Hypersensitivity disorders worsen urinary symptoms associated with overactive bladder

Women with overactive bladder (OAB) affected by central sensitization have more severe urinary symptoms and a lower quality of life compared with other patients with OAB, according to a study presented at the 2025 Annual Meeting of the American Urological Association in Las Vegas, Nevada.

Central sensitization syndrome (CSS) is characterized by an amplified sensory input, which causes heightened sensitivity and pain. CSS encompasses a group of disorders that share this common mechanism, including fibromyalgia, chronic fatigue syndrome, and temporomandibular joint disorder. Central sensitization may overlap with urinary symptoms in some patients and has been proposed as a possible pathophysiological mechanism for idiopathic OAB.

A study conducted at the Vanderbilt University Medical Center in Nashville, Tennessee, was designed to observe and characterize the differences in urinary symptoms between women with and without CSS. Nearly 140 adult women with OAB who were enrolled in a clinical trial for patients with central sensitization were included in a secondary analysis that focused on OAB symptom severity and quality of life. Urinary symptoms were assessed via the LURN SI-29 questionnaire, with subscales for incontinence, pain, voiding dysfunction, urgency, and nocturia analyzed individually. OAB-specific questionnaires were used to assess symptom severity and quality of life. The researchers then compared the responses between women with and without central sensitization, which was diagnosed based on a CSS inventory.

Nearly 30% of women with OAB in the cohort were found to have central sensitization. Those with CSS features had more severe urinary symptoms compared with the rest of the OAB cohort. While no significant differences were documented in nocturia, urgency, or incontinence scores, women with OAB and central sensitization had more pain and voiding dysfunction than those without CSS. Not surprisingly, women with central sensitization who had more severe urinary symptoms also experienced greater impairment in quality of life.

“Interestingly, the urinary symptoms that seem to be driving this difference are pain and voiding dysfunction,” said lead author Amanda Sherman, MD, who presented the findings. “Better understanding the symptomatic differences between OAB patients with and without central sensitization will help us to target therapeutic efforts and develop a more nuanced understanding of this patient phenotype.”