Ultrasound measurement of visceral and subcutaneous fat in morbidly obese patients before and after laparoscopic adjustable gastric banding: comparison with computerized tomography and with anthropometric measurements.

BACKGROUND

There are now a variety of methods to assess body fat distribution, anthropometric (waist circumference and waist/hip W/H ratio), computed tomography (CT), and ultrasound (US) measurements, with CT considered as the reference method. Bariatric surgery leads to a significant and usually durable weight loss in morbidly obese patients; when assessing its results, it is of interest to measure changes of total fat tissue and of body fat distribution.

METHODS

In this study, we compared anthropometric, US, and CT measurements of body fat distribution under basal conditions and 1 year after laparoscopic adjustable gastric banding (LAGB); 120 morbidly obese patients were considered at baseline, and 40 patients were re-evaluated 1 year after LAGB.

RESULTS

Thickness of visceral and subcutaneous fat measured through CT and US methods was superimposable both under basal conditions and 1 year after LAGB, and the highest correlation was found between CT and US data on visceral fat, followed by CT and US data on subcutaneous fat; a fair correlation was also found between CT and US data on visceral fat and waist circumference.

CONCLUSION

We suggest that evaluation of body fat distribution is accomplished by US instead of CT measurement, because of its lower cost and low exposure risk. Waist circumference stands as a reasonable surrogate of both methods, while W/H ratio is poorly correlated with other measures of body fat distribution.