Gastroesophageal reflux in asymptomatic obese subjects: An esophageal impedance-pH study

AIM: To investigate the relationship between reflux and body mass index (BMI) in the asymptomatic obese population using the impedance-pH technique. METHODS: Gastroesophageal reflux is frequent in the obese population. However, the relationship between acid reflux and BMI in asymptomatic obese people is unclear. Forty-six obese (BMI > 25 kg/m(2)) people were enrolled in this prospective study. We evaluated the demographic findings and 24-h impedance pH values of the whole group. Gas, acid (pH < 4), weak acid (pH = 4-7) and weak alkaline (pH = 7) reflux parameters were analyzed. RESULTS: The mean age of patients was 49.47 +/- 12.24 years, and half of them were men. The mean BMI was 30.64 +/- 3.95 kg/m(2) (25.14-45.58 kg/m(2)). BMI of 23 was over 30 kg/m(2). Seventeen patients had a comorbidity (hypertension, diabetes mellitus, or ischemic heart disease). Endoscopic examination revealed esophagitis in 13 of the 28 subjects (10 Grade A, 3 Grade B). The subjects were divided into two groups according to BMI (< 30 and > 30 kg/m(2)). Demographic and endoscopic findings, and impedance results were similar in these two groups. However, there was a positive correlation between BMI and total and supine pH < 4 episodes (P = 0.002, r = 0.414; P = 0.000, r = 0.542), pH < 4 reflux time (P = 0.015, r = 0.319; P = 0.003, r = 0.403), and DeMeester score (P = 0.012, r = 0.333). CONCLUSION: Acid reflux is correlated with BMI in asymptomatic obese individuals.