Sarcopenia, sarcopenic obesity, and frailty in individuals with chronic kidney disease: a comprehensive review.

Population aging is a global challenge that increases the burden of chronic kidney disease (CKD) and geriatric syndromes such as sarcopenia, sarcopenic obesity, and frailty. These conditions affect almost half of older CKD individuals and are associated with poor outcomes, including CKD progression, cardiometabolic complications, increased health and social care costs, and mortality. They can be both the cause and consequent of CKD and lead to a vicious downward spiral if not addressed early. Frailty is a multidimensional syndrome characterized by reduced physiological reserve and increased vulnerability to stressors. Sarcopenia refers to the progressive and generalized loss of skeletal muscle mass, strength, and/or physical performance with aging. Sarcopenic obesity denotes the combination of sarcopenia and obesity that synergistically leads to poor outcomes. They share common pathogenic mechanisms, such as multimorbidity, inflammation, oxidative stress, uremic milieu, insulin resistance, endocrine disturbances, CKD complications, and psychosocial factors that may limit access to proper nutrition and resources. Management requires a multidisciplinary and patient-centered approach, taking into consideration their baseline physical function and endurance, CKD stage, nutrition status, comorbidities, symptoms, treatment goals, cost, and accessibility. Interventions include exercise, nutrition, comorbidity optimization, geriatric assessment, sensory training, and kidney-oriented care. This review summarizes the current knowledge on the diagnosis and treatment of sarcopenia, sarcopenic obesity, and frailty in individuals with CKD, followed by up-to-date summaries of how best to manage affected individuals.