Intraabdominal fat is often measured to determine a person's risk of
coronary heart disease and now, new research suggests that MRI
measurement at the second lumbar vertebra usually captures the most
intraabdominal fat.

"Studies that attempt to link intraabdominal fat with cardiovascular
disease risk factors should consider measurement location to
accurately capture the association," lead author Dr. Meghan Warren,
from the University of Minnesota School of Public Health in
Minneapolis, and colleagues note.

The findings, which appear in the February 15th issue of the
American Journal of Epidemiology, are based on a study of 147
subjects who underwent abdominal MRI to determine which vertebral
level provided the best reflection of intraabdominal fat.

The subjects, who were participants in the Atherosclerosis Risk in
Communities Study, were selected during a study visit between 1990
and 1992. The mean age of the men and women was 59.6 and 48.0 years
old, respectively. Most were white and overweight, with a mean BMI
of 26.

After adjusting for body mass index, measuring intraabdominal fat at
the torso significantly predicted intraabdominal fat area in both
men and women, the investigators found. In men, but not women, the
site of maximum intraabdominal fat area moved down the torso with
age.

Overall, measurement just above the umbilicus, which corresponds to
the second lumbar vertebra, detected largest amount of
intraabdominal fat, the authors note.

The "absolute quantity of visceral fat is likely to be
differentially related to risk factors for cardiovascular disease,
and these results provide additional information for guiding
research in population-based intraabdominal fat measurement using
external circumference measures," Dr. Warren's team concludes.

Am J Epidemiol 2006;163:352-358