#3094 Prevalence and risk factors for progression and mortality in patients with advanced chronic kidney disease
Authors: Venda João , Henriques Andreia Dos Santos , Fernandes Beatriz , Leal Rita , Alves Rui 
Published: May 2024

Abstract

Background and Aims
Chronic kidney disease (CKD) is a growing health concern worldwide. Prevalence and risk factors for its progression are highly relevant, given that Portugal has the highest incidence and prevalence rates of dialysis in Europe. With this study, we aimed to estimate the prevalence of patients with CKD stage 4 and 5 in a tertiary center in Portugal, as well as to evaluate risk factors for progression and mortality.

Method
We evaluated all patients followed in the Nephrology outpatient clinic at a tertiary center in Portugal during the year 2021, and selected those with CKD stage 4 and stage 5, based on estimated glomerular filtration rate (eGFR) using CKD-EPI formula. Primary endpoints were CKD progression or mortality after 1 year of follow-up. Progression was defined as initiating renal replacement therapy (RRT) or transition from stage 4 to stage 5 CKD.

Results
We evaluated 4381 patients, of which 1083 (24.7%) were included with CKD stage 4 (n = 856) and CKD stage 5 (n = 227). There was a predominance of males (52.7%), with a mean age of 74.6 ± 12.5 years. We observed a high prevalence of hypertension (94%), diabetes mellitus (46.2%), dyslipidemia (81%), heart failure (34%) and past history of major cardiovascular events (21%). At one year follow-up 108 patients died, 116 lost follow-up, and 256 (26.5%) had CKD progression, of which 179 (18.5%) initiated renal replacement therapy. 33.5% of patients initiating dialysis had a definitive access, mostly in stage 5 CKD (40 vs. 25%, p &lt; 0.05). Risk factors for progression (versus stability) in univariate analysis were male gender (64.5 vs. 50.1, p &lt; 0.001), younger age (68 vs. 75 years, p &lt; 0.001) and lower eGFR (16 vs. 22 mL/min). Progression occurred in 51% of stage 5 CKD vs. 26.5% stage 4. Worse laboratory control of anemia, hyperparathyroidism, acidosis, and albuminuria (urinary albumin/creatinine ratio 1242 vs. 302 mg/g, p &lt; 0.01) were identified risk factors for progression. In multivariate analysis, predictors for CKD progression were younger age (OR: 0.97, CI: 0.95-0.99, p = 0.02), male gender (OR: 2.82, CI: 1.43-5.57, p = 0.003), lower eGFR (OR: 0.80, CI: 0.74-0.86, p &lt; 0.001), lower hemoglobin levels (OR: 0.62, CI: 0.48-0.79, p &lt; 0.001), and proteinuria (OR: 1.44, CI: 1.22-1.53, p 0.003). Regarding mortality, no statically significant differences were observed between CKD stage 4 and 5, and in multivariate analysis the only independent risk factors for death were older age and heart failure, which increased 3.4 times mortality risk (OR: 3.40, CI: 1.48-7.83, p = 0.04).

Conclusion
Our data show a high prevalence of CKD and traditional risk factors, with an annual progression rate of 26.5%. Anemia and proteinuria were identified as modifiable risk factors for progression. In older patients with heart failure, the mortality risk was found to be higher than progression risk, highlighting the importance of cardiovascular protection and consideration of conservative management in this particular subset of patients.