Urinary nerve growth factor in women with overactive bladder syndrome

• To measure urinary nerve growth factor (NGF) in women with overactive bladder (OAB)-dry and OAB-wet and investigate the association of urinary NGF expression with these factors.

• Differentiation between OAB-wet and OAB-dry was based on symptoms and a 3-day voiding diary. • Urinary NGF levels were measured by enzyme-linked immunosorbent assay (ELISA). • The urinary NGF levels were compared among controls, OAB-dry and OAB-wet subgroups, and also between OAB patients ≥ 55 years and < 55 years, as well as between patients with a body mass index (BMI, kg/m²) < 20, 20-30 and > 30.

• A total of 113 women with OAB-dry, 106 with OAB-wet and 84 controls were enrolled. The urinary NGF/creatinine (Cr) levels were significantly highest in OAB-wet (2.13 ± 3.87) and second highest in OAB-dry (0.265 ± 0.59) compared to controls (0.07 ± 0.21). • Analysis of urinary NGF or NGF/Cr levels among controls, OAB-dry and OAB-wet groups by age and BMI showed no significant differences, except for the OAB-dry group. • Urinary NGF/Cr was not significantly correlated with age (P = 0.088) or BMI (P = 0.886) in women with OAB-dry and OAB-wet.

• Urinary NGF levels were significantly higher in women with OAB-dry and even higher in women with OAB-wet. • The urinary NGF level was not associated with ageing, menopause or higher BMI either in controls or OAB patients.