Can Kidney Disease Affect Your Thinking?

Recently in BMC Nephrology, an article by Månsson et al. shows that processing speed is affected by kidney disease in the elderly. In our next BMC Nephrology blog, Blog Editor Dr. Daphne Knicely looks at what this means for treating our elderly population with kidney disease.

Patients with chronic kidney disease (CKD) are at an increased risk of both dementia and its precursor, mild cognitive impairment. Cognitive dysfunction impacts about 20–50% in elderly patients with moderate CKD and may reach as high as 70% in severe CKD/dialysis. Dementia is more common among the elderly, women, and non-white patients with end-stage kidney disease (ESKD).  It has been shown to be less common among patients receiving peritoneal dialysis (PD) and transplant patients. Cognitive dysfunction in patients with CKD likely results from uremic neurotoxins interacting with neural progenitor cells, the brain vasculature, the lymphatic system, and monoaminergic neurons [1].

Månsson et al. set out to examine if having a GFR < 60 mL/min/1.73m2 impacted cognitive development. They specifically looked at the development of dementia or mild cognitive impairment during a 6-year period. They also examined specific cognitive domains: learning and memory, language, complex attention, executive function, perceptual-motor, global cognitive function, and meta-memory. They found that processing speed, a subdomain of complex attention, was affected by kidney disease. There was no statistical significance in dementia or mild cognitive impairment associated with mild renal impairment (mean GFR was 74 mL/min/1.73m2).

Knowing that patients with kidney disease are at risk of cognitive impairment, what can I do to better serve this population as their physician? We should provide this population with support and resources including support groups and patient education with the potential to improve outcomes though there is not strong data yet to support this. Providing additional resources like social workers, counseling with pharmacists, and other therapies might prevent adverse outcomes in this group. After reading Månsson et al. article, I know I will work towards recognizing and accommodating mild cognitive impairment in my CKD clinic. I intend to change my practice by giving patients additional time to complete forms during the visit such as intake forms. I frequently provide patient education during a visit, such as low sodium diet, dialysis modalities, etc. This may be better served through going at a slower pace or incorporating a separate visit focused on CKD education instead of speeding through it in a 20-minute follow-up visit. I don’t always write down all of my treatment changes for the patient such as stop this medication or increase this medication, but I will now. I hope to provide written information that they can return to later by typing out my patient instructions more thoroughly or giving handouts on topics we discuss during our education. And finally, repetition is key to allow them to process it in their own time.


[1] Viggiano, D., Wagner, C.A., Martino, G. et al. Mechanisms of cognitive dysfunction in CKD. Nat Rev Nephrol 16, 452–469 (2020).

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