Critical illness and major infection can lead to brain structure changes and speed up cognitive decline, an analysis conducted by researchers at Baltimore-based Johns Hopkins University found.
For the study, published in the Journal of the American Geriatrics Society, the researchers used data from the Atherosclerosis Risk in Communities Study for a large group of participants who were followed over a 24-year period.
Of the 1,214 hospitalized patients in the analysis, those who had one or more critical illness, such as sepsis or cardiac arrest, had a 3 percent smaller brain volume in brain regions that are implicated in Alzheimer's disease.
Major infection was linked to smaller brain volume in regions vulnerable to Alzheimer's disease (2 percent smaller) and 10 percent larger brain ventricle volume.
Infection can cause critical illness in some cases, but the researchers found infection without critical illness was linked to reduced brain volume later in life.
"The findings do indicate that hospitalization, infection and critical illness may well influence changes in brain regions that underlie dementia," said lead study author Keenan Walker, PhD. "In order to maintain brain health in older adulthood, it is important to maintain bodywide health. Some of the events that can land you in the hospital may serve as risk factors for dementia."