Obesity and gastro-esophageal reflux disease: a 2009 update

The reports describing that obesity per se predisposes to gastroesophageal reflux disease (GERD) have brought conflicting results. Establishing a causal link between these two conditions would be of major public health importance, because of their present epidemic proportions. To date, some large studies examining the relationship between obesity and GERD found a strongly positively relationship while others did not. The main cause of this discordance is the vast heterogeneity of such studies: sufficiently powerful design is found only in few investigations, GERD is defined with a low degree of homogeneity, biases are obvious in the choice of diagnostic methods, thus giving room for large variations in the adjustment of potential confounding factors. Future research should take three directions: 1) prospective population-based studies in which the incidence or recurrence of GERD should be evaluated in correlation with body mass index; 2) intervention trials, focusing on the benefit of weight loss in the prevention of GERD and its recurrence; 3) studies of physiopathology (both in the animal models and humans) to understand the potential biological plausibility.