Effect of Varicocele Repair on Sex Hormone-Binding Globulin (SHBG) Levels
Varicocele repair does not consistently reduce SHBG levels by 10-25%, but it may decrease SHBG levels in some patients while improving overall hormonal balance.
Hormonal Changes After Varicocele Repair
- Varicocele repair has been shown to decrease serum SHBG levels from 32.9 ± 3.5 to 28.6 ± 3.4 nmol/L (approximately 13% reduction) in infertile men 1
- The reduction in SHBG levels corresponds with improvements in the free androgen index, which significantly increased from 66 ± 5.9 to 85 ± 6.8 after treatment 1
- Hormonal improvements typically take up to two spermatogenic cycles (approximately 3-6 months) to manifest following varicocele repair 2
Mechanism of SHBG Changes in Varicocele
- SHBG is produced in the liver, and its synthesis is stimulated by estrogens, which are often elevated in men with varicocele 3
- In chronic liver disease, SHBG levels may rise due to hormonal imbalances, although the exact mechanism in varicocele patients remains unclear 3
- Varicoceles can cause testicular dysfunction through multiple mechanisms including higher scrotal temperature, testicular hypoxia, and reflux of toxic metabolites, all of which may contribute to hormonal imbalances 2, 4
Predictors of Hormonal Response to Varicocele Repair
- Men with excessive preoperative gonadotropin responses to GnRH testing and abnormal free sex steroid levels are more likely to experience hormonal improvements after varicocele repair 5
- Older patient age has been identified as a predictor for having improved total testosterone levels after varicocele surgery 6
- Patients with higher-grade varicoceles show a positive correlation between LH peaks after GnRH testing and varicocele grade, suggesting more significant hormonal disturbances that may respond to treatment 7
Clinical Implications of Hormonal Changes After Varicocele Repair
- Varicocele repair significantly improves serum inhibin B levels (from 133.9 ± 13.4 to 167.8 ± 16.1 ng/L), indicating improvement in Sertoli cell function and spermatogenesis 1
- Total testosterone levels can increase significantly after varicocele repair in hypogonadal men (from 2.55 ± 0.66 ng/mL to 3.72 ± 1.34 ng/mL) 6
- These hormonal improvements correspond with significant improvements in sperm concentration (from 6.5 ± 1.9 to 19.3 ± 4.9 × 10^6/mL) and motility (from 17 ± 3% to 32 ± 4%) 1
Considerations for Patient Selection
- Varicocele treatment should be targeted to men with clinical (palpable) varicoceles and abnormal semen parameters 2, 4
- Treatment of subclinical (non-palpable) varicoceles is not effective at improving fertility outcomes, regardless of hormonal status 2, 8
- 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 4
Timing of Hormonal Changes
- Improvements in hormonal parameters typically take up to two spermatogenic cycles (approximately 3-6 months) after varicocele repair 2, 9
- Spontaneous pregnancy typically occurs between 6 and 12 months after varicocelectomy, corresponding with the timeframe for hormonal and semen parameter improvements 2