Muthita Hirunsai. Effect of caffeine on bladder function in Thai overactive bladder. Master's Degree(Physiology). Mahidol University. : Mahidol University, 2005.
Effect of caffeine on bladder function in Thai overactive bladder
Abstract:
A study was performed to evaluate the effect of caffeine at the dose of 4.5 mg/kg on bladder function in overactive bladder Thai adults. The effect of caffeine on cardiovacular system was also recorded. The patients were nine women and three men aged 21 40 years. Each subject drank 8 ml /kg of water with or without caffeine at two separate sessions. The cystometry and uroflowmetry were performed 30 minutes after water or caffeine drink. The volume of filling and detrusor pressure at filling phase were continuously measured using cystometry technique. The flow time (Q100), time to maximal flow rate (TQmax), maximal flow rate (Qmax), average flow rate (QM90) and voided volume (Vcomp) of emptying phase were measured using uroflowmetry technique. The experiment demonstrated that after caffeine the mean volume at filling phase was significantly decreased at first desire to void (FD) and normal desire to void (ND) (p=0.031, p=0.05). The mean volume at strong desire to void (SD), urgency and maximum cystometric capacity were also tended to decrease though without statistical significance. No change in the detrusor pressure at filling phase compared to water (control) drink. At emptying phase the means Q100 and TQmax were also not changed. The means of Qmax, QM90 and Vcomp were increased (p=0.031, p=0.010, p=0.023). The consumption of caffeine also affected the cardiovascular system. The systolic blood pressure was increased at 10 and 20 minutes and the diastolic pressure was increased at 20 minutes (p=0.030). The heart rate was decreased at 10 and 20 minutes after caffeine ingestion (p=0.040, p=0.043). This study indicated that caffeine 4.5 mg/kg not only caused diuresis but also affected the lower urinary tract function resulting in a decrease threshold of sensation at filling phase especially at FD and ND, with an increase in flow rate and voided volume. So caffeine promotes the early urgency and frequency of urination. In addition, it produces an increase in blood pressure and changes in heart rate. Individuals with lower urinary tract symptom should avoid or be cautious in consuming caffeine containing foodstuffs."