2.4. Anthropometrics and Computed Tomography Morphometrics
cardiometabolic disease
Height (±0.1 cm) was measured using a wall-mounted stadiometer, body weight (±0.1 kg) on a digital platform scale (Model 8437, Detecto, Webb City, MO, USA), and waist and hip circumferences (±0.1 cm) via flexible measuring tape with participants in light clothing without overgarments or shoes and pockets emptied. BMI, waist-to-hip, and waist-to-height ratios were calculated. Abdominal computed tomography (CT) scans were acquired without contrast on a GE Healthcare scanner and analyzed using the axial slice containing the inferior endplate of the 3rd lumbar vertebra. CT images were converted to Digital Imaging and Communications in Medicine (DICOM) format and segmentation of abdominal subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and skeletal muscle (psoas, quadratus lumborum, erector spinae, lateral oblique, internal/external oblique, and rectus abdominus) was performed using an automated version of Slice-O-Matic software (version 4.3, Tomovision, Montreal, QC, Canada). Manual editing of tissue boundaries was performed by trained research technicians (coefficient of variation of 1.2%) to assure complete quantification of cross-sectional tissue depot areas. Radiodensities of SAT, VAT, and skeletal muscle were quantified based on established attenuation thresholds in Hounsfield Units as indicators of lipid accumulation in these tissues. VAT/SAT ratio was calculated as a metric that predicts cardiometabolic disease independent of VAT [