Diabetes is highly prevalent worldwide, with an estimated 382 million people carrying the diagnosis in 2013 and a projected increase to 592 million by 2035.1 Diabetic bladder dysfunction is thought to affect up to 80-93% of those with diabetes and typically encompasses a triad of decreased bladder sensation, impaired contractility, and urinary retention.2 We aimed to determine the specific urodynamic parameters affected by diabetes and describe the effect of varying hemoglobin A1c levels.

We reviewed an institutional review board approved database of all females undergoing urodynamic studies for various reasons from 2014-2020 at a single, tertiary care university hospital system. Females were considered diabetic if they met ADA criteria as determined by the primary care provider or at any point recorded a hemoglobin A1c (HbA1c) level measured at 6.5% or greater. All HbA1c data were extracted from electronic medical record systems as well as demographic data including body mass index (BMI), age, and the presence of insulin-dependence, peripheral neuropathy, and retinopathy. All urodynamic studies were performed using Laborie Delphis™ or Aquarius™ urodynamic equipment with gas-charged catheters to measure pressure. Independent variables included duration of diabetes, presence of insulin-dependence, HbA1c average, and HbA1c max.   Dependent variables included urodynamic parameters such as compliance, bladder voided efficiency, bladder contractility index (BCI), postvoid residual (PVR), maximum flow rate, capacity, voided volume, and detrusor overactivity (DO) which were collected by two reviewers. Statistical analyses were performed using logistic and linear regression, and Mann-Whitney U test on STATA 17.0.

A total of 666 females underwent urodynamic studies during this timeframe with a mean age of 62.1 years (Standard Deviation (SD)16.0). There were 152 (22.8%) females with diabetes, and they carried the diagnosis for an average of 82.3 months (SD44.9). The average HbA1c was 7.0 (SD1.4) and BMI 31.4 (SD8.0). Of the diabetic females, 18% had retinopathy, 55.3% had peripheral neuropathy, and 23.0% were insulin-dependent. . 

Patients with DM exhibited DO much more often than those without DM (OR 1.9, p<0.05).  Detrusor underactivity (DU) in females was highly influenced by increased AGE in regression analysis; bladder contractility index (BCI) 78.4±41.2(SD) for age >60, vs. 100.8±46.2, age <60, p<0.001.  Because of the strong confounding effect of age, women >60 years old were excluded from a sub-analysis to determine the effect of poorly controlled HgbA1c on contractility. BCI was 108.5±35.5 for HgbA1c<7.0 BMI>30 and age <60, suggesting increased contractility at low average A1c levels averaged over 6.3 years.  A striking decrease in contractility was noted at higher average A1c levels (HgbA1c>7.5), BCI 80.1±29.7, p<0.05.  

The presence of diabetes led to a statistically significant decrease in compliance (36.4 vs. 10.1, p=0.04). There was a loss of capacity with insulin-dependence (357mL vs. 282mL, p=0.02) and a decrease in voided volume (348mL vs. 186mL, p=0.005).

Diabetic bladder dysfunction is a dynamic condition that can incorporate both increased bladder contractility in well-controlled diabetics while demonstrating decreased capacity and voided volumes in the poorly controlled diabetic. Overall, diabetes is associated with decreased bladder compliance and an increase in detrusor overactivity.

We present a large single-institution study of urodynamic data in female diabetic and non-diabetic patients which demonstrates a progressive change in bladder urodynamic parameters with more poorly controlled diabetes.

Federation, I. D.: IDF Diabetes Atlas, 6th edn. Brussels, Belgium: International Diabetes Federation, 2013
Wittig, L., Carlson, K. V., Andrews, J. M. et al.: Diabetic Bladder Dysfunction:A Review. Urology, 123: 1, 2019