Review: Cognitive Function in Chronic Kidney Disease

Abstract

Chronic kidney disease (CKD) is a growing public health problem. The incidence of kidney failure is rising in all age groups but particularly in older adults. Individuals in all stages of CKD are at higher risk for development of cognitive impairment and this may be a major determinant in their quality of life. Furthermore, cognitive impairment is associated with an increased risk of death in dialysis patients. Cerebrovascular disease is a strong risk factor for development of cognitive impairment and vascular disease is a more likely cause of cognitive impairment than Alzheimer's disease in patients with CKD. Both traditional and nontraditional vascular risk factors are more common in CKD and dialysis patients may also be at risk for cognitive impairment via nonvascular risk factors and the hemodialysis procedure itself. Unfortunately, because risk factors for cognitive impairment in CKD have not been thoroughly ascertained, evaluation of potential treatments has been limited. Given the high prevalence of cognitive impairment in all stages of CKD, additional studies are needed to evaluate potential risk factors and treatments in this vulnerable population.

Neurological complications of chronic kidney disease

“…Large randomised clinical trials have consistently demonstrated that using higher haemoglobin targets has resulted in worse outcomes including death. 10,13 Finally, the process of dialysis causes significant haemodynamic shifts, these changes in blood flow are hypothesized to adversely affect endorgans and result in perfusion related brain injury. 12 As such, strategies that improve haemodynamic stability such as cooling the dialysate, haemodiafiltration or lower ultrafiltration rate may be beneficial.…”

Cognitive Disorders and Dementia in CKD

“…60 Nontraditional vascular risk factors, such as hyperhomocysteinemia, hypercoagulable states, inflammation, and oxidative stress, have also been linked to cognitive impairment. 61 These factors could accelerate the progression of atherosclerosis and vascular endothelial dysfunction, both of which are associated with dementia risk. 62,63 Interestingly, elevated homocysteine levels are present in 85% of dialysis patients but only 10% of the general population.…”

Cognitive Impairment in Chronic Kidney Disease-Prevalence, Mechanisms and Consequences

“…Interestingly, patients with early stages of CKD already show cognitive impairment [20]. Depending on CKD stage, CKD is frequently associated with prevalence of cognitive impairment in different domains including executive function, information processing speed, memory and language, which range from 17% to 87% [7,[9][10][11][12][13][14][15].…”

“…The MiniMental State Examination (MMSE) test is currently the most widely used screening tool for cognitive impairment in the general population, however it is not able to detect mild cognitive impairment and especially not impairment in executive function which is highly prevalent in CKD [40]. For the CKD context, further the Cognitive Capacity Screening Examination (CCSE) has been suggested to complement MMSE to evaluate cognitive function and the Kidney Disease Quality of Life (KDQOL) self-report instrument including a cognitive function subscale (KDQOL-CF) to additionally assess health-related quality of life [12]. To complement cognitive screening, magnetic resonance imaging could be useful to detect cerebrovascular disease as important determinant of cognitive impairment in CKD.…”

“…Regarding consequences of CKD, most studies concentrate on cardiovascular morbidity and mortality [6], while cognitive function, which is an important determinant of adherence to CKD therapy, is often overlooked [7]. Cognitive impairment in CKD is getting an increasingly relevant topic for healthcare systems, since CKD prevalence worldwide is estimated to be about 12% [8] and cognitive impairment to affect 17% to 87% of CKD patients, depending on CKD severity [7,[9][10][11][12][13][14][15].…”