FEMALE UROLOGY

The effect of fluid intake on urinary symptoms in women
Swithinbank L, Hashim H, Abrams P
Bristol Urological Institute, Southmead Hospital, Westbury-on-Trym, Bristol, UK
J Urol. 2005; 174: 187-9

• Purpose: We determined the effect of caffeine restriction and fluid manipulation in the treatment of patients with urodynamic stress incontinence and detrusor overactivity.
• Materials and Methods: This was a 4-week randomized, prospective, observational crossover study in 110 women with urodynamic stress incontinence (USI) or idiopathic detrusor overactivity (IDO) to determine the effect of caffeine restriction, and of increasing and decreasing fluid intake on urinary symptoms. Data were recorded in a urinary diary for the entire study period on urgency episodes, frequency, pad weight increase, wetting episodes and quality of life.
• Results: A total of 69 women with a mean age of 54.8 years completed the study, including 39 with USI and 30 with IDO. In the IDO group decreasing fluid intake significantly decreased voiding frequency, urgency and wetting episodes with improved quality of life. In the USI group there was a significant decrease in wetting episodes when fluid intake was decreased. Changing from caffeine containing to decaffeinated drinks produced no improvement in symptoms.
• Conclusions: Conservative and life-style interventions are first line treatments in the management of incontinence and storage lower urinary tract symptoms. This study shows that a decrease in fluid intake improves some of these symptoms in patients with USI and IDO and, therefore, it should be considered when treating such patients.
  
  
• Editorial Comment
  The authors reviewed the effect of restricting caffeine and manipulating fluid intake in patients who had been diagnosed urodynamically with stress incontinence or detrusor overactivity. The study cohort was a 69 woman. The participants were analyzed after a 4-week randomized prospective observational crossover study where they underwent caffeine restriction and either increase or diminution of fluid intake. Data was recorded in the urinary diary. Findings included that changing from caffeine to non-caffeine drinks did not improve symptoms. They also found that in patients suffering from detrusor overactivity, decreased fluids significantly diminished the urgency and frequency syndrome and improved the quality of life, which was also mirrored in the stress urinary incontinent patients.
  An excellently written article that provides sound scientific analysis for the common advice given to patients for the conservative management of urinary incontinence. It is noteworthy that by not taking in caffeine there was no true improvement in the patients’ urinary symptoms while diminishing fluid intake did significantly help diminish incontinent episodes whether the patient had overactive bladder or stress urinary incontinence. This lack of effect by diminishing caffeine has been noted by other researchers (1). The authors make a very salient point that in by asking patients to stop caffeine a serendipitous secondary effect may be that overall fluid intake is diminished as well thus causing the perception that less caffeine improves overall bladder control. It would be of interest to find that if patients who suffered from urinary urgency and frequency with the diagnosis of interstitial cystitis would also not have an improvement in their voiding symptoms when stopping caffeine in view that caffeine may be a mild urothelial irritant as well as a mild diuretic. Nevertheless, the authors should be complimented on analyzing a very common first line treatment and illuminating the readership to the value of this counsel.

Reference
1. Bird ET, Parker BD, Kim HS, Coffield KS: Caffeine ingestion and lower urinary tract symptoms in healthy volunteers. Neurourol Urodyn. 2005; 24: 611-5.

Dr. Steven P. Petrou
Associate Professor of Urology
Mayo Clinic College of Medicine
Jacksonville, Florida, USA