[Elderly patients with Chronic Kidney Disease: what is their course at one year?]

Aging is associated to several structural and functional kidney changes. Recently, there is a great interest in the detection of Chronic Kidney Disease (CKD) in the general population. A classification of CKD, based on several stages of the estimated glomerular filtration rate (eGFR), has been established. In this study we followed up, clinically and biochemically, during one year eighty patients older than 65 years so as to ascertain the applicability and utility of such classification to those patients.

80 clinically stable patients, with a median age of 83 years, recruited within January and April 2006, were followed up during one year. We separated them in two groups: Group 1: 38 patients with serum creatinine pound sterling 1,1 mg/dl (range 0,7-1,1) and with no proteinuria; and Group 2: 42 patients with serum creatinine > or =1.1 mg/dl (range 1,2-3) and with proteinuria <3 grs/24 hours. Clinically we registered morbimortality and treatments received, and biochemically we measured serum creatinine and eGFR at the time of recruitment and after one year of follow up using two equations: Cockroft and abbreviated MDRD. Statistical comparisons were made using the general lineal model for repeated measures of the SPSS 11.0 program.

10% of the patients died during the follow up. Cardiac problems were the kind of morbidity more frequently found. Only a small proportion (23%) of group 2 patients were receiving erythropoietin (EPO) treatment. Estimated GFR and proteinuria remained stable at the end of one year independently of basal GFR; we found no significant differences between groups in the rest of analytical parameters.

in old patients with no significant proteinuria, the similarity of their clinical evolution and the stability of their eGFR (independently of its basal value), as well as the lack of differences in other analytical parameters, appears not to confer any advantages to the use of mathematical formulae to classified them according to their eGFR.