VALIDATION OF ULTRASOUND EXAMINATION FOR ASSESSMENT OF THE ABDOMINAL VISCERAL FAT IN CLINICALLY SERIOUS OBESE PATIENT Validação da ultrassonografia para a avaliação da gordura abdominal visceral em obesos clinicamente graves

HEADINGS Ultrasonography. Visceral fat. Obesity. Bariatric surgery. ABSTRACT Background: Computerized tomography is the gold-standard for measurement of abdominal visceral fat. However, it is costly and involves submitting patients to ionizing radiation. Aim: To validate the use of ultrasonography in assessing abdominal visceral fat among clinically serious obese patients of both genders. Methods: The sample included adult patients with clinically serious obesity with body mass index of 40kg/m2 or from 35kg/m2 to 40kg/m2 with co-morbidities. Abdominal visceral fat thickness was measured using ultrasound and tomography. Two ultrasonographic exams were conducted to assess the interobserver reproducibility among a patient subsample. Validation was done by comparing these results with the tomographic findings. Results: The study included 13 patients (61.54% female) with an average BMI of 38.82 kg/m2. In terms of validation, the result obtained from applying the Pearson correlation coefficient was equal to 0.94 (p = 0.0005), showing a strong positive correlation between the two measurements. As for the results for reproducibility, the interobserver was equal to 0.822, with a confidence interval of 95% (-0.076 to 0.980), revealing good interobserver agreement. The average difference between the two ultrasound interobserver examination was equal to 0.10 ± 1.51 (p=0.8898) and so not significant. Interobserver bias was also not significant. Conclusion: The validation of ultrasonographic examination to replace tomographic method in assessing abdominal visceral fat among clinically serious obese patients was effective. The ultrasound measurement is independent of the examiner.