Tchistiakova Ekaterina, Anderson Nicole D, Greenwood Carol E, MacIntosh Bradley J
Department of Medical Biophysics, University of Toronto, 610 University Ave., Toronto, ON M5G 2M9, Canada ; Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, 2075 Bayview Ave., Toronto, ON M4N 3M5, Canada ; Brain Sciences Research Program, Sunnybrook Research Institute, 2075 Bayview Ave., Toronto, ON M4N 3M5, Canada.
Department of Psychology, University of Toronto, 100 St. George Street, Toronto, ON M5S 1A8, Canada ; Rotman Research Institute, Baycrest, 3560 Bathurst Street, Toronto, ON M6A 2E1, Canada ; Department of Medicine (Psychiatry), University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
Neuroimage Clin. 2014 Jun 5;5:36-41. doi: 10.1016/j.nicl.2014.05.020. eCollection 2014.
Type 2 diabetes mellitus is characterized by metabolic dysregulation in the form of hyperglycemia and insulin resistance and can have a profound impact on brain structure and vasculature. The primary aim of this study was to identify brain regions where the combined effects of type 2 diabetes and hypertension on brain health exceed those of hypertension alone. A secondary objective was to test whether vascular impairment and structural brain measures in this population are associated with cognitive function.
We enrolled 18 diabetic participants with hypertension (HTN + T2DM, 7 women, 71.8 ± 5.6 years) and 22 participants with hypertension only (HTN, 12 women, 73.4 ± 6.2 years). Cerebrovascular reactivity (CVR) was assessed using blood oxygenation level dependent (BOLD) MRI during successive breath holds. Gray matter structure was evaluated using cortical thickness (CThk) measures estimated from T1-weighted images. Analyses of cognitive and blood data were also performed.
Compared to HTN, HTN + T2DM had decreased CVR and CThk in a spatially overlapping region of the right occipital lobe (P < 0.025); CVR group differences were more expansive and included bilateral occipito-parietal areas (P < 0.025). Whereas CVR showed no significant associations with measures of cognitive function (P > 0.05), CThk in the right lingual gyrus ROI and regions resulting from a vertex-wise analysis (including posterior cingulate, precuneus, superior and middle frontal, and middle and inferior temporal regions (P < 0.025) were associated with executive function.
Individuals with T2DM and HTN showed decreased CVR and CThk compared to age-matched HTN controls. This study identifies brain regions that are impacted by the combined effects of comorbid T2DM and HTN conditions, with new evidence that the corresponding cortical thinning may contribute to cognitive decline.
2型糖尿病的特征是出现高血糖和胰岛素抵抗形式的代谢失调，并且会对脑结构和脉管系统产生深远影响。本研究的主要目的是确定2型糖尿病和高血压对脑健康的联合影响超过单纯高血压影响的脑区。次要目的是测试该人群中的血管损伤和脑结构测量指标是否与认知功能相关。
我们招募了18名患有高血压的糖尿病参与者（高血压+2型糖尿病，7名女性，71.8±5.6岁）和22名仅患有高血压的参与者（高血压，12名女性，73.4±6.2岁）。在连续屏气期间使用血氧水平依赖（BOLD）磁共振成像评估脑血管反应性（CVR）。使用从T1加权图像估计的皮质厚度（CThk）测量值评估灰质结构。还对认知和血液数据进行了分析。
与高血压组相比，高血压+2型糖尿病组在右侧枕叶的一个空间重叠区域CVR和CThk降低（P<0.025）；CVR的组间差异范围更大，包括双侧枕顶叶区域（P<0.025）。虽然CVR与认知功能测量指标无显著相关性（P>0.05），但右侧舌回感兴趣区的CThk以及顶点分析得出的区域（包括后扣带回、楔前叶、额上回和额中回以及颞中回和颞下回区域，P<0.025）与执行功能相关。
与年龄匹配的高血压对照组相比，2型糖尿病和高血压患者的CVR和CThk降低。本研究确定了受2型糖尿病和高血压合并症联合影响的脑区，并有新证据表明相应的皮质变薄可能导致认知衰退。
