Relationships between stress urinary incontinence and trunk muscle mass or spinal alignment in older women

OBJECTIVES: Relationships between stress urinary incontinence (SUI) and physical function and spinal alignment have not been fully elucidated; therefore, we examined these relationships in older women. METHODS: The participants of this cross‐sectional study comprised 21 women with SUI (SUI group) and 41 continent women (continent group) aged >65 years who participated in a community‐based health‐check survey from 2018 to 2019. We examined age, body mass index, number of deliveries, age at first childbirth, and medical histories as participants' characteristics. SUI was evaluated using the International Consultation on Incontinence Questionnaire‐Short Form (ICIQ‐SF). We also assessed spinal alignment and physical activity, grip strength, trunk and lower limb muscle mass, gait speed, and one‐leg standing time as measures of participants' physical function. RESULTS: Body mass index was significantly higher in the SUI group compared with continents (P = 0.04), and trunk muscle mass in the SUI group was significantly lower (P < 0.01). Additionally, the thoracic kyphosis angle in the SUI group was significantly larger (P = 0.02). In the logistic regression analysis, trunk muscle mass (odds ratio = 0.546, P = 0.03) and increased thoracic kyphosis angle (odds ratio = 1.066, P = 0.045) were independent factors affecting SUI. Furthermore, there was a negative weak correlation between total ICIQ‐SF score and trunk muscle mass (r = −0.36, P < 0.01), and a positive weak correlation between total ICIQ‐SF score and thoracic kyphosis angle (r = 0.27, P < 0.05). CONCLUSION: Trunk muscle mass and thoracic kyphosis angle relate to SUI status and severity among Japanese community‐dwelling older women.