See “Total and Abdominal Obesity Are Risk Factors for Gastroesophageal Reflux Symptoms in Children” by Quitadamo et al on page 72.
The relation between obesity and gastrooesophageal reflux disease (GERD) is well established in adults, although the results of paediatric studies are considerably more controversial. Both conditions are frequent and there is the probability of them often occurring simultaneously in the same individuals. Identifying a relation and causality is a difficult task that requires large epidemiological studies and sensitive diagnostic tools.
Obesity is associated with several well-known risk factors, GERD being only one; however, identification of GERD is important because there is some evidence that obese patients may require more aggressive therapy (1).
The available investigation of the relation between the 2 conditions has not yet provided clear answers. Hancox et al (2) found that the positive strong association between symptoms of GER (heartburn and regurgitation) and asthma assessed by a questionnaire in 1037 young adults was independent of body mass index (BMI) and smoking. Patel et al (1) reviewed oesophageal histology from 230 paediatric patients who underwent upper endoscopy and compared objective signs of reflux oesophagitis with BMI. They could not find a greater prevalence of oesophagitis in overweight children; however, the majority of patients were taking antireflux medication and only histologic criteria was used. Therefore, the true prevalence of reflux symptoms may have been underestimated. On the contrary, other studies have revealed a positive association between obesity and reflux, such as those of Pashankar et al and Teitelbaum et al (3,4).
Identification of obese children in most of the published studies has used BMI to stratify patients and compare groups; however, BMI is related to total body fat, whereas waist circumference (WC) represents a measure of visceral adiposity, which may be more directly related to the factors facilitating GER.
In this issue, Quitadamo et al (5) report the positive relation between WC and presence of GER symptoms. This approach evaluates the possible role of visceral adiposity on the occurrence of reflux. Furthermore, they show that moderate increases of WC even within normal values may be associated with increased risk of GERD. This relation is a new addition to the publications on the issue, although it has some shortcomings. Identification of GER was based on a questionnaire and subsequent composition of scores that have not been fully validated in this setting. The study was conducted in a well-child clinic in children without obvious complaints of GERD. Some of the items such as respiratory symptoms or dysphagia in the questionnaire are not specific for reflux; however, heartburn, epigastric pain, and regurgitation were more frequently associated with signs of obesity.
Development of questionnaires to identify subclinical signs of gastrooesophageal reflux is a difficult issue (6). Invasive tests may not be ethically acceptable in the absence of clinical complaints or suspicion of disease requiring treatment. Attempts have been published to identify appropriate questions that may be related to reflux (7). The increasing use of impedance may further help to validate the questionnaires. These diagnostic instruments are needed to identify a subset of patients who may require detailed investigation to document and treat clinically relevant gastrooesophageal reflux.
The relation between increasing body mass and subtle signs of reflux seems to emerge from the present study. This only adds another dimension to the well-known risks of obesity. The observation of Patel et al that a relevant number of overweight children had signs of oesophagitis despite the ongoing antireflux treatment may indicate that these obese patients require more aggressive treatment if GERD is diagnosed. All of these findings combined may alert physicians to the increased risk of reflux in overweight children and the need for assessing the efficacy of treatment.
The present evidence points to a possible risk of reflux with moderate increases in body mass and that methods that evaluate the visceral fat may be sensitive indicators to be used in future studies to assess signs of reflux.
1. Patel NR, Ward MJ, Beneck D, et al. The association between childhood overweight and reflux esophagitis. J Obes
2. Hancox RJ, Poulton R, Taylor DR, et al. Associations between respiratory symptoms, lung function and gastro-oesophageal reflux symptoms in a population-based birth cohort. Respir Res
3. Pashankar DS, Corbin Z, Shah SK, et al. Increased prevalence of gastroesophageal reflux symptoms in obese children evaluated in an academic medical center. J Clin Gastroenterol
4. Teitelbaum JE, Sinha P, Micale M, et al. Obesity is related to multiple functional abdominal diseases. J Pediatr
5. Quitadamo P, Buonavolontà R, Miele E, et al. Total and abdominal obesity are risk factors for gastroesophageal reflux symptoms in children. J Pediatr Gastroenterol Nutr
6. Kleinman L, Rothman M, Strauss R, et al. The infant gastroesophageal reflux questionnaire revised: development and validation as an evaluative instrument. Clin Gastroenterol Hepatol
7. Stordal K, Johannesdottir GB, Bentsen BS, et al. Gastroesophageal reflux disease in children: association between symptoms and pH monitoring. Scand J Gastroenterol