Quantitative assessment of visceral fat in morbidly obese patients by means of wide-bore MRI and its relation to lower esophageal sphincter pressure and signs of gastroesophageal reflux.

BACKGROUND: The aim of this study was to quantitatively assess visceral adipose tissue (VAT) by means of a wide-bore MR scanner in a cohort of morbidly obese patients referred for bariatric surgery. Furthermore, it was investigated whether gastroesophageal reflux disease (GERD) and lower esophageal sphincter pressure (LESP) are related to the volume of visceral fat masses.
METHODS: Twenty-five morbidly obese patients (nine male, 16 female) were prospectively enrolled. In addition to common anthropometric measures of obesity, VAT was determined quantitatively by multi-slice MRI. Symptoms of GERD were evaluated using a standardized questionnaire, while endoscopy of the upper gastrointestinal tract was performed to reveal pathologies of the gastroesophageal junction. LESP was evaluated by esophageal manometry.
RESULTS: Study population showed a body mass index (BMI) between 35.2 and 59.1 kg/m(2). Waist-to-hip ratio and VAT were significantly higher (p < 0.0001; p = 0.0021) in males (1.05 +/- 0.05; 8.89 +/- 2.33 l) than in females (0.86 +/- 0.07; 6.04 +/- 1.28 l). VAT was not correlated to BMI. LESP values and GERD-related symptoms were neither dependent on anthropometric measures nor on VAT in our cohort.
CONCLUSIONS: VAT did not show a positive correlation with BMI in our cohort of extremely obese subjects, indicating a pronounced fat deposition in subcutaneous tissue compartment. Moreover, this indicates that VAT is limited to a gender-dependent maximum volume for each individual and seems to be no further increasing in extremely obese subjects. This might be the reason that neither symptoms nor endoscopic findings of GERD nor LESP were significantly influenced by the stage of morbid obesity.