OBESITY and GERD: Are They Related?
Obesity and GERD
Obesity is the accumulation of excessive fat due to an imbalance between energy intake and energy expenditure over a prolonged period of time. Obesity is found in adults, teenagers, and children. Over 1.4 billion adults are overweight and over 500 million adults worldwide are obese (WHO, 2008). Obesity is closely related to the occurrence of non-communicable diseases and causes 2.8 million adult deaths each year (WHO, 2013).
In Indonesia, based on Basic Health Research (Riskesdas), there has been an increase in the prevalence of obesity among individuals aged 18 years and older from 11.7% in 2010 to 15.4% in 2013. Obesity is a risk factor that leads to various diseases, one of which is gastroesophageal reflux disease (GERD) and diabetes mellitus (DM).
The occurrence of GERD is influenced by genetic and environmental factors. Many studies have shown that obesity, body weight, and an increase in body mass index (BMI) are associated with GERD. Obesity is an important factor that is becoming increasingly common in the world population.
Gastroesophageal reflux (GER) or the reflux of stomach contents into the esophagus is a normal physiological process. On the other hand, GERD is a pathological condition where gastroesophageal reflux causes symptoms such as nausea, regurgitation, and/or vomiting, as well as complications such as esophagitis, strictures, and/or extraintestinal manifestations.
The prevalence of obesity among adults in the United States was 34.9% in 2011-2012. In 2013, the prevalence of obesity among adult males in Indonesia was 19.7% and among adult females was 32.9%.
Why is obesity a risk factor for GERD?
Obesity is an important factor that is becoming increasingly common in the world population. The relationship between the increasing prevalence of GERD and obesity has attracted significant interest in both conditions. Several studies have discussed the potential relationship between GERD and obesity as shown in the table on the side.
Studies using high-resolution manometry have found that obesity increases the risk of hiatal hernia (HH). HH can lead to GERD by reducing the pressure of the lower esophageal sphincter (LES), interfering with acid clearance in the esophagus, and increasing the sensitivity of transient lower esophageal sphincter relaxation (TLESR) induced by distension.
In addition to increased intra-abdominal pressure, obesity also plays a role in GERD through humoral factors. Visceral fat (abdominal fat) is different from subcutaneous fat. Visceral fat is more metabolically active, has more inflammatory cells, and is more resistant to insulin, making it more dangerous than subcutaneous fat. Visceral fat increases the levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in the blood. These inflammatory mediators induce an inflammatory response, leading to esophagitis.
Obesity, especially visceral obesity, increases the risk of GERD. This process occurs through several mechanisms, including mechanical factors such as increased intra-abdominal pressure, increased risk of Hiatal Hernia, increased sensitivity of TLESRs induced by distension, and decreased pressure of the lower esophageal sphincter (LES). It also occurs through humoral factors such as increased levels of TNF-α and IL-6, as well as through motility disturbances such as delayed gastric emptying and delayed esophageal clearance.
Naomi D., 2014, Obesity as Risk Factor of Gastroesophageal Reflux Disease, J Majority Volume 3 No 7