Validity of current equations to estimated glomerular filtration rate in geriatric population

Background Despite the estimation of glomerular filtration rate (GFR) being the best index of kidney function, and estimated glomerular filtration rate (eGFR) being limited by differences in creatinine generation among different age groups, the data regarding the accuracy of serum creatinine-based formulae on the geriatric population is still scarce.Aim Our aim is to investigate the accuracy of the eGFR equations to predict renal function in geriatric population versus the measurement of true GFR by diethylenetriaminepentaacetic acid (99mTc-DTPA).Patients and methods The study included 160 elderly persons, with 93 (58%) females. All persons were from Minia Governorate, Egypt. GFR was estimated using Modification of Diet in Renal Disease, abbreviated Modification of Diet in Renal Disease, Walser, Nankivell, Cockcroft–Gault, Mayo Clinic, and Chronic Kidney Disease Epidemiology Collaboration. The true GFR was determined for all participants with 99mTc-DTPA.Results All the seven eGFR estimations correlated with 99mTc-DTPA clearance (P<0.05), but their r2 was low, ranging from 0.69 to 0.54. Their respective r2 values were as follows: Modification of Diet in Renal Disease 0.69, Chronic Kidney Disease Epidemiology Collaboration 0.63, abbreviated Modification of Diet in Renal Disease 0.62, Cockcroft–Gault 0.58, Mayo Clinic 0.55, Walser 0.55, and Nankivell 0.54.Conclusion In the geriatric population, the overall performance of these seven prediction equations did not give a precise assessment of kidney function, that is, all analyzed formulae lacked the precision to estimate true GFR.