Application of MDRD formula in old men with normal serum creatinine level

Objective To appraise the correlation between serum creatinine (SCr) level and estimated glomerular filtration rate(GFR) in a population with normal SCr. Methods The simplified Modification of Diet in Renal Disease(MDRD) formula was used to estimate GFR. Eight hundrad and eighteen subjects were divided into subgroups by their levels of estimated GFR GFR:60 mL/(min·1.73 m2),60-89 mL/(min·1.73 m2),≥90 mL/(min·1.73 m2) and their ages (60-69 years,and ≥70 years). Linear regression and ROC curve were applied to analyze the correlation between SCr and estimated GFR and compare the difference among the subgroups. Results Of the 818 subjects examined,53(6.5%) subjects had a moderate reduced GFR 60 mL/(min·1.73 m2),mean (57±2) mL/(min·1.73 m2) and higher SCr(112±6) μmol/L,with an average age (79±6) years. SCr levels were higher in group ≥70 years old than that in group 70 years old (P0.05). In subjects ≥70 years old,the prevalence of hypertension and type 2 diabetes was 39.2%,while in subjects below 70 years old was 15.0%. In subjects without hypertension and type 2 diabetes,the sensitivity of SCr 109.5 μmol/L in diagnosing chronic kidney disease (CKD) was 100%,and the misdiagnosis rate was 3.1%. In subjects (aged≥70 years) with these two risk factors,the sensitivity of SCr 108.5 μmol/L in diagnosing CKD was 100% and the misdiagnosis rate was 3.2%. Conclusions In subjects aged ≥70 years and with high risk factors of chronic kidney disease (such as hypertension,type 2 diabetes),SCr at high limit of normal value (108.5 μmol/L) in association with GFR estimated by simplified MDRD formula could help the early detection of chronic kidney disease.