426 Prevalence of Gastroparesis in Achalasia: A U.S. Population-Based Study

Abstract

INTRODUCTION: Patients with achalasia often present with symptoms including bloating, early satiety and abdominal discomfort suggesting there might be an underlying concomitant gastric motility dysfunction. Moreover, treatments such as botulinum toxin injection are efficacious in both achalasia and gastroparesis. There are a lack of studies in the literature examining the association between achalasia and gastroparesis. We hypothesized that patients with achalasia would have a higher prevalence of gastric motility dysfunction, contributing, in part to the upper GI symptoms. The aim of this study was to compare the prevalence of gastroparesis in achalasia to the general population using a large population based commercial database. METHODS: The database used was Explorys Inc. (Cleveland, OH, USA) which contains electronic health records from 26 major integrated US healthcare systems. We identified patients with achalasia who were diagnosed with gastroparesis in the last 5 years based on Systemized Nomenclature of Medicine – Clinical Terms and compared it to patients with gastroparesis in the general population without achalasia. RESULTS: Of the 36,825,640 active patients within the last 5 years in the database, we identified 19,630 (0.05%) patients who had a diagnosis of achalasia and 104,140 (0.28%) patients with gastroparesis out of which only 600 (0.57%) were related to diabetes mellitus. A total of 990 cases of gastroparesis were observed in patients with achalasia, and 103,150 cases of gastroparesis in patients without achalasia. The overall Relative Risk (RR) of developing gastroparesis in patients with achalasia was 17.96 (95% CI 16.90 to 19.10; P < 0.0001) compared to general population without achalasia. Patients aged 18-64 (RR 20.50, 95% CI 18.94 to 22.39, P < 0.0001) and those aged ≥ 65 (RR 10.24, 95% CI 9.38 to 11.19, P < 0.0001) both had an increased risk of developing gastroparesis. Gender-based and race-based relative risk are shown in Table 1. CONCLUSION: Gastroparesis has a higher prevalence among people with achalasia compared to general population, with a relative risk of nearly 18. This increase in risk is seen across all age-groups. The findings of this analysis prove that there might be an underlying pathophysiological relationship between the esophageal and gastric motility disorders.