Association of Hospitalization, Critical Illness, and Infection with Brain Structure in Older Adults

• Published in: Journal of the American Geriatrics Society (JAGS) Vol. 66; no. 10; pp. 1919 - 1926
• Main Authors: Walker, Keenan A., Gottesman, Rebecca F., Wu, Aozhou, Knopman, David S., Mosley, Thomas H., Alonso, Alvaro, Kucharska‐Newton, Anna, Brown, Charles H.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.10.2018; Wiley Subscription Services, Inc
• Subjects: Adult; Aged; Alzheimer's disease; Anisotropy; Arteriosclerosis; Brain - diagnostic imaging; Brain - pathology; Communicable Diseases - diagnostic imaging; Communicable Diseases - pathology; Critical Illness - epidemiology; Dementia; Diffusion Tensor Imaging - methods; Female; Hospitalization; Hospitalization - statistics & numerical data; Humans; Illnesses; Infections; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Middle Aged; Neurodegenerative diseases; Neuroimaging; NMR; Nuclear magnetic resonance; Older people; Organ Size; Prospective Studies; Regression Analysis; risk factor; Risk Factors; Substantia alba; Surveillance; Ventricle; White Matter - diagnostic imaging; White Matter - pathology; dementia; magnetic resonance imaging; Alzheimer's disease; risk factor
• DOI: 10.1111/jgs.15470
• ISSN: 0002-8614; 1532-5415

Objectives To examine the association between hospitalization, critical illness, and infection occurring during middle‐ and late‐life and structural brain abnormalities in older adults. Design Prospective cohort study. Setting Atherosclerosis Risk in Communities (ARIC) Study. Participants A community sample of adults who were 44 to 66 years of age at study baseline. Measurements Active surveillance of local hospitals and annual participant contact were used to gather hospitalization information (including International Classification of Diseases, Ninth Revision, codes) on all participants over a 24‐year surveillance period. Subsequently, a subset of participants underwent 3‐Tesla brain magnetic resonance imaging (MRI) to quantify total and regional brain volumes, white matter hyperintensity (WMH) volume, and white matter microstructural integrity (fractional anisotropy (FA) and mean diffusivity (MD) as measured using diffusion tensor imaging (DTI)). Results Of the 1,689 participants included (mean age at MRI 76±5), 72% were hospitalized, 14% had a major infection, and 4% had a critical illness during the surveillance period. Using covariate‐adjusted regression, hospitalization was associated with 0.12–standard deviation (SD) greater WMH volume (95% confidence interval (CI)=0.00–0.24) and poorer white matter microstructural integrity (0.17‐SD lower FA, 95% CI=–0.27 to –0.06; 0.16‐SD greater MD, 95% CI=0.07–0.25) than no hospitalization. There was a dose‐dependent relationship between number of hospitalizations, smaller brain volumes, and lower white matter integrity (p‐trends ≤.048). In hospitalized participants, critical illness was associated with smaller Alzheimer's disease (AD) signature region (–1.64 cm3, 95% CI=–3.16 to –0.12); major infection was associated with smaller AD signature region (–1.28 cm3, 95% CI=–2.21 to –0.35) and larger ventricular volume (3.79 cm3, 95% CI= 0.81–6.77). Conclusions Whereas all‐cause hospitalization was primarily associated with lower white matter integrity, critical illness and major infection were associated with smaller brain volume, particularly within regions implicated in AD.