A VAN ZWIETEN1,2, G WONG1,2.3, M RUOSPO4,5, SC PALMER6, MR BARULLI7, A IURILLO7, V SAGLIMBENE1,4, P NATALE4, L GARGANO4, M MURGO4, CT LOY1,8, R TORTELLI7, JC CRAIG1,2,9, DW JOHNSON10,11, M TONELLI12, J HEGBRANT4, C WOLLHEIM4, G LOGROSCINO7,13, GFM STRIPPOLI1,4,14 ON BEHALF OF THE COGNITIVE-HD STUDY INVESTIGATORS
1Sydney School of Public Health, University of Sydney, Sydney, New South Wales; 2Centre for Kidney Research, Children’s Hospital at Westmead, Westmead, New South Wales;3 Department of Renal Medicine, Westmead Hospital, Westmead, New South Wales; 4Diaverum Medical-Scientific Office, Lund, Sweden; 5Division of Nephrology and Transplantation, Amedeo Avogadro University of Eastern Piedmont, Novara, Italy; 6Department of Medicine, University of Otago Christchurch, Christchurch, New Zealand; 7Neurodegenerative Diseases Unit, Department of Clinical Research in Neurology, University of Bari “A. Moro”, “Pia Fondazione Cardinale G. Panico”, Tricase, Lecce, Italy; 8Huntington Disease Service, Westmead Hospital, Westmead, New South Wales; 9Department of Nephrology, Children’s Hospital at Westmead, Westmead, New South Wales; 10Department of Nephrology, Princess Alexandra Hospital, Woolloongabba, Queensland; 11Translational Research Institute, University of Queensland, Woolloongabba, Queensland; 12Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; 13Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari “A. Moro”, Bari, Italy; 14Department of Emergency and Organ Transplantation, University of Bari, Piazza Giulio Cesare, Bari, Italy.
Aim: To evaluate the prevalence and patterns of cognitive impairment in adults on haemodialysis, across five domains of learning and memory, complex attention, executive function, language, and perceptual-motor function.
Background: Existing evidence indicates that haemodialysis patients are at increased risk of cognitive impairment, yet the extent of impairment and patterns of co-occurrence across the spectrum of cognitive domains are understudied.
Methods: We recruited patients from a network of 20 dialysis centres in Italy, and conducted a cross-sectional assessment of their cognitive function (learning and memory, complex attention, executive function, language, and perceptual-motor function) using a neuropsychological battery of ten tests. We calculated test and domain z-scores relative to population norms, defining cognitive impairment as a z-score ≤ -1.5.
Results: Overall 676 of 958 patients in the network participated (70.6%), with a median age of 70.9 years (range 21.6–94.1) and 262 (38.8%) women. Proportions of participants with impairment on each domain were: perceptual-motor function 31.5% (n=150/476), language 41.2% (n=273/662), executive function 41.7% (n=281/674), learning and memory 42.2% (n=269/638) and complex attention 48.8% (n=329/674). Among the 474 participants with data for all domains, 28.9% (n=137) were not impaired on any domain, with 25.9% impaired on a single domain (n=123), 17.3% on two domains (n=82), 13.9% on three domains (n=66), 9.1% on four domains (n=43) and 4.9% (n=23) on all five domains.
Conclusions: Cognitive impairment is extremely common among older hemodialysis patients, across a diverse range of domains, and individual patients often experience multiple deficits. Cognitive function should be routinely considered in clinical care for this patient group, and future research should focus on identifying risk factors for cognitive decline, to facilitate the development of targeted interventions.