美国加州大学戴维斯分校研究人员日前发表报告说,他们的研究结果显示,高血压会加速中年患者大脑老化的进程。
该研究对象包括579名中年人,2009年参与研究时他们的平均年龄为39岁。根据受试者血压状况,他们被分为3组:正常血压组、临近患高血压组和高血压组。研究人员利用磁共振成像仪确定受试者的大脑健康状况。
研究人员发现,高血压患者的大脑健康状况明显不及血压正常者——高血压组受试者大脑额叶各向异性比血压正常者平均低6.5%,前叶和颞叶灰质容量平均低9%;高血压患者的大脑看起来“更老”,例如,一名33岁典型高血压患者的大脑与40岁血压正常者的大脑相似。
研究人员没有提出造成这种损伤的机制,不过他们指出,高血压会导致动脉硬化,进而减少了流向大脑的血流,大脑获得的氧气和营养也相应降低。
相关研究报告已发表在英国《柳叶刀·神经病学》杂志网络版上。研究负责人、戴维斯分校神经病学教授查尔斯·德卡利表示,这项研究传递的信息很清楚:年轻时就了解并治疗自己的高血压可以避免其影响晚年时的大脑健康。(生物谷Bioon.com)
doi: 10.1016/S1474-4422(12)70241-7
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Effects of systolic blood pressure on white-matter integrity in young adults in the Framingham Heart Study: a cross-sectional study
Maillard P, Seshadri S, Beiser A, Himali JJ, Au R, Fletcher E, Carmichael O, Wolf PA, Decarli C.
BACKGROUND: Previous studies have identified effects of age and vascular risk factors on brain injury in elderly individuals. We aimed to establish whether the effects of high blood pressure in the brain are evident as early as the fifth decade of life. METHODS: In an investigation of the third generation of the Framingham Heart Study, we approached all participants in 2009 to ask whether they would be willing to undergo MRI. Consenting patients underwent clinical assessment and cerebral MRI that included T1-weighted and diffusion tensor imaging to obtain estimates of fractional anisotropy, mean diffusivity, and grey-matter volumes. All images were coregistered to a common minimum deformation template for voxel-based linear regressions relating fractional anisotropy, mean diffusivity, and grey-matter volumes to age and systolic blood pressure, with adjustment for potential confounders. FINDINGS: 579 (14·1%) of 4095 participants in the third-generation cohort (mean age 39·2 years, SD 8·4) underwent brain MRI between June, 2009 and June, 2010. Age was associated with decreased fractional anisotropy and increased mean diffusivity in almost all cerebral white-matter voxels. Age was also independently associated with reduced grey-matter volumes. Increased systolic blood pressure was linearly associated with decreased regional fractional anisotropy and increased mean diffusivity, especially in the anterior corpus callosum, the inferior fronto-occipital fasciculi, and the fibres that project from the thalamus to the superior frontal gyrus. It was also strongly associated with reduced grey-matter volumes, particularly in Brodmann's area 48 on the medial surface of the temporal lobe and Brodmann's area 21 of the middle temporal gyrus. INTERPRETATION: Our results suggest that subtle vascular brain injury develops insidiously during life, with discernible effects even in young adults. These findings emphasise the need for early and optimum control of blood pressure. FUNDING: National Institutes of Health and National Heart, Lung, and Blood Institute; National Institute on Aging; and National Institute of Neurological Disorders and Stroke