Urinary bladder wall thickness in type 2 diabetes mellitus patients

Diabetes mellitus is an increasing health challenge with accompanying urological complications. Over 50% of men and women with diabetes have bladder dysfunction. According to the current understanding of bladder dysfunction, it refers to a progressive condition encompassing a broad spectrum of lower urinary tract symptoms including urinary urgency, frequency, nocturia, and incontinence. Urinary bladder dysfunction has been classically described as diminished bladder sensation, poor contractility, and increased post-void residual urine, termed bladder cystopathy. Ultrasonography of the urinary bladder, which is a cheap, safe, radiation free, non-invasive and reliable imaging modality, may help to identify diabetes mellitus patients prone to develop urinary bladder dysfunction.

The study population comprised 80 diabetic subjects recruited from the diabetic outpatient clinic and another 80 age- and sex-matched asymptomatic control subjects. Ultrasound scan of their urinary bladder wall was performed using a curvilinear transducer to determine the thickness and other sonographic features.

Out of the 80 diabetic subjects, 30 (37.5%) were males, while 50 (62.5%) were females; of 80 non-diabetic control subjects, 40 (50%) were males and 40 (50%) were females. The mean age of the diabetic subjects was 59.5 ± 10.4 years with a range of 40-82 years, while that of the controls was 60.2 ± 7.4 years with a range of 40-85 years. There was no statistically significant difference (p = 0.637) between the mean age of the diabetic and control subjects. The mean urinary bladder wall thickness in the diabetics was greater than in the non-diabetics in the study subjects. There was a statistically significant difference between the urinary bladder thickness of diabetic subjects and the control group (p <0.001). The mean urinary bladder wall thickness of the male and female subjects included in this study was 2.84 ± 1.31 mm and 2.9 ± 1.37 mm, respectively, with no statistically significant difference between them (p = 0.159). It was statistically significant between diabetic men and women (p = 0.027). Using Spearman's rank correlation to test the relationship between the glycaemic haemoglobin level of diabetic subjects and urinary bladder wall thickness, it was revealed that there was no correlation between these variables (Spearman's rho = 0.119, p = 0.309). The relationship between the urinary bladder volume of diabetic subjects and their mean urinary bladder wall thickness showed no correlation either (Spearman's rho = -0.009, p = 0.937). Only gender was a statistically significant predictor of urinary bladder wall thickness among other variables.

Mean bladder wall thickness in patients with type 2 diabetes mellitus was greater than in the control subjects, and also greater in diabetic men compared to diabetic women, but the difference did not attain statistical significance. Urinary bladder wall thickness of the diabetics did not correlate with their glycaemic haemoglobin levels. Only gender was found to be a predictor of bladder wall thickness.