Chemerin Is a Biomarker of ACS but not Angina Pectoris
Chemerin Is a Biomarker of ACS but not Angina Pectoris
We recruited 220 patients who underwent diagnostic coronary angiography between Augest 2012 and March 2013 in Beijing Anzhen Hospital, the People's Hospital of Guangxi Zhuang Autonomous Region, and Union Hospital, China. The patients were classified into 4 groups: (1) Stable angina pectoris (SAP). The inclusion criteria for this group were typical exertional chest discomfort that was associated with down sloping or horizontal ST-segment depression >1 mm in an exercise test); (2) Unstable angina pectoris (UAP). The inclusion criteria for this group were chest pain at rest with definite ischemic electrocardiographic changes: ST-segment changes and/or T-wave inversions; (3) Acute myocardial infarction (AMI). The inclusion criteria for this group were myocardial infarction that was confirmed by a significant increase of troponin I and Creatine Kinase MB levels; and (4) Control group, which consisted of 40 subjects with normal coronary artery findings.
Written informed consent was obtained from each patient. The study was approved by the Ethics Committee of Beijing Anzhen Hospital, the People's Hospital of Guangxi Zhuang Autonomous Region, and Union Hospital. Patients with valvular heart disease, thromboembolism, collagen disease, disseminated intravascular coagulation, advanced liver disease, renal failure, malignant disease, septicemia, other inflammatory disease, or current steroid therapy were excluded from the study.
Clinical data were obtained upon admission to hospital. Demographic data, height, body weight, medical history, and medication use were recorded. Body mass index (BMI) was calculated as weight (kg) divided by square of height (m).
In the AMI group, blood samples were obtained from the patients upon arrival at the emergency unit. Fasting blood samples were obtained the morning after admission for the rest of the study groups. The samples were collected in sodium heparin Vacutainers (Becton-Dickinson). Blood was centrifuged for 15 min at 3,000 × g and the plasma was stored at -80°C until further use.
The levels of plasma chemerin and adiponectin (R&D Systems, USA) were measured by an enzyme-linked immunosorbent assay (ELISA), following the manufacturer's instructions. The ELISA intra-assay and inter-assay coefficients of variation were <5% and <10%, respectively. All of the samples were measured in duplicate.
The levels of lipid and lipoprotein fractions, fasting glucose, creatinine and C-reactive protein (CRP) at baseline were measured in central laboratory of Beijing Anzhen Hospital.
The patients underwent M-mode and 2D-echocardiography using a GE ViVid E7 ultrasonography machine (GE Healthcare, America) with a transthoracic 1.5–4.3 MHz probe (M5S-D). Left ventricular end-diastolic diameter (LVEDD) and fractional shortening were measured. Left ventricular ejection fraction (LVEF) was calculated from apical four chambers position by the area–length method.
The severity of coronary stenosis in patients was estimated with a Gensini coronary score following coronary angiography.
All of the data were given as the mean ± SD. When comparing only 2 groups, Student's T-test was used. For comparisons involving 3 or more groups, one-way ANOVA followed by Neuman-Keuls post-hoc test was used. Spearman's correlation was used to calculate the correlations between the plasma chemerin levels and the other measured parameters. To identify the independent predictors of the presence of ACS, simple linear regression analyses were firstly performed and the candidate variables entered in the model included age, sex, BMI, hypertension, diabetes, smoking, lipid and lipoprotein fractions, fasting glucose, creatinine, CRP, chemerin and adiponectin, and then those variables exhibited a trend (p < 0.05) toward an association with the presence of ACS were entered in binary logistic regression analyses. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. In all of the tests, a value of P < 0.05 was considered to be statistically significant.
Methods
Patients
We recruited 220 patients who underwent diagnostic coronary angiography between Augest 2012 and March 2013 in Beijing Anzhen Hospital, the People's Hospital of Guangxi Zhuang Autonomous Region, and Union Hospital, China. The patients were classified into 4 groups: (1) Stable angina pectoris (SAP). The inclusion criteria for this group were typical exertional chest discomfort that was associated with down sloping or horizontal ST-segment depression >1 mm in an exercise test); (2) Unstable angina pectoris (UAP). The inclusion criteria for this group were chest pain at rest with definite ischemic electrocardiographic changes: ST-segment changes and/or T-wave inversions; (3) Acute myocardial infarction (AMI). The inclusion criteria for this group were myocardial infarction that was confirmed by a significant increase of troponin I and Creatine Kinase MB levels; and (4) Control group, which consisted of 40 subjects with normal coronary artery findings.
Written informed consent was obtained from each patient. The study was approved by the Ethics Committee of Beijing Anzhen Hospital, the People's Hospital of Guangxi Zhuang Autonomous Region, and Union Hospital. Patients with valvular heart disease, thromboembolism, collagen disease, disseminated intravascular coagulation, advanced liver disease, renal failure, malignant disease, septicemia, other inflammatory disease, or current steroid therapy were excluded from the study.
Clinical Data Collection
Clinical data were obtained upon admission to hospital. Demographic data, height, body weight, medical history, and medication use were recorded. Body mass index (BMI) was calculated as weight (kg) divided by square of height (m).
Blood Samples Measurements
In the AMI group, blood samples were obtained from the patients upon arrival at the emergency unit. Fasting blood samples were obtained the morning after admission for the rest of the study groups. The samples were collected in sodium heparin Vacutainers (Becton-Dickinson). Blood was centrifuged for 15 min at 3,000 × g and the plasma was stored at -80°C until further use.
The levels of plasma chemerin and adiponectin (R&D Systems, USA) were measured by an enzyme-linked immunosorbent assay (ELISA), following the manufacturer's instructions. The ELISA intra-assay and inter-assay coefficients of variation were <5% and <10%, respectively. All of the samples were measured in duplicate.
The levels of lipid and lipoprotein fractions, fasting glucose, creatinine and C-reactive protein (CRP) at baseline were measured in central laboratory of Beijing Anzhen Hospital.
Doppler Echocardiography
The patients underwent M-mode and 2D-echocardiography using a GE ViVid E7 ultrasonography machine (GE Healthcare, America) with a transthoracic 1.5–4.3 MHz probe (M5S-D). Left ventricular end-diastolic diameter (LVEDD) and fractional shortening were measured. Left ventricular ejection fraction (LVEF) was calculated from apical four chambers position by the area–length method.
Gensini Score
The severity of coronary stenosis in patients was estimated with a Gensini coronary score following coronary angiography.
Statistical Analysis
All of the data were given as the mean ± SD. When comparing only 2 groups, Student's T-test was used. For comparisons involving 3 or more groups, one-way ANOVA followed by Neuman-Keuls post-hoc test was used. Spearman's correlation was used to calculate the correlations between the plasma chemerin levels and the other measured parameters. To identify the independent predictors of the presence of ACS, simple linear regression analyses were firstly performed and the candidate variables entered in the model included age, sex, BMI, hypertension, diabetes, smoking, lipid and lipoprotein fractions, fasting glucose, creatinine, CRP, chemerin and adiponectin, and then those variables exhibited a trend (p < 0.05) toward an association with the presence of ACS were entered in binary logistic regression analyses. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. In all of the tests, a value of P < 0.05 was considered to be statistically significant.