October 4, 2018
Older men and women undergoing dialysis for kidney disease face an increased risk of developing Alzheimer’s disease and other forms of dementia, according to a new report. And those who do develop Alzheimer’s disease have an increased risk of dying sooner than others on dialysis who did not develop dementia.
Kidney disease is common among older Americans, and as kidney disease advances and the kidneys begin to fail, patients must undergo lifesaving dialysis to filter and remove toxins from the blood. Dialysis is required on an ongoing basis, often several times a week.
Earlier studies have shown that declines in thinking and memory skills are common among those who undergo dialysis for years. Kidney-related cognitive decline was particularly noticeable for executive functions such as attention and impulse control.
To assess the risks, researchers at the Johns Hopkins Bloomberg School of Public Health reviewed the medical records of more than 350,000 men and women undergoing dialysis. Their average age was 66.
The researchers found that the chance of developing Alzheimer’s or other forms of dementia in the first year of initiating dialysis were 4.6 percent for women and 3.7 percent for men. The risk of developing dementia over five years was 16 percent for women and 13 percent for men.
“The dementia risk in this population seems to be much higher than what we see among healthy community-dwelling older adults,” said the study lead, Mara McAdams-DeMarco, assistant professor of epidemiology at the Bloomberg School.
The researchers calculated that over a 10-year period, about 19 percent of those undergoing dialysis beginning at ages 66 to 70 would develop dementia. The risk of dementia among healthy 65-year-olds is only about 1 percent to 2 percent.
For those starting dialysis at ages 76 to 80, the 10-year risk of developing dementia was 28 percent, compared to a 7 percent to 8 percent risk in the general population.
In addition, older dialysis patients who did develop Alzheimer’s or another form of dementia had a two-fold higher risk of dying than dialysis patients who didn’t develop dementia. The findings appeared in the Clinical Journal of the American Society of Nephrology.
The researchers say that doctors should be doing more to monitor, and if possible to slow or prevent, cognitive decline among older dialysis patients. “The high incidence of dementia seems to be overlooked in this population,” Dr. MacAdams-DeMarco said. “We’re currently setting up a large clinical trial to identify appropriate interventions to preserve cognitive function in these patients,” she said.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Mara McAdams-DeMarco, Matthew Daubresse, Sunjae Bae, et al: “Dementia, Alzheimer’s Disease, and Mortality After Hemodialysis Initiation” Clinical Journal of the American Society for Nephrology, August 9, 2018.