Impact of interaction between CYP1A1 genetic polymorphisms and smoking on coronary artery disease in the Han of China.

AIMS: To investigate the association of CYP1A1 genotype and additional gene-smoking interaction with coronary artery disease (CAD) risk based on a Chinese case-control study. METHODS: A total of 1862 participants (1134 men, 728 women) were selected, including 620 CAD patients and 1242 normal controls. Logistic regression was performed to investigate association of CYP1A1 genotype, gene-gene, and gene-smoking interaction with CAD. Generalized multifactor dimensionality reduction (GMDR) was used to screen the best gene-gene and gene-smoking interaction combination, cross-validation consistency, the testing balanced accuracy, and the sign test, to assess if each selected interaction was calculated. RESULTS: The carriers of homozygous mutant of rs4886605 polymorphism and heterozygous of rs4646903 are associated with increased CAD risk than those with wild-type homozygotes; OR (95% CI) was 1.98 (1.53-2.61) and 1.58 (1.24-1.96), respectively. The carriers of homozygous mutant of rs1048943 polymorphism is associated with decreased CAD risk than those with wild-type homozygotes, OR (95% CI) = 0.75 (0.60-0.93). GMDR model indicated a potential gene-gene interaction between rs4886605 and rs4646903 and a potential gene-smoking interaction between rs4886605 and smoking. Participants with rs4886605-CT or TT and rs4646903-TC or CC genotype have the highest CAD risk, compared to participants with rs4886605-CC and rs4646903-TT genotype; OR (95% CI) was 2.72 (2.03-3.61). In addition, we also found that smokers with rs4886605-CT or TT genotype have the highest CAD risk, compared to nonsmokers with rs4886605-CC genotype; OR (95% CI) was 3.07 (2.23-3.96). CONCLUSIONS: rs4886605 and rs4646903 are associated with increased CAD risk, but rs1048943 is associated with decreased CAD risk; we also found gene-gene interaction between rs4886605 and rs4646903 and gene-environment interaction between rs4886605 and smoking.

SLCO1B1 521T-->C functional genetic polymorphism and lipid-lowering efficacy of multiple-dose pravastatin in Chinese coronary heart disease patients.

AIMS: Pravastatin is a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, which is widely used both in primary and secondary prevention of coronary heart disease (CHD). Pravastatin is not subject to metabolism by cytochrome P450s, but it is actively transported from blood into target tissues (e.g. hepatocytes in the liver) by the organic anion transporting polypeptide 1B1 (OATP1B1), encoded by SLCO1B1. The aim of the present study was to evaluate the impact of SLCO1B1 521T-->C (Val174Ala) functional genetic polymorphism on the lipid-lowering efficacy of multiple-dose pravastatin in Chinese patients with CHD. METHODS: Forty-five hospitalized patients with CHD prospectively received pravastatin as a single-agent therapy (20 mg day(-1) p.o.) for 30 days. Serum triglycerides, total cholesterol, low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol concentrations were determined before and after pravastatin treatment. RESULTS: Pravastatin treatment significantly decreased plasma lipids in all patients (P < 0.001). Importantly, we showed an attenuated pravastatin pharmacodynamic effect on total cholesterol in patients with 521TC heterozygote genotype (from 5.52 +/- 0.51 mmol l(-1) to 4.70 +/- 0.35 mmol l(-1), % change -14.5 +/- 6.6%, N = 9) compared with 521TT homozygote genotype (from 5.47 +/- 1.15 mmol l(-1) to 4.21 +/- 0.89 mmol l(-1), % change -22.4 +/- 10.3%, N = 36) (mean +/- SD, P = 0.03, two-tailed test with alpha set at 5%). SLCO1B1 521T-->C functional polymorphism did not significantly influence pravastatin pharmacodynamics on other plasma lipids (P > 0.05). CONCLUSIONS: The 521T-->C polymorphism of SLCO1B1 appears to modulate significantly the total cholesterol-lowering efficacy of pravastatin in Chinese patients with CHD. Further studies are warranted to determine the extent to which SLCO1B1 genetic variation may contribute to resistance to pravastatin in Asian patients treated with standard doses of pravastatin.

[Effects of intracoronary diltiazem on no-reflow phenomenon after emergent percutaneous coronary intervention in patients with acute myocardial infarction].

OBJECTIVE: To assess the effects of intracoronary diltiazem on no-reflow phenomenon of infarct-related artery (IRA) after emergent percutaneous transluminal coronary angioplasty or/and intracoronary stenting (PTCA/Stenting) in the patients with acute myocardial infarction (AMI). METHODS: We studied 34 AMI patients with no-reflow phenomenon of IRA after emergent PTCA/Stenting between January 1999 and August 2005. Urokinase-treated group (n=16) was given intracoronary urokinase 30,0000 - 50,0000 units within 15 - 30 minutes between January 1999 and April 2002 while diltiazem-treated group (n=18) was given intracoronary diltiazem 0.5 - 2 mg within 10 - 30 minutes between May 2002 and August 2005. Fifteen minutes later, coronary arteriography (CAG) was performed and the thrombolysis in myocardial infarction (TIMI) flow grade was measured. RESULTS: No apparent change of TIMI flow grade was found between pre-administration and post-administration of intracoronary urokinase, but TIMI flow grade was significantly improved after intracoronary diltiazem (P<0.01). TIMI flow grade of diltiazem-treated group was significantly higher than that of urokinase-treated group after the administration (P<0.05). The percentage of the patients who reached TIMI flow grade 3 after the intracoronary administration was higher in the diltiazem-treated group than that in the urokinase-treated group (P<0.01). CONCLUSION: The intracoronary administration of diltiazem 0.5~2mg can effectively improve the no-reflow phenomenon after emergent PTCA/Stenting in patients with AMI.