OCTOGENARIANS REFERRED TO THE NEPHROLOGIST: EVOLUTION AND PROGRESSION RISK FACTORS

Abstract BACKGROUND AND AIMS The actual definition of chronic kidney disease (CKD) applied to patients ˃80 years has generated an increase in the number of referrals to Nephrology for consultation. Nowadays there is a debate about the evolution of kidney function in elderly patients, from physiological evolution of kidney function to identifying which factors are associated with a real progression of CKD. The aim of this study is to analyse the evolution of kidney function in patients ˃80 years referred to Nephrology for consultation for the first time. METHOD A single-centre retrospective study in which we included patients ˃80 years with an estimated glomerular filtration rate (eGFR) <60 mL/min/1,73m2 who were referred to Nephrology consultation from 2015 to 2018. We collected clinical and analytical parameters at the following points in time: 12 months before the visit, baseline and 12 months after the initial visit. We divided patients into two groups based on annual eGFR loss: Group 1 progressors (>5 mL/min/1.73m2) and group 2 non-progressors (≤5 mL/min/1.73m2). RESULTS A total of 348 patients were included in the study, 55.2% were women and the mean age was 84 years (80–97). At the time of first medical visit, the mean creatinine value was 1.6 ± 0.6 mg/dL, median eGRF was 38 mL/min/1.73m2 (29–44) and median albumin/creatinine ratio was 55 mg/g (6–419), with 12% of the patients, presenting albuminuria over 1000 mg/g. The most frequent referral criteria were worsening of renal function (85.6%). Comorbidities were very common, and hypertension, dyslipidaemia and diabetes mellitus were present in 89.4%, 42.8% and 42.2% respectively. A total of 51% of the patients met the definition of progressor at baseline (initial-progressors) and 29.4% were progressors after a 12-month follow-up. Interestingly, only 21.6% of initial-progressors kept meeting this definition 12 months after (Figure 1). The main risk factors for progression were a higher baseline eGFR (P < 0.001) and albuminuria (P < 0.002). No association with comorbidities was found in the multivariate analysis. CONCLUSION The majority of patients ˃80 years evaluated by a Nephrologist were non-progressors at 12 months according to our definition (70.6%). It is more important to estimate the progression of CKD patients and request albuminuria and/or proteinuria than an isolated GFR value. It is likely that non-progressors do not need to be followed by a Nephrologist and may remain under primary care control.