Association Between Metabolic Syndrome and Risk of Esophageal Cancer: a Nationwide Population-Based Study

Background: Metabolic syndrome (MetS) is believed to increase the risk of esophageal cancer. However, most studies have been conducted in Western countries, focusing on esophageal adeno-carcinoma (EAC). We aimed to investigate the association between MetS and risk of esophageal cancer in nationally representative large dataset in Korea, where esophageal squamous cell carcinoma (ESCC) is predominant.Methods: We analyzed the health examinations and claims data from the Korean National Health Insurance Service (NHIS). A total of 6,795,738 subjects who received an NHIS provided health examination in 2009 (index year) were included. Cox proportional hazards models were used to estimate multi -variable adjusted HRs (aHR) and 95% confidence intervals (CI) for the association of MetS and its components (elevated waist circumference, blood pressure, triglycerides, fasting blood glucose, reduced high-density lipoprotein cholesterol) with the risk of esophageal cancer.Results: During a mean (+/- SD) follow-up of 8.2 (+/- 1.1) years, 6,414 cases of esophageal cancer occurred. MetS was associated with an increased risk of esophageal cancer (aHR, 1.11; 95% CI, 1.05- 1.18). Among the components of MetS, elevated waist circumfer-ence (aHR, 1.24; 95% CI, 1.16-1.33), high blood pressure (aHR, 1.29; 95% CI, 1.22-1.37), and fasting blood glucose (aHR, 1.16; 95% CI, 1.11-1.22) were associated with increased risk of esophageal cancer.Conclusions: MetS was associated with an increased risk of esophageal cancer.Impact: Our findings suggest that individuals with MetS may be at increased risk for esophageal cancer, specifically ESCC. Further studies are needed to establish the relationship between MetS and esophageal cancer.