ABSTRACT
<p><b>BACKGROUND</b>Smoking is known to be a strong risk factor for premature atherosclerosis, acute myocardial infarction (AMI) and sudden cardiac death. According to a cross-sectional survey conducted in 2000 - 2001 in China, the prevalence of smoking among the Chinese men was 60.2%, the highest prevalence in the world. Up to date, the relationship between smoking and AMI in Chinese male smokers is still unclear. This study analyzed the baseline characteristics for male smokers hospitalized with AMI and investigated the effect of cigarette smoking on their clinical outcomes.</p><p><b>METHODS</b>A total of 890 men aged 18 years or over with AMI were prospectively recruited from 1 January 2007 to 31 December 2009 from Shanxi Provincial People's Hospital. Patients were grouped into smokers and nonsmokers. The relationships between baseline characteristics and clinical outcomes were tested using either the chi-square test for trend for discrete variables or analysis of variance for continuous variables.</p><p><b>RESULTS</b>Smokers accounted for 66.7% (594), more than twice of nonsmokers (296 (33.3%)), and were averaged 7 years younger ((56.61 ± 11.44) vs. (63.61 ± 11.62) years, P < 0.001). Smokers had the higher rate of TIMI flow grade 2 or 3 after thrombolytic therapy (42.4% vs. 24.5%, P = 0.002), 1 vessel disease (25.5% vs. 14.5%, P = 0.003) than nonsmokers. Smokers had better in-hospital outcome with lower in-hospital mortality rate than nonsmokers (6.2% vs. 10.8%, P = 0.023).</p><p><b>CONCLUSIONS</b>Male smokers suffered from AMI in this study presented an average of 7 years earlier than nonsmokers and were more than twice as likely to have AMI as nonsmokers in China. Smoking appeared to result in earlier infarction, especially ST elevated myocardial infarction in otherwise healthier patients who are likely to survive.</p>
Subject(s)
Adult , Aged , Humans , Male , Middle Aged , Acute Disease , China , Hospital Mortality , Hospitalization , Myocardial Infarction , Mortality , SmokingABSTRACT
To investigate the correlation between methylation and expression of multidrug resistance (mdr1) gene, restriction endonuclease HpaII combined with competitive PCR technique was used to quantitatively detect the methylation status of two CCGG sites located at -110 and -50 bp (region I and II) up to the transcription start site in mdr1 promoter in 54 AL and 9 MM patients. Semi-quantitative RT-PCR was used to detect the expression level of mdr1 gene. The results showed that inverse correlation between methylation rate of either region or total methylation rate and expression of mdr1 gene was observed. The correlation in the region I (r = -0.64) was closer than that in the region II (r = -0.4). High expression rate of mdr1 ascended significantly in low methylation group (n = 36) (P < 0.001). In comparison with chemotherapy sensitive group (n = 8), the methylation rate in refractory AL patients (n = 16) was lower (P = 0.05) in the region I, P < 0.05 in the region II and total regions. Comparing with the untreated patients (n = 36), the methylation rate in the region I and total methylation rate were lower in the patients with chemotherapy (n = 14) (P < 0.05). The methylation rate in the region II was also decreased after chemotherapy, however, no statistical significance was shown (P > 0.05). Increased mdr1 expression level accompanying with decreased methylation rate after chemotherapy was found, although no significant difference was shown (P = 0.06). It is concluded that the expression level of mdr1 gene was associated with the methylation status of CCGG in -110 and -50 bp upstream to the transcription start site, especially the -110 site. In both the patients treated with chemotherapy and the refractory patients, the methylation level of mdr1 gene decreased relatively. The rising expression of mdr1 gene after chemotherapy was associated with the decrease of methylation level.