Cognitive impairment, endothelial biomarkers and mortality in maintenance haemodialysis patients: a prospective cohort study

Background. Haemodialysis (HD) patients have a high prevalence of cardiovascular disease risk factors as well as cognitive impairment. The objective of the present study was to evaluate the interrelationship between cognitive impairment, endothelium-related biomarkers and cardiovascular/non-cardiovascular mortality. Methods. A total of 216 outpatients were recruited from three centres in a dialysis network in Brazil between June 2016 and June 2019. Sociodemographic and clinical data were obtained by applying a patient questionnaire, reviewing medical records data and conducting patient interviews. Cognitive function was assessed using the Cambridge Cognitive Examination. Plasma endothelium-related biomarkers [syndecan-1, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion protein-1 (VCAM-1) and angiopoietin-2 (AGPT2)] were measured. Patients were followed for 30 months. Cox proportional hazards regression models were used to assess the associations of the cognitive function scores and each endothelium-related biomarker with cardiovascular/non-cardiovascular mortality. Results. Cognitive function was associated with cardiovascular mortality {feach standard deviation [SD] better cognitive score was associated with a 69% lower risk for cardiovascular mortality [hazard ratio (HR) 0.31 [95% confidence interval (CI) 0.17-0.58]} but not with non-cardiovascular mortality. Moreover, cognitive function was also correlated with all endothelial-related biomarkers, except VCAM-1. ICAM-1, AGPT2 and syndecan-1 were also associated with cardiovascular mortality. The association between cognitive function and cardiovascular mortality remained significant with no HR value attenuation [fully adjusted HR 0.32 (95% CI 0.16-0.59)] after individually including each endothelial-related biomarker in the Cox model. Conclusions. In conclusion, cognitive impairment was associated with several endothelium-related biomarkers. Moreover, cognitive impairment was associated with cardiovascular mortality but not with non-cardiovascular mortality, and the association between cognitive impairment and cardiovascular mortality in HD patients was not explained by any of the endothelial-related biomarkers.