Assessment of Visceral Adipose Tissue by Dual Energy X‐Ray Absorptiometry and Magnetic Resonance Imaging among a Young Adult Obese Population

Abstract

BackgroundDevelopment of successful weight loss interventions requires accurate assessment of body composition especially when measuring effects of dietary and exercise weight loss approaches. Because increasing proportions of the population are becoming obese, translation of measurement‐rich assessments from the clinical setting into the population setting are essential. Increasing visceral adipose tissue in the intra‐abdominal area during weight gain, independent of total adipose tissue, is associated with cardiovascular disease, metabolic syndrome, type‐2 diabetes, and cancer risk of several sites. The most accurate imaging of visceral fat (VF) is abdominal X‐ray computed tomography (CT) and Magnetic Resonance Imaging (MRI). Dual‐energy X‐Ray absorptiometry (iDXA) with the enCORE™ CoreScan software specifically designed to estimate visceral fat can measure body composition with low radiation exposure and potentially high precision. The iDXA could represent an accurate and less‐expensive option to CT and MRI, although only a few studies have validated iDXA abdominal visceral fat imaging against MRI or CT.Aims and MethodsTo more accurately estimate associations between metabolic parameters associated with adipose tissue, we conducted tandem measurements of abdominal visceral and subcutaneous fat using the MRI and iDXA to determine if iDXA was accurately estimating visceral fat.ResultsA total of 37 subjects, with average age of 28 years old who were mostly female (58%) and Caucasian (62%) had iDXA scans conducted at baseline. On average, they had class 1 obesity (BMI = 38 kg/m2), with average weight of 253 pounds. Their visceral fat averaged 1633 ± 929 grams and total android fat mass was 5531 ± 2160 grams. Of the 37 subjects who had iDXA scans, 13 subjects also had MRI scans within one to two days of the iDXA scan. These 13 subjects had an average MRI assessment of 7918.38±1778.74 cm3 visceral adipose tissue and 12180.08±3702.56 cm3 subcutaneous. Correlations for visceral adipose tissue measurement by both the iDXA and MRI was r=0.59, p=0.04.ConclusionsWhile MRI is the gold standard for assessing visceral abdominal fat, scanning with the iDXA is reasonably accurate. Precision could be improved with a larger sample size.Support or Funding InformationNIH, R01 DK090406