Obesity and gastroesophageal reflux disease and gastroesophageal reflux symptoms in children.

Background: The association between body mass index (BMI) and gastroesophageal reflux disease (GERD) has been extensively studied among adults but few studies have examined such association in children.

Aims: 1) to determine the relationship between BMI in children and GERD, and 2) to use the National Center for Health Statistics (NCHS) values for BMI as a valid source for comparison.

Methods: We identified two cohorts of children aged between two and 17 years who were seen at Texas Children's Hospital (TCH). The first cohort consisted of children diagnosed with GERD based on upper gastrointestinal endoscopic and histologic evaluation, which was recorded in the Pediatric Endoscopic Database System-Clinical Outcomes Research Initiative (PEDS-CORI) at TCH. A diagnosis of GERD was based on the presence of erosive esophagitis or esophageal ulcers. Endoscopic reports that were incomplete or did not include demographic features, indications for endoscopy, or endoscopic findings were excluded. The second cohort consisted of all children with symptoms due to gastroesophageal reflux (GER) who received outpatient gastrointestinal (GI) consultation at TCH for any 9th revision of the International Statistical Classification of Diseases (ICD-9) code suggestive of GER. There was no overlap between the two cohorts as each child was indexed only once. Children with any comorbid illnesses were excluded.

Measurements: The records for each child namely, age, gender, height, and weight were obtained on the same date as that of the diagnosis. Using the growth curves published by the NCHS, the gender/age specific weight-for-age Z-score (WAZ), and height-for-age Z-score (HAZ) were calculated. BMI was calculated as the weight in kilograms divided by height in meters squared. Children having values greater than the 95th percentile for their age/gender-specific BMI were defined as obese.

Results: In a one-year period (January 2006 to December 2006), a total of 627 children who attended the GI clinic at TCH were identified with GERD symptoms of whom 131 underwent endoscopic examination. The mean age was 9.7 years; 42% were females; 57% were Caucasians; 15% were African Americans, and 28% were Hispanics. Using National Health and Nutrition Examination Survey (NHANES) data obtained from the same period as the the current data as a baseline for comparison, the BMI of children diagnosed with GERD was higher than the BMI reported by NHANES data. The final analysis of test proportion showed an overall proportion of 0.207 for the current study versus NHANES data (0.174). The current study also showed that more boys than girls have BMI greater than 95th percentile (24.7% vs 16.5%, respectively, OR = 1.7, 95% CI = 1.2-2.6, p = 0.04).

Conclusions: Children diagnosed with GERD or those who presented with symptoms of GERD are more likely to be obese. The findings of this study show a possible association between obesity and GERD in children. Further understanding about the co-morbidity between GERD and obesity in children may have important implications on GERD management and treatment in children.