Nephrosclerosis impacts time trajectory of renal function and outcomes in elderly individuals with chronic kidney disease

Abstract

Despite hypertension ranks among the leading causes of chronic kidney disease (CKD), the impact of chronic hypertensive nephropathy, the so-called ‘nephrosclerosis’ (NS), on CKD progression is often unpredictable, particularly in elderly population. We have conducted a prospective, observational study to define renal function patterns and outcomes in elderly CKD individuals with or without NS. Three hundred four individuals with an already established CKD were categorized according to the etiology of CKD. NS was defined as the presence of CKD associated with long-term essential hypertension, hypertensive retinopathy, left ventricular hypertrophy and minimal proteinuria. Time trajectories in estimated glomerular filtration rate (eGFR) (CKD-Epi) were computed over a 4-year follow-up. In addition, we analyzed the occurrence of a composite outcome of doubling of serum creatinine levels, eGFR reduction ≥25% and/or the need of chronic renal replacement therapy. CKD was secondary to nephrosclerosis (CKD-NS) in 220 (72.3%). In the whole cohort, the average estimated annual GFR slope was 1.8 mL/min/1.73 m2. eGFR decline was slower in CKD-NS as compared with others (1.4 vs 3.4 mL/min/1.73 m2; p<0.001). The composite renal outcome during follow-up occurred less frequently among elderly with CKD-NS (16/204 vs 14/70; p=0.01, crude HR 0.43, 95% CI 0.22 to 0.85) and was associated at logistic analyses with the etiology of CKD, background cardiovascular disease, total and low density lipoproteins (LDL) cholesterol, and glycemia levels (p value was ranging from 0.01 to 0.05). Despite being highly prevalent in the elderly, NS is associated with a more favorable renal disease course as compared with other conditions.