Overactive bladder changes with time: a 5-year longitudinal followup of changes in overactive bladder symptoms,...

We compared clinical symptoms, urodynamic diagnoses and urinary nerve growth factor levels at baseline and 5 years later in patients with overactive bladder.

Patients diagnosed with overactive bladder at a tertiary teaching hospital who underwent urinary nerve growth factor tests 5 years previously were identified by chart review. Patients were invited to return for symptom evaluation, urodynamic studies and a repeat urinary nerve growth factor test. Changes in overactive bladder subtype, urgency severity score and urodynamic diagnosis were classified as improved, stable or worse. Changes in urinary nerve growth factor/creatinine were compared between baseline and 5 years later according to changes in bladder conditions.

A total of 30 women and 45 men completed the study. Mean±SD age was 73.5±10.3 years. Urinary nerve growth factor/creatinine showed no significant difference among patients with improved, stable or worse bladder conditions based on overactive bladder or urgency severity score subtypes. However, urinary nerve growth factor/creatinine was significantly decreased in patients with an improved urodynamic diagnosis (mean 0.94±1.36 vs 0.17±0.19 pg/mg, p=0.02), significantly increased in patients with a worse urodynamic diagnosis (0.55±0.85 vs 2.08±2.81 pg/mg, p=0.04) and showed no change in those with a stable urodynamic diagnosis. Multiple linear regression analysis revealed that the change in urodynamic diagnosis was still predictive of the change in urinary nerve growth factor/creatinine after adjusting for age, gender, overactive bladder and urgency severity score subtypes (p=0.001).

Urinary nerve growth factor/creatinine did not reflect the changes in bladder conditions based on subjective symptoms. However, the levels reflected dynamic changes in bladder pathophysiology according to urodynamic findings.