Ultrasound measurement of bladder wall thickness is associated with the overactive bladder syndrome

To assess the relationship between mean bladder wall thickness and components of the overactive bladder (OAB syndrome).

Women attending urogynaecology clinic was categorized into overactive bladder syndrome, stress urinary incontinence (SUI), and mixed urinary continence (MUI) according to International Continence Society (ICS) definitions based on symptom history. Women completed a bladder diary, visual analog score (VAS) for urgency, and the mean bladder wall thickness (BWT) was determined. Comparison was made between the mean BWT and symptom history, daytime frequency, nocturia, VAS scores.

Three hundred seventy-nine women were recruited to the study with a mean age of 56 years (range: 24-92 years). The mean bladder wall thickness did not show any age-related difference. Of these women 138/379 (36%) reported overactive bladder symptoms (mean BWT = 5.6 mm) 75/379 (20%) gave a history of stress urinary incontinence (mean BWT = 4.7 mm), and 166/379 (44%) had mixed urinary incontinence (mean BWT = 5.4). Women with nocturia >1 had mean BWT 5.6 mm, with nocturia <1 a mean BWT 4.9 mm. Women with daytime frequency >7 had mean BWT 5.7 mm and those <7 had mean BWT 5.1 (P < 0.001). Women with a mean BWT of ≤5 mm had a mean VAS score lower than women with a BWT >5 mm (P < 0.001).

Mean BWT is associated with a symptom history of OAB and MUI, higher daytime and nightime frequency, and higher VAS scores.