Body composition profiles derived from dual-energy X-ray absorptiometry, total body scan, and mortality

Little has been reported on the association of derived body composition data and cardiovascular mortality. The authors defined body composition profiles based on one- and two-variable measures from dual-energy x-ray absorptiometry (DXA) total body scans. Scan results are labeled "apple" if Z score for percent of total fat in trunk is >0 and "pear" if Z score for height-corrected limb fat is > or = 0. The fat measures were combined to define four body composition profiles: "pickle," "avocado," "mango," and "barrel." A third axis, the Z score of height-corrected limb lean tissue, is an index of skeletal muscle mass and was used to label subjects as "hard" or "soft." Subjects (n=324) who were in good health from Malmö, Sweden, underwent body composition analysis using DXA and were followed for 10 years. The distribution of body composition profiles was similar for both genders and across age groups. Among subjects aged 50-74 years at baseline (n=116), there were 21 deaths. Barrel had the highest mortality rate: 13/39 (33.3%) mortality for barrels, compared with 8/77 (10.4%) mortality for non-barrels; mortality odds ratio, 3.2; 95% confidence interval, 1.45-7.08. The increased mortality was principally attributable to cardiovascular cause-related deaths. Soft (sarcopenia) was also associated with increased mortality (25.9%; p=0.05), but not cardiovascular cause-related deaths, whereas the total mortality among apples was not significantly increased but cardiovascular cause-related deaths were predominant (75%; p=0.02). The authors propose that DXA-body composition profiles can identify increased mortality risk of magnitude similar to major cardiovascular risk factors and may prove useful in health assessment.