Relationship between MRI and amyloid PET measures with cognition in the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study

Abstract

AbstractBackgroundThe U.S. population is aging and becoming more diverse. The Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study enrolled 1,712 participants with the aim of evaluating how race/ethnicity and life‐course factors influence late‐life brain health. We examined the association between brain images and cognition in this cohort.MethodTo date, 164 participants have received MRI and PET imaging (25% Asian, 20% Black, 25% Latino, and 30% White). MRI analyses included regional gray matter, cerebrospinal fluid, and white matter hyperintensity (WMH) volumes. Amyloid PET used AV45 and standard SUVR analysis with cerebellar gray matter as the reference region. Participants underwent neuropsychologic testing and received diagnoses of cognitively normal or impaired (syndrome). Cognitive domains of verbal episodic memory, working memory, and executive function were measured using the Spanish and English Neuropsychological Assessment Scales (SENAS). Linear and logistic regressions were used to assess associations between imaging measures with cognition. Race/ethnicity interactions were tested (significant interaction p<0.10).ResultParticipants had a mean age of 75 (SD=6) years. Verbal memory was positively associated with hippocampal volume [β(95% CI):0.16(0.03, 0.28)] and negatively associated with amyloid burden [β:‐0.20(‐0.33, ‐0.06)]. Cerebral and parietal cortex volumes were associated with better working memory [cerebral β:0.21(0.07, 0.35); parietal β:0.15(0.03, 0.28)] and executive function [cerebral β:0.25(0.11, 0.38); parietal β:0.17(0.05, 0.30)]. Lateral and third ventricle volumes were negatively associated with working memory [lateral ventricle β:‐0.17(0.30, ‐0.04); third ventricle β:‐0.22(‐0.34, ‐0.10)] and executive function [lateral ventricle β:‐0.15(0.28, ‐0.02); third ventricle β:‐0.16(‐0.29, ‐0.04)]. Odds of syndrome were lower in those with greater cerebrum gray matter [OR:0.54(0.32, 0.90)], hippocampal [OR:0.27(0.14, 0.52)], and temporal cortex [OR:0.61(0.38, 0.98)] volumes. The positive associations of hippocampal (interaction p=0.08) and occipital cortex (p=0.02) volumes with verbal memory were significant for Asians and Latinos. Cerebrum gray matter (p=0.06) and parietal cortex (p=0.07) volumes were positively associated with working memory in Blacks. Occipital cortex volume (p=0.07) was positively associated with executive function in Asians. Racial/ethnic differences were seen in the relationship of WMH (p=0.07) and amyloid burden (p=0.04) with syndrome, but small numbers prevented race‐stratification.ConclusionRegional MRI and amyloid burden were associated with cognition and there were significant racial/ethnic differences.