Potential Biomarkers for Diagnosis of Overactive Bladder Patients: Urinary Nerve Growth Factor, Prostaglandin E2, and Adenosine Triphosphate

PURPOSE This study aimed to investigate potential biomarkers for the diagnosis of overactive bladder (OAB). METHODS A total of 219 subjects were enrolled and divided into 2 groups: OAB subjects (n=189) and controls without OAB symptoms (n=30). Three-day voiding diaries and questionnaires were collected, and urinary levels of nerve growth factor (NGF), prostaglandin E2, and adenosine triphosphate were measured and normalized to urine creatinine (Cr). Baseline characteristics and urinary levels of markers were analyzed. A receiver-operator characteristic (ROC) curve was used to analyze the diagnostic performance of urinary markers. Urinary levels of markers according to subgroup and pathogenesis of OAB were evaluated. Correlation analyses were used to analyze the relationship between urinary levels of markers and voiding diary parameters and questionnaires. RESULTS There was no difference between the 2 groups with regards to age, sex ratio, or urine Cr (P>0.05). The urinary levels of NGF/Cr were higher in OAB subjects than in controls (P<0.001). Urinary NGF/Cr was a sensitive biomarker for discriminating OAB patients (area under the curve=0.741; 95% confidence interval, 0.62-0.79; P=0.001) in the ROC curve. The urinary levels of NGF/Cr were significantly higher in OAB subjects than in controls regardless of subgroup or pathogenesis. Correlation analysis demonstrated urinary urgency was significantly related to urinary NGF/Cr level (correlation coefficient, 0.156). Limitations include a relatively wide variation of urinary markers. CONCLUSIONS Urinary NGF is a potential biomarker that could serve as a basis for adjunct diagnosis of OAB.