1,721,039 research outputs found
The effects of ezetimibe on LDL-cholesterol: Quantitative or qualitative changes?
Ezetimibe represents the first of a new class of agents, the cholesterol absorption inhibitors, able to reduce low-density lipoproteins (LDL)-cholesterol by 15-25% from baseline in monotherapy and on top of statins and fibrates. To-date all the data regarding the efficacy of ezetimibe comes from the studies of its lipid-lowering power. Yet, recent findings from the ENHANCE study on atherosclerosis progression showed that the addition of ezetimibe to simvastatin in patients with heterozygous familial hypercholesterolemia did not affect the mean change in carotid intima-media thickness, although a significant reduction in LDL-cholesterol levels was present. Therefore, we cannot exclude that ezetimibe is treating mainly LDL-cholesterol and not the underlying dyslipidemia. Reviewing all available evidences on the effects on atherogenic small, dense LDL, it seems that ezetimibe produce quantitative rather than qualitative changes in LDL, with small net effects on LDL subclass distribution. Yet, we cannot exclude that clinical and laboratory factors influenced this result. We found important differences in the methodology used to measure LDL size and subfractions and this represents a crucial point, since these methods cannot be fully used interchangeably. In addition, it is reasonable to imagine that ezetimibe may be more effective on small, dense LDL in subjects with hypertriglyceridemia. Further formal cardiovascular event outcome trials are underway and this will provide additional insights into the long-term effects of ezetimibe. Future prospective studies are also needed to clarify to which extent ezetimibe is able to reduce atherogenic dyslipidemia, beyond LDL-cholesterol levels
Is diabetes the cost to pay for a greater cardiovascular prevention?
The recent JUPITER (Justification for the Use of statins in Primary prevention: an Intervention Trial Evaluating Rosuvastatin) trial is another study providing evidence about the effectiveness of statin therapy in reducing cardiovascular risk. Yet, in this study significantly higher glycated hemoglobin levels and incidence rates of diabetes were observed in persons treated with rosuvastatin than the placebo group. It should be noted that adverse effects on glucose metabolism have already been reported, albeit rarely, in previous trials with statins. Although the exact mechanisms involved are unknown, it seems that statins may deteriorate glycemic control by decreasing different metabolites, including isoprenoid and ubiquinone, normally produced during the process of cholesterol synthesis. We therefore suggest that, if statins are prescribed, patients should be monitored closely for blood glucose control even though the higher incidence of diabetes by statin therapy may represent a rare finding
Small, dense low-density lipoproteins are predictors of cardio- and cerebro-vascular events in subjects with the metabolic syndrome.
Glucose lowering and anti-atherogenic effects of incretin-based therapies: GLP-1 analogues and DPP-4-inhibitors
BACKGROUND: Type 2 diabetes is a chronic, progressive disease with a multi-faceted pathophysiology. Beyond the known defects of insulin resistance and beta-cell insufficiency, derangement of incretin hormones normally produced from the gut wall in response to food intake play an important role. In recent years, the 'incretin-based' therapies (IBTs) have been developed to address hyperglycemia through either mimicking the action of the endogenous incretin glucagon-like polypeptide (GLP-1) (GLP-1 receptor agonists) or by inhibiting the activity of the enzyme that degrades GLP-1 (the dipeptyl peptidase-4 inhibitors). OBJECTIVE: We reviewed available evidence on the glucose lowering and anti-atherogenic effects of IBT. RESULTS: In addition to their glucose-lowering and weight-neutral or weight-reducing actions, IBT decrease systolic blood pressure and improve fasting and postprandial lipid parameters by reducing total-cholesterol, low-density lipoprotein-cholesterol and triglycerides concentrations, and increasing high-density lipoprotein-cholesterol values. Reduced high-sensitivity C-reactive protein levels and improved endothelial dysfunction have been reported too. CONCLUSIONS: IBT have several beneficial effects on cardiovascular risk factors and, for this reason, it has been recently suggested to extend the use of these drugs in diabetic patients with cardiovascular complications. Yet, the long-term effects of IBT on subclinical or clinical atherosclerosis remain to be established by future studies
Long-term consequences of polycystic ovary syndrome on cardiovascular risk
Most available data suggest that the prevalence of cardiovascular diseases in women with polycystic ovary syndrome (PCOS) is smaller than expected based on risk calculations during fertile years; therefore, more studies are needed on long-term cardiovascular consequences. Evidence is accumulating that postmenopausal women with PCOS have an increased risk of cerebrovascular events and cardiovascular morbidity. These events are partially related to persisting hyperandrogenism but are mostly correlated with excessive body weight (mainly visceral obesity); this suggests that our best long-term strategy is to ensure that women with PCOS are informed about their high risk for metabolic and cardiovascular diseases
Quantitative and qualitative effects of rosuvastatin on LDL-cholesterol: what is the clinical significance?
BACKGROUND: Statins have emerged as the global leader in pharmacologic therapy for dyslipidaemia, and rosuvastatin has demonstrated clinical efficacy as well as safety in several clinical trials and postmarketing analyses. AIM: The present article reviewed the effects of rosuvastatin on the quantity and the quality of low-density lipoproteins (LDL). METHODS: We searched for and reviewed all the available evidence in a systematic way. A literature search (by Medline and Scopus) was performed using the following headings: 'LDL-cholesterol', 'LDL size', 'LDL subclasses', 'small dense LDL', 'apolipoprotein B, apo B' and 'rosuvastatin' up to 11 November 2008. The authors also manually reviewed the references of selected articles for any pertinent material. RESULTS: Rosuvastatin reduces LDL-cholesterol levels to a greater extent than other statins and is able to modulate significantly LDL size and subclasses towards less atherogenic particles as well as the LDL particle number, as indirectly measured by the levels of apo B. DISCUSSION AND CONCLUSIONS: The recent Justification for the Use of statins in Primary prevention: an Intervention Trial Evaluating Rosuvastatin study provides more evidence about the effectiveness of rosuvastatin therapy in reducing cardiovascular risk, even among persons who would not currently be considered for pharmacotherapy. Further insights on cardiovascular outcomes will be available by the on-going trials included in the GALAXY program that includes subjects with type-2 diabetes, haemodialysis recipients, patients with congestive heart failure and specific ethnic groups, such as African American, Hispanic and South Asian populations
Atherogenic lipoprotein phenotype and LDL size and subclasses in drug-naïve patients with early rheumatoid arthritis
OBJECTIVE: Subjects with rheumatoid arthritis (RA) have increased cardiovascular risk and may show atherogenic forms of dyslipidemia. The present study investigated whether patients with early RA, beyond alterations in plasma lipids, also show lower LDL size and altered LDL subclass distribution. DESIGN AND METHODS: We identified 25 subjects with RA (47+/-8 years, body mass index (BMI) 25+/-4kg/m(2)) by the American College of Rheumatology diagnostic criteria, with a disease durations <1 year and no prior treatment against it. In patients and 22 healthy subjects matched for age and BMI (controls) we measured plasma lipids and LDL size and subclasses by gradient gel electrophoresis. RESULTS: As compared to controls RA patients had higher plasma triglycerides (1.8+/-0.5 vs. 1.0+/-0.5mmol/L, p<0.0001) and lower HDL-cholesterol concentrations (1.2+/-0.2 vs. 1.4+/-0.2mmol/L, p=0.0027), while total- and LDL-cholesterol concentrations were similar. LDL particle size was lower in RA patients than controls (264+/-7 vs. 281+/-9A, p<0.0001), due to less LDL-I (31+/-6 vs. 38+/-7%, p=0.0004) and LDL-IIA (14+/-3 vs. 16+/-3%, p=0.0182), and more LDL-IIIB (7+/-1 vs. 5+/-1%), -IVA (11+/-2 vs. 8+/-2%) and -IVB particles (12+/-2 vs. 9+/-2%,) (p<0.0001 for all). Further, about 1/3 of patients showed the complete "atherogenic-lipoprotein-phenotype" (e.g. the concomitant presence of high triglycerides, low HDL-cholesterol and elevated small, dense LDL). CONCLUSIONS: Beyond plasma lipids, increased levels of small, dense LDL seems to be common in drug-naïve patients with early RA. Yet, whether these findings affect the atherogenic process and the clinical endpoints in these subjects remains to be determined by future prospective studies
The differential effects of thiazolidindiones on atherogenic dyslipidemia in type 2 diabetes: what is the clinical significance?
BACKGROUND: Diabetic dyslipidemia is typically characterized by an increase in plasma triglycerides, a decrease in high-density lipoprotein cholesterol and a concomitant increase in atherogenic small dense low-density lipoproteins. Thiazolidindiones are able to lower the levels of fasting glucose and glycated hemoglobin significantly by improving insulin sensitivity, as well as improving some aspects of diabetic dyslipidemia: total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol tend to increase while triglycerides are generally decreased. OBJECTIVE: This paper reviewed the effects of pioglitazone and rosiglitazone on atherogenic diabetic dyslipidemia, in particular on small dense low-density lipoprotein particles. Methods: A literature search (by Medline and Scopus) was performed up to 15 March 2008. The authors also manually reviewed the references of selected articles for any pertinent material. RESULTS: Pioglitazone showed an additional beneficial effect on triglycerides, high-density lipoprotein cholesterol and the levels of small dense low-density lipoprotein compared to rosiglitazone. CONCLUSIONS: Since recent studies have suggested that these agents may also have a differential effect on long-term cardiovascular end-points despite similar improvements in glycated hemoglobin and insulin sensitivity, the different impact on atherogenic diabetic dyslipidemia may help to explain these findings
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