Assessment of cognitive impairment and related risk factors in hemodialysis patients

Abstract

Background Cognitive impairment in hemodialysis patients has been acknowledged over the last years and has been reported in up to 80% of patients. Older age, high prevalence of cardiovascular risk factors, such as stroke and transient ischemic attack, uremia, and multiple metabolic disturbances represent the most common factors for cognitive impairment in hemodialysis patients. Methods We conducted a prospective cohort study on 408 patients from 10 hemodialysis centers in the regional government district of Middle Hesse (Germany). Patients underwent a neuropsychological test battery consisting of five tests, in addition to a phonemic fluency test, to assess cognitive profile. The patients were classified into no cognitive impairment mildly-, moderately- or severely-impaired cognitive function, depending on the degree of impairment and number of domains where the deficit was determined. We analyzed the cognitive profile and the change in performance over time in hemodialysis patients based on their cognitive status at baseline vs. 1-year follow-up. Results Of 479 eligible patients, 408 completed all tests at baseline. Only 25% (n = 102) of the patients had no cognitive impairment. Fourteen per cent (n = 57), 36.5% (n = 149), and 24.5% (n = 100) of patients showed mild, moderate, and severe impairment, respectively. In patients with cognitive impairment, all cognitive domains were affected, and impairment was significantly associated with depression and education. The most impaired cognitive performance was immediate memory recall, and the best performance was found in naming ability. No significant change was observed after 1 year- follow up in any domain. Conclusion Our study shows that the prevalence of cognitive impairment in hemodialysis patients is high and that it is affected by the presence of depression. Furthermore, education has an effect on cognitive test results. As depression has a significant influence on cognitive impairment, its early identification is essential in order to initiate treatment at an early stage, hoping to positively influence cognitive performance. Graphic abstract

Neuropsychological Assessment of Cognitive Impairment in Kidney Transplantation (NAsKiT) and its related risk factors: a study protocol

“…We use a more comprehensive neurocognitive test battery, which is then also able to establish a neurocognitive profile in individuals after kidney transplantation. A recently published study showed a high prevalence of cognitive impairment in dialysis individuals [5], examined by the CERAD Test battery [43].…”

“…We extended this questionnaire to include stress levels before and after testing prior to planned transplantation by the item "How stressed do you feel at the moment?" (1)(2)(3)(4)(5)(6)(7)(8)(9)(10).…”

“…The development of cognitive functioning and the detailed degree (i.e., which cognitive domains are particularly affected) has not yet been well studied in kidney transplant individuals. Previous studies in individuals with end-stage renal disease have shown that executive functions are particularly affected [5].…”

“…To date, efforts to improve cardiovascular and metabolic parameters after transplantation have been made, but the cognitive aspects of chronic kidney disease (CKD) have been relatively overlooked. Association of cognitive impairment with CKD has been reported over the last decade [1][2][3][4][5]. Several studies suggested a prevalence of cognitive impairment in up to 80% of individuals with CKD [1,2,[5][6][7][8][9].…”

“…Association of cognitive impairment with CKD has been reported over the last decade [1][2][3][4][5]. Several studies suggested a prevalence of cognitive impairment in up to 80% of individuals with CKD [1,2,[5][6][7][8][9]. It has been demonstrated that individuals showed better cognitive performance after kidney transplantation than dialysis individuals [10] but these individuals are also significantly more likely to be affected by cognitive impairment or dementia than agematched comparison groups [11][12][13].…”