Association between Statin Treatment and the Incidence of Achalasia: A Nationwide, Population-Based Cohort Study in South Korea.

Background/Aims Achalasia is a rare esophageal motility disorder characterized by aberrant peristalsis and insufficient relaxation of the lower esophageal sphincter, mainly causing dysphagia. Risk factors for achalasia remain poorly understood. Considering studies reporting the relevance of statins to muscle toxicity, this study aimed to explore the association between statin use and the development of achalasia. Methods Using data from the Korean National Health Insurance Service, individuals ≥ 20 years of age who underwent the National Health Screening Program in 2009 were identified and followed-up until December 2018. Statin users were defined as patients who underwent statin therapy for >3 months within 1 year of the screening date. The risk for achalasia development according to statin use was compared using a Cox proportional hazards model adjusted for age, sex, income, smoking, alcohol, exercise, body mass index (BMI), low-density lipoprotein (LDL) level, and history of autoimmune disease. Results Of the 8,988,875 individuals in the study population, 698,560 (7.77%) were statin users and 8,290,315 (92.23%) were non-users; of these, 2610 (0.03%) developed achalasia (3.16 per 100,000 person-years). Statin treatment was associated with a significantly higher risk for developing achalasia compared with non-use (adjusted hazard ratio [aHR] 1.43 [95% confidence interval (CI) 1.27–1.60]). This association remained consistent in subgroup analyses according to age, sex, comorbidities, BMI, LDL, smoking, alcohol, and exercise (all p-values for interaction >0.05), as well as in sensitivity analysis (aHR 1.50 [95% CI 1.33–1.70]). Conclusion Statin use was associated with an increased risk for the development of achalasia. [ABSTRACT FROM AUTHOR]