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The Overlooked Link Between Kidney Disease, Dialysis, and Cognitive Decline

April 28, 2026
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Geriatrician and dementia researcher, Anne Murray, MD, MSc

Geriatrician and dementia researcher, Anne Murray, MD, MSc

Anne Murray, MD, MSc, is an internal medicine doctor, a geriatrician (a doctor who cares for senior citizens), and a dementia epidemiologist. A dementia epidemiologist explores the different subtypes of dementia and cognitive impairment (CI) in aging populations and their associated risk factors to better understand how to prevent them. Dr. Murray is also the Medical Director of the Berman Center for Outcomes and Clinical Research and a Professor of Medicine/Adjunct Professor of Neurology at the University of Minnesota.

Throughout her career, Murray has been fascinated by the complexities and natural history of aging and has challenged the status quo. One topic she has explored over the past twenty years is chronic kidney disease (CKD).

According to the National Kidney Foundation, “Chronic kidney disease is when the kidneys have become damaged over time (for at least 3 months) and have a hard time doing all their important jobs. CKD also increases the risk of other health problems like heart disease and stroke. Developing CKD is usually a very slow process with very few symptoms at first.”

One complexity she’s explored is why patients with moderate to end-stage chronic kidney disease (CKD) on hemodialysis have two to four times the rate of cognitive impairment and dementia compared to those without CKD. Murray has conducted several studies in hemodialysis patients, patients who receive treatment from a machine that removes waste and toxins from the blood. As the Principal Investigator (PI), she’s led the National Institutes of Health (NIH) National Institute of Aging (NIA)-funded study on the BRain IN Kidney disease (BRINK) study in patients in the Twin Cities with moderate CKD, who have about half or less of their kidney function.

Unfortunately, cognitive function in hemodialysis patients had largely been ignored by the neurology and nephrology communities prior to the year 2000. Noticing this underserved population, Murray decided to study the epidemiology of cognitive impairment in hemodialysis patients after observing several frequently confused dialysis patients during their treatments. She hypothesized that the hemodialysis process induced recurrent acute confusion, or delirium, and thus increased stroke risk due to the decreased blood flow to the brain during the dialysis session, which can later result in patients with CI.

To explore this hypothesis, she and her team conducted several studies, resulting in the following results:

FINDING 1

  • Cognitive function fluctuates during the two-day dialysis process, similar to delirium, with the worst symptom presentation during dialysis and the best symptom presentation on the day after dialysis, especially with memory and executive function.
  • Verbal memory (list of items) fell from seven to four items, and executive function was impaired (decision-making skills).
  • The best time for physicians and staff to talk to hemodialysis patients is before their dialysis treatment or on their day off. In this study, 21 hemodialysis patients had cognitive testing four times over the two-day dialysis cycle: at dialysis session start, one hour later, an hour after the session, and in between dialysis sessions.

FINDING 2

  • Over two-thirds of hemodialysis patients 55+ years had moderate to severe CI (equivalent to dementia), using a standardized cognitive battery, and only 7% had been previously diagnosed.
  • This study measured CI occurrence and CI risk factors in 374 hemodialysis patients in 13 urban hemodialysis units in the Twin Cities region of Minnesota.
  • Hemodialysis may help cognitive function at first, but after one or more years, it increases the risk of cognitive impairment.
  • Patients considering hemodialysis may want to discuss delaying initiation or using peritoneal or home dialysis (home-based treatment for kidney failure), which carries lower risks of cognitive impairment.

FINDING 3 Detailed medical illustration of brain stroke with highlighted affected area and neural connections.

  • The process of first starting (initiating) hemodialysis appears to greatly increase the risk of stroke.
  • Hemodialysis initiation was associated with a four to seven-fold increased risk of new strokes during the first month and later declined to twice their pre-dialysis stroke rate at one year.
  • Study: analysis of Medicare data using the United States Renal Data Systems (USRDS) database, in collaboration with epidemiologists at the Hennepin Healthcare Research Institute (HHRI) Chronic Disease Research Group (CDRG).

FINDING 4

  • About 25-30% of patients with moderate to severe CKD with an estimated kidney function rate or estimated glomerular filtration rate (eGFR) under 45 have cognitive impairment.

FINDING 5

  • Small blood vessels or microvascular disease, as measured by eGFR and inflammation markers such as albuminuria (urine protein) and Tumor Necrosis Factor Receptor 1 (TNFR1), are important mechanisms that play a role in the brain’s white matter changes and brain shrinkage on Magnetic Resonance Imaging (MRIs), leading to cognitive impairment in CKD.

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