Is my newly diagnosed hypogonadism a recent development or a long-standing condition?

Understanding Your Sudden Onset of Hypogonadism

Your hypogonadism is most likely functional/secondary hypogonadism related to your diabetes and hypothyroidism, rather than a long-standing condition, given your recent symptom onset despite previously normal sexual function. 1

Why This Represents Recent-Onset Functional Hypogonadism

Your clinical presentation strongly suggests functional secondary hypogonadism rather than a chronic condition you've had for years:

• Your previous normal sexual function (good erections, high libido, normal semen volume) indicates your hypothalamic-pituitary-gonadal axis was functioning properly until recently 1
• Functional hypogonadism is diagnosed when low testosterone occurs in symptomatic men primarily as a consequence of comorbidities (like diabetes and hypothyroidism), without organic alterations in the HPG axis 1
• Type 2 diabetes and metabolic conditions are specifically listed as systemic diseases that impact the hypothalamus/pituitary, causing secondary hypogonadism 1

Understanding Your Laboratory Values

Your testosterone level of 40 nmol/L (approximately 1,154 ng/dL) is actually normal to high, not low:

• The diagnostic threshold for hypogonadism is typically <10.5 nmol/L (~300 ng/dL) 2
• Your total testosterone of 40 nmol/L falls well within the normal range 1

However, your SHBG of 90 nmol/L is significantly elevated, which is the critical finding:

• High SHBG binds testosterone, reducing the amount of free (bioavailable) testosterone despite normal total testosterone 1, 2
• Hypothyroidism is a known cause of increased SHBG levels 1
• In men with elevated SHBG, free or bioavailable testosterone levels should be measured to determine true androgen status 1

What Likely Happened 6 Months Ago

Your hypothyroidism control may have changed, leading to:

• Increased SHBG production 1
• Reduced free testosterone despite normal total testosterone 1
• Resultant hypogonadal symptoms (ED, low libido) 1

Alternatively, worsening diabetes control or metabolic changes could have triggered functional hypogonadism through central suppression of the HPG axis 1

Essential Next Steps for Diagnosis

You need the following measurements to clarify your diagnosis:

1. Free testosterone by equilibrium dialysis (the gold standard method) 2
2. LH and FSH levels to distinguish primary from secondary hypogonadism 1, 2
3. Thyroid function tests (TSH, free T4) to assess current hypothyroidism control 1
4. HbA1c to evaluate diabetes control 1
5. Morning testosterone measurement (8-10 AM) repeated on a second occasion to confirm low levels if free testosterone is low 2

Expected Findings and Their Implications

If you have functional secondary hypogonadism (most likely):

• Free testosterone will be low despite normal total testosterone 1, 2
• LH and FSH will be low or inappropriately normal (not elevated) 2, 3
• This indicates your pituitary is not responding appropriately to low testosterone 1, 2

This diagnosis matters because:

• Secondary hypogonadism is potentially reversible by optimizing your diabetes and hypothyroidism control 1, 2
• You can potentially achieve both normal testosterone levels AND maintain fertility with appropriate treatment 2
• Treatment options differ significantly from primary hypogonadism 2, 4

Treatment Approach Based on Your Situation

First-line management should focus on optimizing your underlying conditions:

• Improve hypothyroidism control to normalize SHBG levels 1
• Optimize diabetes management through weight loss, diet, and medication adjustment 1
• Weight loss through low-calorie diets and physical activity can reverse obesity-associated secondary hypogonadism 2

If symptoms persist despite optimized comorbidity management:

• If fertility is not a concern: Testosterone replacement therapy is appropriate 1, 2
• If fertility is desired: Gonadotropin therapy (hCG with FSH) is recommended, as testosterone therapy suppresses spermatogenesis 2, 4, 5

Critical Pitfalls to Avoid

Do not start testosterone therapy without:

• Measuring free testosterone and confirming true hypogonadism 1, 2
• Checking LH/FSH to determine the type of hypogonadism 2, 3
• Considering whether you want to preserve fertility, as testosterone therapy will suppress it 2, 5

Do not assume this is permanent:

• Functional hypogonadism related to comorbidities should be treated by addressing the underlying conditions first 1
• Reversal of hypogonadism can occur in up to 10% of patients with appropriate management 4