Acute kidney injury linked to higher risk of some forms of dementia

• Researchers recently published a study about whether acute kidney injuries raise the risk of dementia.
• The researchers looked at the health data from thousands of older adults who had an acute kidney injury, which is when the kidneys suddenly stop functioning correctly.
• They found that acute kidney injuries are associated with a substantially increased risk for dementia, particularly Lewy body dementia or Parkinson’s disease-related dementia.

Dementia affects millions of people in the United States, and some experts believe that case numbers will continue to rise in the coming years.

With this in mind, researchers look for early interventions, treatments, and ways to predict whether someone is at a higher risk for dementia .

Researchers from the Department of Medical Epidemiology and Biostatistics Karolinska Institutet in Sweden used data from the Stockholm CREAtinine Measurement (SCREAM) project , which studies kidney disease.

The scientists checked to see what percentage of participants had an incidence of acute kidney injury , and whether or not they developed any form of dementia.

They learned that people who had acute kidney injuries had a 49% higher chance of dementia than people who did not have an acute kidney injury.

The study appears in the journal Neurology .

Why it’s important to identify dementia risk factors

Dementia affects cognitive abilities and can cause memory loss, loss of language skills, and emotional issues. According to the National Institute on Aging , dementia occurs because of “changes in certain brain regions that cause neurons (nerve cells) and their connections to stop working properly.”

The Population Reference Bureau reports that around 7 million older adults in the U.S. have some form of dementia, and the group anticipates that number to nearly double by 2040.

Alzheimer’s disease makes up the majority of dementia cases, and some other types of dementia include Lewy body dementia , vascular dementia , and mixed dementia.

There is currently no cure for dementia, but some medications can slow down progression or help manage symptoms.

The authors of the current study noted that certain risk factors, such as hypertension , obesity, and alcohol use may contribute to dementia, and they wanted to focus on whether acute kidney injury increases the risk.

“Ascertaining additional risk factors of dementia is important for identifying high-risk individuals early and advancing preventative and monitoring strategies,” the authors write .

The authors noted that acute kidney injury carries a higher risk of mortality, and may disrupt the blood-brain barrier .

Creatinine measurements as kidney injury indicators

The researchers used data from the SCREAM project, which tracks healthcare data from Swedish citizens.

The researchers analyzed data from around 300,000 adults who were at least 65 years old at the time of their first outpatient creatinine measurement. Creatinine measurement assesses kidney function.

Part of the researchers’ inclusion criteria was that participants could not have a dementia diagnosis at the beginning of the study.

The participants had a mean age of 75 years, and 56.6% of the participants were female. The participants had a median follow-up of 12.3 years.

The researchers used follow-up creatinine measurements to assess for acute kidney injury events. The authors considered acute kidney injury events to have occurred when participants had a creatinine measurement of 1.5 times higher than their baseline, a creatinine measurement of 0.3 milligrams per deciliter (mg/dL) higher than average, or an incidence of temporary dialysis .

The researchers took note of any dementia findings. They based this on whether participants started antidementia drugs, diagnostic codes, or registration in the Swedish registry of cognitive/dementia disorders (Sve/Dem) .

Acute kidney injuries lead to an increase in the risk of dementia

After going through the SCREAM project records, the scientists were able to link an incident of acute kidney injury to developing dementia.

Around 26% of the participants had at least one incident of an acute kidney injury, and 16% developed dementia.

The study found that the rate of dementia was significantly higher after an acute kidney injury incident, and individuals had a 49% increased risk of developing dementia compared to before experiencing an acute kidney injury.

When taking the severity of the acute kidney injury into consideration, the authors noted that people who had more severe acute kidney injury cases, or acute kidney injuries that required hospitalization had a higher dementia risk.

The researchers also looked at specific dementia types to see whether the acute kidney injury risk was higher for some types over others. The authors noted an increased risk in the following:

• 88% for Lewy body dementia or Parkinson’s disease-related dementia
• 47% for vascular dementia
• 31% for Alzheimer’s disease.

Overall, the study highlights that people who have acute kidney injuries – especially those who have severe acute kidney injury incidents – may need extra attention in terms of monitoring their cognitive health.

“As a clinical application, this study thus identifies individuals with [acute kidney injury] as a population in which monitoring for dementia and potential preventive and therapeutic strategies may be indicated,” note the authors.

Study findings may change clinical practice

Jason Krellman, PhD , an associate professor of Neuropsychology in Neurology at Columbia University Irving Medical Center in New York and president of the New York Neuropsychology Group, who was not involved in this study, spoke with Medical News Today about the research.

“[Acute kidney injury] is associated with hypertension and heart disease, so damage to blood vessels in the brain might help explain the increased risk of dementia, especially vascular dementia,” explained Krellman. “Relatedly, there might be a link between blood vessel disease and inflammation in the brain with other types of conditions that cause dementia too, but the mechanisms are still unclear.”

Krellman also explained that the study results could make providers aware of the possible need to see a neurologist after a severe acute kidney injury for assessment or to “get a baseline in case there is change in the future so that symptoms are caught early.”

In addition to acute kidney injuries, chronic kidney disease can also impact the risk of dementia.

“We have known for some time that kidney disease or failure contributes to cognitive decline and possible dementia, especially in sicker individuals and those well over 65,” said Krellman.

For people concerned about their dementia risk, Krellman had a few suggestions:

“Patients with [acute kidney injury] should do everything possible to lower their vascular risk factors, such as hypertension, high cholesterol, and diabetes,” noted Prof. Krellman. “This means adopting a heart-healthy lifestyle, including aerobic exercise as tolerated, proper diet, and cutting out smoking.”

Sham Singh, MD , a psychiatrist at Winit Clinic in Santa Monica, CA, who was not involved in the study, also spoke with MNT about its findings.

“The recent findings linking acute kidney injury with an increased risk of dementia could lead to significant changes in clinical practice,” Singh told us.

Singh further explained that the findings would help enhanced monitoring, integrative care approaches, and preventative strategies.

“Given the connection between [acute kidney injury] and cognitive decline, I think there will likely be a need for more rigorous monitoring of cognitive function in these patients,” he commented. “Regular cognitive assessments could become a standard part of follow-up care, enabling early detection of potential dementia.”

Singh also said the findings emphasize the need for an multidisciplinary care approach.

“Collaboration among nephrologists, neurologists, and geriatricians will be essential to provide comprehensive care,” explained Singh. “This multidisciplinary approach ensures that both kidney and brain health are addressed simultaneously, optimizing patient outcomes through coordinated care.”