Comperative analysis of DEXA and bioelectric impedance measurements in determination of bady composition changes occuring hemodialysis session

SUMMARY Because of decreased protein and energy intake, hormonal changes, disturbances in fluid and electrolyte metabolism and calcium and phosphorus balance and many other reasons, chronic renal failure causes changes in body composition. Reliable techniques are required to determine and follow up changes in body composition. Dual-Energy X-Ray Absorbsiometry ( DEXA ) and bioelectric impedance analysis are the frequently applied techniques to evaluate body composition in chronic renal failure. In the present study, we aimed to perform comparative analysis of DEXA and bioelectric impedance analysis in determination of minor changes in body composition occurring during dialysis session. Eight female, 7 male stable hemodialysis patients were enrolled in the study. Each patient was weighed by the same digital scale before and after dialysis and body composition was measured by DEXA and bioelectric impedance analysis before and after dialysis in each patient. When measurements before and after dialysis by DEXA were considered, changes in fat mass ( FM ) and bone mineral content were not statistically significant, whereas lean body mass ( LBM ) and total weight measurements before and after dialysis differed significantly. When bioelectric impedance analysis was considered, fat mass, lean body mass and water content before and after dialysis were found to be statistically significantly different. When results obtained by DEXA and bioelectric impedance analysis were compared differences in means of FM and LBM were not statistically significant and they were found to be positively correlated. As a conclusion; DEXA is a quite sensitive technique in determination of FM, LBM and bone mineral content and can be used in dialysis patients to determine short and long term changes in body composition. Despite bioelectric impedance analysis is less reliable in determination of body composition, it can be still used in determination of dry weight in conjunction with clinical parameters since it is a noninvasive and easy to perform technique at bedside.