Efficacy and safety of ezetimibe co-administered with simvastatin in thiazolidinedione-treated type 2 diabetic patients

AIM

In patients with type 2 diabetes mellitus (T2DM), combination therapy is usually required to optimize glucose metabolism as well as to help patients achieve aggressive targets for low-density lipoprotein cholesterol (LDL-C) and other lipid parameters associated with cardiovascular risk. The thiazolidinediones (TZDs) are increasingly being used for both their blood glucose-lowering properties and their modest beneficial effects on triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C). Ezetimibe, an intestinal cholesterol absorption inhibitor, has a mechanism of action that differs from that of statins, which inhibit hepatic cholesterol synthesis. We compared the lipid-modifying efficacy and safety of adding ezetimibe to simvastatin, vs. doubling the dose of simvastatin, in TZD-treated T2DM patients.

METHODS

This was a randomized, double-blind, parallel group, multicentre study in T2DM patients, 30-75 years of age, who had been on a stable dose of a TZD for at least 3 months and had LDL-C > 2.6 mmol/l (100 mg/dl) prior to study entry. Other antidiabetic medications were also allowed. Following 6 weeks of open-label simvastatin 20 mg/day, patients were randomized to the addition of either blinded ezetimibe 10 mg/day (n = 104) or an additional blinded simvastatin 20 mg/day (total simvastatin 40 mg/day; n = 110) for 24 weeks. Patients were stratified according to TZD type and dose (pioglitazone 15-30 vs. 45 mg/day; rosiglitazone 2-4 vs. 8 mg/day).

RESULTS

LDL-C was reduced more (p < 0.001) by adding ezetimibe 10 mg to simvastatin 20 mg (-20.8%) than by doubling the dose of simvastatin to 40 mg (-0.3%). Ezetimibe plus simvastatin 20 mg also produced significant incremental reductions in non-HDL-C (p < 0.001), very low-density lipoprotein cholesterol (p < 0.05) and apolipoprotein B (p < 0.001) relative to simvastatin 40 mg. There were no differences between the groups with respect to changes in TG and HDL-C levels, and both treatments were well tolerated.

CONCLUSIONS

Co-administration of ezetimibe with simvastatin, a dual inhibition treatment strategy targeting both cholesterol synthesis and absorption, is well tolerated and provides greater LDL-C-lowering efficacy than increasing the dose of simvastatin in T2DM patients taking TZDs.

A multicenter, randomized, double-blind, placebo-controlled, factorial design study to evaluate the lipid-altering efficacy and safety profile of the ezetimibe/simvastatin tablet compared with ezetimibe and simvastatin monotherapy in patients with primary hypercholesterolemia

OBJECTIVE

The purpose of this study was to evaluate the efficacy and safety profile of ezetimibe/simvastatin(EZE/SIMVA) combination tablet, relative to ezetimibe (EZE) and simvastatin (SIMVA) monotherapy, in patients with primary hypercholesterolemia.

METHODS

This was a randomized, multicenter, double-blind, placebo-controlled, factorial design study After a 6- to 8-week washout period and 4-week, single-blind, placebo run in, hypercholesterolemic patients (low-density lipoprotein cholesterol [LDL-C], 145-250 mg/dL; triglycerides [TG], < or =350 mg/dL) were randomized equally to 1 of 10 daily treatments for 12 weeks: EZE/SIMVA 10/10, 10/20, 10/40, or 10/80 mg; SIMVA 10, 20, 40, or 80 mg; EZE 10 mg; or placebo. The primary efficacy analysis was mean percent change from baseline in LDL-C to study end point Secondary end points included percent changes in other lipid variables and C-reactive protein [CRP].

RESULTS

There were 1528 patients randomized to treatment (792 women, 736 men); mean (SD) age ranged from 54.9 (112) years to 56.4 (10.6) years across pooled treatment groups. The treatment groups were well balanced for baseline demographics. Pooled EZE/SIMVA was associated with greater reductions in LDL-C than pooled SIMVA or EZE alone (P < 0.001). Depending on dose, EZE/SIMVA was associated with reductions in LDL-C of -44.8% to -602%, non-high-density lipoprotein cholesterol of -40.5% to -55.7%, and TG of -22.5% to -30.7%; high-density lipoprotein cholesterol increased by 5.5% to 9.8%. EZE/SIMVA was associated with greater reductions in CRP and remnant-like particle-cholesterol than SIMVA alone (P < 0.001). More patients receiving EZE/SIMVA versus SIMVA achieved LDL-C concentrations <100 mg/dL (78.6% vs 45.9%; P < 0.001). EZE/SIMVA was generally well tolerated, with a safety profile similar to SIMVA monotherapy There were no significant differences between EZE/SIMVA and SIMVA in the incidence of consecutive liver transaminase levels > or =3 times the upper limit of normal (ULN) (1 .5% for EZE/SIMVA and 1.1% for SIMVA; P = NS) or creature kinase levels > or =10 times ULN (0.0% for EZE/SIMVA and 02% for SIMVA; P = NS).

CONCLUSION

The EZE/SIMVA tablet was a highly effective and well-tolerated LDL-C-lowering therapy in this study of patients with primary hypercholesterolemia.

Effects of simvastatin on the lipid profile and attainment of low-density lipoprotein cholesterol goals when added to thiazolidinedione therapy in patients with type 2 diabetes mellitus: A multicenter, randomized, double-blind, placebo-controlled trial

BACKGROUND

Coronary heart disease is the major cause of mortality in individuals with diabetes mellitus (DM). Given the increasingly aggressive low-density lipoprotein cholesterol (LDL-C) goals for patients with DM set by the National Cholesterol Education Program Adult Treatment Panel III and the American Diabetes Association, many patients remain above target. Treatment with thiazolidinediones (TZDs) improves glycemic control but does not lower (and may raise) LDL-C concentrations.

OBJECTIVE

This study assessed the lipid-modifying efficacy and tolerability of adding the hydroxymethylglutaryl coenzyme A-reductase inhibitor simvastatin to existing TZD therapy in patients with type 2 DM.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled, parallel-group trial. Patients with type 2 DM who were taking a stable dose of pioglitazone or rosiglitazone and had a glycosylated hemoglobin (HbA1c) value < or =9.0% and an LDL-C concentration > 100 mg/dL were randomized to receive simvastatin 40 mg (the recommended initial dose for patients with DM) or placebo for 24 weeks. The primary end point was the effect of treatment on LDL-C concentrations. Other lipid, lipoprotein, and safety measures were also assessed.

RESULTS

Two hundred fifty-three patients (127 [50.2%] men, 126 [49.8%] women; mean age, 56 years) were randomized to treatment (123 simvastatin, 130 placebo). At the end of the study, mean LDL-C concentrations were reduced 34.)% from baseline (from 134.3 to 89.5 mg/dL) in the simvastatin group and were unchanged in the placebo group (P<0.001). Simvastatin produced significant reductions in concentrations of total cholesterol, triglycerides (TG), non-high-density lipoprotein cholesterol, and apolipoprotein (apo) B compared with placebo (all, P<0.001 ) and significant increases in concentrations of high-density lipoprotein cholesterol (HDL-C) ( P=0.002 ) and apo A-I ( P=0.006 ). In patients who had not attained target concentrations of LDL-C (<100 mg/dL), TG (<150 mg/dL), or HDL-C (>45 mg/dL) at baseline, significantly more simvastatin recipients had achieved these goals at the end of the study compared with placebo recipients (LDL-C: 67.3% vs 5.2%, respectively, P<0.001; HDL-C: 95.3% vs 83.6%, P<0.05; TG: 40.8% vs 11.0%, P<0.001 ). Simvastatin was well tolerated, and no clinically meaningful differences in the incidence of serious adverse events, treatment-related adverse events, or discontinuations due to adverse events were observed between groups. There were no significant between-group differences in glycemic control (HbA1c) or concentrations of fasting insulin, creatine phosphokinase, or hepatic transaminases.

CONCLUSION

Simvastatin was an effective and generally well tolerated treatment for hyperlipidemia when used in combination with TZD therapy in this population of patients with type 2 DM.

A population-based treat-to-target pharmacoeconomic analysis of HMG-CoA reductase inhibitors in hypercholesterolemia

The 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors have become the drugs of choice for the treatment of patients with hypercholesterolemia. However, one of the major concerns with these drugs is cost. In an attempt to develop a cost-effective treatment strategy for patients referred to our lipid clinic, we conducted a meta-analysis to estimate the lipid-lowering efficacy of the various HMG-CoA reductase inhibitors alone or in combination with niacin or cholestyramine. Based on cholesterol-lowering efficacy estimates derived from a literature-based meta-analysis, we performed a population-based treat-to-target analysis. Fifty-six trials with 101 monotherapy cohorts and 20 trials with 31 combination-therapy cohorts (573 patients) were included in the meta-analysis. Based on reduction in low-density lipoprotein cholesterol (LDL-C), the most effective monotherapy was atorvastatin and the least effective monotherapy was fluvastatin. Combination therapy was more effective in reducing LDL-C than monotherapy with the respective HMG-CoA reductase inhibitor. However, on the basis of dollars spent per percentage of LDL-C reduction, combination therapy was frequently less cost-effective than monotherapy. In addition, combination therapy was associated with a higher rate of noncompliance and a greater risk of drug-drug interactions. As a result, we based our treat-to-target analysis on the use of monotherapy as first-line treatment, with combination therapy reserved for patients failing to achieve the target LDL-C levels of the US National Cholesterol Education Program Adult Treatment Panel II (NCEP ATP-II) with monotherapy. In the population-based treat-to-target analysis, atorvastatin was the most cost-effective drug for high-risk patients (those with coronary heart disease [CHD]), whereas fluvastatin was the most cost-effective agent for low-risk patients (<2 risk factors for CHD) and moderate-risk patients (> or =2 risk factors for CHD). If 1 drug is chosen to treat all patients (i.e., in cases of formulary restriction), atorvastatin would be the most cost-effective agent. In adapting the findings on cholesterol-lowering efficacy from this analysis to our lipid clinic, we concluded that the most cost-effective treatment approach is to individualize the selection of an HMG-CoA reductase inhibitor based on both coronary risk and the LDL-C reduction required to achieve NCEP ATP-II goals. Based on our results, 2 agents--atorvastatin and fluvastatin--should be available on the formulary.

Crossover trial of simvastatin versus pravastatin in patients with primary hypercholesterolemia

The effects of simvastatin and pravastatin administered alone at initial doses of 5 and 10 mg/day, respectively, on normalization of abnormal lipid metabolism in patients with hypercholesterolemia were evaluated by a crossover method. Patients whose serum levels of total cholesterol (TC) were > or = 220 mg/dl were randomly divided into two groups, and one of the groups (group S-P: 17 patients) was treated with simvastatin first and then with pravastatin whereas the other group (group P-S: 19 patients) was treated with pravastatin first and then with simvastatin. Simvastatin or pravastatin was replaced with the other drug after 8-week administration in each group. These drugs were administered for 8 weeks each. Simvastatin and pravastatin significantly reduced the following serum lipids as compared with the levels in the observation period: TC by 23.2 +/- 8.1% and 18.1 +/- 10.9%, triglyceride (TG) by 13.0 +/- 24.7% and 5.8 +/- 47.1%, and low-density lipoprotein cholesterol (LDL-C) by 31.3 +/- 10.1% and 23.1 +/- 14.3%, respectively. TC and LDL-C levels were significantly (p < 0.001) lower and decreased to significantly (p < 0.001) greater degrees after simvastatin treatment than after pravastatin treatment. TC was normalized in 77.8% of the patients (28 of 36) after simvastatin treatment and in 68.9% of the patients (23 of 36) after pravastatin treatment. LDL-C was normalized in 63.9% of the patients (23 of 36) after simvastatin treatment and in 44.4% of the patients (16 of 36) after pravastatin treatment. The percentage of patients whose LDL-C was normalized by simvastatin was significantly (p < 0.05) higher as compared with pravastatin. Results of this trial, which was conducted by a crossover method, show that the initial dose of simvastatin reduces serum cholesterol and LDL-C more potently than the initial dose of pravastatin in patients with hypercholesterolemia.

The diet-heart disease hypothesis: a response to Atrens

In a recent examination of the main tenets of the widely accepted diet-heart disease hypothesis, Atrens concluded that the evidence to date is not sufficient to support the hypothesis. Reviewing Atrens' critique highlights both strengths and limitations in his case against the role of dietary lipids and cholesterol in coronary heart disease mortality. Research on the following hypothesized relationships is discussed in light of the objections raised by Atrens: the relationships between fat intake and heart disease mortality; dietary fat and serum cholesterol; serum cholesterol and atherosclerosis; atherosclerosis and heart disease death; and serum cholesterol and heart disease death. The inconsistency of the findings suggests that definitive answers regarding the diet-heart disease hypothesis are premature and that the polarized positions of acceptance vs rejection of the hypothesis fail to account for the full range of results.

Effects of simvastatin on plasma lipoprotein subfractions, cholesterol esterification rate, and cholesteryl ester transfer protein in type II hyperlipoproteinemia

We investigated the effects of simvastatin on plasma levels of lipoprotein subfractions, cholesterol esterification rates and activities of cholesteryl ester transfer protein in 28 patients with type II hyperlipoproteinemia (i.e., nonfamilial hyperlipoproteinemia type IIa and type IIb, and heterozygous familial hypercholesterolemia (FH)). Plasma levels of VLDL-cholesterol (C) and VLDL-triglyceride (TG) were significantly reduced overall by 12.9 +/- 58.0% (mean +/- S.D.; P < 0.05) and 4.2 +/- 54.2% (P < 0.05) respectively, but not in FH. Plasma levels of IDL-C and IDLT-G were decreased overall by 23.2 +/- 47.5% (P < 0.001) and 12.3 +/- 49.7% (P < 0.05), respectively, again mainly due to decreases seen in nonfamilial type II hyperlipoproteinemia. Plasma levels of LDL1 (1.019 < d < 1.045)-C and LDL1-TG were significantly reduced by 33.1 +/- 12.9% (P < 0.001) and 23.3 +/- 24.7% (P < 0.001), respectively. Plasma levels of LDL2 (1.045 < d < 1.063)-C were significantly reduced by 22.9 +/- 18.1% (P < 0.001) overall but not in FH. Gradient PAGE showed no consistent changes in the distribution of LDL particles. Thus, plasma levels of all apo B-containing lipoprotein subfractions were reduced by simvastatin, but its effects varied among the three subgroups. Cholesterol esterification rates were suppressed by 9.3 +/- 19.7% (P < 0.01) and activities of cholesteryl ester transfer protein were reduced by 30.6 +/- 21.5% (P < 0.001). Changes in CETP activity and in plasma levels of cholesterol in lipoprotein subfractions were not correlated. Thus, the changes in distribution of lipoprotein subfractions were not due mainly to CETP suppression.

Dextran-sulfate cellulose adsorption for lowering Lp[a]

Dextran sulfate selectively adsorbs lipoproteins that contain apolipoprotein-B100, including those associated with apolipoprotein-a, from human plasma with high affinity. Dextran sulfate immobilized on cellulose is incorporated into the Liposorber LA-15 system (Kaneka Corporation, Osaka, Japan). This system was evaluated in a nine-center controlled study of patients with familial hypercholesterolemia (FH) who had not responded adequately to diet and drug therapy. There were 54 patients with heterozygous FH: 45 randomized to treatment, 9 controls) and 10 patients with homozygous FH, all of whom received LDL apheresis. Removal of both LDL and Lp[a] was specific and highly efficient, > 90% of theory. Plasma LDL and Lp[a] concentrations were effectively lowered by repetitive LDL apheresis during the study and returned to baseline levels 3 to 4 weeks after the last apheresis treatment. The kinetics of the LDL rebound fit a simple one-pool kinetic model with a constant synthetic rate and constant fractional catabolic rate. The kinetics of the Lp[a] rebound are more complex and may require a model that includes a large extravascular Lp[a] pool in slow equilibrium with the plasma pool.

The efficacy of intensive dietary therapy alone or combined with lovastatin in outpatients with hypercholesterolemia

BACKGROUND

A diet low in saturated fat and cholesterol is the standard initial treatment for hypercholesterolemia. However, little quantitative information is available about the efficacy of dietary therapy in clinical practice or about the combined effects of diet and drug therapy.

METHODS

One hundred eleven outpatients with moderate hypercholesterolemia were treated at five lipid clinics with the National Cholesterol Education Program Step 2 diet (which is low in fat and cholesterol) and lovastatin (20 mg once daily), both alone and together. A diet high in fat and cholesterol and a placebo identical in appearance to the lovastatin were used as the respective controls. Each of the 97 patients completing the study (58 men and 39 women) underwent four consecutive nine-week periods of treatment according to a randomized, balanced design: a high-fat diet-placebo period, a low-fat diet-placebo period, a high-fat diet-lovastatin period, and a low-fat diet-lovastatin period.

RESULTS

The level of low-density lipoprotein (LDL) cholesterol was a mean of 5 percent (95 percent confidence interval, 3 to 7 percent) lower during the low-fat diet than during the high-fat diet (P < 0.001). With lovastatin therapy as compared with placebo, the reduction was 27 percent. Together, the low-fat diet and lovastatin led to a mean reduction of 32 percent in the level of LDL cholesterol. The level of high-density lipoprotein (HDL) cholesterol fell by 6 percent (95 percent confidence interval, 4 to 8 percent) during the low-fat diet (P < 0.001) and rose by 4 percent during treatment with lovastatin (P < 0.001). The ratio of LDL to HDL cholesterol and the level of total triglycerides were reduced by lovastatin (P < 0.001), but not by the low-fat diet.

CONCLUSIONS

The effects of the low-fat-low-cholesterol diet and lovastatin on lipoprotein levels were independent and additive. However, the reduction in LDL cholesterol produced by the diet was small, and its benefit was possibly offset by the accompanying reduction in the level of HDL cholesterol.

[Comparison of the efficacy between simvastatin and gemfibrozil in primary hypercholesterolemia]

The efficacy on plasma lipids, apo A1 and B of a HMG Co A Reductase inhibitor, simvastatin, and a fibrate derivative, gemfibrozil, were compared in 136 hypercholesterolemic patients. The study was randomized, double-blinded and the active drug was given after a 4 week period of placebo. Gemfibrozil (n = 69) was given at 900 mg q.p.m. during the entire study. The primary dose of simvastatin was 10 mg q.p.m. during the first 6-weeks of treatment. At the end of this period, the dose was doubled if the cholesterol level was above 2 g/l (5,16 mmol/l). The same modification was carried out 12 weeks after the beginning active drug treatment with the same criteria. The baselines of total cholesterol were 3.24 +/- 0.69 g/l (8.38 +/- 1.78 mmol/l) 3.21 +/- 0.72 g/l (8.31 +/- 1.87 mmol/l) for patients with simvastatin and those with gemfibrozil respectively. So, at the end of active treatment, 64% of patients in the simvastatin group (n = 67) received 40 mg q.p.m. After 18 weeks of treatment, 89% of patients treated with Simvastatin and 37% with gemfibrozil had more than 20% reduction in LDL cholesterol. Simvastatin was more efficient on total cholesterol, LDL-C and apo B. The increase of HDL-C is similar in both groups of patients. In contrast, the level of triglycerides was further decreased by gemfibrozil. The tolerance was good in the two groups of patients and no difference in the frequency of side effects was observed.

Simvastatin improves chylomicron remnant removal in familial combined hyperlipidemia without changing chylomicron conversion

It is unknown whether the clearance of atherogenic chylomicron remnants and the postprandial lipoprotein metabolism in general can be improved by 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in subjects with familial combined hyperlipidemia (FCH). Therefore, the postprandial chylomicron remnant clearance was studied in nine normolipidemic untreated controls and seven FCH patients before and after treatment with simvastatin using an oral vitamin A-fat load (24 hours, 50 g/m2). Treatment with simvastatin reduced plasma cholesterol level by 16% (mean +/- SEM, 8.1 +/- 0.8 v 6.8 +/- 0.8 mmol/L; P < .05) and plasma apolipoprotein (apo) B level by 19% (1.6 +/- 0.2 v 1.3 +/- 0.2 g/L; P < .05). Plasma apo E level (89.6 +/- 21.0 mg/L) was reduced by 29% (63.5 +/- 14.1 mg/L; P < .05). High-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels did not change; consequently, the reductions seen had been due to a decrease in very-low-density lipoprotein (VLDL) levels. Fasting plasma triglyceride (30% reduction) and plasma apo C-II (31% reduction) levels did not change significantly. Mean postheparin plasma lipoprotein lipase (LPL) activity increased by 13% after treatment (90.4 +/- 19.8 v 102.6 +/- 20.3 mU/mL; P < .05), but hepatic lipase (HL) activity was not altered. The clearance of chylomicrons (Sf > 1,000), expressed as the area under the 24-hour retinyl palmitate curve, did not change with simvastatin (52.8 +/- 12.9 v 51.8 +/- 13.4 h.mg-1/L).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative hypolipidemic effects of lovastatin and simvastatin in patients with heterozygous familial hypercholesterolemia

We have compared the effects of lovastatin and simvastatin on plasma lipoproteins, fibrinogen and urinary mevalonic acid excretion in twenty-three patients with heterozygous familial hypercholesterolemia. After a baseline period patients were randomly assigned to receive lovastatin or simvastatin at doses of 10, 20 and 40 mg twice daily, for a period of 2 months each, and then, after a 4-week wash-out period, all patients received the alternate drug for a similar period of therapy. Both drugs were well-tolerated and no patients were withdrawn due to side effects. Lipid values returned to baseline after discontinuation of therapy and no carry-over effect was observed. Treatment with lovastatin resulted in decreases in LDL cholesterol concentrations from 274 mg/dl at baseline to 211, 192 and 178 mg/dl, respectively, on doses of 20, 40 and 80 mg/day. Treatment with simvastatin reduced concentrations of LDL cholesterol to 194, 168 and 156 mg/dl, respectively, on doses of 20, 40 and 80 mg/day. Concentrations of HDL cholesterol increased on both drugs, but no dose response relationship was apparent. Both drugs reduced the 24-h urinary excretion of mevalonic acid, an intermediate in cholesterol biosynthesis, but the magnitude of decrease was similar with lovastatin and simvastatin. Small, but statistically non-significant decreases in fibrinogen occurred with both drugs. Patients who showed the greatest hypolipidemic effect during treatment with lovastatin also showed an excellent therapeutic response to simvastatin and vice versa. We conclude that, on a milligram per milligram basis, simvastatin is twice as potent as lovastatin in the treatment of familial hypercholesterolemia and that with both drugs, reductions in LDL cholesterol concentrations are accompanied by decreases in the urinary excretion of mevalonic acid.