The quantification of abdominal fat is a marker of health risk. While dual-energy x-ray absorptiometry (DEXA) is easily applied,
it measures overall fat, although abdominal fat may be a better indicator of health risk from obesity. We have evaluated whether
a subcomponent of DEXA measurements correlates better with computed tomography (CT) for body fat than those traditionally
used. Forty-seven healthy adults (22 M/25 F), aged 54.5±15.8 yr (mean±SD), with BMI of 27.1±4.6 kg/m
2 participated in a cross-sectional study. Body fat was measured using abdominal CT and DEXA for total fat, trunk fat, and
a modified trunk measurement that excludes the chest, termed “lower trunk,” and compared. The coefficient of variation for
DEXA measurements for trunk, lower trunk, and total body were 1.98, 3.12, and 0.85%, respectively. Mean DEXA for percentage
fat ranged from 31.7% to 34.1% for trunk, lower trunk, and total body, compared to 54.2% for abdominal CT (
p<0.003 for each pairwise comparison). Lower trunk, whole trunk, and total body DEXA measurements were not different. Measurement
of subcomponents of fat content by DEXA is not superior to whole body measurements and remains consistently lower than measurements
by CT.
Key Words Fat - visceral - insulin - resistance - DEXA