FEMALE UROLOGY

Nutrient composition of the diet and the development of overactive bladder: a longitudinal study in women
Dallosso HM, McGrother CW, Matthews RJ, Donaldson MM; Leicestershire MRC Incontinence Study Group
Department of Health Sciences, University of Leicester, Leicester, United Kingdom
Neurourol Urodyn. 2004; 23: 204-10

• Aims: Evidence for an association between diet and the symptom syndrome overactive bladder (OAB) would be valuable in understanding its aetiology. The present study investigates prospectively the association between the nutrient composition of the diet and the onset of OAB.
• Methods: A random sample of community dwelling women aged 40 years or over was studied. Baseline data on urinary symptoms and diet were collected from 6,371 women using a postal questionnaire and food frequency questionnaire. Follow-up data on urinary symptoms were collected from 5,816 of the women in a postal survey 1 year later. Logistic regression was used to investigate the association of diet (daily intakes of energy, macro and micronutrients) with 1 year incidence of OAB.
• Results: There was evidence that three nutrients may be associated with OAB onset. Higher intakes of vitamin D (P = 0.008), protein (P = 0.03), and potassium (P = 0.05) were significantly associated with decreased risks of onset. Although overall the associations with vitamin B6 and niacin were not significant (P = 0.08 and P = 0.13), there was some evidence of a decreased risk of onset with higher intakes.
• Conclusions: The results from this prospective study suggest possible aetiological associations between certain nutrients and OAB onset. The findings need confirmation and possible mechanisms to explain these associations need further investigation.
  
  
• Editorial Comment
  This is a very interesting paper, which expands on the earlier work of these authors regarding dietary associations with overactive bladder (OAB). Their past work noted that lower intakes of either vegetables, chicken or breads were independently associated with increased risks of OAB. In this publication, the authors investigated the association between the onset of symptoms of the OAB and routine dietary composition of a specific population with specific regard to both vitamins and macronutrients. The population examined was analyzed using a validated food frequency questionnaire for population in the United Kingdom. Demographic similarity was pursued by relying on census data (those patients who were from South Asian origin were excluded). The data was accumulated through a food frequency postal questionnaire (FFQ) that had been validated for use in a population of the United Kingdom. Statistical analysis was completed to examine the nutrient intakes of patients who had the onset of new OAB cases after 1 year and compare it to those who did not have the symptom complex both at the baseline and follow-up questionnaire. Each nutrient was analyzed with adjustments made for energy intake, age and the presence of stress urinary incontinence. The authors found that there was a definite possible ideological association between the onset of overactive bladder and nutrient composition of the diet. Specifically, they found that higher intakes of potassium, protein, and vitamin E were significantly associated with a decreased risk of onset of OAB. In addition, vitamin B6, niacin and retinol intake had an association that was approaching but not quite establishing statistical significance.
  With the aging population and the increased incidence of overactive bladder, research such as this is extremely valuable for its potentially cost effective prophylaxis against the onset of this malady. The value of vitamin D and its association with exposure to light gives a measure of scientific support to the common feeling that fresh air and sunlight does have the potential to be restorative to good health. Though the questionnaire was validated to a certain population it would be of genuine interest to have similar questionnaire addressed to other populations which show a strong degree of genetic similarity whether it be in Europe, Asia or Africa. With patients continually pressing physicians for a holistic pathway to retain good health and stave off the common maladies associated with aging, this paper makes for valuable reading to give advice on same.

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