Associations between cerebral amyloid and changes in cognitive function and falls risk in subcortical ischemic vascular cognitive impairment

作者：Dao Elizabeth; Best John R; Hsiung Ging Yuek Robin; Sossi Vesna; Jacova Claudia; Tam Roger; Liu Ambrose Teresa^*

来源：BMC Geriatrics, 2017, 17(1): 133.

DOI：10.1186/s12877-017-0522-4

• Vascular cognitive impairment
• Alzheimer's disease
• Amyloid
• Cognitive impairment
• Executive functions
• Falls risk

Background: To determine the association between amyloid-beta (A beta) plaque deposition and changes in global cognition, executive functions, information processing speed, and falls risk over a 12-month period in older adults with a primary clinical diagnosis of subcortical ischemic vascular cognitive impairment (SIVCI).
Methods: This is a secondary analysis of data acquired from a subset of participants (N = 22) who were enrolled in a randomized controlled trial of aerobic exercise (NCT01027858). The subset of individuals completed an C-11 Pittsburgh compound B (PIB) scan. Cognitive function and falls risk were assessed at baseline, 6-months, and 12-months. Global cognition, executive functions, and information processing speed were measured using: 1) ADAS-Cog; 2) Trail Making Test; 3) Digit Span Test; 4) Stroop Test, and 5) Digit Symbol Substitution Test. Falls risk was measured using the Physiological Profile Assessment. Hierarchical multiple linear regression analyses determined the unique contribution of A beta on changes in cognitive function and falls risk at 12-months after controlling for experimental group (i.e. aerobic exercise training or usual care control) and baseline performance. To correct for multiple comparisons, we applied the Benjamini-Hochberg procedure to obtain a false discovery rate corrected threshold using alpha = 0.05.
Results: Higher PIB retention was significantly associated with greater decrements in set shifting (Trail Making Test, adjusted R-2 = 35.3%, p = 0.002), attention and conflict resolution (Stroop Test, adjusted R-2 = 33.4%, p = 0.01), and information processing speed (Digit Symbol Substitution Test, adjusted R-2 = 24.4%, p = 0.001) over a 12-month period. Additionally, higher PIB retention was significantly associated with increased falls risk (Physiological Profile Assessment, adjusted R-2 = 49.1%, p = 0.04). PIB retention was not significantly associated with change in ADAS-Cog and Verbal Digit Span Test (p > 0.05).
Conclusions: Symptoms associated with SIVCI may be amplified by secondary A beta pathology.

• 出版日期2017-6-28