Apathy associates with cognitive dysfunction and mortality in older ckd patients

Abstract BACKGROUND AND AIMS The growing population of older patients with chronic kidney disease (CKD) often faces unidentified cognitive impairments and high prevalence of depressive symptoms. Apathy is a clinical syndrome associated with both depression and cognitive decline in community-dwelling older people. Furthermore, apathy has been more often linked to vascular impairments, which are also highly prevalent in the CKD population. However, so far, prevalence and consequences of apathy in older CKD patients have not been studied. We aimed (1) to investigate the prevalence of apathy symptoms in an older population with CKD stage G4/G5 (eGFR < 20 mL/min/1.73 m2), and (2) to assess if apathy is associated with, frailty, cognitive and functional impairments and mood. In addition, we (3) investigated the relation between apathy at baseline and mortality during four years of follow-up. METHOD Data was used from the prospective multicenter COPE (Cognitive Decline in Older Patients with ESKD) cohort, which included CKD patients aged ≥65 years with an eGFR of ≤20 mL/min/1.73 m2. Symptoms of apathy were assessed with the 3-item subscale of the 15-item Geriatric Depression (GDS-3A score ≥2) and depressive symptoms with the remaining items of this scale (GDS-12D ≥2). Frailty, (Fried Frailty Index ≥3), functional dependence (GARS score), handgrip strength and walking speed were measured. Cognitive functioning was assessed by means of global cognition (Mini Mental State Examination), visuoconstruction (Clock drawing), memory (15-Word Verbal Learning Test and Visual Association Test), executive function (Trail Making Test-B) and psychomotor speed (Letter Digit Substitution Test, Trail Making Test -A). Cross-sectional correlations between groups were tested with t-tests, Mann–Whitney and Chi-squared tests. Hazard ratio for mortality was analysed with Cox regression adjusting for age, gender and primary vascular kidney disease. RESULTS In total n = 180 patients, 67% male, were included with a median age of 75.5 years (IQR 71.0–80.9) and mean eGFR of 16.5 (SD 4.6). Symptoms of apathy and isolated apathy (i.e. with no symptoms of depression) were seen in respectively 36% (n = 64) and 17% (n = 30) of the study population. Presence of apathy symptoms at baseline was associated with primary vascular kidney disease (P = 0.031), depression (P < 0.001), frailty (P < 0.001) and decreased physical functioning (i.e. functional dependence; P < 0.001, handgrip strength; P = 0.026 and walking speed; P < 0.001). Presence of apathy symptoms was also associated with reduced executive function (P = 0.045) and psychomotor speed (P = 0.022). Furthermore, patients with apathy symptoms had a 1.9 times higher mortality risk (P = 0.022, adjusted for age, gender and primary vascular renal disease). CONCLUSION Symptoms of apathy occurred in one third of this cohort of older advanced CKD patients. Although apathy was associated with presence of depressive symptoms, half of the cases were not. Apathy is associated with multiple functional and cognitive measures and two-fold increased mortality. Future investigations should focus on cause of apathy and its value in predicting cognitive decline in older CKD patients. Because of the relation of apathy with future outcomes, assessment of apathy might be of value in shared decision making on renal replacement therapy in older CKD patients.