Epidemiological Investigation Of Carotid Atherosclerosis Among The Middle And Old Aged Senior Intellectuals In Higher Education Institutions Of Chongqing

Objective: To investigate the prevalence and the risk factors of carotid atherosclerosis(CAS) by researching the incidence of CAS and its associated factors among the middle and old aged senior intellectuals in higher education institution of Chongqing. Additionally, in order to confirm the clinical significance of serum inflammatory markers which reflecting the vulnerability of plaque, We proceeded the carotid ultrasound examination and detected the serum Hypersensitive C-reactive protein(Hs-CRP) and Matrix metalloproteinases-9,MMP-9(MMP-9).Methods: Collected 45～85 years old intellectuals from three higher education institutions in Nanan district of Chongqing from March to October in 2010. We sampled 750(actual 686) individuals randomly according to four age grades(45～, 55～, 65～and 75～years old) to proceed the standard research which comprised the general state of health(age, gender and amount of exercise), past history(hypertension, diabetes, hyperlipidemia and ischemic events), family history(hypertension, diabetes, hyperlipidemia and ischemic events), physical examination(height, weight, blood pressure and abdominal circumference) and auxiliary examinations(blood lipids, blood glucose, serum Hs-CRP, serum MMP-9 and carotid artery ultrasound). The individuals were divided into the CAS group and the control group according to the results of carotid ultrasound, the differences between the two groups of the investigation factors were compared. Factors which may be related to CAS were analyzed by logistic regression analysis. The vulnerable plaque group, stable plaque group and control group were composed from the total individuals respectively. The differences among the above three groups of the investigation factors were compared. Factors which may be related to the vulnerability of plaque were analyzed by logistic regression analysis. In order to confirm the clinical significance of serum inflammatory markers which reflecting the degree of CAS, the relationship between internal-media thickness(IMT) and serum Hs-CRP or MMP-9 was analyzed.Results: 1. The prevalence of CAS was 41.98% among the total individuals, the prevalence of vulnerable plaque, stable plaque and internal-media thickening was 11.52%, 16.62% and 13.85% respectively. The prevalence in 45～, 55～, 65～and 75～years old individuals were 25.18%, 35.91%, 51.06% and 81.97% respectively(P<0.001). With the increasing of age grades, the prevalence of CAS increased. 2. The risk factors related to CAS included age(OR 1.144, 95%CI 0.806～1.623, P< 0.001), smoking(OR 4.244, 95%CI 1.831～9.838, P<0.001), systolic blood pressure(SBP)(OR 1.028, 95%CI 1.014～1.044, P<0.001), fasting blood glucose(FBG)(OR 1.215, 95%CI 0.985～1.498, P=0.049), total cholesterol(TC)(OR 3.064, 95%CI 1.262～7.437, P=0.013), Hs-CRP(OR 2.933, 95%CI 2.300～3.738, P<0.001) and MMP-9(OR 1.023, 95%CI 1.017～1.028, P<0.001). The protectant factors related to CAS included amount of exercise(OR 0.490, 95%CI 0.337～0.712, P<0.001) and high density lipoprotein(HDL)(OR 0.481, 95%CI 0.244～0.949, P=0.035). 3. The prevalence of CAS increased with the increasing number of the risk factors. The prevalence increased 0.826 times(OR 1.826, 95%CI 0.727～4.586, P=0.047) with one risk factor, 1.517 times(OR 2.517, 95%CI 1.842～3.439, P<0.001) with two risk factors and 2.252 times(OR 3.252, 95%CI 1.274～8.302, P=0.014) with three risk factors. 4. The risk factors related to vulnerable plaque included Hs-CRP(OR 1.642, 95%CI 1.243～2.170, P<0.001) and MMP-9(OR 1.008, 95%CI 1.004～1.012, P<0.001). The prevalence of vulnerable plaque increased 0.642 and 0.008 times with the increasing level of Hs-CRP per 1mg/L and MMP-9 per 1ng/ml respectively. According to the diagnosis by carotid artery ultrasound, we found that the sensitivity and specificity of Hs-CRP to decide vulnerable plaque were 63.29% and 49.12% respectively. 5. There was a linear correlation between carotid IMT and serum Hs-CRP(r=0.557, P<0.001) or MMP-9(r=0.474, P<0.001) level. Conclusion: 1. There was a high prevalence(41.98%) of CAS among the middle and old aged senior intellectuals who were high-risk group of ischemic cerebrovascular disease in higher education institutions of Chongqing, which was increased with the increasing number of the risk factors including age, smoking, SBP, FBG, TC, Hs-CRP and MMP-9. Amount of exercise and HDL were protectant factors related to CAS. 2. Hs-CRP and MMP-9 were both the independent predictors for vulnerable plaque. There was a linear correlation between carotid IMT and serum Hs-CRP or MMP-9 levels. Detecting various serum biochemical markers combined with carotid ultrasound examination has benefited to discriminate the vulnerable plaque in the early stage and preventing the ischemic stroke.