Estimated glomerular filtration rate in elderly patients with type 2 diabetes

IntroductionPeople in old age with diabetes are at high risk of kidney damage. Data regarding optimal methods for estimation glomerular filtration rate (eGFR) in this group of patients are limited.Material and methodsThe purpose of the study was to check the results of eGFR calculated using 9 selected formulae based on serum creatinine or cystatin C in clinically stable, outpatient people aged ≥ 70 years with diabetes and to compare the classification to chronic kidney disease (CKD) stages based on different eGFR equations. TIPCO Statistica version 13.3 and Origin Pro 2022 statistical software were used for statistical analysis. According to the data distribution the Student’s t-test or the Mann-Whitney U test were used for intergroup comparison. The non-parametric Friedman ANOVA test of dependent variables was also performed. P < 0.05 was considered as statistically significant.ResultsThe study group consisted of 132 patients (83 women and 49 men) with a mean age of 75.4 years and mean glycated haemoglobin 7.8%. 71.2% of patients had eGFR < 60 ml/min/1.73 m2. No significant differences were found between eGFR calculated by The Modification of Diet in Renal Disease (MDRD) formula and The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) (SCr), and the Perkins and Ma formulae. Significant differences were found between the eGFR MDRD formula and the CKD-EPI (SCys), CKD-EPI (SCr,SCys) and Rule formulae. The CKD-EPI (SCr) overestimated, while CKD-EPI (SCys) underestimated eGFR compared to MDRD.ConclusionsThe results of eGFR calculations according to the studied equations are not consistent, hence a single calculation of eGFR does not allow to provide a clear classification of patients into CKD stages.