Examining the Effects of Hospitalization in ADNI Subjects: Characterizing Changes in Cognition and Glucose Metabolism Associated with Inpatient Hospital Stays

Abstract

AbstractBackgroundRisk of inpatient hospitalization and dementia both increase with age, though no study has attempted to characterize lasting changes in regional brain metabolism occurring after inpatient hospitalization.MethodWe screened adverse events reported to the Alzheimer’s Disease Neuroimaging Initiative (ADNI), identifying subjects with minimum one‐night hospitalizations and two pre‐ and two post‐hospitalization ADNI visits. 523 visits from 133 subjects were included in neuropsychological analysis, with 55 subjects hospitalized for major surgery. An analogous “event date” was set in demographically matched control subjects using the median elapsed time from first visit to hospitalization; 352 visits from 88 controls were included. Memory and executive function composite scores were used to calculate pre‐ and post‐event cognitive trajectories. Pre‐ and post‐event FDG‐PET images were acquired and quantitatively examined using standardized volume of interest (sVOI) analysis. Students t‐tests were used to determine the difference in pre‐ and post‐event trajectories within groups and between groups.ResultWithin‐group analysis of inpatient subjects revealed significantly declined trajectory of memory and executive function after hospitalization (p<0.001, p = 0.02), though the difference in pre‐ and post‐event trajectory did not differ significantly from the control group. There was no significant difference in change in trajectory between subjects with surgical and non‐surgical hospitalizations. To prevent the dilution of metabolic alterations that may begin on one‐side, the sVOI with the greatest decline between post‐ and pre‐event trajectory was chosen for all bilateral volumes. Within the inpatient group, significant decline in metabolic trajectory after hospitalization was observed in the inferior lateral anterior and medial anterior temporal volumes (p<0.005, p<0.0005). This change in metabolic trajectory in the anterior temporal volumes after hospitalization was not significantly different between surgical and non‐surgical subjects. Finally, the decline in trajectory observed in the inferior lateral and medial anterior temporal volumes in the inpatient group was significantly greater than the control group (p = 0.05, p = 0.005), in which no significant decline in trajectory was observed.ConclusionInpatient hospitalization is associated with accelerated decline in metabolic trajectory after discharge in two anterior temporal volumes, regardless of whether the hospitalization was associated with a major surgery.