Bladder pain syndrome/interstitial cystitis is associated with hyperthyroidism.

Background: Although the etiology of bladder pain syndrome/interstitial cystitis (BPS/IC) is still unclear, a common theme with BPS/IC patients is comorbid disorders which are related to the autonomic nervous system that connects the nervous system to end-organs. Nevertheless, no study to date has reported the association between hyperthyroidism and BPS/IC. In this study, we examined the association of IC/BPS with having previously been diagnosed with hyperthyroidism in Taiwan.

Design: Data in this study were retrieved from the Longitudinal Health Insurance Database. Our study consisted of 736 female cases with BPS/IC and 2208 randomly selected female controls. We performed a conditional logistic regression to calculate the odds ratio (OR) for having previously been diagnosed with hyperthyroidism between cases and controls.

Results: Of the 2944 sampled subjects, there was a significant difference in the prevalence of prior hyperthyroidism between cases and controls (3.3% vs. 1.5%, p<0.001). The conditional logistic regression analysis revealed that compared to controls, the OR for prior hyperthyroidism among cases was 2.16 (95% confidence interval (CI): 1.27∼3.66). Furthermore, the OR for prior hyperthyroidism among cases was 2.01 (95% CI: 1.15∼3.53) compared to controls after adjusting for diabetes, coronary heart disease, obesity, hyperlipidemia, chronic pelvic pain, irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, depression, panic disorder, migraines, sicca syndrome, allergies, endometriosis, and asthma.

Conclusions: Our study results indicated an association between hyperthyroidism and BPS/IC. We suggest that clinicians treating female subjects with hyperthyroidism be alert to urinary complaints in this population.