Combination therapy for combined dyslipidemia

Co-Encapsulation of Drugs for Topical Application-A Review

Achieving the best possible outcome for the therapy is the main goal of a medicine. Therefore, nanocarriers and co-delivery strategies were invented to meet this need, as they can benefit many diseases. This approach was applied specifically for cancer treatment, with some success. However, these strategies may benefit many other clinical issues. Skin is the largest and most exposed organ of the human body, with physiological and psychological properties. Due to its exposition and importance, it is not difficult to understand how many skin diseases may impact on patients' lives, representing an important burden for society. Thus, this review aims to summarize the state of the art in research concerning nanocarriers and co-delivery strategies for topical agents' applications targeting skin diseases. The challenge for the medicine of the future is to deliver the drug with spatial and temporal control. Therefore, the co-encapsulation of drugs and the appropriate form of administration for them are so important and remain as unmet needs.

Hypocholesterolaemic effect of rat-administered oral doses of the isolated 7S globulins from cowpeas and adzuki beans

The role of seed proteins, especially soyabean 7S globulins, in controlling dyslipidaemia is widely acknowledged. Amino acid sequence homology among the proteins of this family could reflect similar biological functions in other species. The aim of the present study was to unveil a hypolipidaemic effect of the 7S globulins from cowpeas (7S-C) and adzuki beans (7S-A), administered orally to rats fed a hypercholesterolaemic (HC; high cholesterol and TAG) diet for 28 d. A total of forty-five rats were divided into five groups (nine rats per group): (1) standard (STD) diet; (2) HC diet; (3) HC diet + 7S-C (300 mg/kg per d); (4) HC diet + 7S-A (300 mg/kg per d); and (5) HC diet + simvastatin (SVT; 50 mg/kg per d), as a control. Significant decreases in food intake and final body weight of rats receiving HC + 7S-C and HC + 7S-A diets compared with groups fed the HC and STD diets were observed. Significant decreases in serum total and non-HDL-cholesterol of 7S-C, 7S-A and SVT groups were also observed. HDL-cholesterol levels increased in the 7S-C, 7S-A and SVT groups, while hepatic cholesterol and TAG concentrations were significantly lower than in the HC diet group for the 7S-C-supplemented group only. Faecal excretions of fat and cholesterol in HC diet groups were considerably higher in animals consuming the 7S globulins. The results show that cowpea and adzuki bean 7S globulins promote cholesterol-decreasing effects in hypercholesterolaemic rats even at low dosages, as already observed for other legume seed storage proteins of this family. This main effect is discussed in relation to the possible mechanisms of action.

Extended-release niacin/lovastatin: the first combination product for dyslipidemia

Many clinical studies have demonstrated that lipid-altering drug treatments, including the use of statin and niacin monotherapy, can be effective in the primary and secondary prevention of coronary heart disease, but only in a minority of patients relative to placebo. Since statins and niacin have entirely different mechanisms of action and predominantly different effects on blood lipid levels, the combined use of both a statin and niacin may confer complementary benefits on multiple lipid parameters, produce a more global improvement in lipid blood levels and result in greater reductions in coronary heart disease risk factors than the administration of either agent alone. This may be of particular importance in patients with complex dyslipidemias, such as those with Type 2 diabetes mellitus and metabolic syndrome. This review summarizes the efficacy and safety of extended-release niacin/lovastatin (Advicor, Kos Pharmaceuticals Inc.), the first combination product approved for the management of dyslipidemia.

Statins and their interactions with other lipid-modifying medications: safety issues in the elderly

Inhibitors of the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, commonly known as statins, are widely used in both primary and secondary prevention of occlusive cardiovascular disease. Statins are effective not only in improving total and low-density lipoprotein cholesterol concentrations in blood but also in decreasing morbidity and mortality associated with cardiovascular diseases resulting from underlying atheroma. There is, however, evidence that statins are underutilized in elderly patients, possibly due to concerns about safety/tolerability issues or potential drug interactions, including interactions with other lipid-modifying medications, or both. In this review, we summarize the major adverse events associated with statin use, with particular reference to the elderly patient, including factors which might increase the risk of adverse effects. Potential drug interactions between statins and other lipid-modifying medications including fibrates, ezetimibe, nicotinic acid, bile acid sequestrants and omega-3-acid ethyl esters (fish oils) are specifically discussed. Clinical management strategies to avoid these drug interactions are outlined.

β-conglycinin combined with fenofibrate or rosuvastatin have exerted distinct hypocholesterolemic effects in rats

BACKGROUND

There is increasing interest in non-pharmacological control of cholesterol and triglyceride levels in the plasma and diet-drug association represent an important area of studies. The objective of this study was to observe the hypocholesterolemic effect of soybean β-conglycinin (7S protein) alone and combined with fenofibrate and rosuvastatin, two hypolipidemic drugs.

METHODS

The protein and drugs were administered orally once a day to rats and the effects were evaluated after 28 days. Wistar rats were divided into six groups (n = 9): hypercholesterolemic diet (HC), HC+7S protein (300 mg.kg-1 day-1) (HC-7S), HC+fenofibrate (30 mg.kg-1 day-1)(HC-FF), HC+rosuvastatin (10 mg.kg-1 day-1)(HC-RO), HC+7S+fenofibrate (HC-7S-FF) and HC+7S+rosuvastatin (HC-7S-RO).

RESULTS

Animals in HC-7S, HC-FF and HC-RO exhibited reductions of 22.9, 35.8 and 18.8% in total plasma cholesterol, respectively. In HC-7S-FF, animals did not show significant alteration of the level in HC+FF while the group HC-7S-RO showed a negative effect in comparison with groups taking only protein (HC-7S) or drug (HC-RO). The administration of the protein, fenofibrate and rosuvastatin alone caused increases in the plasma HDL-C of the animals, while the protein-drug combinations led to an increase compared to HC-FF and HC-RO. The plasma concentration of triacylgycerides was significantly reduced in the groups without association, while HC-7S-FF showed no alteration and HC-7S-RO a little reduction.

CONCLUSION

The results of our study indicate that conglycinin has effects comparable to fenofibrate and rosuvastatin on the control of plasma cholesterol, HDL-C and triacylglycerides, when given to hypercholesterolemic rats, and suggests that the association of this protein with rosuvastatin alters the action of drug in the homeostasis of cholesterol.

Hypolipidemic effects and mechanisms of Panax notoginseng on lipid profile in hyperlipidemic rats

Maintenance of normal lipid levels has implicated the involvement of genes induced by liver X receptor alpha (LXRalpha) and Farnesoid X receptor (FXR). This study was designed to evaluate the hypolipidemic effects of n-butanol extract (NE3) of Panax notoginseng (Burk.) F.H. Chen root on lipid homeostasis and investigate the possible mechanisms in animal experiments. In the transactivation assays, NE3 was identified as a dual FXR/LXRalpha agonist. Subsequently, Sprague-Dawley male rats on a high-fat/high-cholesterol diet were treated orally with NE3 or vehicle alone. As expected, the concentrations of serum TC, TG and LDL-C in rats treated with various concentrations of NE3 showed significant (P<0.01) and dose-dependent decrease, respectively, accompanied with a significant (P<0.01) and dose-dependent decrease in the concentration of hepatic TC and TG. Express-level analysis indicated that both LXRalpha target genes including ABCA1, ABCG5, ABCG8 and FXR target genes including ApoCII and SHP were significantly induced by NE3 (P<0.01). Interestingly, LDLR mRNA level was significantly higher by NE3 (P<0.01), accompanied with the significantly decreased expression levels of CYP7A1, ApoCIII and SREBP1c genes (P<0.01). Based on these results, it can be concluded that NE3 as a dual FXR/LXRalpha agonist largely prevented the accumulation of abnormal lipid in the hyperlipidemic rats.

Dose-Dependent Effects of Docosahexaenoic Acid Supplementation on Blood Lipids in Statin-Treated Hyperlipidaemic Subjects

The objective of the study was to evaluate potential benefits of docosahexaenoic acid (DHA) rich fish oil supplementation as an adjunct to statin therapy for hyperlipidaemia. A total of 45 hyperlipidaemic patients on stable statin therapy with persistent elevation of plasma triglycerides (averaging 2.2 mmol/L) were randomised to take 4 g/day (n = 15) or 8 g/day (n = 15) of tuna oil or olive oil (placebo, n = 15) for 6 months. Plasma lipids, blood pressure and arterial compliance were assessed initially and after 3 and 6 months in 40 subjects who completed the trial. Plasma triglycerides were reduced 27% by 8 g/day DHA-rich fish oil (P < 0.05) but not by 4 g/day when compared with the placebo and this reduction was achieved by 3 months and was sustained at 6 months. Even though total cholesterol was already well controlled by the statin treatment (mean initial level 4.5 mmol/L), there was a further dose-dependent reduction with fish oil supplementation (r = -0.344, P < 0.05). The extent of total cholesterol reduction correlated (r = -0.44) with the initial total cholesterol levels (P < 0.005). In the subset with initial plasma cholesterol above 3.8 mmol/L, plasma very low density lipoprotein (VLDL), intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) were isolated and assayed for cholesterol and apolipoprotein B (apoB) at the commencement of the trial and at 3 months of intervention. Fish oil tended to lower cholesterol and apoB in VLDL and raise both in LDL. There were no changes in IDL cholesterol, IDL apoB and high-density lipoprotein cholesterol. The results demonstrate that DHA-rich fish oil supplementation (2.16 g DHA/day) can improve plasma lipids in a dose-dependent manner in patients taking statins and these changes were achieved by 3 months. Fish oil in addition to statin therapy may be preferable to drug combinations for the treatment of combined hyperlipidaemia.

Optimal medical management of peripheral arterial disease

Patients with peripheral vascular disease are less likely to receive optimal medical management than patients with coronary artery disease. However, early medical treatment is critical because it is profoundly beneficial and the benefits are maximized. Even in patients with advanced disease requiring invasive intervention, medical management has been proven to improve outcome, prolong the success of the intervention, improve functional capacity, and prolong life. The vascular surgeon should be knowledgeable enough to initiate basic medical therapy and to define for their patients the goals that need to be met to optimize their medical management. The vascular surgeon should be instrumental in assuring that the peripheral vascular patient receives medical therapy of the same standard as the patient with coronary disease. The major modifiable risk factors in the vascular patient are: smoking, high blood pressure, hyperlipidemia, physical inactivity, obesity, and diabetes. In addition, the use of beta blockers for patients with coronary disease and antiplatelet therapy as well as angiotensin-converting enzyme (ACE) inhibitors are recommended for all patients with peripheral vascular disease. Statins have favorable effects on multiple interrelated aspects of vascular biology important in atherosclerosis. In particular they have beneficial effects on inflammation, plaque stabilization, endothelial dysfunction, and thrombosis. Statins have also been shown to be beneficial in acute vascular events. Angiotensin-converting enzyme inhibitors have been shown to reduce cardiovascular morbidity and mortality in patients with peripheral arterial disease regardless of the presence or absence of hypertension. A number of the pleiotropic effects of statins are shared by ACE inhibitors. In summary, patients with known vascular disease should be treated aggressively with a combination of a HMG CoA reductase inhibitor, an angiotensin-converting enzyme inhibitor, an antiplatelet agent and a beta blocker if there is a history of coronary disease. They should also receive tight control of their blood pressure and blood sugar. Smokers should be encouraged to stop smoking and should be provided with pharmaceutical and emotional support by their physicians. All of these patients should have their body mass index as close to normal as possible and be on a therapeutic lifestyle diet. Regular aerobic exercise is also indicated. Patients with symptomatic claudication should be considered for cilostazol. Patients with multiple risk factors for vascular disease, but who do not have documented disease should also be on statin therapy. As more studies define the linear relationship between lower LDL-C levels and lowered risk of vascular events, indicating that the lower the LDL-C level, the lower the risk, experts are advocating more aggressive lipid-lowering therapy. In patients with peripheral arterial disease, some experts now advocate lowering the goal of LDL therapy to 70 mg/dL.

Common Questions in Managing Hyperlipidemia

Hyperlipidemia is a serious disease that affects the health and well-being of many, and further complicates other chronic illnesses. When treating a patient who has a lipid disorder, it is wise to take a global approach to the problem by assessing the patient's history and risk factors, collaborating on developing a healthy lifestyle plan to which the patient can commit, and initiating appropriate therapy when indicated.

Combination therapy with statins and omega-3 fatty acids

Combined dyslipidemia is the concurrent presence of multiple abnormalities in various lipid subfractions, including elevated concentrations of low-density lipoprotein (LDL) cholesterol and triglycerides (TGs), as well as decreased concentrations of high-density lipoprotein (HDL) cholesterol. The Adult Treatment Panel III (ATP III) guidelines of the US National Cholesterol Education Program (NCEP) lowered the cut points for classification of TG levels, established non-HDL cholesterol levels as a secondary target of therapy in patients with TGs of >or=2.26 mmol/L (200 mg/dL), and defined the metabolic syndrome as a secondary target of therapy. Although 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) are first-line therapy for most patients with elevated LDL cholesterol, statin monotherapy may not be sufficient to achieve recommended non-HDL cholesterol goals, and statins have only modest effects on reducing TG levels. Similarly, patients whose TG levels remain elevated despite treatment with a TG-lowering agent may require the addition of a statin to provide further TG reduction. In addition, statin therapy may be needed to offset the secondary increase in levels of LDL cholesterol that frequently results from treatment with a TG-lowering agent in patients with marked hypertriglyceridemia. In a number of small studies, the combination of statins and omega-3 fatty acids has been consistently shown to be an effective, safe, and well-tolerated treatment for combined dyslipidemia. Patients with recent myocardial infarction may also benefit from this combination. When considering risks and benefits of adding a second agent to statins for treatment of combined dyslipidemia, omega-3 fatty acids provide additional lipid improvements without requiring additional laboratory tests and do not increase risk for adverse muscle or liver effects.

N-3 fatty acid supplementation decreases plasma homocysteine in diabetic dyslipidemia treated with statin–fibrate combination

The aim of this study was to study the effect of adding polyunsaturated fatty acid (PUFA) n-3 or placebo (containing oleic acid) to a combined statin-fibrate treatment on plasma lipoproteins, lipoperoxidation, glucose homeostasis, total homocysteine (tHcy) and microalbuminuria (MA) in patients with diabetic dyslipidemia (DDL). Twenty-four patients, who did not fulfill the recommended target lipid values with combined hypolipidemic therapy (pravastatin 20 mg+micronized fenofibrate 200 mg daily), were supplemented with 3.6 g PUFA n-3 daily for 3 months or placebo (olive oil) for the next 3 months. The concentrations of plasma lipids, fatty acid (FA) profiles of phosphatidylcholine (PC), cholesteryl esters (CE) and triglycerides (TG), tHcy levels, concentrations of conjugated dienes (CD) in low-density lipoprotein (LDL), and MA were determined in baseline state, after the PUFA n-3 and placebo treatment period. Supplementation with PUFA n-3 led to a significant decrease in plasma tHcy (-29%, P < .01) and TG (-28%, P < .05) levels, as well as to a significant decrease in MA (-24%, P < .05). The decrease in MA correlated significantly with the increase in total PUFA n-3 (r = -.509, P < or = .05) and docosahexaenoic acid (r = -.52, P < .01) in TG. The concentrations of CD in LDL increased significantly (+15%, P < .05). The supplementation with PUFA n-3 to the combined statin-fibrate treatment in patients with DDL decreased the TG and tHcy levels as well as MA. It could lead to decreased risk of atherothrombosis and delay of diabetic nephropathy onset and progression.

[Treatment of dyslipidemia: how and when to combine lipid lowering drugs]

Familial combined hyperlipidemia (FCH) is a frequent familial lipid disorder associated with insulin resistance, low HDL cholesterol, high triglycerides and cholesterol levels with variable phenotypes within the same family. FCH is linked to a high risk for cardiovascular diseases. Treatment goals for lipid abnormalities are changing in recent years. Lowering elevated levels of LDL e Non HDL-cholesterol levels are primary targets of therapy. Lower LDL-C than 70 mg/dL seems to be useful to lower cardiovascular risk in patients with very high risk. Many statins are available, with different potencies and drug interactions. Combination therapy of statins and bile acid sequestrants or ezitimibe may be necessary to further decrease LDL cholesterol levels in order to meet guideline goals. High triglycerides and low HDL cholesterol are also important goals in the treatment of these patients, and frequently statins alone are insufficient to normalize the lipid profile. Combination therapy with fibrates will further lower triglycerides and increase HDL cholesterol levels; this combination is also associated with higher incidence of myopathy and liver toxicity; appropriate evaluation of patients' risk and benefits is necessary. Association of statin/niacin seems be very useful in patients with FCH, especially as niacin is the best drug to increase HDL cholesterol; this association is not linked to a higher frequency of myopathy. Niacin causes flushing, that can in part be managed with use of aspirin and extended release forms (Niaspan); niacin also may increase plasma glucose and uric acid levels. Evaluation of risks and benefits for each patient is needed.

Efficacy and safety of statins in hypercholesterolemia with emphasis on lipoproteins

Information of the effect of statin on lipoproteins such as apolipoprotein (apo) A-I, lipoprotein (a) [Lp (a)], or apolipoprotein B levels is limited. This investigation was a crossover study designed to evaluate the efficacy and safety of atorvastatin and simvastatin in patients with hyperlipidemia. Sixty-six patients were involved in the study. Group I consisted of 32 patients, who were first treated with atorvastatin (10 mg) then switched to simvastatin (10 mg). Group II consisted of 34 patients, who were first treated with simvastatin then switched to atorvastatin. Each regimen was used for 3 months (phase I), stopped for 2 months, and then restarted for another 3 months (phase II). Both statins effectively reduced total cholesterol, low-density lipoprotein cholesterol (LDL-C), apo B, and Lp (a) (P < 0.001 in all comparisons). A significant increase in the high-density lipoprotein cholesterol (HDL-C) was noted after both statin treatments (P < 0.05 in all comparisons). Both statins caused an increase in the apo A-I levels, and the extent of changes in apo A-I revealed no difference between the two drugs. Compared to the simvastatin group, there were more patients in the atorvastatin group achieving the National Cholesterol Education Program ATP-III LDL-C goal (P < 0.05) and European LDL-C goal (P < 0.001). Both treatments were well tolerated; no patient was withdrawn from the study. This study demonstrates that both statins can effectively improve lipid profiles in patients with hyperlipidemia. Atorvastatin is more effective in helping patients reach the ATP-III and European LDL-C goals than simvastatin at the same dosage.

Statin safety: an overview and assessment of the data--2005

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statin drugs, have been studied in numerous controlled human research trials involving hundreds of thousands of study participants. Statins have been prescribed for millions of patients. Based on this vast research and clinical experience, statins have been shown to improve lipid blood levels and reduce atherosclerotic coronary artery disease (CAD) risk, resulting in reduced CAD morbidity and mortality, and in several studies, reduced overall ("all-cause") mortality. From a safety perspective, both research trial evidence and clinical practice experience have demonstrated that statins are generally well tolerated. However, as with all pharmaceuticals, safety considerations exist with both monotherapy and combination statin therapy, mainly involving potential adverse effects on muscle, liver, kidney, and the nervous system. The evidence supporting statin-related potential adverse experiences on these organ systems is sometimes strong and based on clear clinical trial evidence (such as the increased risk of muscle enzyme elevation with higher statin doses). The evidence is at other times more speculative, being based on case reports and inconclusive clinical trial data (such as possible favorable or unfavorable effects of statins on cognition). Because the use of statins is so widespread, it is useful for the clinician to understand statin safety issues and the level of available evidence supporting the contention that various adverse effects are caused by statins. This review presents an assessment of statin safety based on an overview of the current statin safety data and their clinical implications.

Ezetimibe-associated myopathy in monotherapy and in combination with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor

Two cases of myopathy associated with ezetimibe are reported. In the first case, a woman on ezetimibe monotherapy presented with muscle pain and an elevated concentration of creatine kinase (CK) on two occasions, with ezetimibe 10 mg and with ezetimibe 5 mg after a washout period. The recurrence of muscle pain after washout and the CK increase both supported the hypothesis that ezetimibe alone can be linked to myalgia. In the second case, a man had been treated with atorvastatin, and ezetimibe 10 mg was added to improve his lipid profile. Two months later, the patient complained of muscle pain and a CK increase was noted. The appearance of symptoms when adding ezetimibe to atorvastatin supports a potential pharmacokinetic and/or a pharmacodynamic interaction between these two drugs. These cases suggest that ezetimibe monotherapy as well as ezetimibe associated with the use of a statin may induce myalgia. The mechanism by which ezetimibe could cause muscle pain is not known.

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.

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.

Considerations in the treatment of dyslipidemia associated with chronic kidney failure and renal transplantation

In comparison to the general population, individuals with chronic kidney failure experience an increased risk for atherosclerotic cardiovascular disease attributed predominantly to pronounced abnormalities in lipid metabolism. The emerging consensus is that patients with chronic kidney failure should be treated aggressively for dyslipidemia. Statins reduce the risk of cardiovascular disease in a range of at-risk patients; this class of lipid-lowering drugs should be considered first-line treatment of dyslipidemia observed in renal disease patients. Although the statins share a common lipid-lowering effect, there are differences within this class of drugs. The statins differ in their pharmacokinetic effects, drug interaction profiles, and risk of myotoxicity. This article characterizes the dyslipidemia observed in the renal failure setting and reviews the therapeutic considerations involved in selecting among the statins. Lovastatin, simvastatin, pravastatin, fluvastatin, atorvastatin, and rosuvastatin are the available statins in the United States.

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.

Non-high-density lipoprotein cholesterol: the forgotten therapeutic target

The National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) has acknowledged mounting evidence of an independent association between hypertriglyceridemia and coronary artery disease risk by issuing guidelines that identify non-high-density lipoprotein (HDL) cholesterol as a secondary target for therapy in patients with elevated triglyceride levels. In 2003, a national survey of outpatient lipid management was conducted for patients undergoing treatment by physicians who were high prescribers of lipid-altering drugs. Results of the NCEP Evaluation Project Utilizing Novel E-Technology II (NEPTUNE II) survey indicated much higher frequencies of low-density lipoprotein (LDL) cholesterol goal achievement compared with frequencies observed in a similarly designed survey in 1997. However, non-HDL cholesterol treatment success in the NEPTUNE II survey was markedly lower than that for LDL cholesterol overall and across risk categories. More aggressive therapy is therefore needed to achieve non-HDL cholesterol goals than LDL cholesterol goals. After achievement of LDL cholesterol goals, non-HDL cholesterol can be managed more aggressively by lowering LDL cholesterol or by using strategies that target a reduction in very-low-density lipoprotein cholesterol. Because the prevalence of hypertriglyceridemia in the United States is high and increasing, enhanced efforts to improve non-HDL cholesterol goal achievement have the potential to produce a substantial effect on public health.

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.

Familial combined hyperlipidemia in a North Indian kindred

Familial combined hyperlipidemia is the most common genetic hyperlipidemia and is responsible for premature coronary artery disease. It is genetically heterogenous and no single diagnostic marker exists. The authors report an affected North Indian kindred spanning three successive generations with a possible autosomal dominant pattern of inheritance and all of them had combined dyslipidemia [elevated total cholesterol, predominantly the low density lipoprotein (LDL) fraction and elevated triglycerides]. The proband, a 4-month-old male baby, was incidentally discovered to have a lipaemic serum and so further evaluated. Both the index case and his maternal grandmother, a non-obese diabetic (type 2) with hypertension, had an atherogenic lipoprotein phenotype. Lipaemia retinalis was documented in this baby but xanthomas and coronary artery disease were not noted in the kindred. The present case report highlights the failure of dietary therapy in the proband and explores new options.

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.

Differences between markers of atherogenic lipoproteins in predicting high cardiovascular risk and subclinical atherosclerosis in asymptomatic men

OBJECTIVE

As main markers of atherogenic lipoproteins, apolipoprotein B (apoB), non-HDL cholesterol (non-HDLC), and LDL cholesterol (LDLC) do not seem equipotent to predict cardiovascular complications, we have compared simultaneously their capacity to predict high cardiovascular risk and subclinical atherosclerosis in a primary prevention population.

METHODS

In 723 asymptomatic men, we measured apoB, non-HDLC, and LDLC, and we determined concomitantly coronary heart disease (CHD) risk equivalent defined by National Cholesterol Education Program guidelines, ultrasound-assessed extra-coronary plaques at multiple sites, and electron beam computed tomography-assessed high coronary calcium.

RESULTS

Odds ratios (95% confidence interval) per standard deviation of apoB, non-HDLC, and LDLC of having: (i) CHD risk equivalent were 1.90 (1.53-2.37), 1.78 (1.43-2.21), 1.47 (1.19-1.81); (ii) extra-coronary plaques were 1.37 (1.16-1.61), 1.31 (1.11-1.56), 1.19 (1.01-1.39); (iii) high coronary calcium were 1.35 (1.09-1.68), 1.33 (1.07-1.64), 1.26 (1.01-1.39), respectively. Risk factors and treatment did not confound the above associations, except triglycerides for which adjustment weakened the risk predictions of lipids and annihilated lipids differences in predicting CHD risk equivalent and atherosclerosis markers.

CONCLUSIONS

ApoB was the best predictor, non-HDLC the second best predictor, and LDLC the poorest predictor of high cardiovascular risk and subclinical extra-coronary and coronary atherosclerosis, and triglycerides participated to these differences.

Insulin Resistance Syndrome

Insulin resistance syndrome, also referred to as the metabolic syndrome, affects 1 in 3 to 4 adults older than 20 years. This syndrome consists of a clustering of metabolic abnormalities that put people at risk for type 2 diabetes and cardiovascular disease. These clinical abnormalities include dyslipidemia, specifically elevated triglycerides and low high-density lipoprotein cholesterol, elevated glucose, and hypertension. The incidence of this morbid syndrome is expected to continue to grow both in the United States and worldwide, and thus is of tremendous interest to nurses seeking to measure their impact on patient outcomes. The key lifestyle interventions essential to treating this syndrome are weight loss and physical activity. The purpose of this article is to (1) describe the insulin resistance syndrome and discuss the current focuses for inquiry in major outcome areas (eg, mortality, morbidity, costs); (2) describe the status of specific lifestyle interventions (weight loss, diet, and exercise); (3) identify outcomes that nurses could measure to assess their impact on patient care; and (4) identify areas for future nursing research.

Statin induction of liver fatty acid-binding protein (L-FABP) gene expression is peroxisome proliferator-activated receptor-alpha-dependent

Statins are drugs widely used in humans to treat hypercholesterolemia. Statins act by inhibiting cholesterol synthesis resulting in the activation of the transcription factor sterol-responsive element-binding protein-2 that controls the expression of genes involved in cholesterol homeostasis. Statin therapy also decreases plasma triglyceride and non-esterified fatty acid levels, but the mechanism behind this effect remains more elusive. Liver fatty acid-binding protein (L-FABP) plays a role in the influx of long-chain fatty acids into hepatocytes. Here we show that L-FABP is a target for statins. In rat hepatocytes, simvastatin treatment induced L-FABP mRNA levels in a dose-dependent manner. Moreover, L-FABP promoter activity was induced by statin treatment. Progressive 5'-deletion analysis revealed that the peroxisome proliferator-activated receptor (PPAR)-responsive element located at position -67/-55 was responsible for the statin-mediated transactivation of the rat L-FABP promoter. Moreover, treatment with simvastatin and the PPARalpha agonist Wy14,649 resulted in a synergistic induction of L-FABP expression (mRNA and protein) in rat Fao hepatoma cells. This effect was also observed in vivo in wild-type mice but not in PPARalpha-null animals demonstrating the direct implication of PPARalpha in L-FABP regulation by statin treatment. Statin treatment resulted in a rise in PPARalpha mRNA levels both in vitro and in vivo and activated the mouse PPARalpha promoter in a reporter assay. Altogether, these data demonstrate that L-FABP expression is up-regulated by statins through a mechanism involving PPARalpha. Moreover, PPARalpha might be a statin target gene. These effects might contribute to the triglyceride/non-esterified fatty acid-lowering properties of statins.

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.

Effect of Colesevelam HCl on Single-Dose Fenofibrate Pharmacokinetics

OBJECTIVE

The primary aim of this study was to determine whether there is an effect of colesevelam HCl (WelChol; Sankyo Pharma Inc., Parsippany, NJ, USA) on fenofibric acid (active metabolite of fenofibrate, TriCor, Abbott Laboratories, North Chicago, IL, USA) pharmacokinetics following single-dose fenofibrate when colesevelam HCl and fenofibrate are administered concomitantly, or when colesevelam HCl is administered 4 hours following fenofibrate therapy.

METHODS

Thirty healthy volunteers were enrolled in a randomised, open-label, three-way crossover, drug interaction study. Subjects received one of three treatments at each of three dose administration periods: (i) treatment A -- fenofibrate 160 mg plus colesevelam HCl 3750 mg (6 x 625 mg tablets) administered with breakfast; (ii) treatment B -- fenofibrate 160 mg administered with breakfast, followed 4 hours later by colesevelam HCl 3750 mg (6 x 625 mg tablets) administered with lunch; or (iii) treatment C -- fenofibrate 160 mg administered with breakfast. Treatments were separated by a 10-day washout period. Blood samples were collected at predetermined time intervals, both before and after drug administration. Plasma concentrations of fenofibrate and fenofibric acid were measured using a validated liquid chromatography/mass spectroscopy/mass spectroscopy method.

RESULTS

Area under the concentration-time curve (AUC) from time zero to the timepoint of the lowest quantifiable concentration (AUCt), AUC from time zero to infinity (AUCinfinity) and maximum plasma concentration (Cmax) for fenofibric acid were 92.1%, 93.9% and 79.8%, respectively, of control values when colesevelam HCl and fenofibrate were coadministered with breakfast; and 91.9%, 93.9% and 99.1%, respectively, when fenofibrate was administered followed 4 hours later by administration of colesevelam HCl. The 90% confidence intervals for the ratios of geometric means for AUCt, AUCinfinity and Cmax comparing the three treatments were contained within the 80-125% equivalence range, with the exception of Cmax for treatment A. Coadministration of fenofibrate with colesevelam HCl resulted in an approximate 20% reduction in Cmax of the active metabolite (fenofibric acid). There were no significant differences in the time to Cmax, elimination rate constant or elimination half-life between any of the treatment groups.

CONCLUSIONS

Colesevelam HCl had no significant effect on fenofibrate bioavailability when administered either concomitantly with fenofibrate or 4 hours after fenofibrate.

Pharmacology and therapeutics of ezetimibe (SCH 58235), a cholesterol-absorption inhibitor

BACKGROUND

Ezetimibe is the first of a new class of antihyperlipidemic agents, the cholesterol-absorption inhibitors. It is indicated for monotherapy or in combination with 3-hydroxy-3-methylglutaryl coenzyme A-reductase inhibitors (statins) in patients with primary hypercholesterolemia, in combination with simvastatin or atorvastatin in patients with homozygous familial hypercholesterolemia, and as monotherapy in patients with homozygous familial sitosterolemia.

OBJECTIVE

This article reviews available data on the clinical pharmacology, clinical efficacy, and tolerability of ezetimibe.

METHODS

A literature review was conducted using the search terms ezetimibe and SCH 58235 to identify articles and abstracts indexed in MEDLINE and the Iowa Drug Information Service from 1966 to February 2003. The reference lists of the identified articles were reviewed for additional publications.

RESULTS

In adults, ezetimibe 10 mg PO given once daily has been reported to reduce intestinal cholesterol absorption by 54% from baseline in association with a compensatory increase in endogenous cholesterol synthesis. Within 2 weeks of its initiation, ezetimibe monotherapy produced a 17% to 20% reduction from baseline in low-density lipoprotein cholesterol (LDL-C); in combination with statins, ezetimibe produced a reduction in LDL-C of up to 40% over the same period. Based on studies performed to date, ezetimibe appears to be well tolerated, with a safety profile similar to that of placebo. Because ezetimibe is eliminated primarily by glucuronidation and not by cytochrome P450 (CYP) oxidation, it is subject to minimal drug interactions involving the CYP enzyme system.

CONCLUSIONS

Ezetimibe is an option for monotherapy in patients with mild hypercholesterolemia or in those requiring adjunctive drug therapy for reduction of LDL-C levels. It may be useful in patients at risk for adverse events (eg, liver toxicity, myopathy) from other hypocholesterolemic agents. Additive LDL-C-lowering effects of ezetimibe may allow use of lower doses of conventional agents (eg, statins, fibric acid derivatives, niacin) to achieve an equivalent effect, thereby reducing the potential for adverse events and drug interactions. However, because trials have lasted no longer than 12 weeks, the long-term effect of ezetimibe on cardiovascular morbidity and mortality remains to be determined.

The place of ezetimibe in clinical practice

Ezetimibe is the first selective cholesterol absorption inhibitor to be licensed in the UK. It interferes both with dietary cholesterol absorption and the enterohepatic circulation of cholesterol synthesized by the liver. As monotherapy it leads to modest reductions in plasma low-density lipoprotein cholesterol levels, but has synergistic effects when used with statins.

An analysis of cholesterol control and statin use in the Losartan Intervention for Endpoint Reduction in Hypertension Study

BACKGROUND

There is general agreement that patients who have elevated lipid levels and/or risk factors for or existing cardiovascular disease should receive aggressive cholesterol-lowering therapy. However, it is not clear whether patients are receiving the recommended treatment.

OBJECTIVE

This study evaluated cholesterol control and statin use in the setting of a large, long-term cardiovascular end point trial.

METHODS

The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study was conducted between 1995 and 2001 to compare the incidence of cardiovascular morbidity and mortality with losartan- or atenolol-based treatment in 9193 patients aged 55 to 80 years with hypertension and left ventricular hypertrophy. The mean (SD) duration of follow-up was 4.8 (0.9) years. Use of lipid-lowering therapy was at the discretion of the investigator. In the present study, analyses of baseline and end-of-study mean total cholesterol (TC) and high-density lipoprotein cholesterol levels and statin use were performed for the combined treatment groups. Based on generally accepted guidelines, achievement of a TC level <5.0 mmol/L (193.5 mg/dL) was used as the treatment target for the purpose of these analyses. The proportions of patients with TC levels above this cutoff were calculated at baseline and at the final visit.

RESULTS

A total of 8653 patients had baseline and end-of-study cholesterol measurements and were included in this analysis. At baseline, 528 (6.1%) patients were receiving statins; TC levels were above the cutoff in 381 (72.2%) of these patients, who had a mean TC level of 6.07 mmol/L (234.7 mg/dL). Of 8125 (93.9%) patients who were not receiving statins at baseline, TC levels were above the cutoff in 6859 (84.4%), with a mean TC level of 6.37 mmol/L (246.4 mg/dL). At the end of the study, 1892 (21.9%) patients were receiving a statin; TC levels were above the cutoff in 1096 (57.9%) of these patients, who had a mean TC level of 5.99 mmol/: (231.6 mg/dL). Of 6761 (78.1%) patients who were not receiving statins at the end of the study, TC levels were above the cutoff in 5316 (78.6%), with a mean TC level of 6.24 mmol/L (241.4 mg/dL).

CONCLUSIONS

In this long-term cardiovascular end point study in patients with moderate to severe hypertension and left ventricular hypertrophy, statins were not optimally administered and cholesterol levels were poorly controlled.