Study On The Clinical Risk Factors, Polymorphism Of Lipoprotein Lipase Gene And Its Post-heparin Plasma Activity Among Patients With Premature Coronary Heart Disease

Background Despite remarkable successes in the treatment and prevention of coronary heart disease(CHD) in the past decades,it is still one of the leading causes of death and premature disability in the world .There is a rising trend according to the morbidity and mortality of CHD in the following 20 years, including premature CHD(male age < 55, female < 65 years ). It's disaster to the families and society for patients suffering from premature CHD. Understanding the environmental and genetic risk factors for premature CHD is of great importance especially for the active treatment and prevention of premature CHD. Objectives This paper will explore:(1) the prevalence of traditional risk factors (such as hyperlipidemia, hypertension, diabetes mellitus ,cigarette smoking) and the characteristics of clinical phenotypes and coronary lesions in patients with premature CHD.(2) the characteristics of some novel possible cardiovascular risk factors as C-reactive protein(CRP),leptin and the intima-mediathickness (IMT) and plaques of the common carotid artery and their possible value in patients with premature CHD .(3) the characteristics of lipoprotein lipase(LPL) P,Hpolymorphism , its post-heparin plasma activity and their relationship with plasma lipids ,clinical phenotypes and severity of coronary lesions in patients with premature CHD. 4 Possible relationship between inflammation index(CRP) and markers of lipids metabolism(leptin,LPL activity). Methods(1) 1132 patients were referred for coronary angiography by Judkins methods due to a concern for coronary heart disease risk. 128 patients with documented premature CHD (Group A) and 116 persons without CHD (Group B) were recruited to participate in this study. Premature CHD was defined as clinical CHD occurring by age < 55 in men or < 65 in women verified by angiography or positive history of myocardial infarction. Patients with stenosis that obstructed the coronary lumen by less than 50%(in diameter) were refered as control group. The clinical phenotypes of premature CHD included stable angina pectoris ,unstable angina pectoris and acute myocardial infarction . Single-vessel disease was defined by > 50% stenosis in one coronary artery and mutli-vessle disease was defined by > 50% stenosis in > 2 coronary arteries or primary branches. The clinical profile, including age, sex,body mass index (BMI), total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol (LDL-C) , high-density lipoprotein(HDL-C), apolipoprotein A (apo A) , apolipoprotein B (apo B) , hypertension, diabetes mellitus , cigarette smoking and familial history of cardiovascular disease(CVD) and angiographic results were analyzed .10(2) Plasma levels of CRP and leptin were measured and the values of average IMT and plaques in the common carotid artery were determined by B-mode ultrasound imaging, a non-invasive arterial evaluation method and its value in predicting premature CHD was also evaluated. The relationship between CRP , leptin and linical phenotypes of premature CHD and the relationship between CRP, IMT and severity of coronary lesions among patients with premature CHD were discussed.(3) With polymerse chain reaction-restriction fragment length polymorphism, P and H genotypes and alleles status of the LPL gene were determined, and LPL activities were measured in post-heparin plasma. Scores reflecting severity and extent of CHD were calculated and patients were classified into three groups according to the degree of anatomical complexity . The relationship between LPL genetypes , LPL activity and the lipids parameters , the extent score and numbers of diseased vessels were analyzed .Results(1) Among 1132 patients referred for coronary angiography, angiographically significant CHD was demonstrated in 606 patients(53.5%),152 of whom were premature CHD(25.1%). Patients in Group A had higher average levels of serum TC,TG,Lp(a) and lower level of apo A (P<0.05~0.01). Compared to those patients without CHD , patients with premature CHD had a h...