Department of Psychiatry, New York University Grossman School of Medicine, New York, New York, USA.
Department of Population Health, New York University Grossman School of Medicine, New York, New York, USA.
Physiol Rep. 2024 Jun;12(11):e16084. doi: 10.14814/phy2.16084.
Hypertension disproportionately affects African Americans and is a risk factor for Alzheimer's disease (AD). We investigated the relationship of blood pressure (BP) with medial temporal lobe (MTL) dynamic network flexibility (a novel AD biomarker) and cognitive generalization in older African Americans. In a cross-sectional study, 37 normotensive (systolic BP <130 mmHg, 82.5% F, 64.4 ± 4.9 years; 14.3 ± 2.1 years of education) versus 79 hypertensive (systolic BP ≥130 mmHg, 79.5% F, 66.8 ± 4.1 years; 14.0 ± 0.2 years of education) participants were enrolled. All participants completed a 10-min resting-state functional magnetic resonance imaging scan to assess MTL dynamic network flexibility and two generalization tasks to assess cognition. Anthropometrics and aerobic fitness (via 6-min walk test) were also determined. There was no difference in BMI (29.7 ± 6.4 vs. 31.9 ± 6.3 kg/m, p = 0.083) or aerobic fitness (15.5 ± 2.6 vs. 15.1 ± 2.6 mL/kg/min; p = 0.445) between normotensive and hypertensive groups. However, normotensive participants had higher MTL dynamic network flexibility compared to hypertensive participants (0.42 ± 0.23 vs. 0.32 ± 0.25 mL, p = 0.040), and this was associated with higher mean arterial blood pressure (r = -0.21, p = 0.036). Therefore, hypertensive older African Americans demonstrated lower MTL dynamic network flexibility compared to their normotensive counterparts independent of BMI and aerobic fitness. Further studies are required to determine how blood pressure mediates AD risk in African Americans.
高血压在非裔美国人中发病率不成比例，是阿尔茨海默病（AD）的一个风险因素。我们研究了血压（BP）与内侧颞叶（MTL）动态网络灵活性（一种新的 AD 生物标志物）和老年非裔美国人认知泛化之间的关系。在一项横断面研究中，纳入了 37 名血压正常（收缩压 <130mmHg，82.5% 为女性，66.8±4.1 岁；受教育 14.0±0.2 年）和 79 名高血压患者（收缩压≥130mmHg，79.5% 为女性，64.4±4.9 岁；受教育 14.3±2.1 年）。所有参与者均完成了 10 分钟的静息态功能磁共振成像扫描，以评估 MTL 动态网络灵活性，并完成了两项认知泛化任务以评估认知。还确定了人体测量学和有氧健身（通过 6 分钟步行测试）。血压正常组和高血压组的 BMI（29.7±6.4 与 31.9±6.3kg/m，p=0.083）或有氧健身（15.5±2.6 与 15.1±2.6mL/kg/min；p=0.445）无差异。然而，与高血压组相比，血压正常组的 MTL 动态网络灵活性更高（0.42±0.23 与 0.32±0.25mL，p=0.040），这与平均动脉血压更高相关（r=-0.21，p=0.036）。因此，与血压正常的同龄人相比，高血压的老年非裔美国人的 MTL 动态网络灵活性较低，这独立于 BMI 和有氧健身。需要进一步的研究来确定血压如何介导非裔美国人的 AD 风险。
