The Association between Obesity and Gastroesophageal Reflex (GERD) in Iranian Adults

Obesity is among the factors that are linked with gastroesophageal reflux disease (GERD). However, findings of previous studies on the relationship between obesity and GERD were conflicting. We aimed to assess the relationship between obesity and GERD in a large group of Iranian adults.
This cross-sectional study was performed on 4457 adults. Anthropometric measures were obtained by the use a validated self-reported questionnaire. Subjects were classified into three categories based on their body mass index (BMI): normal weight, overweight and obese. Also they were classified into three categories based on their waist circumference: normal, abdominally overweight and abdominally obese. The prevalence of gastrointestinal reflux disease was assessed according to Rome III criteria. Additional information about other variables was obtained using a self-administered questionnaire.
Findings: The prevalence of GERD among study population was 23.9%. In crude model, the obese individuals had a 58% greater chance for GERD [odds ratio (OR) = 1.58, 95% confidence interval (CI): 1.25-1.98), compared to those with normal weight. However, after adjustment for dietary habits and waist circumference, this association disappeared (OR = 1.06, 95%CI: 0.75-1.48). After adjustment for confounders, those with abdominal obesity had a 43% greater odd for GERD (OR = 1.43, 95%CI: 1.13-1.85). However further adjustment for weight interaction lead to a non-significance association (OR = 1.26, 95%CI: 0.96-1.65). Stratified analysis by gender revealed no significant association between obesity and GERG in men. But obese women had 43% increased odds of GERD and abdominally obese women had 51% higher odds of GERD; although adjustment for the mutual effects of waist circumference and weight disappeared these relations. There was no significant association between general or abdominal obesity and frequency or severity of GERD, after adjustment for all potential confounders.
General obesity was significantly associated with increased risk of GERD; however, this association disappeared after controlling for dietary habits and waist circumference. Abdominally obese individuals had higher odds of GERD, compared to those with normal waist circumference.