An approach to treating older adults with chronic kidney disease

**Background:** Chronic kidney disease (CKD) in older adults is a worldwide epidemic, affecting nearly 40% of people aged 65 or older in the United States, where it is more common than in all other age groups. Over the last 4 decades, patients older than 75 years are the fastest-growing group to start dialysis, and in Canada, more than half of patients starting dialysis are 65 years or older. CKD confers considerable morbidity and consumes substantial health care resources, yet few evidence-based guidelines specifically address management in older adults, many of whom are frail and have multiple comorbidities. This narrative review discusses causes and consequences of CKD through a geriatric lens and outlines principles of best practice.

**Methods:** This is a narrative review summarizing evidence on CKD in older adults. The evidence underpinning the review is summarized in Box 1 of the paper. The authors discuss physiologic versus pathologic causes of kidney dysfunction, diagnostic workup, risk prediction, management of risk factors, and special considerations including electrolyte management, anemia, bone health, and goals of care.

**Key Results:** Physiologic age-related GFR decline begins around the fourth decade of life at about 8 mL/min per decade and usually does not lead to end-stage kidney disease (ESKD). A hallmark of age-related kidney decline is the absence of proteinuria, which portends a favourable prognosis. Patients with slow eGFR decline (< 2 mL/min/yr) and minimal proteinuria (albumin-to-creatinine ratio [ACR] < 3 mg/mmol) are unlikely to reach ESKD. The Kidney Failure Risk Equation (KFRE) predicts 2- and 5-year risk of ESKD using 4 variables: age, gender, eGFR and ACR. The Ontario Renal Network suggests that people with a 5-year KFRE score greater than 3%–5% may benefit from a nephrology referral. Hypertension Canada (2020) recommends a target BP goal of less than 130/80 in patients with CKD and diabetes mellitus, and less than 120/80 in patients with CKD without diabetes mellitus, irrespective of age. The KDIGO 2021 guidelines recommended intensive BP lowering (systolic < 120 mm Hg) irrespective of diabetes status and age, but acknowledge limitations of evidence for patients older than 75 years. For glycemic control, the 2018 Diabetes Canada guideline recommends HbA1c targets of 7.1%–8.5% in patients with dementia and 7.5%–9.0% for most other older patients. Statin use reduces cardiovascular events and mortality, but this effect is attenuated or lost in those older than 85 years. In Canada, patients with ESKD who are older than 70 years have a 1- and 5-year survival of 76% and 28%, respectively.

**Clinical Implications:** Management of risk factors for CKD should be individualized with consideration of less aggressive targets for frail patients at risk of polypharmacy. The KFRE is a useful tool for both general practitioners and nephrologists to identify patients who warrant more intensive management versus those who may benefit from less aggressive targets. Clinicians should have open discussions with older patients with CKD regarding goals of care and the potential benefits and harms of renal replacement therapy. Conservative kidney management without dialysis is a reasonable course for patients with multiple comorbidities and high degree of frailty, focusing on symptom management. Specific symptom management strategies are provided for fatigue, dyspnea, pain, nausea, pruritus, sleep disturbance, restless leg syndrome, and depression. Future research should address gaps in knowledge about optimal blood pressure targets, symptom management, and best care for older patients with ESKD who decide not to start dialysis.