Association between chronic idiopathic urticaria and hypertension A population-based retrospective cohort study

Background Chronic idiopathic urticaria (CIU) is defined as urticaria that is not caused by external triggers. The pathogenesis of CIU remains unknown. A previous study investigated whether hypertension is associated with extended duration of CIU. Objective To investigate the possible association between CIU and hypertension. Methods We performed a population-based retrospective cohort study of 2,460 patients with CIU and 9,840 age-, sex-, and index year-matched comparison patients, using the National Health Insurance of Taiwan database. The median follow-up periods were 7.13 years for the CIU cohort and 7.20 years for the non-CIU cohort. The distributions by sex and age were similar for both cohorts. Results The CIU cohort had a 1.37-fold (95% CI, 1.22-1.53) greater risk of developing subsequent hypertension than the non-CIU cohort after adjusting for sex, age, comorbidities, and nonsedating antihistamine use. Conclusion This nationwide retrospective cohort study found that CIU is associated with a higher future risk of hypertension after adjusting for sex, age, comorbidities, and nonsedating antihistamine use. The detailed pathophysiologic mechanisms require further clarification in prospective studies.