THE USE OF BIOELECTRICAL-IMPEDANCE ANALYSIS (BIA) TO ESTIMATE BODY-COMPOSITION IN THE DIABETES CONTROL AND COMPLICATIONS TRIAL (DCCT)

Although weight gain often accompanies intensive treatment regimens de signed to achieve near-normal glycemia in insulin-dependent diabetes m ellitus (IDDM), body composition (BC) has not been well studied. Bioel ectrical impedance analysis (BIA) is a safe, rapid, and non-invasive m ethod of assessing no but has not been utilized widely in IDDM. Data f rom 46 adults with IDDM were used to develop a regression model estima ting fat-free body mass (FFM) from bioimpedance measurements obtained using a proximal electrode placement. Reference values of FFM were det ermined by dual x-ray absorptiometry (DXA). A model using the ratio of height squared to the minimum resistance of 4 limb-lead combinations (H-2/R), total body weight, and a weight-gender interaction achieved a high level of accuracy (R(2) = 0.982, residual standard deviation = 1 .43 kg), while studies of 10 subjects before and after a light meal fo und no short-term effect of glycemia on measured BIA variables. BIA wi ll therefore be used in combination with waist-to-hip ratios to study the composition and distribution of the increased weight associated wi th intensive therapy in the DCCT.