Relationship between diaphragmatic muscle function and urinary incontinence in individuals with stroke: a prospective observational study

Background Weakness in respiratory muscles following a stroke may hinder the regulation of intra-abdominal pressure, potentially escalating the risk and severity of urinary incontinence (UI). A thorough understanding of how respiratory muscle strength and diaphragm function relate to UI in stroke patients is essential for comprehensive clinical assessment.Objectives This study aimed to explore the connection between maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), diaphragm function, and symptoms of urinary incontinence in stroke patients.Methods Fifty stroke patients (mean age 60.16 ± 9.56 years; 74% male) participated in the study. Respiratory muscle strength was assessed through standardized measurements of MIP and MEP. Endurance was evaluated with the Inspiratory Threshold Load (ITL) test. The effect of UI on quality of life was assessed using the Urogenital Distress Inventory (UDI-6) and the Incontinence Impact Questionnaire (IIQ-7). Diaphragm function was measured with specific tests based on the Dynamic Neuromuscular Stabilization (DNS) method. Differences between symptomatic and asymptomatic groups were analyzed using Pearson correlation, independent t-tests, Mann-Whitney U tests, and chi-square tests.Results Significant negative correlations were found between MIP and ITL scores and the severity of urinary incontinence (p < 0.001), while MEP exhibited weaker but still significant correlations (p < 0.05). Patients with urinary incontinence demonstrated significantly reduced diaphragm function compared to their asymptomatic counterparts (p < 0.01).Conclusions In individuals with stroke, diminished respiratory muscle strength, particularly diaphragm dysfunction, is linked to increased severity of UI. These findings highlight the necessity of evaluating respiratory muscle function in this population.Registration No NCT07048210