The relationship between obesity and GERD: "big or overblown".

The rates of obesity have doubled over the last 22 yr in the United States. Similarly, the prevalence of gastroesophageal reflux disease (GERD) has also been rising in the United States, with studies suggesting it may now be as high as 1 in 5. Given these parallel time trends, it is tempting to speculate that obesity may, in some way, promote the development of GERD. Of the proposed mechanisms, the most attractive ones focus on the mechanical stresses imposed on the antireflux barrier, specifically increased pressure gradients across the esophagogastric junction (EGJ). In this issue of the American Journal of Gastroenterology, de Vries et al. provide a comprehensive retrospective analysis of the relationship among body mass index (BMI), pressure gradients across the EGJ, and objective evidence of GERD. While their results support that increased BMI is associated with increased pressure gradients through the EGJ and the propensity to develop hiatus hernia, they do not illustrate a direct relationship between increased gastroesophageal pressure gradients and abnormal acid exposure in the esophagus. These results highlight the complexity of this relationship and once more support the concept that GERD is a multifactorial disease that cannot be defined by a single anatomical or functional abnormality.