Measurement of abdominal fat by CT compared to waist circumference and BMI in explaining the presence of coronary calcium.

OBJECTIVE

To evaluate the association between standard and computed tomography (CT)-based measures of obesity and subclinical atherosclerosis, defined as coronary artery calcium (CAC) by Electron Beam Computed Tomography (EBCT).

DESIGN

Cross-sectional, observational study of anthropometric and CT obesity measures and presence of CAC.

SUBJECTS

Participants were 383 men and 379 women, aged 20-58 y and asymptomatic for coronary artery disease (CAD).

MEASUREMENTS

Intra-abdominal fat (IAF) and subcutaneous fat (SQF) were measured at the level of lumbar 2-3 and 4-5 spaces, using EBCT. Body mass index (BMI) was calculated from height and weight, and minimum waist circumference and maximum hip circumference were measured. CAC was measured by EBCT.

RESULTS

In both men and women, BMI, waist circumference, IAF, and SQF were significantly related to CAC. However, BMI or waist circumference explained variation in the presence of CAC as well as IAF or SQF, univariately and after adjustment for additional cardiovascular risk factors.

CONCLUSION

CT-based obesity exposure measures are not superior to BMI or waist circumference in association studies of subclinical CAD.