testosterone measurement, add LH, FSH, prolactin, and SHBG
3. If secondary hypogonadism is confirmed (low testosterone with low/normal LH): Evaluate pituitary function (TSH, free T4, morning cortisol) and consider pituitary MRI
4. If primary hypogonadism is confirmed (low testosterone with elevated LH): Consider genetic testing if fertility is desired
5. For all patients with ED: Assess cardiovascular risk factors and consider specific erectile function tests based on age and clinical presentation

Common Pitfalls to Avoid

• Failure to measure morning testosterone: Testosterone levels show diurnal variation with highest levels in the morning 1
• Relying solely on total testosterone without measuring free testosterone, especially in obese patients 1
• Missing hyperprolactinemia by not checking prolactin in patients with low testosterone and low/normal LH 1, 2
• Overlooking thyroid dysfunction as a potential cause of erectile dysfunction 3, 2
• Not considering cardiovascular risk factors which are commonly associated with erectile dysfunction 1, 4
• Initiating testosterone therapy without proper baseline assessment of PSA and hematocrit in appropriate patients 1