DETERMINING BONE AND TOTAL-BODY MINERAL-CONTENT FROM BODY DENSITY ANDBIOELECTRICAL RESPONSE SPECTROSCOPY

We hypothesized that one could assess total body mineral (TBM) and bon e mineral content (BMC) from measurements of body density and bioelect rical response spectroscopy (BRS)-determined total body water by using a three-compartment (3C) model. We compared TBM and BMC computed from measurements of water ((H2O)-H-2 dilution or BRS) and body density (u nderwater weighing) with [4-compartment (4C)] and without (3C) mineral (dual X-ray absorptiometry) in 15 women and 16 men. BRS used multifre quency or single-frequency estimates of water. Mean differences betwee n the 3C and 4C models ranged from -6.1 to 2.2%. Correlations between models were 0.82-0.91. Standard errors of the estimate of 8.5-9.3% wer e within the range of those previously reported, i.e., 4.9-13%. Use of BRS did not significantly decrease the strength of the correlations b etween the models. A significant mean difference (only in women) was f ound only with 3C single-frequency BRS estimates of TBM and BMC. We co ncluded that investigators can assess TBM and BMC 3C multifrequency BR S estimates in men and women.