Published online Mar 14, 2015. doi: 10.3748/wjg.v21.i10.3030
Peer-review started: April 29, 2014
First decision: May 29, 2014
Revised: August 6, 2014
Accepted: November 8, 2014
Article in press: November 11, 2014
Published online: March 14, 2015
Processing time: 322 Days and 21.6 Hours
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/m2) 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/m2 (25.14-45.58 kg/m2). BMI of 23 was over 30 kg/m2. 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/m2). 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.
Core tip: Obesity is an increasing problem worldwide. Few studies have reported on the association between gastroesophageal reflux symptoms and body mass index (BMI). We aimed to determine the effects of BMI on gastroesophageal reflux using esophageal pH-impedance technique in asymptomatic overweight and obese subjects. We found that BMI is positively correlated with acid reflux. Our study demonstrated that obesity is a risk factor for gastroesophageal reflux even in an asymptomatic healthy individuals. These findings are important for the obese population who are referred for bariatric surgery. Gastroesophageal reflux should be evaluated carefully before surgery, even in the absence of symptoms.