Tracy R P, Psaty B M, Macy E, Bovill E G, Cushman M, Cornell E S, Kuller L H
Department of Pathology and Biochemistry, University of Vermont, Colchester 05446, USA.
Arterioscler Thromb Vasc Biol. 1997 Oct;17(10):2167-76. doi: 10.1161/01.atv.17.10.2167.
Blood levels of C-reactive protein (CRP), a marker of inflammation, are related to cardiovascular disease risk. To determine cross-sectional correlates in the elderly, we measured CRP in 400 men and women older than 65 years and free of clinical cardiovascular disease at baseline as part of the Cardiovascular Health Study. Only 2% of the values were greater than 10 mg/L, the cut-point usually used to identify inflammation. CRP levels appeared tightly regulated, since there were strong bivariate correlations between CRP and the following: inflammation-sensitive proteins such as fibrinogen (r = .52); measures of fibrinolysis such as plasmin-antiplasmin complex (r = .23); pack-years of smoking (r = .30); and body mass index (r = .24; all P values < or = .001). The association with pack-years was independent of the length of time since cessation of smoking. CRP levels were also associated with coagulation factors VIIc, IXc, and Xc; HDL cholesterol (negative) and triglyceride; diabetes status; diuretic use; ECG abnormalities; and level of exercise. Because of effect modification, two multiple linear regression prediction models were developed for CRP, one each for never smokers and ever smokers. An a priori physiologic model was used to guide these analyses, which disallowed the use of other inflammation-sensitive variables such as fibrinogen. In never smokers, the independent predictors were body mass index (+), diabetes status (+), plasmin-antiplasmin complex (+), and the presence of ECG abnormalities (+); this model predicted 15% of the CRP population variance. In ever smokers, the predictors were body mass index (+), plasmin-antiplasmin complex (+), pack-years of smoking (+), HDL cholesterol (-), and ankle-arm blood pressure index (-); this model predicted 42% of the population variance. We conclude that levels of CRP in the healthy elderly are tightly regulated and reflect lifetime exposure to smoking as well as level of obesity, ongoing level of fibrinolysis, diabetes status, and level of subclinical atherothrombotic disease. Moreover, exposure to smoking affects the relation of CRP to these other factors.
炎症标志物C反应蛋白（CRP）的血液水平与心血管疾病风险相关。为了确定老年人中的横断面相关性，作为心血管健康研究的一部分，我们对400名65岁以上且基线时无临床心血管疾病的男性和女性进行了CRP测量。只有2%的值大于10mg/L，这是通常用于识别炎症的切点。CRP水平似乎受到严格调节，因为CRP与以下各项之间存在很强的双变量相关性：炎症敏感蛋白如纤维蛋白原（r = 0.52）；纤维蛋白溶解指标如纤溶酶 - 抗纤溶酶复合物（r = 0.23）；吸烟包年数（r = 0.30）；以及体重指数（r = 0.24；所有P值≤0.001）。与吸烟包年数的关联独立于戒烟后的时间长度。CRP水平还与凝血因子VIIc、IXc和Xc；高密度脂蛋白胆固醇（呈负相关）和甘油三酯；糖尿病状态；利尿剂使用；心电图异常；以及运动水平有关。由于存在效应修正，针对CRP开发了两个多元线性回归预测模型，从不吸烟者和曾经吸烟者各一个。使用先验生理模型来指导这些分析，该模型不允许使用其他炎症敏感变量如纤维蛋白原。在从不吸烟者中，独立预测因素是体重指数（+）、糖尿病状态（+）、纤溶酶 - 抗纤溶酶复合物（+）以及心电图异常的存在（+）；该模型预测了CRP总体方差的15%。在曾经吸烟者中，预测因素是体重指数（+）、纤溶酶 - 抗纤溶酶复合物（+）、吸烟包年数（+）、高密度脂蛋白胆固醇（-）以及踝臂血压指数（-）；该模型预测了总体方差的42%。我们得出结论，健康老年人中的CRP水平受到严格调节，反映了一生的吸烟暴露以及肥胖程度、持续的纤维蛋白溶解水平、糖尿病状态和亚临床动脉粥样硬化血栓形成疾病的程度。此外，吸烟暴露会影响CRP与这些其他因素的关系。
