The Association Between The Serum Gonadal Hormone Level And Coronary Artery Disease In Male And Its Influence On Lipid Metabolism

According to the statistics of WHO, coronary heart disease (CHD) is the most common cause of death in the world. Many animal studies and clinical evidences indicate that the reasons that result in CHD are interactive factors, now the risk factors that are widespread accepted include hypertension,hypercholesteremia,diabetes,smoking and so on. But these factors can not completely explain the morbidity of CHD. For example, A great quantity epidemiologic studies indicate that the incidence of a CHD has an apparent sex differences. Compare with female, the morbility and case fatality of CHD is significantly higher in male before 50 years old. This kind phenomenon hint that gonadal hormone effect in the morbidity of CHD.Tradition studies think androgens promoted the development of CHD . With deeply investigation, many scholars discovered that the patients of male CHD have apparently lower than normals in androgens level and higher than those in the proportion of estrogens and androgens; Androgens substitute treat in hypogonadal males with CHD can relief from angina. So they think that low androgens level is an independent risk factor in male CHD; The proportion disequilibri-um of estrogens and androgens will promote the development of artherosclerosis (AS) and CHD;Physiological dose's androgens has effection in resisting the development of AS and appropriate supplement of androgens can improve male heart muscle ischemia. But some scholars had a contrary view. They think androgens restrain- ed the composition of liver high density lipoprotein and promoted its degradation, and enhanced the level of oxidation low density lipopro- tein and its injury to the macrophage; Androgens also enhanced the adhesiveness of monocyte and vascular endothelial cell. So androgens promoted the development of AS,CHD.Objective: For further study of the relation of male gonadal hormone and the pathogenesy in the development of CHD and it's effect in lipid metabolism by detect gonadal hormone and blood fat level in male coronary heart disease patients.Methods: The sample take from 72 male patients with CHD who at least have 1 coronary artery narrowed≥50%, and 60 health males as control group at the same time. We devide CHD group into 4 subsets. There are 14 patients in stable angina pectoris (SAP) group, 28 patients in unstable angina pectoris (UAP) group, 16 patients in myocardialinfarction (MI) group and 14 patients in ischemic cardiomyopathy (ICM) group. First, we use radioimmunoassay to detect the serum of estradiol and testosterone; Second, we use American BECKMAN SYNCHRON LX20 automatic biochemistry analyzer to detect cholest- erol total,triglyceride,low density lipoprotein cholesterol,high density lipoprotein cholesterol,apolipoprotein A?,apolipoprotein B;Finally, we calculate estradiol / testosterone and apolipoprotein A?/ apolipoprotein B.Results:①The serum testosterone level in patient of CHD group is obviously lower than control group(P<0.05);The serum estradiol level of CHD group is a little higher than control group, but it has not statistically significant(P>0.05); Estradiol/testosterone is obviously higher than control group(P<0.05).②If we separate these patients by the CHD types, the serum testosterone level of SAP group is a little higher than UAP,MI and ICM group, but it has not statistically significant(P>0.05);The serum estradiol level of SAP group is a little higher than UAP,MI and ICM group, but it has not statistically significant(P>0.05); Estradiol/testosterone of UAP,MI and ICM group is obviously higher than SAP group (P<0.05).③Testosteroneand the total cholesterol,low density lipoprotein cholesterol offer negative correlation (r=-0.487,-0.53 respectively, P<0.05); Testoster- one and high density lipoprotein cholesterol,apolipoprotein A?/ apolipoprotein B offer positive correlation(r=0.376,0.416 respectively, P<0.05).Experimental result show:The patients of male CHD have obviously disbalance in gonadal hormone, the testosterone level is apparently lower than normals, but estradiol/testosterone is apparently higher than normals; If the patient's testosterone level is lower, his level of total cholesterol and low density lipoprotein cholesterol will show an ascensus tendency, and the level of high density lipoprotein cholesterol apoprotein and apolipoprotein A?/apolipoprotein B will show a downtrend. Compare with the paitent of stable angina pectoris, estradiol/testosterone of the patient of myocardial infarction,arrhyth- mia and heart failure has significant difference. So we can conclude that endogenous androgen has a good effect to male lipid metabolism; Low testosterone level and the increase of estradiol/ testosterone will promote the disorder of lipid metabolism and the development of AS and CHD; the level of estradiol/ testosterone has relation to the severityof CHD.A great quantity investigation show androgens have protection to cardiovascular syetem and effect CHD morbidity and development by regulating demic lipid metabolism,endothelial function,angiotasis and coagulation-fibrinolytic system. The possible pathogenesy of testoster- one influence on lipid metabolism is that testosterone not only can be aromatize to estradiol, but also increase receptor's activity of low density lipoprotein cholesterol and promote low density lipoprotein cholesterol cohere with it's receptor and degrade low density lipopro- tein cholesterol. Testosterone is able to increase the key enzyme's (li- poproteinesterase) activity in the lipid metabolism, promote chylomicra and very low density lipoprotein hydrolyse and release fatty acid too. At the same time it augment the ability that hepatocyte intake the lipide. It can provide prosoma for high density lipoprotein cholesterol, so that the patient's total cholesterol will be lower and the high density lipo- protein cholesterol will be higher, and the effect of resist AS will be get. Because the androgens effect the lipid metabolism and blood vessel endothelium function is partly by aromatized to estrogens and active estrogen receptor to come true indirectly, we think that lower level'sandrogens probably affect estrogen cohere with it's acceptor or weaken their biological effect after they binding. When the ratio of estradiol/ testosterone maintains in a certain level, it can educe beneficial biolo- gical effect.Just as we described above, we think that androgens educe impor- tant affection in the morbidity of CHD, which also have the effect of resisting AS and prevention CHD by regulating demic lipid metaboli- sm,endothelial function,angiotasis and coagulation-fibrinolytic system. Now some scholars have already paid close attention to testosterone replacement and its influence on CHD in male. Webb etc. infuses testosterone into the coronary artery of male patients with CHD and observes the change of coronary arteriongraphy and intravascular unltrasound pretherapy after treatment. The result shows obviously increases the caliber of conorary artery and the blood flow rate after medicine. The study of Malkin etc. shows testosterone substitute treat- ment in hypogonadal males with ischemic cardiomyopathy can delay time to ischemia and enhance the exercise tolerance of patients. These studies provide clinical evidences to androgens substitute treatment. But the concrete applied dose of androgens and its concrete mechanismof action is still not ascertainment. Now it still has a great deal of different opinions and need advanced investigation to confirm that.