HIPPOCAMPAL CEREBRAL BLOOD FLOW DEPENDS ON SYSTEMIC ENDOTHELIAL FUNCTION IN INDIVIDUALS WITH MILD COGNITIVE IMPAIRMENT

Le résumé fourni par la source

Objective: Dementia has been recently viewed as a predominantly vascular disorder. Indeed, reduced brain NO availability causes increased ß-amyloid deposition by several mechanisms, including hypoperfusion. We sought to investigate the relationship between cerebral blood flow in the hippocampal and parahippocampal regions (CBF-hipp and CBF-parahipp), crucial areas for memory and processing of non-verbal/spatial information, and systemic endothelial function in individuals with mild cognitive impairment (MCI), a subclinical condition predisposing to dementia.Design and method: CBF-hipp and CBF-parahipp were evaluated by magnetic resonance imaging (arterial spin labeling, GE HDxt 1.5 T Signa Neuro-optimized System) and systemic endothelial function by flow-mediated dilation (FMD) in the brachial artery. Results: Complete data about CBF and FMD at enrollment were available for 66 individuals with MCI and 32 without (non-MCI). The two groups were matched for age (75 ± 5 vs 74 ± 5years, p = 0.22), sex (men 45 vs 50%, p = 0.18) and mean BP (96 ± 10 vs 97 ± 9 mmHg, p = 0.41). FMD was significantly lower in MCI than in non-MCI (2.93 ± 2.18 vs 3.74 ± 2.03%, p = 0.02); CBF-hipp (64.3 ± 9.43 vs 69.5 ± 7.03 ml/100 gr/min, p = 0.002) and CBF-parahipp (66.3 ± 8.02 vs 70.0 ± 8.12 ml/100 gr/min, p = 0.002) were significantly lower in MCI as well. Among MCI, FMD was significantly correlated with CBF- parahipp (r = 0.26,p = 0.03) and CBF-hipp (r = 0.32,p = 0.009). In multiple regression models, including age, sex, mean BP, BMI, brachial artery diameter as confounders, FMD remained an independent determinant of CBF-parahipp (beta = 0.93, r2 = 0.063, p = 0.04) and CBF-hipp (beta = 1.31, r2 = 0.089, p = 0.01). Nor CBF-parahipp (r = −0.13, p = 0.48) neither CBF-hipp (r = 0.05, p = 0.80) were correlated with FMD in non-MCI group. Conclusions: An independent association between hippocampal and parahippocampal CBF and systemic endothelial function is present in individuals with MCI.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.