Centre for Population Health Sciences, University of Edinburgh, Scotland, UK.
Age Ageing. 2010 May;39(3):354-9. doi: 10.1093/ageing/afq021. Epub 2010 Mar 2.
the association between the rheological factors haematocrit and plasma viscosity and cognitive ability has not been extensively studied. It is possible that blood viscosity affects cerebral blood flow and cognitive function. This study tested the contemporaneous associations between these two markers of rheology and cognitive ability and estimated lifetime cognitive change in an elderly population with type 2 diabetes.
a cross-sectional cohort of 1,066 men and women with type 2 diabetes (Edinburgh Type 2 Diabetes Study) was used for the analysis. Plasma viscosity and haematocrit were measured in venous blood samples at baseline. Contemporaneously, a battery of seven cognitive tests was administered to all participants. These data were used to derive a general intelligence factor, g. A vocabulary-based test was also administered as an estimate of prior intelligence, and adjustment for scores on this test was used to estimate lifetime cognitive decline.
increased plasma viscosity was associated with poorer age- and sex-adjusted scores on the cognitive domains of processing speed, mental flexibility and general intelligence, g, with standardised regression coefficients -0.092 (P < 0.01), -0.077 (P < 0.05) and -0.093 (P < 0.01), respectively. After adjusting for vocabulary, education level, cardiovascular dysfunction, duration of diabetes and glycaemic control, the associations remained significant for the measure of processing speed and g, with standardised regression coefficients -0.059 (P < 0.05) and -0.051 (P < 0.05). Increased haematocrit was significantly associated with better age- and sex-adjusted cognitive scores on the majority of the tests and with g. However, significant associations were not retained after adjustments for additional covariates.
increased plasma viscosity is associated with decreased cognitive ability and increased estimated lifetime cognitive decline. The relationship between haematocrit and cognitive ability requires further study.
血液流变学因素血细胞比容和血浆黏度与认知能力之间的关系尚未得到广泛研究。血液黏度可能会影响脑血流和认知功能。本研究在 2 型糖尿病老年人群中，检测了这两种流变学标志物与认知能力的同期相关性，并估计了终生认知变化。
本研究使用了一项横断面队列研究，纳入了 1066 名患有 2 型糖尿病的男性和女性（爱丁堡 2 型糖尿病研究）。在基线时采集静脉血样以测量血浆黏度和血细胞比容。同期对所有参与者进行了七项认知测试的测试。这些数据用于得出一般智力因素 g。还进行了基于词汇的测试，作为先前智力的估计，对该测试的分数进行调整，用于估计终生认知下降。
血浆黏度升高与认知领域的加工速度、心理灵活性和一般智力 g 的年龄和性别调整后的得分较差相关，标准化回归系数分别为-0.092（P<0.01）、-0.077（P<0.05）和-0.093（P<0.01）。在校正词汇、教育程度、心血管功能障碍、糖尿病病程和血糖控制后，加工速度和 g 的测量值的相关性仍然显著，标准化回归系数分别为-0.059（P<0.05）和-0.051（P<0.05）。血细胞比容升高与大多数测试的年龄和性别调整后的认知得分以及 g 呈显著正相关。然而，在调整了其他协变量后，显著的相关性没有保留。
血浆黏度升高与认知能力下降和估计的终生认知下降增加相关。血细胞比容与认知能力之间的关系需要进一步研究。
