Apathy Symptoms, Physical and Cognitive Function, Health-Related Quality of Life, and Mortality in Older Patients With CKD: A Longitudinal Observational Study

Abstract

Apathy reflects diminished motivation, goal-directed behavior, and emotions, as well as less engagement in social interactions. Apathy overlaps with depression and is associated with cognitive decline. In the older individuals with chronic kidney disease (CKD), both depression and cognitive impairments are common, but apathy symptoms have been underreported. We investigated the occurrence of apathy symptoms and their associations with physical and cognitive functioning, health-related quality of life (HRQoL), and mortality in older patients with CKD. Prospective observational cohort study. 180 outpatients aged≥65 years with estimated glomerular filtration rate≤20mL/min/1.73m2 from 5 Dutch nephrology centers. Apathy symptoms at baseline were considered present when a Geriatric Depression Scale's 3-item apathy subscale score was≥2 points. Physical and cognitive functioning, HRQoL (assessed in annual geriatric assessments), and 4-year mortality. Linear regression for cross-sectional associations, linear regression models for longitudinal associations, and Cox regression models for mortality over 4 years of observation. Apathy symptoms were present in 64 patients (36%; 67% men; median age 75.5 years), of whom 32 (50%) had no depressive symptoms. At baseline, the presence of apathy symptoms was associated with significantly more frailty, more functional dependence, less physical capacity, lower visuoconstructive performance, worse delayed recall, and lower HRQoL scores. The presence of apathy symptoms at baseline was also associated with a higher mortality risk (hazard ratio, 2.3 [95% CI, 1.3-4.2], P=0.005 adjusted for age, sex, and high education level), but not with changes in physical and cognitive functioning or HRQoL during the follow-up period. Risk of selection bias and residual confounding. Apathy symptoms were highly prevalent and associated with concurrent lower physical and cognitive status, lower HRQoL, and increased mortality. These findings highlight apathy as a potentially important clinical phenotype in older CKD patients. We observed that older kidney patients often present apathy symptoms, such as less motivation, fewer goal-directed behaviors, fewer emotions, and less social engagement. Prior research has not extensively described apathy in kidney disease. We investigated the link between apathy symptoms and poor outcomes. We measured physical functioning, cognitive functioning, and quality of life. We learned that one-third of our older kidney patients showed symptoms of apathy, only half of whom had symptoms of depression. Patients with apathy symptoms showed lower quality of life and lower physical and cognitive performance. They also had a higher risk of death. These findings highlight the need for awareness of apathy symptoms in older kidney patients.