Relationship Between Heart-type Fatty Acid Binding Protein And Cardiac Syndrome X

BackgroundsCardiac syndrome X (CSX) is a clinical condition characterized by the presence of typical exertional chest pain, a positive response to exercise stress testing, and normal coronary angiograms. In spite of receiving the best treatment, there are still20%patients having progressive serious symptoms and the quality of their life is reducing. Statistics show that, compared with normal people, the CSX patients have the higher incidence rate of myocardial infarction and stroke. Fatty acid binding protein (FABP) is a small molecule cytoplasmic proteins largely expressed in the tissues which the fat metabolism is active. Its main function is promoting long chain fatty acids transportation in the cells. At present,there are nine kinds of FABP has been confirmed. Heart-type fatty acid binding protein (H-FABP) is special in myocardial cells, accounting for about4%～8%of myocardial soluble protein, combined with the long-chain fatty acids in the myocardial cells, and transports the long-chain fatty acids from the cell membrane to the intracellular binding sites. Then into the energy metabolism system, produce ATP, which provides energy for myocardial cells. If the myocardial cells are impaired or the myocardial cells have ischemia or hypoxia, fatty acids will be mobilized to provide energy, which will make H-FABP increase in the cells, and be release to the circulation. As a marker of myocardial cells, H-FABP is related to AMI, which is more sensitive than CK-MB, and more special than myoglobin. Experiments show that besides acute myocardial infarction, H-FABP will increase in the pathogenesis of many diseases, such as chronic cardiac insufficiency, myocardial damage after implantable cardioverter-defibrillators (ICD)、trauma-induced myocardial injury, myocardial injury caused by CO poisoning, kidney diseases, acute pulmonary embolism, cerebral apoplexy, pyemia and septic shock, atherosclerosis, metabolic syndrome. But it has not been confirmed that H-FABP has a relationship with the CSX.ObjectiveTo study the relationship between H-FABP and CSX.MethodsPatients visiting the Department of Cardiology of the First Affiliated Hospitalof Zhengzhou University from June2011to January2012were included. The people who had typical exertional chest pain, a positive response to exercise stress testing, and normal coronary angiograms were Group A(n=50),50healthy asymptomatic control individuals were Group B(n=50). Venous blood samples were collected for serum H-FABP, uric acid, total cholesterol (T-CHO), LDL-cholesterol(LDL-C), HDL-cholesterol(HDL-C) and triglyceride(TC) levels measurements. The positive standard ECG exercise test is defined as ST horizontal or oblique depress more than lmm during exercise or after exercise.When the result is probable positive or negative,the myocardium perfusion imaging will be used.Results1、 H-FABP, T-CHO, LDL-C, and TG levels were significantly higher in Group A than in Group B(P<0.05). HDL-cholesterol was no significant difference between the two groups.2、 Logistic regression analysis showed the OR of H-FABP is2.3762,95%CI (1.302,5.860), the OR of UA is1.100,95%CI (1.046,1.158), the OR of LDL-C is2.967,95%CI (1.437,6.126).ConclusionsSerum H-FABP and LDL-C were associated with CSX, and they were probable the independent risk factors of CSX.