Statin therapy in South-Asian patients: clinical implications beyond lipid lowering?

Impact of High-Dose Atorvastatin on Endothelial, Platelet, and Angiogenic Indices

Lipid lowering with statins improves morbidity and mortality, particularly in diabetics, and may have additional nonlipid effects. South Asians (SAs) are at higher risk of cardiovascular disease and diabetes compared with white Europeans (WEs). We hypothesized that abnormal endothelial (marked by von Willebrand factor), angiogenesis (VEGF, angiopoietins 1 and 2) and platelet function (soluble P selectin, soluble CD40L) improve with statin treatment in diabetics in different ethnic groups. Plasma was obtained before and 8 weeks after treatment with atorvastatin (80 mg/day) by SAs and WEs with or without diabetes. Research indices were measured by enzyme-linked-immunosorbent assay (ELISA). Treatment increased angiopoietin-2 ( P < .04) in all groups regardless of diabetes or ethnicity. In those free of diabetes, angiopoietin-2 increased 3-fold, whereas in diabetes, it increased 2-fold. We suggest that an additional effect of statins is to increase levels of growth factor angiopoietin-2 in the direction of normality. This effect is weaker in participants with diabetes.

Vascular risk factors in South Asians

South Asians originate from the Indian sub-continent (India, Pakistan, Bangladesh, Sri Lanka and Nepal) and represent one fifth of the world's population. Several studies suggested that South Asians have an increased risk of developing coronary heart disease (CHD) when compared with European populations. We review the role of traditional and emerging risk factors in the increased CHD risk in South Asians. The high prevalence of insulin resistance and type 2 diabetes mellitus in South Asians may be a major cause for their elevated vascular risk. However, other established and emerging risk factors are also overrepresented in South Asians. Large-scale prospective studies could determine the relative contribution of established and emerging vascular risk factors in South Asians. There is an urgent need for trials in South Asians that will evaluate clinical outcomes following treatment of these risk factors.

Temporal gene expression analysis of human coronary artery endothelial cells treated with Simvastatin

Increasing evidence indicates that the beneficial "pleiotropic" effects of statins on clinical events involve nonlipid mechanisms including the modification of blood vessel endothelial cell function. However, the involved molecular events and pathways are not completely understood. In the present study, Affymetrix microarrays were used to monitor the temporal gene expression of human coronary artery endothelial cells (HCAEC) treated with simvastatin (Sim) to gain insight into statins' direct effects on the endothelial function. We isolated and labeled mRNA from HCAEC treated with Sim for 0, 3, 6, 12, 24, and 48 h and hybridized these samples to Affymetrix GeneChip HG-U95Av2 to analyze the temporal gene expression profile. Out of 12,625 genes present on the HG-U95Av2 GeneChip, expression of 5,432 genes was detected. There were 1,475 of 5,432 genes that displayed the differential expression compared to baseline (0 h). Fifty-four genes were upregulated (< or = twofold) while 61 genes were downregulated ( > or = twofold) at 24-48 h after the Sim treatment. Many new target genes and pathways modulated by Sim were uncovered. This study indicates that many aspects of the pleiotropic effect of Sim on the endothelial cell function can be mediated by transcriptional control. Physiological function of 22% of 115 differentially expressed genes in Sim-treated HCAEC are currently unknown. These newly identified genes could be useful for new mechanistic study and new therapeutic modalities. Expressions of 13 out of 18 genes (> 70%) in the cell cycle/proliferation control process were significantly inhibited by the Sim treatment. CDC25B and ITGB4 gene expressions were validated by RT-PCR and Western blotting. Sim's inhibitory effect of on HCAEC growth was confirmed by the measurement of [3H]thymidine incorporation into the DNA synthesis. Further in-depth analysis of this effect may shed light on molecular mechanisms of Sim's beneficial inhibition of neointima formation in the atherosclerotic artery stenosis.