Hypothyroidism and urinary incontinence: Prevalence and association in a Danish, female sample from the Lolland-Falster Health study

Introduction: We aimed to estimate the prevalence of urinary incontinence (UI) in women with hypothyroidism and subclinical hypothyroidism and to examine the association of hypothyroidism and UI. Methods: This cross-sectional study was based on the population-based Lolland-Falster Health Study (LOFUS), Denmark. Data comprising a questionnaire, physical examination, and blood samples were collected between 2016 and 2020. Multiple logistic regression was used to estimate odds ratios (OR) and control for possible confounders: age, body mass index, diabetes, smoking, and education. Results: Of 7,699 women included in the study, 7.9% had hypothyroidism, and 2.4% had subclinical hypothyroidism. The prevalence of any UI in women with hypothyroidism, subclinical hypothyroidism, and a control group (normal level of thyroid hormones) was 43.6%, 38.1%, and 39.3%, respectively. After controlling for confounders, no association between hypothyroidism and any UI (OR 1.01, 95% CI 0.85-1.20) or frequent UI (OR 1.05, 95% CI 0.84-1.32) were demonstrated. Additional, no association between subclinical hypothyroidism and any UI (OR 0.87, 95% CI 0.64-1.18) or frequent UI (OR 1.15, 95 CI 0.79-1.69) were demonstrated. Conclusions: In our female sample, the prevalence of UI was high regardless of the thyroid status. No association between hypothyroidism and any or frequent UI was demonstrated. The prevalence of hypothyroidism was 7.9%.