科研之友
微信
新浪微博
Facebook
分享链接
摘要
IMPORTANCE Motor slowing appears in preclinical Alzheimer disease (AD), progresses with AD progression, and is associated with AD pathologic findings at autopsy. Whether amyloid-beta (A beta) is associated with gait speed in elderly individuals without dementia and whether cognition and apolipoprotein E epsilon 4 (APOE e4) influence this association remain unknown. OBJECTIVES To examine the association between A beta and gait speed in elderly individuals without dementia and to study the influence of cognition and APOE e4 status on this association. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional analysis included 183 elderly individuals without dementia, including a cognitively normal (CN) subsample of 144 adults, enrolled in the Ginkgo Evaluation of Memory study at a university center from January 1, 2000, through December 31, 2009, and enrolled in a follow-up substudy a mean (SD) of 10 (3) months after the initial study closeout. Data analysis was performed from October 1, 2015, to June 1, 2016. MAIN OUTCOMES AND MEASURES We assessed cerebral A beta on Pittsburgh Compound B (PiB) positron emission tomography, gait speed over 4.57m(15 ft), and cognition on the Mini-Mental State Examination and Trail Making Test Parts A and B. We grouped participants into high A beta (PiB(+)) and low A beta (PiB(-)) groups on standardized global PiB cutoffs and examined group differences. We studied the influence of cognition and APOE e4 on the global and regional associations between gait speed and A beta in the whole sample and the CN subsample. RESULTS Among the 183 study participants, mean (SD) age was 85.5 (3) years, 76 were women (41.5%), and 177 were white (96.7%). The PiB+ individuals were comparable to the PiB-individuals on demographics, comorbidities, cognition, hippocampal volume, and small-vessel disease but not on gait speed (0.85 vs 0.92m/s, P = .01) or proportion of APOE e4 carriers (29 [29.0%] vs 5 [6.0%], P <.001). In the whole sample and the CN subsample, the association between global PiB retention and slower gait withstood adjustment for covariates (beta = -0.068, P =.03 and beta = -0.074, P =.04, respectively); however, this association was attenuated by Mini-Mental State Examination and Trail Making Test Parts A and B and was rendered statistically nonsignificant by APOE e4 in both samples (beta = -0.055 and beta = -0.058, respectively; both P >= .10). Several regional associations between gait speed and PiB uptake withstood relevant adjustments; however, APOE e4 rendered only the medial (beta = -0.22, P =.03) and lateral (beta = -0.08, P =.03) temporal regions, subcortical white matter (beta = -0.13, P =.02), and occipital regions (beta = -0.15, P =.03) in the whole sample and the occipital regions (beta = -0.21, P =.01) in the CN subsample statistically significant. CONCLUSIONS AND RELEVANCE Cerebral A beta deposition is associated with slower gait speed in elderly individuals without dementia; however, this association is weaker in those who are CN. Cognition and APOE e4 carrier status influence the association between A beta and gait speed in elderly individuals without dementia.
- 出版日期2017-1-1
