Background The bladder's regulatory function is influenced by central serotonergic modulation. T102C polymorphism of the serotonin 2A (5-HT2A) receptor gene is associated with urinary incontinence (UI) that has been reported by older community dwellers. We analyzed the association between 5-HT2A receptor gene polymorphism and urodynamic tests for UI in older women.
Methods A case-control study was performed with 68 older women submitted to urodynamic evaluation and 162 older women without urinary problems (self-reported), all community dwellers enrolled in the Gravataí-GENESIS Project, Brazil. Clinical interviews, complete urodynamic evaluation following the International Continence Society Report on Good Urodynamic Practice (case group), and molecular analyses were performed (case and control groups). Serotonin 2A receptor gene genotyping was carried out by polymerase chain reaction-restriction fragment length polymorphism using the restriction enzyme HpaII. We excluded patients with diabetes mellitus, neurologic damage, and diuretic intake.
Results The subjects' mean (SD) age was 68.1 (6.5) years (range, 60-92 years). We found an association between the TT genotype versus CC + CT genotypes and UI (P = 0.013; odds ratio, 2.69; 95% confidence interval, 1.37-5.29) and, in addition, an association with urgency UI, maximal cystometric capacity (TT, 349 mL; CC + CT, 429.5 mL [P = 0.047]), detrusor pressure at maximum cystometric capacity (TT, 11 cm H2O; CC + CT, 6.75 cm H2O [P = 0.032]), and detrusor compliance (TT, 34 mL/cm H2O; CC + CT, 61.25 mL/cm H2O [P = 0.006]).
Conclusions We confirmed our previous findings of a genetic influence of the TT genotype on UI involving the serotonergic pathway among older women. Further investigations including 5-HT2A expression in the bladder, pelvic floor, and striated sphincter muscle must be performed.