Filtrado glomerular estimado por fórmulas en pacientes obesos

Abstract

IntroductionEstimating glomerular filtration rate (GFR) in obese subjects is a challenge. An analysis is made of the performance of equations to estimate GFR in this population. Material and methodsThis cross-sectional study included 100 obese subjects evaluated between 2008 and 2015. The GFR was measured with urinary iothalamate clearance (reference standard) and estimated using creatinine-based formulas: Cockroft Gault, MDRD, CKD-EPI, MCQ,and CKD-MCQ (mean of these). A Global Performance Score (G-P-Score) was created to unify all the analysis criteria. ResultsCKD-MCQ equation had the best performance in obesity grade I (n=53) [bias=1.6+/- 17.4ml / min x 1.73 m2; Correlation (r)=0.87; Area under the curve (AUC)=0.978; Sensitivity (S)=100%; Specificity (E)=87.8%]. MCQ and CKD-MCQ had the lowest bias in obesity grade II (n=25) (bias=1.8+/- 22.3 and -4.4+/- 21.9ml / min x 1.73m2), and CKD-MCQ the highest r (r=0.89), with the same AUC, S, and E (AUC=0.976, S=85.7%, E=100%). MDRD equation had the lowest bias in obesity grade III (n=22) (bias=-0.2+/- 31.1ml/min x 1.73 m2), and CKD-MCQ had the highest r and AUC (r=0.66, AUC=0.929), with the same S and E (S=80%, E=94.1%) than MDRD.CKD-MCQ was the only equation without significant differences compared to the reference standard in any of the obesity levels. The highest score was obtained in the G-P-Score (39/48). ConclusionCKD-MCQ had the better overall performance for estimating GFR in subjects with different degrees of obesity.