Study design, materials and methods
A cross-sectional questionnaire survey assessing the role of pre-stage diabetes on OAB was conducted. We collected data on participants aged 40-69 years who participated in a multiphasic health screening, from April 2015 to March 2016, with written informed consent. All participants underwent a detailed health evaluation, including age, body mass index (BMI), blood pressure, a blood laboratory study, and current medical therapies including medication for diabetes, hypertension, and dyslipidemia. A blood laboratory study evaluated FPG level, HbA1c, Triglyceride, and HDL cholesterol. All participants were asked to answer a standardized self-reported questionnaire for OAB screening (SQOAB, Screening Questionnaire for Overactive Bladder). One of the screening questions we used is “It is difficult to hold on when I have the sudden compelling desire to urinate” with a choice of the following two responses: yes or no. Participants who answered ‘yes’ were identified they had OAB. Baseline characteristics of the study population were calculated both overall and according to categories of with or without OAB. Subjects were stratified into three 10-years age groups (40-49, 50-59, and 60-69 years). Univariate analyses were initially performed to assess the relationships between OAB and the characteristics or associated health factors including FPG and HbA1c. Variables were added simultaneously to multivariable regression models. We report the OR and 95% confidence interval (95%CI) for the multivariable logistic regression, with a p-value of <0.05 regarded as statistically significant.
A total of 6,133 individuals aged 40-69 years were participated in in a multiphasic health screening. Of all participants, we excluded 353 participants with prior diagnosis of diabetes and 9 participants without complete response for the questionnaire, leaving a sample of 5,771 participants (2,298 males and 3,473 females) for analysis. Median age was 65 years. Overall, 189 men (8.2%) and 409 women (11.8%) reported urgency. Multivariate regression showed that even modestly raised FPG (110-125 mg/dL) and HbA1c (5.5-5.9%) levels were independent associated with OAB in women (OR 1.46 (1.04-1.83, 95%CI) compared with FPG <100 mg/dL, and OR 1.31 (1.04-1.65, 95%CI) compared with HbA1c of <5.5%, respectively) (Figure). No statistical difference was found between FPG/HbA1c levels and OAB in men.
Figure.Multivariate analyses of the risk factors for overactive bladder in women.
Interpretation of results
To our knowledge, this is the first study in a population-based sample of men and women to assess the potential role of pre-diabetes in the development of OAB.
In the present study, multivariate analysis showed a statistically significant association between OAB and FPG/HbA1c levels in women, but not in men. These results indicate that bladder storage function may be affected even in pre-diabetes in women.