Abdominal obesity and risk for esophageal cancer: A nationwide population-based cohort study of South Korea.

Abstract

446 Background: The relationship between overall obesity, as measured by body mass index (BMI), and risk of esophageal squamous cell carcinoma (ESCC) has been reported, and it has a negative correlation. However, the relationship with abdominal obesity, as measured by waist circumference, may be different. We investigated the association between abdominal obesity and ESCC. Methods: Retrospective cohort study with 22,809,722 individuals who had undergone regular health check-ups provided by the National Health Insurance Corporation between 2009 and 2012 (median follow-up period was 6.4 years) in South Korea. Abdominal obesity was defined as a waist circumference over 90 cm for men and 85 cm for women. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using Chi-squared test and Cox proportional hazard model adjusted for confounding factors. Primary outcome was newly developed esophageal cancer. Results: After adjusting for BMI, abdominal obesity increased the risk of ESCC (HR 1.29, 95% CI 1.23–1.36). Waist circumference is associated with increased risk of ESCC in a dose-dependent manner ( P for trend < 0.0001). We analyzed individuals divided into five categories of BMI. Among individuals with overweight (BMI 23–24.9 kg/m2) and obese I (BMI 25–29.9 kg/m2), abdominal obesity was a risk factor associated with developing ESCC (HR 1.22, 95% CI 1.11–1.34; HR 1.28, 95% CI 1.18–1.39, respectively). Conclusions: Abdominal obesity, not BMI itself, is associated with an increased risk for ESCC. Therefore, reducing abdominal obesity may affect decreasing the development of ESCC.