Atorvastatin and micronized fenofibrate alone and in combination in type 2 diabetes with combined hyperlipidemia

Effective use of combination lipid therapy

Despite the benefits of statin therapy, low-density lipoprotein (LDL) cholesterol management remains suboptimal and many patients do not achieve their recommended target goals. The aim of combination lipid drug therapy in high-risk patients is to achieve LDL cholesterol and non-high-density lipoprotein (HDL) cholesterol goals with a minimum of serious adverse effects. Although statins are the drug of first choice, statin monotherapy may be limited by intolerance of dose escalation or failure to attain non-HDL cholesterol goals in those with mixed hyperlipidemia. Statins plus bile acid resins or ezetimibe can achieve greater than 50% reduction in LDL cholesterol, with little or no increase in adverse effects. Fibrates, niacin, and omega-3 fatty acids, when added to statins, can reduce triglycerides, increase HDL cholesterol, and reduce non-HDL cholesterol to a greater extent than statin monotherapy. The safety profile of combination lipid therapy is acceptable if the global coronary heart disease risk of the patient is high, thus producing a favorable risk to benefit ratio. Careful surveillance of hepatic transaminases, avoidance of gemfibrozil in statin-fibrate combinations, and awareness of statin-concomitant drug interactions is key to safe and efficacious use of combination lipid drug therapy.

HDL-raising strategies in the treatment of coronary artery disease: perspectives from the Armed Forces Regression Study

PURPOSE OF REVIEW

Even with the aggressive reduction of LDL-cholesterol, the risk of cardiovascular events in patients with coronary artery disease remains substantial. The Armed Forces Regression Study was a randomized, double-blind, placebo-controlled trial of combination drug therapy aimed at raising HDL-cholesterol in patients with angiographically evident coronary artery disease. Drug therapy ultimately resulted in regression of the angiographic lesions and a reduction in cardiovascular events. This review places the Armed Forces Regression Study within the context of other recent studies.

RECENT FINDINGS

In the past few years a number of other important papers have further defined the important role HDL-cholesterol plays in the pathobiology of atherosclerosis. These studies have focused on three general areas: HDL-cholesterol metabolism and the reverse cholesterol transport pathway; novel therapeutic interventions and their effects on coronary artery disease as assessed through non-invasive imaging modalities; and finally a re-analysis of previous outcomes trials with established HDL-cholesterol modifying agents.

SUMMARY

The results of the Armed Forces Regression Study fit nicely within the evolving paradigm of targeting HDL-cholesterol in patients at risk of cardiovascular events. The use of niacin and well-tolerated fibrates as an adjunct to statins or as primary therapy in patients intolerant of statins appears reasonable in patients with low levels of HDL-cholesterol and at high risk of cardiovascular events. The further development of novel therapeutic approaches, in addition to broadening our pharmacological armamentarium, should further advance our understanding of HDL-cholesterol.

Reducing cardiovascular risk in diabetes: beyond glycemic and blood pressure control

Patients with diabetes mellitus have a much higher rate of cardiovascular disease (CVD) than the general population, and, in addition to glycaemia and hypertension, dyslipidemia has emerged as an important modifiable cardiovascular risk factor in these patients. In most patients with type 2 diabetes, the major features of dyslipidemia are increased triglyceride levels, decreased high-density lipoprotein cholesterol (HDL-C) levels, and changes in the composition and level of low-density lipoprotein cholesterol (LDL-C). Clinical trials evaluating both primary and secondary prevention of CVD demonstrate that lipid-lowering therapy results in a substantial reduction of cardiovascular risk in patients with type 2 diabetes. Low-density lipoprotein cholesterol is the first priority for treatment, with a statin in adequate dosage as the first choice for pharmacological therapy. The first statin trial conducted solely in patients with type 2 diabetes and no prior CVD demonstrated a 37% reduction in cardiovascular events in patients randomized to atorvastatin 10 mg compared with placebo. Additional trials that further address the benefits of lipid-lowering therapy in patients with diabetes are near completion, or are underway, and should provide important information about further attenuating risk in patients with diabetes.

High-density lipoprotein as a therapeutic target: clinical evidence and treatment strategies

The clinical importance of low serum levels of high-density lipoprotein (HDL) cholesterol is often under-recognized and underappreciated as a risk factor for premature atherosclerosis as well as for cardiovascular morbidity and mortality. Low serum levels of HDL are frequently encountered, especially in patients who are obese or have the metabolic syndrome. In prospective epidemiologic studies, every 1-mg/dL increase in HDL is associated with a 2% to 3% decrease in coronary artery disease risk, independent of low-density lipoprotein (LDL) cholesterol and triglyceride (TG) levels. The primary mechanism for this protective effect is believed to be reverse cholesterol transport, but several other anti-inflammatory, antithrombotic, and antiproliferative functions for HDL have also been identified. In recognition of these antiatherogenic effects, recent guidelines have increased the threshold for defining low levels of HDL for both men and women. The first step in achieving these revised targets is therapeutic lifestyle changes. When these measures are inadequate, pharmacotherapy specific to the patient's lipid profile should be instituted. Niacin therapy, currently the most effective means for raising HDL levels, should be initiated in patients with isolated low HDL (HDL <40 mg/dL, LDL and non-HDL at or below National Cholesterol Education Program (NCEP) targets based on global cardiovascular risk evaluation). Patients who have both low HDL and elevated LDL should receive a statin or statin-niacin combination therapy, and patients with concomitant low HDL and elevated TGs should receive a fibrate initially, with a statin, niacin, or ezetimibe added thereafter as needed to help attain NCEP lipoprotein targets.

Modifying plasma low-density lipoprotein and high-density lipoprotein cholesterol: what combinations are available in the future?

Despite a growing body of research on the benefit of combination drug therapy for dyslipidemia in the metabolic syndrome or diabetes mellitus, there are insufficient outcome data on the use of combination therapy as well as inadequate data to compare certain combination regimens. The focus of the therapeutic approach in treating the metabolic syndrome has been almost exclusively on low-density lipoprotein (LDL) cholesterol for approximately the past 10 years, and specifically on statin therapy. Although results of epidemiologic studies as well as clinical trials using angiographic and clinical end points confirm the association of LDL cholesterol and risk of coronary artery disease, data are lacking regarding the effects of combination therapy in the management of coronary artery disease. Management of the metabolic syndrome focusing on the modification of plasma LDL as well as high-density lipoprotein cholesterol is reviewed. Future management strategies with the use of novel combination therapy is also discussed.

Combination Drug Therapy: A Strategy for Aggressive Lipid Modification

This continuing feature will update readers on recent developments in cardiovascular pharmacotherapy. Cardiovascular disease remains the number one killer in the US, and more clinical outcome trials have been conducted in cardiology than in any other field of medicine. Given this rapidly expanding knowledge base, pharmacists can have a significant impact on prevention and treatment — if they keep current with developments in drug therapy.

Effective use of combination lipid therapy

Despite the benefits of statin therapy, low-density lipoprotein cholesterol (LDL-C) management remains suboptimal and many patients do not achieve their recommended target goals. The aim of combination lipid drug therapy in high-risk patients is to achieve LDL-C and non-high-density lipoprotein cholesterol (HDL-C) goals with a minimum of serious adverse effects. Although statins are the drug of first choice, statin monotherapy may be limited by intolerance of dose escalation or failure to attain non-HDL-C goals in those with mixed hyperlipidemia. Statins plus bile acid resins or ezetimibe can achieve greater than 50% reduction in LDL-C, with little or no increase in adverse effects. Fibrates, niacin, and omega-3 fatty acids, when added to statins, can reduce triglycerides, increase HDL-C, and reduce non-HDL-C to a greater extent than statin monotherapy. The safety profile of combination lipid therapy is acceptable, if the global coronary heart disease risk of the patient is high, thus producing a favorable risk to benefit ratio. Careful surveillance of hepatic transaminases, avoidance of gemfibrozil in statin-fibrate combinations, and awareness of statin-concomitant drug interactions is key to safe and efficacious use of combination lipid drug therapy.

Beneficial vascular and metabolic effects of peroxisome proliferator-activated receptor-alpha activators

Fibric acid is a synthetic ligand of the nuclear receptor peroxisome proliferator-activated receptor (PPAR)-alpha that is highly expressed in skeletal muscle and heart, where it promotes beta-oxidation of fatty acids to mediate hypolipidemic actions. PPAR-alpha regulates expression of key proteins involved in atherogenesis, vascular inflammation, plaque instability, and thrombosis. Thus, PPAR-alpha may exert direct antiatherogenic actions in the vascular wall. Endothelial dysfunction associated with the metabolic syndrome and other insulin-resistant states is characterized by impaired insulin-stimulated nitric oxide production from the endothelium and decreased blood flow to skeletal muscle. Thus, improvement in insulin sensitivity leads to improved endothelial function. This may be an additional mechanism whereby fibrates decrease the incidence of coronary heart disease. Adiponectin is a protein secreted specifically by adipose cells that may couple regulation of insulin sensitivity with energy metabolism and serve to link obesity with insulin resistance. In this review, we discuss the mechanisms underlying the vascular and metabolic effects of fibrates that may act synergistically to prevent or regress atherosclerosis and coronary heart disease.

Targeting vascular risk in patients with metabolic syndrome but without diabetes

There are no prospective data on the effect of a multitargeted treatment approach on cardiovascular disease (CVD) risk reduction in nondiabetic patients with metabolic syndrome (MetS). Furthermore, the optimal hypolipidemic drug treatment in these patients remains controversial. In this prospective, randomized, open-label, intention-to-treat, and parallel study, 300 nondiabetic patients with MetS, free of CVD at baseline, were studied for a period of 12 months. Age- and sex-matched subjects without MetS (n = 100) acted as controls. All patients received lifestyle advice and a stepwise-implemented drug treatment of hypertension, impaired fasting glucose, and obesity. For hypolipidemic treatment, the patients were randomly allocated to 3 treatment groups: atorvastatin (n = 100, 20 mg/d), micronized fenofibrate (n = 100, 200 mg/d), and both drugs (n = 100). Clinical and laboratory parameters, including the lipid profile and C-reactive protein (CRP), were assessed at the baseline and at the end of the study. The primary end point was the proportion of patients not having MetS or its component features at the end of the 12-month treatment period. The secondary end points were the difference in 10-year CVD risk (Prospective Cardiovascular Munster risk calculator) and the degree of CRP reduction. By the end of the study, 76% of the patients no longer had MetS, and 46% had only one diagnostic MetS factor. The estimated 10-year (Prospective Cardiovascular Munster) risk of all patients with MetS at baseline was 14.6%. This was reduced in the atorvastatin group to 6.4%, in the fenofibrate group to 9.2%, and in the combination group to 5.5% (P < .0001 for all vs baseline). The 10-year risks of the atorvastatin and combination groups were not different from that of the control group (5.0%). C-reactive protein was significantly reduced in all treatment groups, with the atorvastatin and combination groups having the greatest reduction (65% and 68%, respectively, P < .01 vs the fenofibrate group, 44%). Lipid values were significantly improved in all 3 treatment groups, with those on the combined treatment attaining lipid targets to a greater extent than those in the other 2 groups. A target-driven and intensified intervention aimed at multiple risk factors in nondiabetic patients with MetS substantially offsets its component factors and significantly reduces the estimated CVD risk. The atorvastatin-fenofibrate combination had the most beneficial effect on all lipid parameters and significantly improved their CVD risk status. Atorvastatin and combination treatment were more effective than fenofibrate alone in reducing CRP levels.

Pathogenesis and management of diabetic dyslipidemia

Patients with diabetes mellitus have a 2- to 4-fold increased risk of atherosclerotic cardiovascular, peripheral vascular, and cerebrovascular disease, which are the leading causes of morbidity and mortality in this population. Several epidemiological studies have shown an association between diabetic dyslipidemia, which is characterized by hypertriglyceridemia, low levels of high density lipoprotein-cholesterol, postprandial lipemia and small, dense low density lipoprotein-cholesterol (LDL-C) particles, and the occurrence of cardiovascular disease. Other studies have established the beneficial effects of lipid lowering on the reduction of major coronary events in diabetic patients. The recent National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) guidelines emphasize diabetes as a coronary heart disease risk equivalent. The NCEP ATP III states that elevated LDL-C is a major risk factor for coronary heart disease, and the primary goal of risk-reduction therapy is the reduction of LDL-C levels to 100 mg/dL. This article defines and describes diabetic dyslipidemia and its etiology and pathogenesis, as well as reviewing guidelines and recommendations for treatment of this disorder. Treatment of diabetic dyslipidemia includes 1) lifestyle modifications: physical activity and a diet low in saturated fats and cholesterol and high in complex carbohydrates and fiber; and 2) pharmacological treatment with (i) oral antihyperglycemic agents: metformin and thiazolidinediones; (ii) weight reduction drugs: orlistat and sibutramine and; (iii) lipid-lowering drugs: HMG-CoA reductase inhibitors, fibric acid derivatives, nicotinic acid, and bile acid sequestrants.

Low high-density lipoprotein cholesterol disorders and cardiovascular risk: contribution of associated low-density lipoprotein subclass abnormalities

PURPOSE OF REVIEW

Discuss the contribution of low-density lipoprotein subclass abnormalities to cardiovascular risk among individuals with low high-density lipoprotein cholesterol levels.

RECENT FINDINGS

Low high-density lipoprotein cholesterol levels are commonly encountered among patients with early onset cardiovascular disease. Most often, a low high-density lipoprotein cholesterol level is not an isolated abnormality, but it is usually associated with a number of other lipoprotein abnormalities. Data from the Framingham Offspring Study demonstrate that among subjects with high-density lipoprotein cholesterol, 1.0 mmol/L (39 mg/dL), low-density lipoprotein particle numbers were considerably higher than indicated by the level of low-density lipoprotein cholesterol because these subjects had excess numbers of small cholesterol-depleted low-density lipoprotein particles. Elevated numbers of low-density lipoprotein particles identify individuals at highest risk for atherosclerotic vascular disease and cardiovascular events.

SUMMARY

As high levels of low-density lipoprotein particles are a robust predictor of cardiovascular events, strategies targeted at raising low levels of high-density lipoprotein cholesterol must account for low-density lipoprotein particle interactions.

Efficacy and safety of the coadministration of ezetimibe with fenofibrate in patients with mixed hyperlipidaemia

AIMS

To examine the efficacy and safety of coadministered ezetimibe (EZE) with fenofibrate (FENO) in patients with mixed hyperlipidaemia.

METHODS AND RESULTS

This was a multicentre, randomized, double-blind, placebo-controlled, parallel arm trial in patients with mixed hyperlipidaemia [LDL-cholesterol (LDL-C), 3.4-5.7 mmol/L (2.6-4.7 mmol/L for patients with type 2 diabetes); triglycerides (TG), 2.3-5.7 mmol/L] and no history of coronary heart disease (CHD), CHD-equivalent disease (except for type 2 diabetes), or CHD risk score>20%. A total of 625 patients was randomized in a 1:3:3:3 ratio to one of four daily treatments for 12 weeks: placebo; EZE 10 mg; FENO 160 mg; FENO 160 mg plus EZE 10 mg (FENO+EZE). The primary endpoint compared the LDL-C lowering efficacy of FENO+EZE vs. FENO alone. LDL-C, non-HDL-cholesterol (non-HDL-C), and apolipoprotein B were significantly (P<0.001) reduced with FENO+EZE when compared with FENO or EZE alone. TG levels were significantly decreased and HDL-C was significantly increased with FENO+EZE and FENO treatments when compared with placebo (P<0.001). Coadministration therapy reduced LDL-C by 20.4%, non-HDL-C by 30.4%, TG by 44.0%, and increased HDL-C by 19.0%. At baseline, >70% of all patients exhibited the small, dense LDL pattern B profile. A greater proportion of patients on FENO+EZE and FENO alone treatments shifted from a more atherogenic LDL size pattern to a larger, more buoyant, and less atherogenic LDL size pattern at study endpoint than those on placebo or EZE. All three active therapies were well tolerated.

CONCLUSION

Coadministration of EZE with FENO provided a complementary efficacy therapy that improves the atherogenic lipid profile of patients with mixed hyperlipidaemia.

Management of diabetic dyslipidemia

Identification and management of dyslipidemia is an important element in the multi-factorial approach to prevent coronary heart disease. Diabetic dyslipidemia typically consists of elevated triglyceride, low high-density lipoprotein cholesterol, predominance of small, dense low-density lipoprotein (LDL) particles, and average LDL cholesterol (LDL-C). Lipid-lowering therapy has a beneficial effect on cardiovascular outcomes. Statin treatment is beneficial in patients who are older than 40 years of age, irrespective of the LDL-C value. To achieve lipid targets, attention should be directed first toward nonpharmacologic therapeutic interventions, such as diet, exercise, smoking cessation, weight loss, and improving glycemic control. Although statin therapy is recommended for most subjects, judicious use of combination therapy should be considered in the highest risk subjects.

The dyslipidemia of diabetes mellitus: giving triglycerides and high-density lipoprotein cholesterol a higher priority?

CVD is the primary cause of morbidity and mortality in patients who have diabetes mellitus. Most such patients have at least one lipid abnormality. Managing these complex lipid disorders is a crucial component of comprehensive diabetes mellitus care and limits the risk for cardiovascular morbidity and mortality. With the high prevalence of mixed lipid disorders, management must focus on all components of the lipid profile. Lowering LDL-C levels remains the first priority, but abnormalities in HDL-C and TG levels also should be treated aggressively. Statins, fibrates, and niacin, along with newer therapies such as ezetimibe, can improve significantly components of the lipid profile. Alone or in combination, these agents can treat the dyslipidemia of diabetes mellitus effectively and safely.

The role of lipid management in diabetes

This article discusses the role of lipid management in diabetes.

Management of dyslipidemia in patients with metabolic syndrome

OBJECTIVE

To review the management of dyslipidemia in patients with metabolic syndrome.

DATA SOURCES

Medline search (2000-2002) conducted for English language articles using the search terms metabolic syndrome, impaired fasting glucose, glucose intolerance, and antilipemic agents; selective search for clinical trials of lipid therapy conducted in dialogue databases (1990-2002). In addition, current dyslipidemia treatment guidelines reviewed.

STUDY SELECTION

By the author.

DATA EXTRACTION

By the author.

DATA SYNTHESIS

The metabolic syndrome is increasingly recognized as a strong predictor of patient risk for developing coronary artery disease (CAD). It is associated with an atherogenic dyslipidemia characterized by elevated levels of triglycerides, reduced levels of high-density lipoprotein cholesterol (HDL-C) and a preponderance of small dense low-density lipoprotein (LDL) particles. Controlled clinical trials show similar or greater cardiovascular benefits from lipid-modifying therapies in patient subgroups with diabetes, impaired fasting glucose, and metabolic syndrome, compared with overall study populations. Current guidelines recommend intensified lipid management. Therapeutic lifestyle changes, with emphasis on weight loss, are particularly important for patients with metabolic syndrome. Statins are first-line therapy for all patients whose LDL-C levels are above goal. Combination therapy may often be necessary to control all lipid abnormalities adequately. Both niacin and fibrates provide additional benefits, particularly on triglyceride and HDL-C levels. Recent clinical studies show that these agents, in combination with statins, are safe and effective for the treatment of atherogenic dyslipidemia.

CONCLUSION

Atherogenic dyslipidemia represents an important modifiable CAD risk factor. Combination therapy with agents that focus on all of the components of the mixed dyslipidemia that often occurs in persons with diabetes and the metabolic syndrome may be expected to reduce cardiovascular morbidity and mortality.

Mechanisms, Significance and Treatment of Vascular Dysfunction in Type 2 Diabetes Mellitus

Endothelial dysfunction and increased arterial stiffness occur early in the pathogenesis of diabetic vasculopathy. They are both powerful independent predictors of cardiovascular risk. Advances in non-invasive methodologies have led to widespread clinical investigation of these abnormalities in diabetes mellitus, generating a wealth of new knowledge concerning the mechanisms of vascular dysfunction, risk factor associations and potential treatment targets. Endothelial dysfunction primarily reflects decreased availability of nitric oxide (NO), a critical endothelium-derived vasoactive factor with vasodilatory and anti-atherosclerotic properties. Techniques for assessing endothelial dysfunction include ultrasonographic measurement of flow-mediated vasodilatation of the brachial artery and plethysmography measurement of forearm blood flow responses to vasoactive agents. Arterial stiffness may be assessed using pulse wave analysis to generate measures of pulse wave velocity, arterial compliance and wave reflection. The pathogenesis of endothelial dysfunction in type 2 diabetes is multifactorial, with principal contributors being oxidative stress, dyslipidaemia and hyperglycaemia. Elevated blood glucose levels drive production of reactive oxidant species (ROS) via multiple pathways, resulting in uncoupling of mitochondrial oxidative phosphorylation and endothelial NO synthase (eNOS) activity, reducing NO availability and generating further ROS. Hyperglycaemia also contributes to accelerated arterial stiffening by increasing formation of advanced glycation end-products (AGEs), which alter vessel wall structure and function. Diabetic dyslipidaemia is characterised by accumulation of triglyceride-rich lipoproteins, small dense low-density lipoprotein (LDL) particles, reduced high-density lipoprotein (HDL)-cholesterol and increased postprandial free fatty acid flux. These lipid abnormalities contribute to increasing oxidative stress and may directly inhibit eNOS activity. Although lipid-regulating agents such as HMG-CoA reductase inhibitors (statins), fibric acid derivatives (fibrates) and fish oils are used to treat diabetic dyslipidaemia, their impact on vascular function is less clear. Studies in type 2 diabetes have yielded inconsistent results, but this may reflect sampling variation and the potential over-riding influence of oxidative stress, dysglycaemia and insulin resistance on endothelial dysfunction. Results of positive intervention trials suggest that improvement in vascular function is mediated by both lipid and non-lipid mechanisms, including anti-inflammatory, anti-oxidative and direct effects on the arterial wall. Other treatments, such as renin-angiotensin-aldosterone system antagonists, insulin sensitisers and lifestyle-based interventions, have shown beneficial effects on vascular function in type 2 diabetes. Novel approaches, targeting eNOS and AGEs, are under development, as are new lipid-regulating therapies that more effectively lower LDL-cholesterol and raise HDL-cholesterol. Combination therapy may potentially increase therapeutic efficacy and permit use of lower doses, thereby reducing the risk of adverse drug effects and interactions. Concomitant treatments that specifically target oxidative stress may also improve endothelial dysfunction in diabetes. Vascular function studies can be used to explore the therapeutic potential and mechanisms of action of new and established interventions, and provide useful surrogate measures for cardiovascular endpoints in clinical trials.

Optimal lipid modification: the rationale for combination therapy

BACKGROUND

An emphasis on more aggressive lipid-lowering, particularly of low-density lipoprotein cholesterol, to improve patient outcomes has led to an increased use of combination lipid-lowering drugs. This strategy, while potentially beneficial, has triggered concerns regarding fears of adverse effects, harmful drug interactions, and patient nonadherence.

OBJECTIVE

To present key data regarding combination lipid-altering therapy including use, rationale, major trials, benefits, potential adverse effects, compliance issues, and limitations.

METHOD

Literature was obtained from MEDLINE (1966 - June 2005) and references from selected articles.

RESULTS

A substantial body of evidence from epidemiological data and clinical trials indicates that aggressive lipid modification, especially low-density lipoprotein reduction, is associated with reduced cardiovascular events. Numerous studies utilizing various combinations of cholesterol-lowering agents including statin/fibrate, statin/niacin, statin/bile acid resin, and statin/ezetimibe have demonstrated significant changes in the lipid profile with acceptable safety. Long-term trials of combination therapy evaluating clinical outcomes or surrogate markers of cardiovascular disease, while limited, are promising.

CONCLUSION

Combining lipid-altering agents results in additional improvements in lipoproteins and has the potential to further reduce cardiovascular events beyond that of monotherapy.

Usefulness of total cholesterol/HDL-cholesterol ratio in the management of diabetic dyslipidaemia

AIMS

Our aim was to evaluate the usefulness of the total cholesterol/HDL-cholesterol ratio (TC/HDL) in predicting the cardiovascular risk of Type 2 diabetic patients.

METHODS

Prospective cohort study with inclusion of 418 Type 2 diabetic individuals with follow-up until the appearance of a cardiovascular event. The predictive power of updated mean lipid values during follow-up was analysed by means of Cox proportional hazard models. An estimate was made of the relative risk (RR) conferred by high levels of TC/HDL stratified by LDL-cholesterol levels.

RESULTS

Sixty-six cardiovascular events occurred during an average follow-up of 4.7 years (sd 1.5). The main lipid predictor of vascular events was mean TC/HDL ratio [hazard ratio (HR) = 1.46; 95% confidence interval (CI) 1.25, 1.7; P < 0.0001]. In the multivariate model with simultaneous inclusion of mean TC/HDL and mean LDL-cholesterol, both were significant predictors of cardiovascular disease [HR (1 unit) = 1.37; 95% CI 1.16, 1.62; P = 0.0003 and HR (1 mmol/l) = 1.5; 95% CI 1.04, 2.18; P = 0.03, respectively]. The LDL adjusted RR for cardiovascular events due to high TC/HDL ratio, with 4.5 cut-off point, was 2.5 (95% CI 1.4, 4.3; P = 0.0007). For the stratum of subjects with average LDL cholesterol < 3.5 mmol/l, RR was 1.2 (95% CI 0.5, 2.8; P = NS) and for the stratum of average LDL cholesterol > 3.5 mmol/l, RR was 4 (95% CI 1.8, 9; P = 0.00013), with heterogeneity among strata (P = 0.044).

CONCLUSIONS

It could be useful to include the TC/HDL ratio in treatment guides for diabetic dyslipidaemia, given their high predictive value and strong interaction with LDL cholesterol.

Management of diabetic dyslipidemia: need for reappraisal of the goals

Cardiovascular disease is the leading cause of mortality among people with diabetes mellitus, accounting for 70% of all deaths. As the prevalence of diabetes increases significantly worldwide, greater attention must be focused on preventing cardiovascular events in this group. One contributor to this increased event rate is the characteristic pattern of dyslipidemia in diabetic patients, consisting of elevated serum triglyceride levels, decreased high-density lipoprotein levels, and an increased proportion of small, dense, low-density lipoproteins. Several pharmacologic agents have been used to treat this dyslipidemia including HMG-CoA reductase inhibitors, fibric acid derivatives, niacin (nicotinic acid), thiazolidinediones, and fish oils, as well as other non-pharmacologic measures. Currently, the most extensive data for a reduction in cardiovascular events in patients with diabetes exist for HMG-CoA reductase inhibitors. The results of these trials indicate that HMG-CoA reductase inhibitor therapy should be considered for all patients with diabetes at sufficient risk for cardiovascular events, regardless of serum low-density lipoprotein-cholesterol level. Several ongoing trials of various pharmacologic agents should help clarify the role of these agents alone and in combination with HMG-CoA reductase inhibitors in the management of diabetic dyslipidemia.

Treatment of lipids and type 2 diabetes

The development of type 2 diabetes is increasing in epidemic proportions. There is a significant risk for cardiovascular disease, which is the most prevalent and detrimental complication for the diabetic population. Serum lipid abnormalities are common in patients with diabetes, and due to this increased vascular risk, it is recommended to aggressively treat the hyperlipidemia. Therefore, intensive lipid-lowering therapy should be used for primary and secondary prevention against macrovascular complications for patients with type 2 diabetes. In this article some of the key studies justifying the need for lipid reduction in patients with type 2 diabetes are reviewed and practical guidelines for management of the dyslipidemia are suggested.

The effect of high dose atorvastatin therapy on lipids and lipoprotein subfractions in overweight patients with type 2 diabetes

Few data are available on the effects of high dose statin therapy on lipoprotein subfractions in type 2 diabetes. In a double blind randomised placebo-controlled trial we have studied the effects of 80 mg atorvastatin over 8 weeks on LDL, VLDL and HDL subfractions in 40 overweight type 2 diabetes patients. VLDL and LDL subfractions were prepared by density gradient ultracentrifugation. Triglycerides, cholesterol, total protein and phospholipids were measured and mass of subfractions calculated. HDL subfractions were prepared by precipitation. Atorvastatin 80 mg produced significant falls in LDL subfractions (LDL(1) 66.2 mg/dl:36.6 mg/dl, LDL(2) 118:56.6 mg/dl, LDL(3) 36.9:19.9 mg/dl all P < 0.01 relative to placebo) and VLDL subfractions (VLDL(1) 55:22.1 mg/dl, VLDL(2) 40.1:19.1 mg/dl, VLDL(3) 52.6:30 mg/dl all P < 0.01 relative to placebo). There was no change in the proportion of LDL present as LDL(3). There was a reduction in the proportion of VLDL as VLDL(1) and a reciprocal increase in the proportion as VLDL(3). Changes in VLDL subfractions were associated with changes in lipid composition, particularly a reduction in cholesterol ester and a reduction in the cholesterol ester/triglyceride ratio. Effects on HDL subfractions were largely neutral. High dose atorvastatin produces favourable effects on lipoprotein subfractions in type 2 diabetes which may enhance antiatherogenic potential.

A review of the efficacy of rosuvastatin in patients with type 2 diabetes

It has been estimated that 92% of individuals with type 2 diabetes, without cardiovascular disease (CVD), have a dyslipidaemic profile. Several guidelines on cardiovascular risk now recommend that patients with diabetes should be considered at high risk of CVD and should thus receive lipid-lowering therapy to reduce low-density lipoprotein cholesterol (LDL-C) to below 2.5 mmol/L. Since their introduction in 1987, statins have revolutionized the management of CVD. The most recent statin to be introduced, rosuvastatin, has been shown to be the most effective at lowering LDL-C, as well as consistently raising HDL-C across the 10-40 mg dose range. This has been confirmed by many studies, including the Measuring Effective Reductions in Cholesterol Using Rosuvastatin Therapy (MERCURY I) study in which rosuvastatin 10 mg was shown to be more effective than commonly used doses of other statins, both for LDL-C reduction and achieving treatment target goals. The effectiveness of rosuvastatin has also been studied in type 2 diabetes patients in three studies: the URANUS (Use of Rosuvastatin vs. Atorvastatin iN type 2 diabetes mellitUS), ANDROMEDA (A raNdomized, Double-blind study to compare Rosuvastatin [10 & 20 mg] and atOrvastatin [10 & 20 Mg] in patiEnts with type II DiAbetes) and CORALL (COmpare Rosuvastatin [10-40 mg] with Atorvastatin [20-80 mg] on apo B/apo A-1 ratio in patients with type 2 diabetes meLLitus and dyslipidaemia) studies. URANUS and ANDROMEDA showed rosuvastatin to be more effective than atorvastatin at reducing LDL-C and achieving treatment target goals. CORALL demonstrated rosuvastatin 10, 20 and 40 mg to be more effective at lowering LDL-C than 20, 40 and 80 mg of atorvastatin, respectively. Ongoing studies will evaluate whether these properties of rosuvastatin translate into beneficial effects on atherosclerosis and significant reductions in cardiovascular events.

Management of metabolic syndrome: statins

Individuals who have the metabolic syndrome are at increased risk for cardiovascular disease. Combined dyslipidemia is an important component of metabolic syndrome, contributing to excess cardiovascular risk. Lifestyle and pharmacologic interventions are warranted for effective management of this syndrome. This article discusses the current evidence supporting the use of statins and their beneficial impact on lipid and nonlipid aspects of metabolic syndrome-related pathology.

Treatment of metabolic syndrome

The metabolic syndrome is intended to identify patients who have increased risk of diabetes and/or a cardiac event due to the deleterious effects of weight gain, sedentary lifestyle, and/or an atherogenic diet. The National Cholesterol Education Program's Adult Treatment Panel III definition uses easily measured clinical findings of increased abdominal circumference, elevated triglycerides, low high-density lipoprotein-cholesterol, elevated fasting blood glucose and/or elevated blood pressure. Three of these five are required for diagnosis. The authors also note that other definitions of metabolic syndrome focus more on insulin resistance and its key role in this syndrome. This review focuses on how treatment might affect each of the five components. Abdominal obesity can be treated with a variety of lower calorie diets along with regular exercise. Indeed, all of the five components of the metabolic syndrome are improved by even modest amounts of weight loss achieved with diet and exercise. For those with impaired fasting glucose tolerance, there is good evidence that a high fiber, low saturated fat diet with increased daily exercise can reduce the incidence of diabetes by almost 60%. Of note, subjects who exercise the most, gain the most benefit. Metformin has also been shown to be helpful in these subjects. Thiazolidinedione drugs may prove useful, but further studies are needed. Although intensified therapeutic lifestyle change will help the abnormal lipid profile, some patients may require drug therapy. This review also discusses the use of statins, fibrates, and niacin. Likewise, while hypertension in the metabolic syndrome benefits from therapeutic lifestyle change, physicians should also consider angiotensin converting enzyme inhibitor drugs or angiotensin receptor blockers, due to their effects on preventing complications of diabetes, such as progression of diabetic nephropathy and due to their effects on regression of left ventricular hypertrophy. Aspirin should be considered in those with at least a 10% risk of a coronary event over 10 years. Finally, three related conditions, nonalcoholic fatty liver disease, polycystic ovary syndrome and protease inhibitor associated lipodystrophy improve with therapeutic lifestyle change. Although metformin is shown to be useful with polycystic ovary syndrome, the data supporting drug therapy for the other syndromes is less convincing. More robust studies are needed before any firm recommendations can be made.

Dyslipidemia in type 2 diabetes

Type 2 diabetes mellitus is associated with a cluster of lipid abnormalities:elevated plasma triglycerides, reduced high-density lipoprotein cholesterol, and smaller and denser low-density lipoproteins,which have been associated with an increased risk of cardiovascular disease. Insulin resistance may contribute to dyslipidemia associated with type 2 diabetes by increasing hepatic secretion of large,triglyceride-rich very low-density lipoprotein particles and by impairing the clearance of lipoprotein particles from plasma. Lifestyle interventions may be effective in improving the diabetic dyslipidemia syndrome. For patients who do not respond to lifestyle changes, pharmacologic therapies (lipid-lowering medications and anti-diabetic agents) are available. Clinical trials demonstrate that the use of such pharmaceutics to treat diabetic dyslipidemia concomitantly reduces the risk of coronary artery disease.

Lipids and lipoproteins in patients with type 2 diabetes

Insulin resistance and type 2 diabetes are associated with a clustering of interrelated plasma lipid and lipoprotein abnormalities, which include reduced HDL cholesterol, a predominance of small dense LDL particles, and elevated triglyceride levels. Each of these dyslipidemic features is associated with an increased risk of cardiovascular disease. Increased hepatic secretion of large triglyceride-rich VLDL and impaired clearance of VLDL appears to be of central importance in the pathophysiology of this dyslipidemia. Small dense LDL particles arise from the intravascular processing of specific larger VLDL precursors. Typically, reduced plasma HDL levels in type 2 diabetes are manifest as reductions in the HDL(2b) subspecies and relative or absolute increases in smaller denser HDL(3b) and HDL(3c). Although behavioral interventions such as diet and exercise can improve diabetic dyslipidemia, for most patients, pharmacological therapy is needed to reach treatment goals. There are several classes of medications that can be used to treat lipid and lipoprotein abnormalities associated with insulin resistance and type 2 diabetes, including statins, fibrates, niacin, and thiazolidinediones. Clinical trials have shown significant improvement in coronary artery disease after diabetic dyslipidemia treatment.

Dyslipidemia in patients with type 2 diabetes. relationships between lipids, kidney disease and cardiovascular disease

Type 2 diabetes mellitus is a leading cause of morbidity and mortality. Cardiovascular disease (CVD) is the most prevalent complication and primarily accounts for the excess morbidity and mortality in diabetic patients, but microvascular complications, such as kidney disease and retinopathy, are frequent and contribute to the total disease burden. Lipid abnormalities in patients with type 2 diabetes are a major problem and associated with the increased risk of CVD. The most common pattern of dyslipidemia in these patients consists of elevated levels of triglycerides and low levels of high-density lipoprotein cholesterol. Low-density lipoprotein levels in these patients are often similar to that of the nondiabetic population, although there may be important qualitative differences in the pattern that contribute to the increased risk of CVD. Abnormal levels of urinary albumin occur in 30-40% of patients with type 2 diabetes and the presence of kidney disease enhances the mortality from CVD. Microalbuminuria, an early marker of diabetic nephropathy, is an independent risk factor for CVD. The increased levels of urinary albumin secretion may represent a more generalized vascular damage than renal microvascular injury alone. This Review focuses on the significance of diabetic dyslipidemia and microalbuminuria to CVD risk as well as to kidney complications. We also discuss the role of aggressive therapy to ameliorate vascular injury in the diabetic patient and reduce or prevent the cardiovascular and renal consequences of the disease.

Rosuvastatin and fenofibrate alone and in combination in type 2 diabetes patients with combined hyperlipidaemia

The aim of this study was to evaluate the effects of rosuvastatin and fenofibrate alone and in combination in type 2 diabetes associated with combined hyperlipidaemia. A total of 216 patients with total cholesterol >/=200 mg/dl (>/=5.17 mmol/l) and triglycerides >/=200 and <800 mg/dl (>/=2.26 and <9.03 mmol/l) were randomised to one of two placebo groups, rosuvastatin 5 mg or rosuvastatin 10 mg for 6 weeks (fixed-dose phase). During the subsequent 18-week dose-titration phase, one placebo group received titrated rosuvastatin 10, 20 and 40 mg (placebo/rosuvastatin); one placebo group received titrated fenofibrate 67 mg once, twice and three times daily (placebo/fenofibrate); and patients receiving 5 or 10 mg rosuvastatin received titrated fenofibrate as above (rosuvastatin 5mg/fenofibrate and rosuvastatin 10 mg/fenofibrate groups). Doses were increased at 6-week intervals if low-density lipoprotein (LDL) cholesterol remained >50 mg/dl (>1.3 mmol/l). At 24 weeks, the placebo/rosuvastatin group and placebo per fenofibrate group had triglyceride reductions of 30.3% versus 33.6%, respectively (P = NS), and LDL cholesterol was reduced by 46.7% in the rosuvastatin group and increased by 0.7% in the fenofibrate group (P < 0.001). The triglyceride reduction in the rosuvastatin 10 mg/fenofibrate group (47.1%) was significantly greater than in the placebo/rosuvastatin group (P = 0.001), with no significant differences in other lipid measures found between these two groups. No significant differences in effect on high-density lipoprotein (HDL) were observed among treatment groups. In the fixed-dose phase, rosuvastatin 5 and 10 mg reduced triglycerides by 24.5 and 29.5%, respectively, and decreased LDL cholesterol by 40.7 and 45.8%, respectively. All treatments were well tolerated. These results indicated that rosuvastatin produces marked reductions in triglycerides and LDL cholesterol when used alone or in combination with fenofibrate in type 2 diabetes patients with elevated cholesterol and triglyceride levels and may constitute a valuable treatment option in the diabetic population.

The role of fibrates in managing hyperlipidemia: Mechanisms of action and clinical efficacy

At a time when the lipid management guidelines give more and more emphasis to the identification and treatment of high-risk patients with the metabolic syndrome and diabetes, there is an obvious need to balance the known effects of low-density lipoprotein (LDL) lowering with the new evidence of clinical efficacy derived from the adjustment of high-density lipoprotein (HDL) and triglyceride levels. Whereas the statins remain the drug of choice for patients who need to reach the LDL goal, fibrate therapy may represent the best intervention for subjects with atherogenic dyslipidemia and an LDL already close to goal. In addition, the concomitant use of fibrates may significantly reduce cardiovascular risk in patients whose LDL is controlled by statin therapy. In this review, we evaluate the pharmacologic properties of the fibrate drugs, with particular attention to the effects of peroxisome proliferator activated receptor a activation in the control of dyslipidemia as well as in the attenuation of arterial inflammation. Clinical trials of fibrates, such as the Helsinki Heart Study, Veterans Affairs High-density lipoprotein Intervention Trial, Diabetes Atherosclerosis Intervention Study, and Bezafibrate Infarction Prevention trial, have conjured up a scenario for the clinical utility of fibrates and their possible superiority to statins in the management of obese, insulin-resistant, and diabetic patients presenting with near-goal LDL and inappropriate HDL and triglyceride levels.

Early benefit from structured care with atorvastatin in patients with coronary heart disease and diabetes mellitus

This is a prospective evaluation of the effect of structured care of dyslipidemia with atorvastatin (strict implementation of guidelines) versus usual care (physician's standard of care) on morbidity and mortality of patients with coronary heart disease (CHD) and diabetes mellitus (DM). From 1600 consecutive CHD patients randomized to either form of care in the GREek Atorvastatin and CHD Evaluation Study (GREACE), 313 had DM: 161 in the structured care arm and 152 in the usual care arm. All patients were followed up for a mean of 3 years. In the structured care group, patients were treated with atorvastatin to achieve the National Cholesterol Education Program (NCEP) low-density lipoprotein cholesterol (LDL-C) treatment goal of <2.6 mmol/L (100 mg/dL). Primary endpoints were all-cause and coronary mortality, coronary morbidity, and stroke. In the structured care group, 156 patients (97%) were taking atorvastatin (10-80 mg/day; mean, 23.7 mg/day) throughout the study; the NCEP LDL-C treatment goal was reached by 150 patients (93%). Only 17% (n=26) of the usual care patients were on long-term hypolipidemic drug treatment and 4% (n=6) reached the NCEP LDL-C treatment goal. During the study, 46 of 152 (30.3%) CHD patients with DM on usual care experienced a major vascular event or died versus 20 of 161 (12.5%) patients on structured care; relative risk reduction (RRR) 58%, p<0.0001. RRR for all-cause mortality was 52%, p=0.049; coronary mortality 62%, p=0.042; coronary morbidity 59%, p<0.002; and stroke 68%, p=0.046. Event rate curves started deviating from the sixth treatment month and the RRR was almost 60% by the 12th month. RRRs remained at that level until the end of the study, when they became statistically significant. The cost/life-year gained with structured care was estimated at 6200 US dollars. In CHD patients with DM, structured care of dyslipidemia with atorvastatin to achieve the NCEP LDL-C treatment goal, reduces all-cause and coronary mortality, coronary morbidity, and stroke by more than one half within a 3-year period, in comparison to usual care. Clinical benefit is manifested as early as the sixth month of treatment.

Therapeutic approaches to dyslipidemia in diabetes mellitus and metabolic syndrome

Type 2 diabetes mellitus and the closely related metabolic syndrome are associated with significant risk for cardiovascular disease. Recent evidence suggests that both conditions are increasing in epidemic proportions. Dyslipidemia is characterized by increased triglyceride-rich lipoproteins; low high-density lipoprotein cholesterol; small, dense low-density lipoprotein particles; increased postprandial lipemia; and abnormal apolipoprotein A1 and B metabolism. All these lipoprotein disturbances accelerate atherosclerosis in these patients. It is likely that many patients will need combinations of lipid-modifying therapy to achieve American Diabetes Association (ADA), Adult Treatment Panel III, and American Heart Association (AHA)/American College of Cardiology (ACC) guidelines to help prevent cardiovascular disease and death.

Update on fenofibrate

Fenofibrate is a fibric acid derivative that has been marketed since the mid-1970's (1998 in the United States). Its active metabolite, fenofibric acid, is responsible for the primary pharmacodynamic effects of the drug: reductions in total plasma cholesterol, low density lipoprotein cholesterol, triglycerides, and very low-density lipoprotein concentrations and increases in high-density lipoprotein cholesterol and apolipoproteins AI and AII concentrations. These effects are mediated by activation of peroxisome proliferator-activated receptor-alpha (PPAR(alpha)). The drug has broad spectrum utility, with documented efficacy in Fredrickson types IIa, IIb, III, IV, and V hyperlipidemias. Fenofibrate is well tolerated, with digestive and musculoskeletal side effects similar to those of other fibrates. Results of the initial cardiovascular morbidity/mortality outcomes study with fenofibrate (known as DAIS [Diabetes Atherosclerosis Intervention Study]) were encouraging vis-à-vis slowing of atherosclerotic progression in the coronary vasculature of type II diabetics. The results of other ongoing outcome trials are eagerly awaited. These results will help to establish the overall place of fenofibrate in the hypolipidemic armamentarium.

Treating dyslipidemic patients with lipid-modifying and combination therapies

Updated guidelines from the National Cholesterol Education Program give greater emphasis to lipoproteins other than low-density lipoprotein cholesterol (LDL) than previous guidelines. Although statins remain first-line therapy for most patients to lower LDL, combination therapy is the next logical step in achieving goals in patients with mixed dyslipidemia or elevated LDL despite statin therapy. As the prevalence of diabetes, metabolic syndrome, and atherogenic dyslipidemia rises, the importance of treating the total lipid profile becomes even more crucial. Niacin, fibrates, and bile acid sequestrants are effective in combination with statins in lowering LDL, triglycerides, and total cholesterol levels and increasing high-density lipoprotein cholesterol (HDL). Although combination therapies may increase the risk of myopathy, both fibrate-statin and niacin-statin combinations are considered safe. In addition, niacin-statin therapy reduces atherosclerotic progression and coronary events. New pharmacologic formulations exist that will further affect treatment: a single-tablet combination of lovastatin and extended-release niacin is available, as is ezetimibe, a cholesterol-absorption inhibitor. In all, both HDL and triglyceride levels correlate with cardiovascular risk and should be considered secondary targets of therapy. Combination therapy can be safe and effective and can be constructed to affect all lipoprotein parameters.

Managing the high-risk patient: therapeutic approaches in 2002

Populations of patients at high risk of coronary heart disease (CHD) include those with type 2 diabetes and those with heterozygous familial hypercholesterolemia (HeFH). Despite benefits of statin lipid-lowering therapy in reducing CHD risk in diabetic patients, screening for dyslipidemia in such patients is inadequate, and patients frequently fail to achieve recommended low-density lipoprotein goals. Diagnosis of HeFH is also suboptimal, despite the reliability of family lipid screening in confirming clinical diagnosis and utility of screening in identifying other family members who are at risk. Patients with HeFH frequently require large reductions in low-density lipoprotein (LDL) cholesterol to achieve target levels. In both of these populations, statins that produce large reductions in LDL cholesterol offer advantages in achieving lipid-lowering goals and in simplifying medical therapy to reduce CHD risk.

Lipid-lowering therapy in people with type 2 diabetes

PURPOSE OF REVIEW

The risk of cardiovascular disease is markedly increased in people with type 2 diabetes. There is abundant epidemiological and clinical trial evidence that lipid abnormalities play a major role in the pathogenesis of atherosclerotic vascular disease in diabetes. Although the benefits of lipid-lowering therapy are well established in people without diabetes, the evidence in people with diabetes is not as well established.

RECENT FINDINGS

Recent population studies of lipid-lowering therapy and cardiovascular disease outcomes that included people with diabetes and performed a separate subgroup analysis were reviewed. Lipid lowering with statins and fibrates is effective in improving cardiovascular disease outcomes in diabetes, and their effectiveness is similar to that in the non-diabetic population. This effect is well established in secondary prevention and is accumulating for primary prevention.

SUMMARY

Individuals with diabetes require aggressive management of dyslipidaemia as part of an overall management strategy to reduce the risk of cardiovascular disease. Individuals with a previous cardiovascular disease event should be on lipid-lowering therapy, whereas in those who have not had a previous cardiovascular disease event, the decision to use lipid-lowering therapy should be based on lipid levels and the overall risk of a future event. The results of large studies that are currently in progress specifically in people with diabetes should resolve outstanding questions in relation to lipid-lowering therapy in diabetes.

Combination therapy for combined dyslipidemia

Patients with combined dyslipidemia are at high risk for coronary artery disease and often require combination drug therapy to achieve lipid levels recommended by the US National Cholesterol Education Program's third Adult Treatment Panel (ATP III). In addition to recommendations for low-density lipoprotein (LDL) cholesterol and triglyceride levels, ATP III established non-high-density lipoprotein (HDL) cholesterol goals for individuals with triglycerides >or=2.26 mmol/L (>or=200 mg/dL). It also introduced certain criteria for the diagnosis of the metabolic syndrome, a clustering of risk factors (abdominal obesity, elevated triglycerides, low HDL cholesterol, elevated blood pressure, impaired fasting glucose) that increases cardiovascular risk and is common in patients with combined dyslipidemia. Statin monotherapy has been shown to benefit these patients, and additional benefit may be obtained by combination therapy that provides greater reductions in both LDL cholesterol and triglycerides as well as greater increases in HDL cholesterol. However, combining a statin with either niacin or a fibrate may increase the risk for myopathy and therefore requires careful monitoring and evaluation of the risk-benefit ratio for each patient. Moreover, combination therapy may be associated with increased drug costs and decreased patient compliance. Recently developed agents that may improve the effectiveness of combination therapy include ezetimibe-a cholesterol absorption inhibitor-and a formulation that combines extended-release niacin and lovastatin in a single pill. Clinical trials are needed to determine the optimal treatment in patients with combined dyslipidemia.