The intensive care unit remains associated with a doubling of the risk of dementia

Older adults who have spent time in the intensive care unit (ICU) are twice as likely to develop dementia in later years compared to older adults who have never stayed in the intensive care unit, new research suggests.

“Hospitalization in the ICU may be an underestimated risk factor for dementia in older adults,” said Dr. Bryan D. James, epidemiologist at Rush Alzheimer’s Disease Center, Chicago, Illinois Medscape Medical News.

“Healthcare providers caring for older patients who have experienced hospitalization for a critical illness should be prepared to assess and monitor their patients’ cognitive status as part of their long-term care plan,” James added.

The findings were presented at the Alzheimer’s Association International Conference (AAIC) 2022.

Hidden risk factor?

ICU hospitalization as a result of critical illness has been associated with subsequent cognitive impairment in elderly patients. However, how hospitalization in the intensive care unit affects the long-term risk of developing Alzheimer’s and other age-related dementias is unknown.

“Given the high rate of ICU hospitalizations among the elderly, particularly during the COVID-19 pandemic, examining this relationship is critical,” James said.

The Rush team assessed the impact of an ICU stay on dementia risk in 3822 older adults (mean age 77 years) with no known dementia at baseline, who participated in five different epidemiological cohorts.

Participants were assessed annually for the development of Alzheimer’s and all types of dementia using standardized cognitive assessments.

Averaging 7.8 years, 1,991 (52%) adults had at least one ICU stay; 1031 (27%) had an ICU stay prior to study entry; and 961 (25%) had an ICU stay during the study period.

In models adjusted for age, sex, education, and race, ICU hospitalization was associated with a 63% greater risk of developing Alzheimer’s dementia (hazard ratio [HR] 1.63; 95% CI, 1.41-1.88) and 71% higher risk of all types of dementia (HR, 1.71; 95% CI, 1.48-1.97).

In models further adjusted for other health determinants, such as vascular risk factors and diseases, other chronic diseases, and functional disabilities, the association was even stronger: ICU hospitalization was associated with about twice the risk of Alzheimer’s dementia (HR 2, 10; 95% CI, 1.66-2.65) and all types of dementia (HR, 2.20; 95% CI, 1.75-2.77).

said James Medscape Medical News It remains unclear why a stay in the intensive care unit can increase the risk of dementia.

“This study was not designed to assess the causes of the higher risk of dementia in people hospitalized in the ICU. However, the researchers looked at a number of factors that may be responsible for this increased risk,” he explained.

One is a critical illness itself, leading to hospitalization that can lead to brain damage; For example, severe COVID-19 has been shown to damage the brain directly, James said.

He also noted that certain events experienced during the ICU stay have been shown to increase the risk of cognitive impairment, including infections and severe sepsis, acute dialysis, neurological dysfunction and delirium, and sedation.

Important work

Commenting on the study for Medscape Medical NewsHeather Snyder, PhD, vice president of medical and scientific relations at the Alzheimer’s Association, said what’s interesting about this study is that it looks at people in the ICU regardless of the cause.

“The study shows that one type of health condition that leads to an ICU stay is associated with an increased risk of cognitive decline,” Snyder said.

“This is really important,” she said, “particularly given the increase in people, particularly those over the age of 60, who have experienced ICU stays in recent years and understanding how this relates to their long-term risk.” associated with Alzheimer’s and other changes in memory.”

“If a person has been in the ICU, that should be part of the discussion with their doctor or healthcare provider,” Snyder advised.

The study was funded by the National Institute on Aging. James and Snyder have not disclosed any relevant financial relationships.

Alzheimer’s Association International Conference (AAIC) 2022: Abstract 67719. Presented on July 31, 2022.

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