1. The purpose of this study was to determine the suitability of ratios derived from dual-energy X-ray absorptiometry (DXA) whole body scans to assess regional fat distribution in older men and women by comparing them with the waist-to-hip ratio (WHR) and to evaluate their clinical utility by applying them in a clinical trial involving resistance exercise and recombinant human growth hormone.
2. Sixty-four healthy older adults (39 women and 25 men), aged 65–82 years, served as subjects. The ratios of trunk fat-to-total fat, trunk fat-to-body weight, trunk fat-to-limb fat and trunk fat % were determined by DXA. WHR was assessed on the same day, as was the ratio of subscapular/triceps skinfolds in men. Cardiovascular disease risk factors, functional capacity and serum lipids were also assessed.
3. A moderate relationship (r = 0.36-0.54) between the WHR- and DXA-derived ratios were observed for both men and women. Both DXA and WHR showed similar associations with cardiovascular disease risk factors. However, in men, all DXA ratios were able to detect subtle changes in regional fat distribution resulting from daily administration of recombinant human growth hormone in conjunction with resistance exercise for 10 weeks, whereas the WHR or subscapular/triceps ratios did not.
4. This suggests that DXA-derived ratios may be more sensitive than conventional anthropometric methods in the assessment and categorization of body fat distribution.