Frailty and urinary symptoms share pathophysiological mechanisms involved in disease progression in people with multiple sclerosis

Background: Urinary symptoms represent a significant source of distress and disability in multiple sclerosis (MS), but the factors influencing their occurrence and exacerbation remain unclear. Frailty has been proposed as a measure of clinical complexity in MS and has been associated with its main phenotypic manifestations. The present study investigated the relationship between frailty and the presence and burden of urinary symptoms in MS. Materials and methods: The present study considered 149 outpatients. The presence of urinary symptoms was systematically explored. Frailty was assessed using a 40-item Frailty Index (FI). Participants with urinary symptoms underwent a urinary evaluation, including the 8-item overactive bladder questionnaire, the Urinary Incontinence Quality of Life Scale, Uroflowmetry, and Ultrasound for Postvoid Residual. Results: The mean disease duration was 13.7 years (SD 10.5), the median EDSS score was 1.5 (IQR = 0-3). Frailty was significantly associated with the presence and burden of urinary symptoms. Additionally, there was a positive correlation between the frailty index and chronological age, EDSS, disease duration, OAB, and I-QOL (all p < 0.05). In people with urinary symptoms, two multivariable logistic regression models showed that only the frailty index score was significantly associated with the Incontinence Quality of Life Scale total score and the 8-item overactive bladder questionnaire. No correlations were found between uroflowmetry data, postvoid residual, and frailty. Conclusion: Frailty is associated with the presence and burden of disability due to urinary symptoms. Frailty possibly affects the pathophysiological mechanisms of MS involved in the development and worsening of urinary symptoms.