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Saturday, December 30, 2006


Atorvastatin (Lipitor) inhibition of cytokine-inducible nitric oxide synthase expression in native endothelial cells in situ.

Animal experimental studies have demonstrated that inducible nitric oxide synthase (iNOS) expression correlates with neointima formation and is prevented by HMG-CoA reductase inhibitors (statins). In the present study we have investigated the underlying mechanism of action of these drugs in isolated segments of the rat aorta. Western blot analysis and immunohistochemistry revealed that tumour necrosis factor alpha (TNFalpha) plus interferon-gamma (IFNgamma) synergistically induce iNOS gene expression in the endothelium but not in the smooth muscle of these segments while constitutive endothelial NO synthase (eNOS) abundance was markedly reduced. Pre-treatment with 1 - 10 microM Atorvastatin (Lipitor), cerivastatin or pravastatin decreased TNFalpha plus IFNgamma stimulated iNOS expression in the endothelium irrespective of the presence of the HMG-CoA reductase product mevalonate (400 microM). Electrophoretic mobility shift assay experiments confirmed that the combination of TNFalpha plus IFNgamma causes activation of the transcription factors STAT-1 and NF-kappaB in native endothelial cells. Neutralization of these transcription factors by employing the corresponding decoy oligonucleotides confirmed their involvement in TNFalpha plus IFNgamma stimulated iNOS expression. Translocation of both transcription factors was attenuated by Atorvastatin (Lipitor), and this effect was insensitive to exogenous mevalonate. The present findings thus demonstrate a specific HMG-CoA reductase-independent inhibitory effect of statins, namely Atorvastatin (Lipitor), on cytokine-stimulated transcription factor activation in native endothelial cells in situ and the subsequent expression of a gene product implicated in vascular inflammation. This effect may be therapeutically relevant and in addition provide an explanation for the reported rapid onset of action of these drugs in humans.

Effect of statins versus untreated dyslipidemia on serum uric acid levels in patients with coronary heart disease: a subgroup analysis of the GREek Atorvastatin (Lipitor) and Coronary-heart-disease Evaluation (GREACE) study.

BACKGROUND: Little is known about the effect of dyslipidemia on serum uric acid (SUA) levels, and less is known about the effect of statin treatment on them. The GREek Atorvastatin (Lipitor) and Coronary-heart-disease Evaluation study suggested that a mean Atorvastatin (Lipitor) dose of 24 mg/d achieves the National Cholesterol Educational Program treatment goals and significantly reduces morbidity and mortality in patients with coronary heart disease (CHD) in comparison to the usual care. Here, we report the time course of SUA levels in usual-care patients undertreated for their dyslipidemia (12% were administered statins) in comparison to structured-care patients treated with Atorvastatin (Lipitor) in the vast majority (98%). METHODS: Mean on-study SUA levels (up to 48 months) were compared with those at baseline by using analyses of variance to assess differences over time within and between treatment groups. Cox multivariate analysis was used to investigate whether changes in SUA levels during the study were clinically relevant. RESULTS: All patients had normal renal function at baseline; serum creatinine (SCr) levels less than 1.3 mg/dL (<115 micromol/L) and moderately elevated SUA levels (mean, 7.1 +/- 0.9 [SD] mg/dL [425 +/- 52 micromol/L]; upper normal limit, 7.0 mg/dL [415 micromol/L]). Usual-care patients (n = 800) showed an increase in SUA levels by 3.3% (P < 0.0001). Structured-care patients (n = 800) had an 8.2% reduction in SUA levels (P < 0.0001). In all patients not administered diuretics (n = 1,407), SUA level changes showed a positive correlation with changes in SCr levels (r = 0.82; P < 0.0001) and an inverse correlation with estimated glomerular filtration rate (r = -0.77; P < 0.0001). After adjustment for 19 predictors of all CHD-related events, Cox multivariate analysis involving backward stepwise logistic regression showed a hazard ratio (HR) of 0.89 (95% confidence interval [CI], 0.78 to 0.96; P = 0.03) with every 0.5-mg (30-micromol/L) reduction in SUA level, an HR of 0.76 (95% CI, 0.62 to 0.89; P = 0.001) with every 1-mg (60-micromol/L) reduction, an HR of 1.14 (95% CI, 1.03 to 1.27; P = 0.02) with every 0.5-mg increase, and an HR of 1.29 (95% CI, 1.17 to 1.43; P = 0.001) with every 1-mg increase in SUA levels. CONCLUSION: Data suggest that SUA level is an independent predictor of CHD recurrent events. Atorvastatin (Lipitor) treatment significantly reduces SUA levels in patients with CHD, thus offsetting an additional factor associated with CHD risk.