Objective: To investigate whether the urinary nerve growth factor (NGF) levels in overactive bladder (OAB) patients is related to the improvement of overactive bladder symptom scores (OABSS) and quality of life index, following treatment of anti-muscarinic agent.
Methods: Forty-seven patients suffered from OAB and twenty normal controls were included in this study. An anti-muscarinic agent (solifenacin succinate 5 mg once a day) was administered for the OAB patients. At enrolment and after 12 weeks of treatment, the OABSS and the quality of life (QOL) score were determined. The urinary NGF/Cr level was also examined.
Results: The urinary NGF/Cr level was higher in the OAB patients than in the controls in baseline (P<0.05). After 12 weeks treatment with anti-muscarinic agent, the OABSS-total and QOL scores were all significantly decreased (P<0.001 each) in the OAB-dry and OAB-wet patients. And the urinary NGF/Cr levels decreased in OAB-wet patients, but not in OAB-dry patients. Furthermore, treatment-related changes of urinary NGF/Cr levels were correlated well with changes in four OABSS subscales (which include daytime voiding, nighttime voiding, urgency, and urge incontinence) (P<0.001) and QOL score (P<0.001) in only OAB-wet patients, but not in OAB-dry patients.
Conclusions: Improvement of OAB symptoms and QOL by treatment with the anti-muscarinic agent was related to the decrease of urinary NGF/Cr level in the OAB-wet patients, but not in OAB-dry patients. Therefore, NGF/Cr level as biomarkers for assessing therapeutic outcome of OAB should be interpreted with caution.
