Correlation Between the NGF Levels and Questionnaire Forms in Patients Receiving Antimuscarinic Treatment and Those Receiving Onabotulinum Toxin-a Injection

OBJECTIVE:To compare nerve growth factor (NGF) levels in patients who received antimuscarinic, versus onabotulinum toxin-A (onaBoNT-A) injection, as well as to investigate whether there is a correlation between NGF levels, and 8-item overactive bladder questionnaire(OAB-V8), urogenital distress inventory (UDI)-6, and incontinence impact questionnaire (IIQ)-7 forms.MATERIAL AND METHODS:Fourty adult patients with OAB were enrolled in this prospective study. An antimuscarinic was prescribed to 20 naive patients, and onaBoNT-A injection was administered to 20 patients, who were refractory to antimuscarinics. Urine samples were obtained before, and after 3rd and 6th months of treatment, and NGF levels were measured. Symptom scores of OAB-V8, UDI-6,and IIQ-7 were recorded.RESULTS:There was no significant difference between groups in terms of the initial OAB-V8, IIQ-7, and UDI-6 scores, whereas NGF values showed no significant difference over time in onaBoNT-A group (p=0.069, p=0.069). NGF levels were significantly lower in 3rd and 6th months, in patients receiving antimuscarinic (p=0.003, p=0.007); a strong correlation was found in 3rd month between the NGF levels, OAB-V8 scores (r=0.704, p=0.001), and IIQ-7 scores (r=0.676, p=0.001), and a moderate correlation between NGF levels, and UDI-6 scores (r=0.583, p=0.007). In the 6th months, a very strong correlation was found between NGF levels, and OAB-V8 scores (r=0.811, p=0.004), and a strong correlation was found between NGF levels, and IIQ-7 scores (r=0.671, p=0.001). In onaBoNT-A group, there was no significant correlation between NGF levels, and other variables.CONCLUSION:NGF level might be a good marker to evaluate effectiveness of treatment in patients receiving antimuscarinics, owing to correlation of urinary NGF levels with symptom scores. Lack of correlation in patients receiving onaBoNT-A injection could be a result of differences in the mechanism of action.