Intensive Care Unit Stays Doubles Risk of Dementia

In a study presented at the Alzheimer's Association International Congress 2022 (AAIC2022), a correlation was found between stays in intensive care units (ICUs) and dementia. 

After adjusting for age, sex, education, and racialized identity, individuals who had a stay in the ICU (n=1,992) before the COVID-19 pandemic had a 63% higher risk of Alzheimer dementia (AD) and a 71% higher risk of all-cause dementia than those who had not had an ICU stay (n=1,831). 

The correlation was not only present but actually stronger after adjusting for certain AD risk factors (eg, hypertension, diabetes, body-mass index, vascular risk and disease burden, other chronic medical conditions, functional disabilities, depression, and physical activity). After these adjustments, individuals who had ICU stays had a hazard ration (HR) of 2.10 (95% CI: 1.66, 2.65) for AD and 2.20 (95% CI: 1.75, 2.77) for all-cause dementias. 

“We found that ICU hospitalization was associated with double the risk of dementia in community-based older adults,” said Bryan D. James, PhD, epidemiologist at the Rush University Alzheimer Disease Center in Chicago, IL. “These findings could be significant given the high rate of ICU hospitalization in older persons, and especially due to the tremendous upsurge in ICU hospitalizations during the COVID-19 pandemic. Understanding the link between ICU hospitalization and the development of dementia is of utmost importance now more than ever. More research is necessary to replicate these findings and elucidate the factors that may increase dementia risk. For example, is it the critical illness that sends someone to the hospital or potentially modifiable procedures during the hospitalization that drives dementia risk?” 

Data for this study came from Medicare claims records between 1991 to 2018 of 5 different cohorts (mean age 77.3±7.5) who participated in studies at the Rush Alzheimer Disease Center in Chicago, IL.