Secondary prevention of cardiovascular events with long-term pravastatin in patients with diabetes or impaired fasting glucose: results from the LIPID trial

Do people with diabetes need statins?

The prevalence of type 2 diabetes mellitus continues to increase rapidly. Persons with diabetes face a 2-fold greater absolute risk of cardiovascular disease (CVD) than those without diabetes. Many diabetic patients die before reaching the hospital after a cardiovascular event. Use of statin therapy for intensive control of diabetic dyslipidemia has produced relative reductions in CVD risk of about 25% in randomized, controlled clinical trials. This is true even though low-density lipoprotein cholesterol, the primary target of statin therapy, might not be markedly elevated in diabetic patients. Most patients with diabetes or diabetes plus established CVD warrant intensive statin therapy. Statin therapy has the ability to achieve low-density lipoprotein cholesterol goals recommended in treatment guidelines. Alone or in combination with an additional lipid-lowering drug, statins may also improve triglyceride and high-density lipoprotein cholesterol abnormalities in patients with diabetes.

Pravastatin reduces the risk for cardiovascular disease in Japanese hypercholesterolemic patients with impaired fasting glucose or diabetes: diabetes subanalysis of the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study

Diabetes mellitus (DM) is a major risk factor for cardiovascular disease (CVD) in patients with no history of CVD. Evidence for the effect of statins on CVD in the diabetic population in low-risk populations (e.g., Japanese) is limited. We evaluated the effect of pravastatin on risk reduction of CVD related to baseline glucose status in a primary prevention setting. The Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study, in patients with mild-to-moderate hypercholesterolemia (220-270 mg/dL), showed that low-dose pravastatin significantly reduced the risk for CVD by 26%. This exploratory subanalyses examined the efficacy of diet plus pravastatin on CVD in 2210 patients with abnormal fasting glucose (AFG, including 1746 patients with DM and 464 patients with impaired fasting glucose (IFG) at 5 years in the MEGA Study. CVD was threefold higher in AFG patients (threefold higher in DM, and twofold higher in IFG) compared with normal fasting glucose (NFG) patients in the diet group. Diet plus pravastatin treatment significantly reduced the risk of CVD by 32% (hazard ratio 0.68, 95% CI 0.48-0.96, number needed to treat, 42) in the AFG group compared with the diet alone group, and no significant interaction between AFG and NFG (interaction P=0.85) was found. Safety problems were not observed during long-term treatment with pravastatin. In conclusion, pravastatin reduces the risk of CVD in subjects with hypercholesterolemia and abnormal fasting glucose in the primary prevention setting in Japan.

The prevention of type 2 diabetes

Type 2 diabetes mellitus (T2DM) affects more than 7% of adults in the US and leads to substantial personal and economic burden. In prediabetic states insulin secretion and action--potential targets of preventive interventions--are impaired. In trials lifestyle modification (i.e. weight loss and exercise) has proven effective in preventing incident T2DM in high-risk groups, although weight loss has the greatest effect. Various medications (e.g. metformin, thiazolidinediones and acarbose) can also prevent or delay T2DM. Whether diabetes-prevention strategies also ultimately prevent the development of diabetic vascular complications is unknown, but cardiovascular risk factors are favorably affected. Preventive strategies that can be implemented in routine clinical settings have been developed and evaluated. Widespread application has, however, been limited by local financial considerations, even though cost-effectiveness might be achieved at the population level.

The effect of statins on the development of new-onset type 2 diabetes: a meta-analysis of randomized controlled trials

OBJECTIVE

To determine the ability of statins to prevent the development of new-onset type 2 diabetes mellitus through a meta-analysis of randomized, controlled trials.

RESEARCH DESIGN AND METHODS

A systematic literature search through November 6, 2007 was conducted to identify randomized, placebo-controlled trials of statins that reported data on the incidence of new-onset diabetes mellitus. Incidence of new-onset type 2 diabetes mellitus was treated as a dichotomous variable. Weighted averages were reported as relative risk (RR) with associated 95% confidence intervals (CI). A random-effects model was used.

RESULTS

Five prospective, randomized controlled trials (n = 39,791) were identified. Upon meta-analysis, the use of a statin did not significantly alter a patient's risk of developing new-onset type 2 diabetes mellitus (relative risk, 1.03; 95% confidence interval 0.89-1.19). Subgroup and sensitivity analyses did not significantly change the results. There was statistical heterogeneity that stemmed from pravastatin's tendency towards a reduction in risk and the other statins showing an increase in risk. The funnel plot could not rule out publication bias.

CONCLUSIONS

Statins, as a class, do not demonstrate a statistically significant positive or negative impact on a patient's risk of developing new-onset type 2 diabetes mellitus.

Effect of lower targets for blood pressure and LDL cholesterol on atherosclerosis in diabetes: the SANDS randomized trial

CONTEXT

Individuals with diabetes are at increased risk for cardiovascular disease (CVD), but more aggressive targets for risk factor control have not been tested.

OBJECTIVE

To compare progression of subclinical atherosclerosis in adults with type 2 diabetes treated to reach aggressive targets of low-density lipoprotein cholesterol (LDL-C) of 70 mg/dL or lower and systolic blood pressure (SBP) of 115 mm Hg or lower vs standard targets of LDL-C of 100 mg/dL or lower and SBP of 130 mm Hg or lower.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, open-label, blinded-to-end point, 3-year trial from April 2003-July 2007 at 4 clinical centers in Oklahoma, Arizona, and South Dakota. Participants were 499 American Indian men and women aged 40 years or older with type 2 diabetes and no prior CVD events.

INTERVENTIONS

Participants were randomized to aggressive (n=252) vs standard (n=247) treatment groups with stepped treatment algorithms defined for both.

MAIN OUTCOME MEASURES

Primary end point was progression of atherosclerosis measured by common carotid artery intimal medial thickness (IMT). Secondary end points were other carotid and cardiac ultrasonographic measures and clinical events.

RESULTS

Mean target LDL-C and SBP levels for both groups were reached and maintained. Mean (95% confidence interval) levels for LDL-C in the last 12 months were 72 (69-75) and 104 (101-106) mg/dL and SBP levels were 117 (115-118) and 129 (128-130) mm Hg in the aggressive vs standard groups, respectively. Compared with baseline, IMT regressed in the aggressive group and progressed in the standard group (-0.012 mm vs 0.038 mm; P < .001); carotid arterial cross-sectional area also regressed (-0.02 mm(2) vs 1.05 mm(2); P < .001); and there was greater decrease in left ventricular mass index (-2.4 g/m(2.7) vs -1.2 g/m(2.7); P = .03) in the aggressive group. Rates of adverse events (38.5% and 26.7%; P = .005) and serious adverse events (n = 4 vs 1; P = .18) related to blood pressure medications were higher in the aggressive group. Clinical CVD events (1.6/100 and 1.5/100 person-years; P = .87) did not differ significantly between groups.

CONCLUSIONS

Reducing LDL-C and SBP to lower targets resulted in regression of carotid IMT and greater decrease in left ventricular mass in individuals with type 2 diabetes. Clinical events were lower than expected and did not differ significantly between groups. Further follow-up is needed to determine whether these improvements will result in lower long-term CVD event rates and costs and favorable risk-benefit outcomes.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00047424.

Type 2 diabetes mellitus: prevention of macrovascular complications

Type 2 diabetes mellitus is a disease that affects a rapidly increasing number of patients. Most patients with Type 2 diabetes will develop vascular complications. This may be microvascular disease, such as nephropathy, retinopathy or polyneuropathy, and also macrovascular disease, such as coronary heart disease, stroke or peripheral artery disease. Optimal control of elevated blood glucose levels will reduce the symptoms of hyperglycemia and help to prevent the development of complications. In addition, treatment of hypertension and lipid disturbances has been shown to reduce the incidence and severity of vascular complications significantly. The current treatment goals focus on adequate and aggressive treatment of these three risk factors. The central dogma for treatment of blood glucose, blood pressure and cholesterol levels is 'the lower the better'. Ongoing trials evaluate the effect of further lowering these treatment goals and of specific types of medication on cardiovascular events.

Endothelial dysfunction in diabetes mellitus

Diabetes mellitus is associated with an increased risk of cardiovascular disease, even in the presence of intensive glycemic control. Substantial clinical and experimental evidence suggest that both diabetes and insulin resistance cause a combination of endothelial dysfunctions, which may diminish the anti-atherogenic role of the vascular endothelium. Both insulin resistance and endothelial dysfunction appear to precede the development of overt hyperglycemia in patients with type 2 diabetes. Therefore, in patients with diabetes or insulin resistance, endothelial dysfunction may be a critical early target for preventing atherosclerosis and cardiovascular disease. Microalbuminuria is now considered to be an atherosclerotic risk factor and predicts future cardiovascular disease risk in diabetic patients, in elderly patients, as well as in the general population. It has been implicated as an independent risk factor for cardiovascular disease and premature cardiovascular mortality for patients with type 1 and type 2 diabetes mellitus, as well as for patients with essential hypertension. A complete biochemical understanding of the mechanisms by which hyperglycemia causes vascular functional and structural changes associated with the diabetic milieu still eludes us. In recent years, the numerous biochemical and metabolic pathways postulated to have a causal role in the pathogenesis of diabetic vascular disease have been distilled into several unifying hypotheses. The role of chronic hyperglycemia in the development of diabetic microvascular complications and in neuropathy has been clearly established. However, the biochemical or cellular links between elevated blood glucose levels, and the vascular lesions remain incompletely understood. A number of trials have demonstrated that statins therapy as well as angiotensin converting enzyme inhibitors is associated with improvements in endothelial function in diabetes. Although antioxidants provide short-term improvement of endothelial function in humans, all studies of the effectiveness of preventive antioxidant therapy have been disappointing. Control of hyperglycemia thus remains the best way to improve endothelial function and to prevent atherosclerosis and other cardiovascular complications of diabetes. In the present review we provide the up to date details on this subject.

Atorvastatin efficacy in the prevention of cardiovascular events in patients with diabetes mellitus and/or metabolic syndrome

Several large-scale clinical trials have assessed the efficacy of atorvastatin in the primary and secondary prevention of cardiovascular events in patients with diabetes mellitus and/or metabolic syndrome. In primary prevention, CARDS (Collaborative Atorvastatin Diabetes Study) showed that atorvastatin 10 mg/day (vs placebo) reduced relative risk of the composite primary endpoint (acute coronary heart disease [CHD] events, coronary revascularisation, or stroke) by 37% (p = 0.001). This decrease was similar to decreases in major cardiovascular events in the ASCOT-LLA (Anglo-Scandinavian Cardiac Outcomes Trial-Lipid Lowering Arm) trial and HPS (Heart Protection Study). However, in CARDS, atorvastatin efficacy was evident as early as 6 months after starting treatment, whereas in HPS, simvastatin efficacy was noticeable only from about 15-18 months after starting treatment. In the ASCOT-LLA trial, in 2226 hypertensive diabetic patients without previous cardiovascular disease, atorvastatin (vs placebo) reduced the relative risk of all cardiovascular events and procedures by 25% (p = 0.038). In secondary prevention, substudies of the GREACE (GREek Atorvastatin and Coronary-heart-disease Evaluation), TNT (Treating to New Targets) and PROVE-IT (PRavastatin Or atorVastatin Evaluation and Infection Therapy) trials reported results for the approximately 15-25% of study participants who had diabetes. In the GREACE substudy, atorvastatin (vs physicians' standard care) significantly reduced the relative risk of total mortality by 52% (p = 0.049), coronary mortality by 62% (p = 0.042), coronary morbidity by 59% (p < 0.002) and stroke by 68% (p = 0.046). In the TNT substudy, incidence of the primary endpoint was significantly lower in diabetic patients treated with atorvastatin 80 mg/day rather than 10 mg/day (13.8% vs 17.9%; relative risk 0.75; p = 0.026). In the PROVE-IT substudy, a significantly lower incidence of acute cardiac events was reported for atorvastatin versus pravastatin recipients (21.1% vs 26.6%; p = 0.03) and, therefore, an absolute risk reduction of 5.5% was associated with atorvastatin therapy. ASPEN (Atorvastatin Study for Prevention of coronary heart disease Endpoints in Non-insulin-dependent diabetes mellitus) - a mixed primary and secondary prevention trial in diabetic patients - found that a 29% lower low-density lipoprotein-cholesterol level was seen with atorvastatin than placebo at endpoint (p < 0.0001); however, the reduction in composite primary endpoint of major cardiovascular events (cardiovascular mortality, nonfatal major cardiovascular event or stroke, and unstable angina requiring hospitalisation) with atorvastatin (13.7% vs 15.0% with placebo), and reduction in acute myocardial infarction relative risk of 27% with atorvastatin were not statistically significant. In CHD patients with metabolic syndrome (n = 5584) in a sub-analysis of the TNT trial, intensive versus lower-dosage atorvastatin therapy reduced the relative risk of major cardiovascular and cerebrovascular events by 29% (p < 0.0001). The analysis also revealed that CHD patients with, rather than those without, metabolic syndrome had a 44% greater level of absolute cardiovascular risk, thus clearly underscoring the clinical feasibility of administering intensive lipid-lowering therapy to CHD patients with metabolic syndrome. In summary, several patient populations, from definitive, large-scale studies, are now available to corroborate the integral place of atorvastatin--in line with various regional and internationally accepted disease management guidelines--in the primary and secondary prevention of cardiovascular events in patients with diabetes and/or metabolic syndrome.

Annual incidence and relative risk of diabetes in people with various categories of dysglycemia: a systematic overview and meta-analysis of prospective studies

BACKGROUND

Several estimates of the risk of progression to diabetes in people with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) have been reported.

OBJECTIVE

To provide an estimate of the risk of progression to diabetes and regression to normoglycemia in these populations.

DESIGN

Systematic overview and meta-analysis of prospective cohort studies published from 1979 until 2004.

SETTING

Global cohort studies.

PATIENTS

People with IFG or IGT detected by a screening oral glucose tolerance test.

MEASUREMENTS

Fasting and post-load plasma glucose levels.

RESULTS

The absolute annual incidence of diabetes in individuals with various categories of IFG or IGT varied from 5 to 10%. Compared to normoglycemic people the meta-analyzed relative risk and 95% confidence interval for diabetes was: 6.35 (4.87-7.82) in people with IGT; 5.52 (3.13-7.91) in people with isolated IGT; 4.66 (2.47-6.85) in people with IFG; 7.54 (4.63-10.45) in people with isolated IFG; and 12.13 (4.27-20.00) in people with both IFG and IGT. People with IGT were 0.33 times as likely to be normoglycemic after 1 year compared to people with normal glucose tolerance (95% CI 0.23-0.43).

LIMITATIONS

Studies that used differing criteria for IFG and IGT were included, and participants were classified on the basis of only one test.

CONCLUSION

IFG and IGT are associated with similar, high relative risk for incident diabetes. The combined abnormality of IFG plus IGT is associated with the highest relative risk.

Stroke prediction and stroke prevention with atorvastatin in the Collaborative Atorvastatin Diabetes Study (CARDS)

AIMS

Patients with Type 2 diabetes have an elevated risk of stroke. The role of lipid levels and diabetes-specific factors in risk prediction of stroke is unclear, and estimates of efficacy of lipid-lowering therapy vary between trials. We examined predictors of stroke and the effect of atorvastatin on specific stroke subtypes in Type 2 diabetes in the Collaborative Atorvastatin Diabetes Study (CARDS) [a trial of 2838 participants with mean low-density lipoprotein cholesterol < 4.14 mmol/l, no history of macrovascular disease and randomized to atorvastatin 10 mg daily or placebo].

METHODS

Median follow-up was 3.9 years. Cox regression models were used to estimate the effect of atorvastatin on stroke rate and risk of stroke associated with baseline risk factors. Risk factors that predicted stroke in univariate models were examined in a multivariable model.

RESULTS

Independent risk factors predicting stroke were age [10-year increments; hazard ratio (HR) 2.3, P < 0.001], microalbuminuria (albumin : creatinine ratio > 2.5 mg/mmol; HR 2.0, P = 0.007) and glycaemic control (HbA(1c) > 10%; HR 2.7, P = 0.007). Women were at lower risk of stroke (HR 0.3, P = 0.004). Lipids did not predict stroke. Of 60 first strokes, 47 were non-haemorrhagic, 13 were indeterminate and none was definitely haemorrhagic. Atorvastatin treatment was associated with 50% reduction in non-haemorrhagic stroke (95% confidence interval 9%-72%P = 0.024), similar to the 48% reduction (11%-69%) for all strokes combined.

CONCLUSIONS

Diabetes-specific risk factors are important predictors of stroke in Type 2 diabetes. Despite the lack of association between baseline lipids and first stroke, there was a reduction of 50% of non-haemorrhagic strokes associated with atorvastatin treatment in the CARDS population.

Prevention of diabetes development in those with the metabolic syndrome

Metabolic syndrome is characterized by abnormal glucose levels, central obesity, hypertension, elevated triglycerides, and low HDL cholesterol. This article reviews available data regarding the impact of lifestyle modification and drug therapies on the progression to diabetes in high risk individuals, such as those with hypertension, dyslipidemia, obesity, and prediabetes. Lifestyle and pharmacological interventions may alter metabolic parameters and impact progression to diabetes. However, the cost-effectiveness of these interventions are unclear.

Effects of simvastatin and metformin on inflammation and insulin resistance in individuals with mild metabolic syndrome

BACKGROUND

In addition to lipid-lowering and insulin-sensitizing actions, statins (HMG-CoA reductase inhibitors) and metformin may have pleiotropic effects.

OBJECTIVE

To study the effect of simvastatin and metformin on insulin sensitivity and inflammatory markers.

METHODS

Forty-one subjects with body mass index (BMI) 25-39.9 kg/m(2) and impaired glucose tolerance were randomized to receive simvastatin or metformin for 16 weeks. Blood samples were obtained for measurement of metabolic and inflammatory parameters before and after each treatment.

RESULTS

As expected, when compared with simvastatin, metformin therapy resulted in significant reductions in mean BMI, fasting plasma glucose, and homeostasis model assessment-insulin resistance (HOMA-IR), whereas simvastatin treatment resulted in significantly reduced total cholesterol, low-density lipoprotein-cholesterol (LDL-C), and apolipoprotein B levels. Independently of the medication used, significant decreases in C-reactive protein (CRP) and interleukin (IL)-6 were detected from baseline to treatment end. CRP showed a mean reduction of 0.12 +/- 0.04 mg/dL (p = 0.002) over the 16-week intervention period and IL-6 a mean reduction was 0.35 +/- 0.17 pg/mL (p = 0.046). No change was observed in the tumor necrosis factor-alpha levels. Baseline values of CRP and IL-6 and their percentage declines were correlated (r = 0.71 and r = 0.67, respectively; p < 0.001). In simvastatin recipients, no correlation was detected between reductions in CRP or IL-6 and lipids, whereas in metformin recipients, reductions in inflammatory markers were not correlated to BMI and HOMA-IR.

CONCLUSION

Our findings suggest that both metformin and simvastatin have similar beneficial effects on low-grade inflammation, in addition to their classical effects on glucose and lipid metabolism. Moreover, they confirm the importance of treating at-risk individuals even before the precipitation of overt diabetes mellitus or full-blown metabolic syndrome.

Undertreatment of cardiovascular risk factors among persons with diabetes in the United States

OBJECTIVE

We examined the extent of control of cardiovascular risk factors and distance from goal for those with uncontrolled levels in a recent sample of U.S. adults with diabetes.

METHODS

In the cross-sectional National Health and Nutrition Examination Survey 2001-2002, 532 (projected to 15.2 million) or 7.3% of adults aged >/=18 years had diabetes. Use of antihypertensive, antidiabetic and antidyslipidemic medications was examined. We determined the proportion of subjects not at goal for blood pressure (BP), lipids and glycosylated hemoglobin (A1C) and examined the distance from goal for those not under control.

RESULTS

Overall, 50.2% of subjects with diabetes were not at goal for A1C, 64.6% for low density lipoprotein-cholesterol (LDL-C), 52.3% for high density lipoprotein-cholesterol (HDL-C), 48.6% for triglycerides and 53.0% BP. Only 5.3% of men and 12.7% of women with diabetes were simultaneously at goal for A1C, LDL-C and BP. Even among those on treatment, most were not at goal for these parameters. Women were more likely to have LDL-C and HDL-C not at goal than men. Non-Hispanic Blacks were more often not at goal for BP and LDL-C. Mean distances from targets were 36mg/dL for LDL-C, 18mmHg for systolic BP, 6mmHg for diastolic BP and 2.0% for A1C in patients not at goal.

CONCLUSIONS

Many U.S. adults with diabetes have sub-optimal control of cardiovascular risk factors and remain far from target goals for BP, lipids and A1C, even if on treatment.

Implications of recent statin trials for primary care practice

3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) are the first-line treatment for dyslipidemia and the results of large statin trials have a significant impact on guidelines for cardiovascular disease (CVD) management, such as those set by the National Cholesterol Education Program Adult Treatment Panel. The benefit of statin therapy in CVD prevention has traditionally been demonstrated in clinical trials by the superior efficacy of statins vs placebo in lowering low-density lipoprotein cholesterol (LDL-C) and preventing hard coronary heart disease (CHD) outcomes including myocardial infarction and CHD death. However, due to earlier and improved treatment of CVD, the clinical manifestations of atherosclerosis are changing and other forms of CVD are now thought to predominate (such as revascularization and stroke). These changes in how CVD manifests in the patient population may have consequences for selection of endpoints when designing future clinical trials. Recent statin trials have also demonstrated the early and improved clinical benefit of lowering LDL-C beyond traditional goals with intensive statin therapy vs more moderate lipid-lowering therapy. This review assesses the impact of early statin trials on current CVD management guidelines, summarizes results of recent landmark statin trials, and evaluates the potential implications of these studies for future clinical trials and CVD management guidelines.

Dyslipidemia in type 2 diabetes mellitus

Cardiovascular disease is a significant cause of morbidity and mortality in patients with diabetes mellitus (DM). DM is now recognized as a risk equivalent for coronary heart disease. The lipid profile in patients with type 2 DM is characterized by elevated triglycerides, low levels of high-density lipoprotein cholesterol, and small dense low-density lipoprotein cholesterol (LDLC) particles and is believed to be a key factor promoting atherosclerosis in these patients. Both primary and secondary prevention studies have provided ample evidence that aggressive statin therapy reduces cardiovascular end points in patients with DM. In all persons with DM, current treatment guidelines recommend reduction of LDLC to less than 100 mg/dL, regardless of baseline lipid levels. Lowering LDLC to less than 70 mg/dL may provide even greater benefits, particularly in very high risk patients with DM and coronary heart disease.

Xuezhikang, an extract of cholestin, reduces cardiovascular events in type 2 diabetes patients with coronary heart disease: subgroup analysis of patients with type 2 diabetes from China coronary secondary prevention study (CCSPS)

Lipid-lowering therapy has been proven to reduce macrovascular complications of type 2 diabetes. Xuezhikang is an extract of cholestin and has a markedly modulating effect on lipids, but the effect of xuezhikang on reducing coronary events in diabetic patients with coronary heart disease (CHD) is less clear. A total of 591 diabetic patients with CHD were randomized to the xuezhikang group (n=306) and the placebo group (n=285). During the average 4 years of follow-up, there were 28 cases of CHD events (9.2%) in the xuezhikang group and 53 cases (18.6%) in the placebo group. Risk reduction for CHD events was 50.8% (P<0.001) by xuezhikang treatment. Xuezhikang decreased the risk of non-fatal MI by 63.8%, fatal MI by 58.5%, CHD sudden death by 26.9%, and other CHD death by 53.4%. CHD death totaled to 21 cases in the xuezhikang group (6.9%) and 35 cases in the placebo group (12.3%), indicating that xuezhikang significantly decreased the risk of CHD death by 44.1% (P<0.05). Seventy-two patients died from various causes, among which there were 27 patients in the xuezhikang group and 45 patients in the placebo group. The risk for all-cause death was 44.1% lower in the xuezhikang group than in the placebo group (P<0.01). This investigation demonstrates that xuezhikang therapy can be effective on reduction of cardiovascular events in diabetic patients with CHD with a reliable safety.

Pitavastatin Restores Vascular Dysfunction in Insulin-Resistant State by Inhibiting NAD(P)H Oxidase Activity and Uncoupled Endothelial Nitric Oxide Synthase-Dependent Superoxide Production

3-Hydroxyl-3-methylglutaryl coenzyme A reductase inhibitors (statins) may benefit the vasculopathy of insulin resistance independent of its lipid-lowering effects. Because imbalance of nitric oxide (NO) and superoxide anion (O(2)(-)) formation may lead to vascular dysfunction, we investigated the effect of statin on vasomotion of insulin-resistant state to clarify the mechanism by which statin ameliorates the impaired function. In the isolated aorta, contraction induced by angiotensin II was more potent in Zucker fatty rats (ZF) compared with that in Zucker lean rats. Both angiotensin II type 1 receptor expression and O(2)(-) production were upregulated in ZF. In addition, deficiency of tetrahydrobiopterin (BH4) contributes to the endothelial dysfunction in ZF. Oral administration of pitavastatin for 8 weeks normalized angiotensin II-induced vasoconstriction and endothelial function in ZF. Pitavastatin treatment of ZF increased vascular BH4 content, which was associated with twofold increase in endothelial NO synthase (eNOS) activity as well as a 60% reduction in endothelial O(2)(-) production. The treatment also markedly downregulated protein expression of angiotensin II type 1 receptor and gp91phox, whereas expression of guanosine triphosphate cyclohydrolase I was upregulated. Pitavastatin restores vascular dysfunction by inhibiting NAD(P)H oxidase activity and uncoupled eNOS-dependent O(2)(-) production.

Fenofibrate

Fenofibrate is a fibric acid derivative indicated for use in the treatment of primary hypercholesterolaemia, mixed dyslipidaemia and hypertriglyceridaemia in adults who have not responded to nonpharmacological measures. Its lipid-modifying effects are mediated by activation of peroxisome proliferator-activated receptor-alpha. Fenofibrate also has nonlipid (i.e. pleiotropic) effects (e.g. it reduces fibrinogen, C-reactive protein and uric acid levels and improves flow-mediated dilatation). Fenofibrate improves lipid levels (in particular triglyceride [TG] and high-density lipoprotein-cholesterol [HDL-C] levels) in patients with primary dyslipidaemia. Its lipid-lowering profile means that fenofibrate is particularly well suited for use in atherogenic dyslipidaemia (characterised by high TG levels, low HDL-C levels and small, dense low-density lipoprotein [LDL] particles), which is commonly seen in patients with the metabolic syndrome and type 2 diabetes mellitus. Indeed, fenofibrate improves the components of atherogenic dyslipidaemia in patients with these conditions, including a shift from small, dense LDL particles to larger, more buoyant LDL particles. Greater improvements in lipid levels are seen when fenofibrate is administered in combination with an HMG-CoA reductase inhibitor (statin) or in combination with ezetimibe, compared with monotherapy with these agents. In the DAIS study, fenofibrate significantly slowed the angiographic progression of focal coronary atherosclerosis in patients with type 2 diabetes. In terms of clinical outcomes, although no significant reduction in the risk of coronary events was seen with fenofibrate in the FIELD trial in patients with type 2 diabetes, treatment was associated with a significantly reduced risk of total cardiovascular disease (CVD) events, primarily through the prevention of non-fatal myocardial infarction and coronary revascularisation. Subgroup analyses revealed significant reductions in total CVD events and coronary heart disease events in patients with no previous CVD, suggesting a potential role for primary prevention with fenofibrate in patients with early type 2 diabetes. Improvements were also seen in microvascular outcomes with fenofibrate in the FIELD trial. Fenofibrate is generally well tolerated, both as monotherapy and when administered in combination with a statin. Combination therapy with fenofibrate plus a statin appears to be associated with a low risk of rhabdomyolysis; no cases of rhabdomyolysis were reported in patients receiving such therapy in the FIELD trial. Thus, fenofibrate is a valuable lipid-lowering agent, particularly in patients with atherogenic dyslipidaemia.

The CARDS trial: diabetic patients dealt a winning hand

Until recently, the role of statin therapy in diabetic patients without clinical signs or symptoms of coronary heart disease had been inadequately defined. The Collaborative Atorvastatin Diabetes Study (CARDS) is a prospective, randomized, placebo-controlled trial designed to compare the effects of atorvastatin with placebo in preventing primary coronary events in diabetic patients. After a median of only 3.9 years (the study was terminated approximately 2 years early due to the magnitude of benefit attributable to atorvastatin therapy), risk for major cardiovascular events was decreased by 37%, acute coronary heart disease-related events were also reduced by 36%, coronary revascularizations by 31%, and stroke by 48%. Benefit emerged within 1 year of initiating therapy.

Reassessment of cardiovascular risk in diabetes

PURPOSE OF REVIEW

To review recent trials and reassess cardiovascular risk in people with diabetes.

RECENT FINDINGS

Recent clinical trials have tended to focus on lower-risk participants with diabetes who have had event rates considerably lower than participants in the early lipid trials. Statin studies have generally shown benefit in those without cardiovascular disease and at lower levels of low-density lipoprotein cholesterol. Results of fibrate and glitazone studies have been mixed; the question of benefit among statin-treated patients remains unanswered. Investigators failed to confirm the benefits of glucose control observed in the original Diabetes Mellitus, Insulin Glucose Infusion in Acute Myocardial Infarction study possibly due to study design issues. Epidemiologic follow-up of the Diabetes Control and Complications Trial showed sustained benefit of glucose control. A number of studies have shown the benefit of inpatient control of blood glucose. We await the results of ongoing blood pressure trials and other ongoing trials, which should provide much new information. A conceptual model of cardiovascular risk for people with diabetes mellitus based on the UK Prospective Diabetes Study outcomes model is discussed.

SUMMARY

The majority of adults with diabetes have a substantially greater risk compared with those without diabetes and a small percentage has very high risk. A minority of individuals may have considerably lower 10-year risk.

Identifying patients for aggressive cholesterol lowering: the risk curve concept

The National Cholesterol Education Program's 2004 report identified more aggressive optional low-density lipoprotein (LDL) cholesterol treatment goals of <70 mg/dl for secondary prevention patients and <100 mg/dl for moderately high risk, primary prevention patients. Although LDL cholesterol reduction is the first step in reducing cardiovascular risk, it may be difficult for clinicians to visualize the risk reduction benefit for patients from various risk interventions. The concept of a "risk curve," or the absolute risk of a patient for subsequent cardiovascular events over a range of LDL cholesterol values, is proposed. In conclusion, placing a patient on the appropriate risk curve may facilitate an individualized clinical management strategy that takes into account the patient's absolute benefit from further LDL cholesterol reduction as well as from shifting the risk curve downward through non-LDL cholesterol interventions.

The effect of diabetes and stroke at baseline and during follow-up on stroke mortality

AIMS/HYPOTHESIS

The aim of this study was to compare the magnitude of the effect of diabetes and stroke at baseline and during follow-up on risk of stroke mortality.

MATERIALS AND METHODS

Study cohorts included 25,155 Finnish men and 26,423 women aged 25-74 years. Data on diabetes and stroke history at baseline, their incidence during follow-up, and stroke death were obtained from national registers.

RESULTS

During a mean follow-up of 18.9 years, 838 stroke deaths were recorded. In the baseline study, hazard ratios (HRs) for stroke mortality were 5.26 for men with prior diabetes only, 4.76 for men with prior stroke only, and 13.4 for men with both prior diabetes and stroke compared with men without diabetes and stroke at baseline and during follow-up. In women, the corresponding hazard ratios were 7.29, 5.27 and 5.52, respectively. When only diabetes and stroke status during the follow-up were considered, the hazard ratios for stroke mortality were 1.41 for men and 1.56 for women with incident diabetes only, 5.62 for men and 5.58 for women with incident stroke only, and 5.59 for men and 4.48 for women with both incident diabetes and stroke compared with men and women without diabetes and stroke at baseline and during follow-up.

CONCLUSIONS/INTERPRETATION

Diabetes and stroke, present either at baseline or during follow-up, markedly increase the risk of stroke death. Prior stroke at baseline carries a similar risk of stroke mortality as prior diabetes. There is a greater risk of stroke mortality associated with incident stroke during follow-up than with incident diabetes.

Management of dyslipidemia in diabetes

Diabetes is associated with a high risk of cardiovascular disease. The management of dyslipidemia, a well-recognized and modifiable risk factor among patients with type 2 diabetes, is an important element in the multifactorial approach to prevent coronary heart disease. Diabetic dyslipidemia typically consists of elevated triglyceride, low high-density lipoprotein cholesterol (HDL-C), and the predominance of small dense low-density lipoprotein (LDL) particles. LDL cholesterol (LDL-C) levels in patients with diabetes are similar to those found in the rest of the population. During the past few years, clinical trials have provided evidence that lipid-lowering therapy has a similar beneficial effect on cardiovascular outcomes in diabetic and nondiabetic individuals. According to current guidelines, the primary lipid target is an LDL-C <100 mg/dL (<70 mg/dL in very high-risk patients) and, to this end, statins are the agents of choice. The appropriate management of dyslipidemia in patients with diabetes, particularly in individuals with low LDL-C, remains controversial. To achieve lipid targets, attention should be directed first toward nonpharmacologic therapeutic interventions to control dyslipidemia, such as diet, exercise, smoking cessation, weight loss, and glycemic control. Statin therapy is recommended for most subjects but, frequently, a combination of lipid-lowering agents is required. A number of combinations are possible, and several factors should be considered to improve the safety of this strategy.

Diabetic dyslipidemia

Type 2 diabetes mellitus is associated with a markedly increased risk of cardiovascular disease. A complex dyslipidemia, which is an integral part of the underlying insulin resistance in this group, is a key to this increased risk. Increased secretion of VLDL from the liver is a central feature of dyslipidemia and is linked significantly to the low HDL and abnormal LDL that are also present. A number of physiologic and pharmacologic approaches are available and should be used aggressively to treat diabetic dyslipidemia.

Management of dyslipidemias in patients with diabetes and chronic kidney disease

Cardiovascular disease (CVD) is the leading cause of death in patients with stage 5 chronic kidney disease (CKD), and the mortality rate in stage 5 CKD is even higher in patients with diabetes. CVD risk reduction includes control of hyperglycemia, dyslipidemia, and BP. An LDL cholesterol goal of 70 mg/dl has been suggested for such high-risk patients. Most studies that have showed CVD risk reduction with statins have been in patients without CKD. However, some studies have had sufficient numbers of patients with CKD stages 2 to 3 to permit analysis, and these generally have shown CVD benefits similar to those found in patients without CKD. Studies that have shown benefit in patients who were on dialysis or after transplantation have been mixed, in part because CVD in such patients is far advanced and may not respond as well to intervention. As GFR falls, the dosages of many of the drugs that are used for the treatment of dyslipidemias need to be modified. In general, however, atorvastatin and fluvastatin dosages do not have to be modified. Drug interactions with cyclosporine also occur. In general, combinations of statins and fibrates should be avoided, and fenofibrate should be avoided in all patients with decreased GFR levels. Overall, on the basis of the very high risk for CVD in patients with diabetes and CKD, aggressive management of dyslipidemias is warranted, with an LDL goal of 70 mg/dl.

Insulin resistance and atherosclerosis

Considerable evidence supports the association between insulin resistance and vascular disease, and this has led to wide acceptance of the clustering of hyperlipidemia, glucose intolerance, hypertension, and obesity as a clinical entity, the metabolic syndrome. While insulin resistance, by promoting dyslipidemia and other metabolic abnormalities, is part of the proatherogenic milieu, it is possible that insulin resistance itself in the vascular wall does not promote atherosclerosis. Recent findings suggest that insulin resistance and atherosclerosis could represent independent and ultimately maladaptive responses to the disruption of cellular homeostasis caused by the excess delivery of fuel.

Efficacy and safety of atorvastatin in the prevention of cardiovascular end points in subjects with type 2 diabetes: the Atorvastatin Study for Prevention of Coronary Heart Disease Endpoints in non-insulin-dependent diabetes mellitus (ASPEN)

OBJECTIVE

Cardiovascular disease (CVD) risk is increased in type 2 diabetes. The purpose of this study was to assess the effect of 10 mg of atorvastatin versus placebo on CVD prevention in subjects with type 2 diabetes and LDL cholesterol levels below contemporary guideline targets.

RESEARCH DESIGN AND METHODS

Subjects were randomly assigned to receive 10 mg of atorvastatin or placebo in a 4-year, double-blind, parallel-group study. The composite primary end point comprised cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, recanalization, coronary artery bypass surgery, resuscitated cardiac arrest, and worsening or unstable angina requiring hospitalization.

RESULTS

A total of 2,410 subjects with type 2 diabetes were randomized. Mean LDL cholesterol reduction in the atorvastatin group over 4 years was 29% versus placebo (P < 0.0001). When we compared atorvastatin versus placebo, composite primary end point rates were 13.7 and 15.0%, respectively (hazard ratio 0.90 [95% CI 0.73-1.12]). In the subset of 1,905 subjects without prior myocardial infarction or interventional procedure, 10.4% of atorvastatin- and 10.8% of placebo-treated subjects experienced a primary end point (0.97 [0.74-1.28]). In the 505 subjects with prior myocardial infarction or interventional procedure, 26.2% of atorvastatin- and 30.8% of placebo-treated subjects experienced a primary end point (0.82 [0.59-1.15]). Relative risk reductions in fatal and nonfatal myocardial infarction were 27% overall (P = 0.10) and 19% (P = 0.41) and 36% (P = 0.11) for subjects without and with prior myocardial infarction or interventional procedure, respectively.

CONCLUSIONS

Composite end point reductions were not statistically significant. This result may relate to the overall study design, the types of subjects recruited, the nature of the primary end point, and the protocol changes required because of changing treatment guidelines. For these reasons, the results of the Atorvastatin Study for Prevention of Coronary Heart Disease Endpoints in Non-Insulin-Dependent Diabetes Mellitus (ASPEN) did not confirm the benefit of therapy but do not detract from the imperative that the majority of diabetic patients are at risk of coronary heart disease and deserve LDL cholesterol lowering to the currently recommended targets.

High Cardiovascular Risk in Patients With Diabetes and the Cardiometabolic Syndrome: Mandate for Statin Therapy

Diabetes mellitus confers a high risk of cardiovascular morbidity and mortality and requires aggressive management of all cardiovascular risk factors, including diabetic dyslipidemia. Although levels of low-density lipoprotein cholesterol are often normal or only slightly elevated in persons with diabetes, lipid-altering therapy with statins has been shown in large, randomized, controlled trials to decrease the risk of cardiovascular complications in this patient population. A target low-density lipoprotein cholesterol level of <70 mg/dL is now a therapeutic option in patients at very high risk for coronary heart disease, including patients with diabetes. Diabetes is also a leading cause of end-stage renal disease. In addition to their lipid-modifying effects, statins have been shown to slow the progression of diabetic nephropathy and potentially exert other renoprotective effects; these benefits, however, remain to be confirmed in clinical trials.

Effect of lowering LDL cholesterol substantially below currently recommended levels in patients with coronary heart disease and diabetes: the Treating to New Targets (TNT) study

OBJECTIVE

The Treating to New Targets study showed that intensive lipid-lowering therapy with atorvastatin 80 mg/day provides significant clinical benefit beyond that afforded by atorvastatin 10 mg/day in patients with stable coronary heart disease (CHD). The objective of our study was to investigate whether similar benefits of high-dose intensive atorvastatin therapy can be achieved in patients with CHD and diabetes.

RESEARCH DESIGN AND METHODS

A total of 1,501 patients with diabetes and CHD, with LDL cholesterol levels of <130 mg/dl, were randomized to double-blind therapy with either atorvastatin 10 (n = 753) or 80 (n = 748) mg/day. Patients were followed for a median of 4.9 years. The primary end point was the time to first major cardiovascular event, defined as death from CHD, nonfatal non-procedure-related myocardial infarction, resuscitated cardiac arrest, or fatal or nonfatal stroke.

RESULTS

End-of-treatment mean LDL cholesterol levels were 98.6 mg/dl with atorvastatin 10 mg and 77.0 mg/dl with atorvastatin 80 mg. A primary event occurred in 135 patients (17.9%) receiving atorvastatin 10 mg, compared with 103 patients (13.8%) receiving atorvastatin 80 mg (hazard ratio 0.75 [95% CI 0.58-0.97], P = 0.026). Significant differences between the groups in favor of atorvastatin 80 mg were also observed for time to cerebrovascular event (0.69 [0.48-0.98], P = 0.037) and any cardiovascular event (0.85 [0.73-1.00], P = 0.044). There were no significant differences between the treatment groups in the rates of treatment-related adverse events and persistent elevations in liver enzymes.

CONCLUSIONS

Among patients with clinically evident CHD and diabetes, intensive therapy with atorvastatin 80 mg significantly reduced the rate of major cardiovascular events by 25% compared with atorvastatin 10 mg.

Efficacy of lipid lowering drug treatment for diabetic and non-diabetic patients: meta-analysis of randomised controlled trials

OBJECTIVE

To evaluate the clinical benefit of lipid lowering drug treatment in patients with and without diabetes mellitus, for primary and secondary prevention.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane, Medline, Embase, and reference lists up to April 2004.

STUDY SELECTION

Randomised, placebo controlled, double blind trials with a follow-up of at least three years that evaluated lipid lowering drug treatment in patients with and without diabetes mellitus.

DATA EXTRACTION

Two independent reviewers extracted data. The primary outcome was major coronary events defined as coronary heart disease death, non-fatal myocardial infarction, or myocardial revascularisation procedures.

RESULTS

Twelve studies were included. Lipid lowering drug treatment was found to be at least as effective in diabetic patients as in non-diabetic patients. In primary prevention, the risk reduction for major coronary events was 21% (95% confidence interval 11% to 30%; P < 0.0001) in diabetic patients and 23% (12% to 33%; P = 0.0003) in non-diabetic patients. In secondary prevention, the corresponding risk reductions were 21% (10% to 31%; P = 0.0005) and 23% (19% to 26%; P < or = 0.00001). However, the absolute risk difference was three times higher in secondary prevention. When results were adjusted for baseline risk, diabetic patients benefited more in both primary and secondary prevention. Blood lipids were reduced to a similar degree in both groups.

CONCLUSIONS

The evidence that lipid lowering drug treatment (especially statins) significantly reduce cardiovascular risk in diabetic and non-diabetic patients is strong and suggests that diabetic patients benefit more, in both primary and secondary prevention. Future research should define the threshold for treatment of these patients and the desired target lipid concentrations, especially for primary prevention.

Que nous apprennent les grands essais cliniques de prévention cardiovasculaire et rénale chez le malade diabétique de type 2 hypertendu ?

Type 2 diabetes mellitus and hypertension are frequently associated. Cardiovascular morbidity is a major burden in these patients. Furthermore a renal disease appears in 40% of them that may lead to chronic terminal renal failure. Whatever the stage of the renal disease, it increases the cardiovascular risk. A majority of type 2 diabetic patients will eventually died of cardiovascular complications before having reached chronic terminal renal failure. Many large clinical trials including type 2 diabetic patients with hypertension have been performed in the last 20 years with cardiovascular morbidity and mortality as primary outcomes. These trials mainly evaluated the role of glycemic control, of hypertension as well as the decrease of LDL-cholesterol. Based on these trials, the prescription type of hypertensive type 2 diabetic patient should include, besides hygienic and dietary advices, antidiabetic treatment, thiazide and/or betablocker and platelet inhibitor. Statin should be prescribed for secondary prevention if serum LDL-cholesterol is above 1,3 g/l and for primary prevention depending on serum LDL-cholesterol and on the number of cardiovascular risk factors. The objectives are an HbA1c below 6,5%, a LDL-cholesterol below 1g/l and a blood pressure below 150/80 mmHg. The appearance of diabetic nephropathy alters the treatment and the therapeutic objectives. Many large trials aimed at preventing microalbuminuria (primary prevention), macroproteinuria (secondary prevention), and chronic renal failure (tertiary prevention) have been conducted. For primary prevention, angiotensin-converting-enzyme inhibitors should be prescribed in case of hypertension because they delay the appearance of microalbuminuria. For secondary prevention, angiotensin-converting-enzyme inhibitors and angiotensin-receptor blockers decrease albuminuria excretion rate and delay the appearance of macroproteinuria whatever the blood pressure. Tertiary prevention is based on angiotensin-receptor blockers since they slow down the decrease of renal function. The objectives are a blood pressure below 130/80 mmHg and the regression or the reduction of albuminuria excretion rate. Intensified and target-driven interventions aimed at multiple risk factors implicated in cardiovascular and renal lesions, as successfully performed in the STENO-2 study, reduce the risk of cardiovascular and renal morbidity and mortality. In this article, large clinical trials having the prevention of cardiovascular and renal risks as primary outcomes were analyzed.

Risk constellations in patients with the metabolic syndrome: epidemiology, diagnosis, and treatment patterns

The prevalence of diabetes mellitus is increasing worldwide. Among other complications, diabetes is associated with the risk of coronary heart disease (CHD) that is thought to be equal to the risk of CHD in subjects without diabetes with previous myocardial infarction. Studies have shown that CHD risk factors start to increase long before the onset of clinical diabetes. Furthermore, the risk factors that are present in prediabetic individuals are also components of the highly prevalent metabolic syndrome. This suggests that treatment of CHD risk factors may effectively reduce the incidence of type 2 diabetes. Lifestyle interventions have proved effective in preventing the onset of type 2 diabetes in subjects with impaired glucose tolerance. A number of post hoc studies have reported consistent reductions in the incidence of type 2 diabetes in hypertensive patients treated with either angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs). As a result of these positive data, ongoing prospective studies are investigating whether antihypertensive agents prevent or delay the onset of diabetes in patients at risk. Telmisartan, a selective oral ARB that is indicated for first-line therapy of essential hypertension, may provide improved tolerability compared with ACE inhibitors. Therefore, the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) program is investigating the effectiveness of telmisartan in the prevention or delay of type 2 diabetes. The program comprises ONTARGET and the Telmisartan Randomized Assessment Study in ACE-Intolerant Subjects with Cardiovascular Disease (TRANSCEND).

Prevenção do diabetes mellitus tipo 2

Diabetes mellitus do tipo 2 (DM2) é uma doença metabólica complexa, multifatorial e de presença global, que afeta a qualidade e o estilo de vida dos acometidos, podendo levar a uma redução pronunciada na expectativa de vida dessa população. Portadores de diabetes podem ter uma redução de 15 ou mais anos de vida, com a grande maioria morrendo em decorrência das complicações cardiovasculares. Faz-se necessário o estabelecimento de estratégias efetivas para a redução do impacto do DM2 para os próximos anos. Para isso, urge a necessidade de maior atenção no tocante às estratégias de prevenção, sobretudo para as populações de maior risco de desenvolvimento da doença. Nesse contexto, os portadores de tolerância diminuída à glicose (TDG) e glicemia de jejum alterada (GJA) devem, cada vez mais, ser alvos de estratégias de intervenção na busca de minimização de risco para o diabetes, devendo para isso terem direcionamento para a efetivação de mudanças comportamentais (fatores dietoterápicos e prática de atividade física) e, quando necessário e aprovado, o uso de agentes farmacológicos. Estudos conduzidos pelo mundo têm confirmado a eficácia do uso de estratégias comportamentais e mesmo do uso de agentes farmacológicos para a prevenção de DM2.

The metabolic syndrome: prevalence, CHD risk, and treatment

An increased risk of coronary heart disease (CHD) morbidity and mortality is associated with the metabolic syndrome, a condition characterized by the concomitant presence of several abnormalities, including abdominal obesity, dyslipidemia, hypertension, insulin resistance (with or without glucose intolerance or diabetes), microalbuminuria, prothrombotic, and proinflammatory states. Estimates of the prevalence of the metabolic syndrome indicate that this condition is now common and likely to increase dramatically over the coming decades, in parallel with greater rates of obesity and Type 2 diabetes. Risk factors for the metabolic syndrome are already present in obese children and adolescents. Thus, identifying and treating all affected individuals promptly and optimally are critical to ensure that this potentially challenging healthcare burden is minimized. Here, we review the prevalence of the metabolic syndrome, dyslipidemias, and CHD risk. Although changes in lifestyle are fundamental to reducing many of the CHD risk factors associated with the metabolic syndrome, pharmacologic interventions also play an important role. Retrospective subanalyses of the effects of statins on coronary event rates and lipid levels in patients with the metabolic syndrome included in clinical trials indicate that these agents are beneficial in correcting the extensive lipid abnormalities that are frequently present in these individuals. However, the optimal management of metabolic syndrome dyslipidemia will depend on the outcomes of future prospective clinical trials. This review examines the underlying causes and prevalence of the metabolic syndrome and its impact on CHD morbidity and mortality and discusses the role of statins in optimizing its management.

Reaching goal in hypercholesterolaemia: dual inhibition of cholesterol synthesis and absorption with simvastatin plus ezetimibe

Lowering serum cholesterol levels reduces the risk of coronary heart disease (CHD)-related events. Statins are commonly prescribed as first-line treatment but many patients at high-risk for CHD still fail to reach their cholesterol or low-density lipoprotein cholesterol (LDL-C) goals with statin monotherapy. National and international guidelines for the prevention of CHD recommend the modification of lipid profiles and particularly LDL-C [e.g. the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III; 2001) and Third Joint Task Force of European and other Societies on Cardiovascular Disease Prevention in Clinical Practice (2003) Guidelines]. Several recent clinical trials indicated an added benefit from aggressive lowering of LDL-C levels. Based on these findings, the NCEP ATP III revised the LDL-C target from < 100 mg/dL (2.6 mmol/L) to < 70 mg/dL (1.8 mmol/L) (optional target) for very high-risk patients and < 130 mg/dL (3.4 mmol/L) to < 100 mg/dL (2.6 mmol/L) for moderately high-risk patients. For patients who fail to achieve their LDL-C target, inhibiting the two main sources of cholesterol - synthesis and uptake - can produce more effective lipid lowering, allowing more patients to reach their LDL-C goal. Ezetimibe is a highly-selective inhibitor of cholesterol absorption and simvastatin is an evidence-based inhibitor of cholesterol synthesis. The LDL-C-lowering efficacy of targeting both major sources of cholesterol with ezetimibe plus simvastatin was demonstrated in several multicentre, double-blind, placebo-controlled trials in patients with hypercholesterolaemia. For patients who do not reach their cholesterol goal with a statin, adding ezetimibe 10 mg significantly reduces LDL-C compared with statin monotherapy. Thus, this treatment option may help patients reach the new 'stricter' cholesterol goals. This review, based on a Medline database search from January 2000 to August 2005, considers the LDL-C-lowering efficacy of ezetimibe and discusses the role of this agent for patients who fail to achieve guideline cholesterol goals with statin monotherapy.

Pioglitazone: an antidiabetic drug with the potency to reduce cardiovascular mortality

Pioglitazone is an antidiabetic drug known to decrease peripheral, hepatic and vascular insulin resistance by the stimulation of PPARgamma. In clinical trials, pioglitazone as monotherapy or in combination with other oral antidiabetic drugs or insulin has demonstrated to effectively improve blood glucose levels, long-term glucose control and the lipid profile. The vascular effects of pioglitazone include improvement of endothelial function and microcirculation, reduction of blood pressure and inflammatory surrogate markers of atherosclerosis, and a reduction of a composite measure of macrovascular events (death, stroke and myocardial infarctions). The drug is well tolerated and has an acceptable side effect profile. Because of its additional microvascular and macrovascular effects, pioglitazone is an attractive and effective treatment option for the management of Type 2 diabetes mellitus.

Are statins created equal? Evidence from randomized trials of pravastatin, simvastatin, and atorvastatin for cardiovascular disease prevention

BACKGROUND

The relative efficacy of different statins for long-term cardiovascular prevention remains largely undetermined.

METHODS

Using adjusted indirect comparison, we compared 3 statins (pravastatin, simvastatin, and atorvastatin) based on published randomized placebo-controlled trials for long-term cardiovascular prevention. A systematic literature search between 1980 and 2004 was conducted. Randomized placebo-controlled trials of the 3 statins, which studied cardiovascular diseases or death as the outcome, enrolled > or = 1000 participants, and had > or = 1-year follow-up, were included. Trials were grouped according to the statin under study. A pooled relative risk (RR) was derived from each set of trials using a random-effects model. Adjusted indirect comparisons using pooled RRs were made between statins with regard to prespecified clinical outcomes.

RESULTS

Eight placebo-controlled trials met the inclusion criteria, including 4 pravastatin trials (n = 25,572), 2 simvastatin trials (n = 24,980), and 2 atorvastatin trials (n = 13,143). All trials had a similar degree of lipid reduction. Graphical and statistical assessments showed minimal heterogeneity in the trials' effect sizes. Adjusted indirect comparisons did not reveal a statistically significant difference between statins in reducing fatal coronary heart disease and nonfatal myocardial infarctions (simvastatin vs pravastatin: RR 0.93 [95% CI 0.84-1.03]; atorvastatin vs simvastatin: RR 0.84 [95% CI 0.66-1.08]; atorvastatin vs pravastatin: RR 0.79 [95% CI 0.61-1.02]). We were unable to detect differences either in outcomes for fatal and nonfatal strokes, all cardiovascular deaths, and all-cause mortality.

CONCLUSION

Evidence from published statin randomized placebo-controlled trials suggests that pravastatin, simvastatin, and atorvastatin, when used at their standard dosages, show no statistically significant difference in their effect on long-term cardiovascular prevention.

REVIEW: Efficacy and mechanisms of action of statins in the treatment of diabetic dyslipidemia

CONTEXT

The Adult Treatment Panel III recommends 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, as first-line lipid-altering therapy for all adult patients with diabetes mellitus. This is based on the well-characterized efficacy and safety profiles of this class of agents as well as several clinical trials demonstrating that statin treatment reduces the risk of cardiovascular events.

EVIDENCE ACQUISITION

This review provides an overview of the effectiveness and mechanisms of action of statins in patients with diabetes mellitus using small efficacy trials and large clinical outcomes trials as well as studies of the effects of statins on apolipoprotein B (apoB) metabolism.

EVIDENCE SYNTHESIS

The major findings presented are a review of mechanistic studies of selected subjects with diabetes mellitus and dyslipidemia and a compilation of results from large-scale clinical trials of patients with diabetes.

CONCLUSIONS

Statins are highly efficacious as low-density lipoprotein cholesterol-lowering agents and have more modest effects on very low-density lipoprotein triglyceride and high-density lipoprotein cholesterol levels. The effects of statins on plasma lipids and lipoproteins result from their ability to both increase the efficiency with which very low-density lipoprotein and low-density lipoprotein are cleared from the circulation and reduce the production of apoB-containing lipoproteins by the liver. Additional investigations are needed to clarify the mechanisms by which statins reduce apoB secretion from the liver.

Diabetes mellitus and stroke

The aim of this article was to describe (i) the epidemiology and outcomes of stroke relating to diabetes; (ii) the pathophysiology of diabetes as a risk factor for stroke; (iii) the management of acute stroke in patients with diabetes; (iv) the evidence of primary and secondary prevention of stroke in patients with diabetes; and (v) the risk of new-onset diabetes using older antihypertensive agents. The combination of diabetes and stroke disease is a major cause of morbidity and mortality worldwide. Evidence from large clinical trials performed in patients with diabetes supports the need for aggressive and early intervention to target patients' cardiovascular (CV) risks in order to prevent the onset, recurrence and progression of acute stroke. Identification of at-risk patients with diabetes and metabolic syndrome has also allowed the delivery of early and effective intervention to reduce stroke risks, while active treatment during the acute phase of stroke will reduce long-term neurological and functional deficits. While the ongoing debate on the risk benefits of different antihypertensive, lipid-lowering and antiplatelet agents should not detract clinicians from pursuing aggressive CV risk reduction, the application of evidence-based medicine specifically in patients with diabetes will facilitate the use of appropriate agents to improve clinical outcomes. The overall management of patients with diabetes and acute stroke or at risk of secondary stroke should also include multifactorial intervention that not only targets patient's CV risk but also includes behavioural, lifestyle and, where appropriate, surgical intervention.

Diabetes mellitus-associated atherosclerosis: mechanisms involved and potential for pharmacological invention

While diabetes mellitus is most often associated with hypertension, dyslipidemia, and obesity, these factors do not fully account for the increased burden of cardiovascular disease in patients with the disease. This strengthens the need for comprehensive studies investigating the underlying mechanisms mediating diabetic cardiovascular disease and, more specifically, diabetes-associated atherosclerosis. In addition to the recognized metabolic abnormalities associated with diabetes mellitus, upregulation of putative pathological pathways such as advanced glycation end products, the renin-angiotensin system, oxidative stress, and increased expression of growth factors and cytokines have been shown to play a causal role in atherosclerotic plaque formation and may explain the increased risk of macrovascular complications. This review discusses the methods used to assess the development of atherosclerosis in the clinic as well as addressing novel biomarkers of atherosclerosis, such as low-density lipoprotein receptor-1. Experimental models of diabetes-associated atherosclerosis are discussed, such as the streptozocin-induced diabetic apolipoprotein E knockout mouse. Results of major clinical trials with inhibitors of putative atherosclerotic pathways are presented. Other topics covered include the role of HMG-CoA reductase inhibitors and fibric acid derivatives with respect to their lipid-altering ability, as well as their emerging pleiotropic anti-atherogenic actions; the effect of inhibiting the renin-angiotensin system by either ACE inhibition or angiotensin II receptor antagonism; the effect of glycemic control and, in particular, the promising role of thiazolidinediones with respect to their direct anti-atherogenic actions; and newly emerging mediators of diabetes-associated atherosclerosis, such as advanced glycation end products, vascular endothelial growth factor and platelet-derived growth factor. Overall, this review aims to highlight the observation that various pathways, both independently and in concert, appear to contribute toward the pathology of diabetes-associated atherosclerosis. Furthermore, it reflects the need for combination therapy to combat this disease.