How to manage hypogonadism with low testosterone and LH levels?

Management of Secondary Hypogonadism with Suppressed LH

Your laboratory values (free testosterone 980 pg/mL, bioavailable testosterone 23 ng/dL, LH 0.1 mIU/mL) indicate secondary (hypogonadotropic) hypogonadism requiring immediate evaluation for pituitary pathology before any treatment decisions. The critically suppressed LH of 0.1 with low bioavailable testosterone defines this as a hypothalamic-pituitary axis disorder, not primary testicular failure 1.

Immediate Diagnostic Workup Required

Measure serum prolactin immediately - this is a strong recommendation for all patients with low testosterone combined with low/normal LH levels to screen for hyperprolactinemia 1. If prolactin is elevated, repeat the measurement to exclude spurious elevation, as persistently elevated prolactin indicates possible prolactinoma requiring endocrinology referral 1.

Obtain pituitary MRI regardless of prolactin level - men with total testosterone <150 ng/dL (your bioavailable testosterone of 23 ng/dL suggests very low total testosterone) combined with low/normal LH should undergo pituitary MRI even if prolactin is normal, as non-secreting adenomas may be present 1.

Check additional pituitary hormones - evaluate for combined pituitary hormone deficiency by measuring TSH, free T4, cortisol, and IGF-1 to assess whether this represents isolated gonadotropin deficiency or panhypopituitarism 1.

Determine the Underlying Cause

Your secondary hypogonadism could result from multiple etiologies that require different management approaches 1:

Drug-induced causes to evaluate:

• Opioid use (chronic narcotic use is a recognized risk factor) 1
• Testosterone or anabolic steroid use (exogenous androgens suppress LH) 1
• GnRH agonists/antagonists, glucocorticoids, or medications causing hyperprolactinemia 1

Pituitary/hypothalamic pathology to exclude:

• Pituitary adenomas (prolactinomas or non-secreting macroadenomas) 1
• Traumatic brain injury, pituitary surgery, or cranial radiation 1
• Infiltrative diseases (sarcoidosis, hemochromatosis, histiocytosis) 1

Systemic conditions that suppress the HPG axis:

• Type 2 diabetes, metabolic syndrome, obesity 1
• Chronic systemic diseases, HIV, chronic organ failure 1
• Critical illness or acute stress 1

Treatment Strategy Based on Etiology

If Reversible Cause Identified (Functional Hypogonadism)

Address underlying conditions first - functional hypogonadism from obesity, diabetes, or medications should be managed by treating the primary condition rather than immediately starting testosterone 1. Discontinue offending medications if possible, optimize metabolic health, and reassess testosterone levels after 3-6 months.

If Irreversible Pathologic Hypogonadism Confirmed

For patients NOT desiring fertility:

Testosterone replacement therapy is appropriate once contraindications are excluded 2:

• Confirm diagnosis with two separate morning total testosterone measurements below 300 ng/dL before initiating treatment 3
• Pre-treatment assessment must include: PSA and digital rectal exam in men >40 years, baseline hemoglobin/hematocrit, cardiovascular risk factor assessment, and sleep apnea screening 1, 3
• Starting dose: Testosterone gel 1.62% at 40.5 mg daily (2 pump actuations) applied to shoulders and upper arms, or injectable testosterone ester as first-line 2, 4
• Titration: Check pre-dose morning testosterone at 14 and 28 days, adjusting dose to achieve mid-to-upper normal range (350-750 ng/dL) 2

For patients desiring fertility:

Gonadotropin therapy is required - testosterone replacement will suppress spermatogenesis and worsen fertility 3, 5. Treatment consists of:

• hCG (human chorionic gonadotropin) combined with FSH preparations (recombinant FSH, highly purified urinary FSH, or human menopausal gonadotropins) 5
• Expected duration: 12-24 months of combination therapy promotes testicular growth in nearly all patients, spermatogenesis in approximately 80%, and pregnancy rates around 50% 5
• Baseline fertility assessment: Measure FSH, perform testicular exam for size/consistency, and consider semen analysis before starting therapy 1
• Better outcomes occur in: post-pubertal onset hypogonadism, larger baseline testicular volume, no history of cryptorchidism, and higher baseline inhibin B levels 5

Critical Monitoring During Treatment

First follow-up at 1-2 months, then every 3-6 months for the first year, then yearly 3:

• Assess symptomatic response (energy, libido, erectile function, mood) 1, 3
• Monitor hematocrit - if >54%, reduce dose or temporarily discontinue due to polycythemia risk 1, 3
• Check PSA levels and perform digital rectal exam 1, 3
• Evaluate for sleep apnea symptoms and fluid retention 3, 2

Key Contraindications and Precautions

Absolute contraindications to testosterone therapy:

• Known or suspected prostate cancer 2
• Breast cancer in men 2
• Pregnancy in female partners (testosterone causes fetal harm) 2

Relative contraindications requiring caution:

• Baseline hematocrit >50% (investigate etiology before starting) 1, 3
• Severe congestive heart failure or renal insufficiency (fluid retention risk) 3, 2
• Untreated severe sleep apnea 3

Common pitfall to avoid: Never initiate testosterone therapy based on symptoms alone without laboratory confirmation of hypogonadism with two separate morning measurements 3. Your suppressed LH mandates ruling out pituitary pathology before any hormonal intervention.