What is the largest reported decrease in Sex Hormone-Binding Globulin (SHBG) after varicocele correction?

Largest Reported Decrease in SHBG After Varicocele Correction

The largest reported decrease in Sex Hormone-Binding Globulin (SHBG) after varicocele correction was approximately 13% (from 32.9 ± 3.5 to 28.6 ± 3.4 nmol/L), as documented in a 2001 study examining hormonal changes following varicocelectomy. 1

Hormonal Changes After Varicocele Repair

• Varicocele affects approximately 15% of the general male population but is present in 35-40% of men presenting with infertility, indicating a significant association between varicocele and fertility issues 2

• The primary hormonal changes after varicocele repair include:

  • Significant decrease in SHBG levels (from 32.9 ± 3.5 to 28.6 ± 3.4 nmol/L) 1
  • Significant increase in testosterone levels, particularly in hypogonadal men (from 215.22 ± 83.31 ng/dL to 326.95 ± 35.125 ng/dL) 3
  • Significant increase in inhibin B levels (from 133.9 ± 13.4 to 167.8 ± 16.1 ng/L) 1
  • Significant decrease in LH levels after varicocelectomy 3

Factors Affecting Hormonal Response

• The magnitude of hormonal improvement appears to correlate with:
  • Pre-operative hormonal status (hypogonadal patients show more significant improvement) 3
  • Varicocele size (larger varicoceles tend to show greater improvement in parameters) 4
  • Severity of reflux (higher grades of spermatic vein reflux correlate with more significant hormonal abnormalities) 5

Clinical Implications

• Hormonal improvements typically parallel the timeline for semen parameter improvements, taking approximately 3-6 months (two spermatogenic cycles) to show enhancement 2, 6

• The decrease in SHBG after varicocelectomy is clinically significant because:

  • It contributes to an increase in the free androgen index (from 66 ± 5.9 to 85 ± 6.8) 1
  • More bioavailable testosterone may improve spermatogenesis and fertility outcomes 1

Treatment Considerations

• Varicocele treatment should be targeted to men with clinical varicoceles and abnormal semen parameters, as treatment of men with normal semen analysis or subclinical varicoceles is not recommended regardless of hormonal status 2, 6

• The European Association of Urology strongly recommends surgery for varicocele when associated with a persistent small testis (size difference >2 mL or 20%), confirmed on two subsequent visits 6 months apart 6

• Routine use of ultrasonography to identify non-palpable varicoceles is discouraged, as treatment of these subclinical varicoceles is not associated with improvement in either semen parameters or fertility rates 2, 6

Pitfalls and Caveats

• Hormonal changes after varicocelectomy are not universal - eugonadal patients may show minimal or no significant changes in testosterone levels (471.90 ± 145.71 ng/dL before surgery to 469.57 ± 145.61 ng/dL after surgery) 3

• The literature contains contradictory results about hormonal status in varicocele patients, with some studies showing decreased testosterone and increased FSH/LH, while others report different patterns 7

• The relationship between clinical varicocele and impaired hormonal production remains incompletely understood, requiring further multicentre, randomized controlled studies to better clarify the hormonal features of patients with varicocele 7