With the aging population, a high prevalence of obesity, systemic arterial hypertension and diabetes mellitus, we are facing an increased incidence of elderly patients with chronic kidney disease (CKD) initiating renal replacement therapy. The correct diagnosis of CKD, the prognosis of the elderly patient with CKD, mainly comparing initiated dialysis vs. remaining in conservative treatment, the nutritional prognostic markers (sarcopenia), cardiovascular, mineral and bone metabolism, geriatric syndromes and sleep disorders are still debatable. Elderly patients are usually excluded from clinical trials and the scientific evidence is either scarce or based on retrospective data. Thus, the present study is a prospective cohort to evaluate the long-term evolution of patients ≥ 70 years with stage 4 or 5 CKD. The main outcomes are mortality and dialysis as a combined event. These endpoints will be correlated with independent parameters: Klotho, FGF23, nutrition and sleep quality. Confounders variables are cognition, depression, demographic, clinical and laboratory parameters, and daytime somnolence. Patients will be followed at the nephrology outpatient clinic of the Hospital das Clinicas, Universidade de Sao Paulo. The sample size was calculated to be 200 subjects. The summary methodology will include a broad geriatric assessment, cognition test, fragility, Charlson comorbidity scores, biochemical measurements of urea, creatinine, alkaline phosphatase, parathyroid hormone, calcium, phosphorus, vitamin D, vitamin B12, folic acid, thyroid hormones, hepatitis virus, serum albumin, albumin/creatinine ratio, protein/creatinine ratio, 24-h urinary protein, Epworth Sleepiness Scale, Pittsburgh questionnaire, segmental electric bioimpedance, and nutritional evaluation by 24h dietary interview.

Main outcome: combined event mortality-dialysis

Independent variables: nutrition status, sleep quality, Klotho and FGF-23 Confounders: clinical and demographic variables, Charlson comorbidity index, Laboratory parameters, depression, functionality, cognition.

• Clinical diagnosis of Chronic Kidney Disease stage 4 or 5
• Minimal age of 70 years
• Must be able to understand and sign the consent form

Exclusion Criteria:

• Patients who did not accept and sign the consent form
• Patients with cancer and life expectance lower than 6 months
• Moderate to advanced dementia

Outpatients with CKD that have been followed in the nephrology service - Nephrogeriatric ambulatory