Could urinary nerve growth factor be a biomarker for overactive bladder? A meta-analysis

Area of Science:

• Urology
• Biomarkers
• Neuropeptides

Background:

• The association between urinary nerve growth factor (NGF) and overactive bladder (OAB) has been debated.
• Previous studies yielded controversial results regarding NGF's role in OAB.

Purpose of the Study:

• To conduct a meta-analysis synthesizing current evidence on the association between urinary NGF and OAB.
• To evaluate the potential of urinary NGF/Cr as a diagnostic biomarker for OAB.

Main Methods:

• A systematic literature search was performed across PubMed, Embase, and Cochrane Library up to September 2016.
• Pooled standardized mean differences (SMD) with 95% confidence intervals (CIs) were calculated using a random-effects model for 17 included studies.

Main Results:

• Patients with OAB exhibited significantly higher baseline urinary NGF/Cr levels compared to controls (SMD = 0.74, P < 0.00001).
• Urinary NGF/Cr levels decreased significantly after treatment in the OAB group.
• No significant difference in urinary NGF/Cr was found between OAB and interstitial cystitis/painful bladder syndrome (IC/PBS) patients (SMD = 0.18, P = 0.14).
• Significant heterogeneity was observed among the studies (I² = 85%).

Conclusions:

• Urinary NGF/Cr shows potential as a future biomarker for OAB, evidenced by elevated levels in OAB patients and reduction post-treatment.
• Currently, NGF/Cr lacks the specificity for standalone OAB diagnosis.
• Combining NGF/Cr with other biomarkers may enhance diagnostic specificity.
• Further high-quality studies with strict control of confounding factors are recommended.