Nomogram for estimating glomerular filtration rate in elderly people.

After the second decade of life, the glomerular filtration rate (GFR) decreases progressively. There is still considerable debate about the importance of this "physiological decrease" in GFR with age in many situations attributed to the effects of concomitant hypertension, atherosclerosis, cardiovascular diseases (among others) observed in the elderly. The GFR is considered the best indicator of renal function and its estimate has been suggested in the guidelines of chronic kidney disease (CKD). However, in the most commonly equations used, the elderly subjects were not included or were underrepresented. The purpose of this is to describe a nomogram based on an equation to estimate GFR based on serum creatinine, age and sex that was developed for the study Berlin Initiative Study (only individuals older than 70 years were included). The performance of the equation, called BIS1 was compared with Hioxal (gold standard), three equations based on serum creatinine (CG, MDRD and CKD-EPI) and three equations based on cystatin C (proposed by the CKD-EPI) and the second showed less bias among that another equations and compared the CG, MDRD and CKD-EPI equations, had the lowest rate of misclassification of CKD in participants with less than 60 mL/min/1.73 m2.