Frailty and chronic kidney disease: current evidence and continuing uncertainties

Frailty, the state of increased vulnerability to physical stressors as the result of a progressive and sustained degeneration in multiple physiological systems, is common in those with chronic kidney disease (CKD). In fact, the prevalence of frailty in the older adult population is reported to be 11%, whereas the prevalence of frailty has been reported to be greater than 60% in dialysis-dependent CKD patients. Frailty is independently linked with adverse clinical outcomes in all stages of CKD, repeatedly shown to be associated with an increased risk of mortality and hospitalisation. In recent years, there have been efforts to create an operationalised definition of frailty to aid its diagnosis and to categorise its severity. Two principal concepts are described, namely the Fried Phenotype Model of Physical Frailty and the Cumulative Deficit Model of Frailty, namely the Frailty Index. There is no agreement on which frailty assessment approach is superior, therefore for the time being emphasis should be placed on any efforts to identify frailty. Recognising frailty should prompt a holistic assessment of the patient to address risk factors that may exacerbate its progression and to ensure that they have appropriate psychological and social support. Adequate nutritional intake is essential and individualised exercise programmes should be offered. The acknowledgement of frailty should prompt discussions that explore the future care wishes of these vulnerable patients. With further study, nephrologists could use frailty assessments to inform discussions with patients about the initiation of renal replacement therapy.