- [Show abstract] [Hide abstract] ABSTRACT: Increased blood pressure and elevated total cholesterol (TC) level are the two most important modifiable risk factors of cardiovascular disease (CVD) in the world. Hypertension and hypercholesterolemia co-exist more often than would be expected and whether there is a synergistic impact on fatal CVD between elevated TC and hypertension need to be further examined in Chinese population. We conducted a cohort study which recruited 5092 Chinese male steelworkers aged 18 - 74 years in 1974 - 1980 and followed up for an average of 20.84 years. Totally 302 fatal CVD events were documented by the year of 2001. Cox proportional hazards regression models were undertaken to adjust for baseline variables with fatal CVD events as the outcome variable. Additive interaction model was used to evaluate the interaction between elevated TC and hypertension. Hypercholesterolemia and hypertension were significantly associated with an increased hazard ratio (HR) of fatal CVD (1.67 (95%CI 1.18 - 2.38) and 2.91 (95%CI 2.23 - 3.80) respectively. Compared to participants with normotension and TC < 240 mg/dl, the HRs were 1.11 (95%CI 0.56 - 2.21), 2.74 (95%CI 2.07 - 3.64) for hypercholesterolemia and hypertension respectively, and 5.51 (95%CI 3.58 - 8.46) for participants with both risk factors. There was an additive interaction with a 2.65 (95%CI 0.45 - 4.85) relative excess risk (RERI) between hypercholesterolemia and hypertension on CVD. We found that the risk of fatal CVD was significantly associated with an additive interaction due to hypercholesterolemia and hypertension besides a conventional main effect derived from either of them, which highlights that the prevention and treatment of both risk factors might improve the individual risk profile thus reduce the CVD mortality.
- [Show abstract] [Hide abstract] ABSTRACT: As a new effective strategy for researching complex diseases, genome-wide association study (GWAS) has being developed rapidly in recent years worldwide. The world genomic study has been taken into a new stage, since a series of disease related genes or variants have been identified by GWAS strategy. Coronary heart disease (CHD) is a complex disease that is caused by both environmental and genetic factors, and has become one of the leading causes of death and disability worldwide. With the application of GWAS strategy, researchers from all over the world have identified many susceptibility loci or regions of CHD that were unable to be identified by candidate gene case-control study. The present paper reviewed the important progresses worldwide attained in GWAS of CHD in recent years. Then it is also expounded the challenges we are facing nowadays in GWAS as well as the future study direction. The information outlined in this paper provides us a valuable guidance upon further exploration into genetic mechanism of CHD.
- [Show abstract] [Hide abstract] ABSTRACT: Total cholesterol (TC) is an important risk factor for myocardial infarction (MI), but the effect of TC on MI in Chinese male hypertension population has not been well documented. We conducted a prospective cohort study to determine the incidence and relative risk for MI across a wide range of TC levels in Chinese male hypertension population. A cohort of 5298 male employees aged 18-74 years recruited from Capital Steel and Iron Company in Beijing of China in 1974-1980 was followed up for an average of 20.84 years. A total of 122 incident MI cases were identified during the period of follow-up. The incidence of MI among participants with elevated TC and those with desirable TC in male non-hypertension population was 137.20 and 63.81 per 100,000 person-years, respectively; and the corresponding incidence in male hypertension population was 279.80 and 130.96 per 100,000 person-years, respectively. After adjustment for important covariables, 10.38%, 16.71%, and 23.80% of MI cases were attributable to hypertension, elevated TC, and hypertension plus elevated TC, respectively. In male hypertension population, the multivariate adjusted hazard ratios of MI were 1.21, 2.39, 3.38, and 3.95 for participants with TC level of 5.17-5.68, 5.69-6.20, 6.21-6.71, and > or = 6.72 mmol/L, compared with those with TC < 5.17 mmol/L. The corresponding population attributable risks were 2.92%, 9.20%, 8.87%, and 9.84%, respectively. Elevated TC is an important independent risk factor of MI both in male non-hypertension and hypertension populations. There is a linear association between TC level and MI incidence in Chinese male hypertension population.
- [Show abstract] [Hide abstract] ABSTRACT: In individuals without cardiovascular disease, elevated body mass index (BMI) is associated with an increased risk of death. However, in patients with certain chronic diseases, including heart failure, low BMI has been associated with increased mortality. We investigated the association between BMI and prognosis in patients with systolic HF. Follow-up was made on 540 patients (mean age 58.53 years, 84.2% men) with systolic HF (LVEF < or = 45%) and association between BMI and adverse cardiac events was analyzed. During a median follow-up of 24 months, 92 patients died including 87 cases of cardiac death and 92 patients were rehospitalized. Compared with patients with BMI higher than 28.0 kg/m(2), patients in lower BMI categories (BMI < or = 18.5 kg/m(2) and > or = 18.5 kg/m(2) < 24.0 kg/m(2)) had a graded increase in the all cause death rate [5.44 (1.78 - 16.66), 4.30 (1.71 - 10.82)], cardiac death rate [OR(95%CI): 5.42 (1.77 - 16.59), 4.00 (1.59 - 10.10)], HF death rate [8.94 (2.37 - 33.74), 4.97 (1.52 - 16.20)] and MACE rate [2.10 (1.09 - 4.07), 1.79 (1.14 - 2.82)]. After adjustment for age, gender, LVEF and NYHA grade using cox regression analysis, BMI categories still significantly associated with all cause death rate (OR = 0.77, P < 0.05), cardiac death rate (OR = 0.78, P < 0.05) and HF death rate (OR = 0.79, P < 0.05). In patients with systolic heart failure, lower BMI was an independent predictor of increased all cause death rate, cardiac death rate and HF death rate.
- [Show abstract] [Hide abstract] ABSTRACT: Although the role of fibrinogen as a predictor of acute myocardial infarction (MI) has been well-established, the association of genetic polymorphisms in the fibrinogen gene with MI is still controversial. This study was conducted to elucidate the association between the genetic polymorphisms of the fibrinogen beta-chain (FGB) gene and MI in Chinese Han population. The occurrence of 3 common polymorphisms (i.e., -455G/A, R448K and 8558C/G) in a case-control study including 508 patients with MI and 503 healthy controls was investigated. Results Analyses of single polymorphisms showed that individuals carrying the rare alleles for the 3 polymorphisms were significantly associated with a decreased risk of MI. Logistic regression analysis indicated that R448K remained independently associated with MI after adjustment for environmental risk factors (adjusted odds ratio(OR) = 0.71 for KK/RK versus RR, P = 0.023). The three polymorphisms were found to be in strong linkage disequilibrium. Haplotype analyses showed that the A-K-G haplotype (-455A, 448K, 8558G) was associated with a protective effect against MI. Compared with the common haplotype G-R-C, the adjusted OR for A-K-G was 0.68 (95% CI, 0.51-0.90; P = 0.006). These data indicate that individuals carrying the FGB 448K allele may be protective against having MI in this population.
- [Show abstract] [Hide abstract] ABSTRACT: To investigate the association between the severity of coronary arteries in patients with coronary artery disease and the single nucleotide polymorphisms of MMP-3 gene. One thousand and three hundred seventy-one patients with coronary artery disease (CAD) diagnosed by coronary angiography and six hundred and ninety-five healthy controls without CAD were enrolled in this study. The SNPs of -1612 5A/6A, -376C/G, Glu45Lys of MMP-3 were genotyped by restriction fragment length polymorphism analysis (RFLP) in all subjects. Univariate analysis was applied to measure the association of the single nucleotide polymorphisms with the severity of coronary arteries. The minor allele frequency of -1612 5A/6A was 0.189, 0.185, 0.183 and 0.152 (P < 0.05 vs. non-CAD control and single stenosis), the minor allele frequency of -376C/G was 0.311, 0.329, 0.326 and 0.325, and the minor allele frequency of Glu45Lys was 0.367, 0.423, 0.417 and 0.405 in non-CAD control, CAD patients with single, two and three vessels stenosis, respectively. 5A allele frequency is significant lower in the group with three vessels stenosis than in non-CAD control and CAD patients with single vessel stenosis (OR = 0.74, P = 0.04). The 5A/5A and 5A/6A genotypes frequency is significant lower in the group with three vessels stenosis than in the non-CAD group and CAD patients with single vessel stenosis (OR = 0.74, P = 0.04). The single nucleotide polymorphism of -1612 5A/6A of MMP-3 gene may be associated with the severity of coronary atherosclerosis in the Chinese Han patients with coronary artery disease, and the 5A allele might therefore, play a protective role on the progression of coronary atherosclerosis.
- [Show abstract] [Hide abstract] ABSTRACT: Hydrogen sulfide (H(2)S) plays an important role in the smooth muscle cell relaxation and thereby participates in the development of hypertension. Cystathionine gamma-lyase is the key enzyme in the endogenous production of H(2)S. Up to now, the reports on the relationship between the polymorphisms of cystathionine gamma-lyase gene (CTH) and essential hypertension (EH) are limited. This study was designed to assess their underlying relationship. A total of 503 hypertensive patients and 490 age-, gender- and area-matched normotensive controls were enrolled in this study. Based on the FASTSNP, a web server to identify putative functional single nucleotide polymorphisms (SNPs) of genes, we selected two SNPs, rs482843 and rs1021737, in the CTH gene for genotyping. Genotyping was performed by the polymerase chain reaction and restriction fragment length polymorphism method (PCR-RFLP). The frequencies of the alleles and genotypes between cases and controls were compared by the chi-square test. The program Haplo. stats was used to investigate the relationship between the haplotypes and EH. These two SNPs were in Hardy-Weinberg Equilibrium in both cases and controls. The genotype distribution and allele frequencies of them did not significantly differ between cases and controls (all P > 0.05). In the stepwise logistic regression analysis we failed to observe their association with hypertension. In addition, none of the four estimated haplotypes or diplotypes significantly increased or decreased the risk of hypertension before or after adjustment for several known risk factors. The present study suggests that the SNPs rs482843 and rs1021737 of the CTH gene were not associated with essential hypertension in the Northern Chinese Han population. However, replications in other populations and further functional studies are still necessary to clarify the role of the CTH gene in the pathogenesis of EH.
- [Show abstract] [Hide abstract] ABSTRACT: Calpain-10 (CAPN10) has been identified as a susceptibility gene in type 2 diabetes mellitus (T2DM) and insulin resistance. The present study aimed to identify the effects of genetic variations in the CAPN10 gene on the development of type 2 diabetes and hypertension in northern Han Chinese population. We performed a case-control study and genotyped single nucleotide polymorphism (SNP)-44, -43, -19 and -63 of CAPN10 gene in 1046 subjects from the northern China, including 493 patients with T2DM and hypertension and 553 age- and gender-matched normal healthy controls. Univariate analysis showed that the four polymorphisms were not independently associated with T2DM and hypertension. However, the frequency distributions of SNP-44 allele C (allele 2) (17.89% vs 9.80%, P = 0.0016) and genotype CC (22) (4.21% vs 1.01%, P = 0.0059) in obese patients (body mass index > or = 30 kg/m2) were different from those in non-obese patients. Logistic regression analyses revealed that carriers of the 1112/1221 diplotype had a significantly lower odds ratio for diabetes and hypertension (OR = 0.399, 95% CI, 0.196 - 0.814, P = 0.0115). The 1112/1121 diplotype associated with significantly increased risk of type 2 diabetes in Mexican-American was not associated with the increased risk in Chinese. These results suggested that CAPN10 gene variations might play roles in the risk of diabetes and hypertension in northern Han Chinese population.