Body Mass Index and GERD: A Systematic Review and Meta-Analysis
Body Mass Index and GERD: A Systematic Review and Meta-Analysis
Background: Gastroesophageal reflux disease (GERD) is a common cause of morbidity and health-care utilization in many countries. Obesity is a potentially modifiable risk factor, but existing studies have conflicting results, possibly due to differences in study design, definitions, or populations.
Methods: We performed a systematic review and meta-analysis of studies identified using MEDLINE, the Web of Science electronic database, manual literature review, and a review of expert bibliographies. Studies were included if they: (1) evaluated obesity, body mass index (BMI), or another measure of body size; (2) included data on reflux symptoms, esophagitis, or a GERD-related hospitalization; and (3) reported a relative risk or odds ratio (OR) with confidence intervals or provided sufficient data to permit their calculation.
Results: We identified 20 studies that included 18,346 patients with GERD. Studies from the United States demonstrated an association between increasing BMI and the presence of GERD (95% confidence interval [CI] = 1.36-1.80, overweight, OR = 1.57, P value homogeneity = 0.51, 95% CI = 1.89-2.45, obese, OR = 2.15, P = 0.10). Studies from Europe provided heterogeneous results despite stratification for several factors; individual studies demonstrated both positive associations and no association.
Conclusions: This analysis demonstrates a positive association between increasing BMI and the presence of GERD within the United States; this relationship became apparent only after stratification by country and level of BMI. These results support the evaluation of weight reduction as a potential therapy for GERD. Further studies are needed to evaluate potential mechanisms and any differences in this relationship among different study populations.
Gastroesophageal reflux disease (GERD), the presence of symptoms or mucosal damage from gastroesophageal reflux, is a common, morbid, and costly medical condition in many countries. The prevalence of at least weekly heartburn or acid regurgitation ranges between 10-20% in Western countries, GERD treatments are costly, and GERD is associated with substantial morbidity, including esophageal adenocarcinoma. The identification of modifiable risk factors for GERD could potentially have a substantial public health impact. One potential major risk factor is obesity, the prevalence of which has increased markedly in recent decades.
Obesity is a postulated risk factor for GERD, although individual studies have conflicting results. Some studies suggest that an increased body mass index (BMI) is associated with increased esophageal acid exposure (28) and with an increased risk of hospitalization for esophagitis. In contrast, other studies, including one of the largest population-based studies to date, have found no association between BMI and GERD. Potential explanations for the disparate results include a true lack of an association between BMI and GERD, differences in definitions or methodology, dissimilar study populations, or a lack of power to detect an effect in some studies.
We evaluated the relationship between BMI and GERD using a systematic review and statistical synthesis; these methods can be valuable tools for the investigation of disease associations. Data pooling can help evaluate the influence of different study definitions, study designs, or study populations on the exposure-disease association. It can also help explore associations that individual studies may lack the power to investigate such as the influence of gender, levels of BMI, or the presence of confounding factors on disease risk. We thus performed an analysis of observational studies for the association between BMI and GERD with an emphasis on the evaluation of differences in study definitions, study design, and study populations and the creation of more standardized exposure definitions to better compare results among studies.
Background: Gastroesophageal reflux disease (GERD) is a common cause of morbidity and health-care utilization in many countries. Obesity is a potentially modifiable risk factor, but existing studies have conflicting results, possibly due to differences in study design, definitions, or populations.
Methods: We performed a systematic review and meta-analysis of studies identified using MEDLINE, the Web of Science electronic database, manual literature review, and a review of expert bibliographies. Studies were included if they: (1) evaluated obesity, body mass index (BMI), or another measure of body size; (2) included data on reflux symptoms, esophagitis, or a GERD-related hospitalization; and (3) reported a relative risk or odds ratio (OR) with confidence intervals or provided sufficient data to permit their calculation.
Results: We identified 20 studies that included 18,346 patients with GERD. Studies from the United States demonstrated an association between increasing BMI and the presence of GERD (95% confidence interval [CI] = 1.36-1.80, overweight, OR = 1.57, P value homogeneity = 0.51, 95% CI = 1.89-2.45, obese, OR = 2.15, P = 0.10). Studies from Europe provided heterogeneous results despite stratification for several factors; individual studies demonstrated both positive associations and no association.
Conclusions: This analysis demonstrates a positive association between increasing BMI and the presence of GERD within the United States; this relationship became apparent only after stratification by country and level of BMI. These results support the evaluation of weight reduction as a potential therapy for GERD. Further studies are needed to evaluate potential mechanisms and any differences in this relationship among different study populations.
Gastroesophageal reflux disease (GERD), the presence of symptoms or mucosal damage from gastroesophageal reflux, is a common, morbid, and costly medical condition in many countries. The prevalence of at least weekly heartburn or acid regurgitation ranges between 10-20% in Western countries, GERD treatments are costly, and GERD is associated with substantial morbidity, including esophageal adenocarcinoma. The identification of modifiable risk factors for GERD could potentially have a substantial public health impact. One potential major risk factor is obesity, the prevalence of which has increased markedly in recent decades.
Obesity is a postulated risk factor for GERD, although individual studies have conflicting results. Some studies suggest that an increased body mass index (BMI) is associated with increased esophageal acid exposure (28) and with an increased risk of hospitalization for esophagitis. In contrast, other studies, including one of the largest population-based studies to date, have found no association between BMI and GERD. Potential explanations for the disparate results include a true lack of an association between BMI and GERD, differences in definitions or methodology, dissimilar study populations, or a lack of power to detect an effect in some studies.
We evaluated the relationship between BMI and GERD using a systematic review and statistical synthesis; these methods can be valuable tools for the investigation of disease associations. Data pooling can help evaluate the influence of different study definitions, study designs, or study populations on the exposure-disease association. It can also help explore associations that individual studies may lack the power to investigate such as the influence of gender, levels of BMI, or the presence of confounding factors on disease risk. We thus performed an analysis of observational studies for the association between BMI and GERD with an emphasis on the evaluation of differences in study definitions, study design, and study populations and the creation of more standardized exposure definitions to better compare results among studies.
