EQUAÇÕES PREDITIVAS DO PERCENTUAL DE GORDURA CORPORAL DE PACIENTES RENAIS CRÔNICOS EM HEMODIÁLISE

Abstract

Introduction: Patients with chronic kidney disease on hemodialysis show hydro electrolytic and metabolic alterations as a consequence of the pathology that affects in their body composition and nutritional status. An alternate method to improve the precision in the measurement of the body composition of these patients is the development of the predictive equations considering their clinical characteristics. Objective: develop predictive equations of the percentage of chronic kidney patients’ body fat (BF%) on hemodialysis, using anthropometric measurements and measurements from bioimpedance (BIA), applying Dual energy X-ray (DEXA) as standard reference technic. Methods: Cross-sectional study with kidney patients on hemodialysis of São Luís – MA, from which were measured: dry weight; height; waist circumferences (WC), neck circumference (NC) and hip circumference (HC). Body mass index (BMI), waist-hip ratio (WHR) and waist-to-height ratio (WHtR) were calculated. To obtain the resistance and the reactance, the BIA was performed. The BF% was gained by BIA and DEXA. For the development of the equations different multiple linear regression (MLR) models were adjusted and the quality of the adjustments of the evaluation of the second higher coefficient of determination (R²) and the lower root-mean-square deviation (RMSD) and mean absolute error (MAE). Results: 305 patients were measured with the average weight of 60.7 ± 11.6 kg, average BMI of 23.8 ± 3.8 kg/m2, average WC of 87.6 ± 11.8 cm, BF%-DEXA of 29.9 ± 9.4%. Following the adjustment of the MLR, the model that best explained the BF% (R² = 83%) included the variations of age, sex, dry weight, height, WC, resistance and reactance. There was higher accordance between the BF%-DEXA and the BF% of the proposed equations, while compared to BF%-BIA. The model 2 showed higher accordance with the DEXA (ρ = 0.82), compared to the BF%-BIA with the BF%- DEXA (ρ = 0.71). Conclusion: The proposed equations to assess the BF% presented a good capacity to predict and a good accordance with the referencing method, being able to be used in the kidney population on hemodialysis, when the DEXA, gold pattern, is not available.