Influence of simvastatin, fenofibrate and/or ezetimibe on correlation of low-density lipoprotein and nonhigh-density lipoprotein cholesterol with apolipoprotein B in mixed dyslipidemic patients

Effects of extended-release niacin/laropiprant on correlations between apolipoprotein B, LDL-cholesterol and non-HDL-cholesterol in patients with type 2 diabetes

BACKGROUND

LDL-C, non-HDL-C and ApoB levels are inter-correlated and all predict risk of atherosclerotic cardiovascular disease (ASCVD) in patients with type 2 diabetes mellitus (T2DM) and/or high TG. These levels are lowered by extended-release niacin (ERN), and changes in the ratios of these levels may affect ASCVD risk. This analysis examined the effects of extended-release niacin/laropiprant (ERN/LRPT) on the relationships between apoB:LDL-C and apoB:non-HDL-C in patients with T2DM.

METHODS

T2DM patients (n = 796) had LDL-C ≥1.55 and <2.97 mmol/L and TG <5.65 mmol/L following a 4-week, lipid-modifying run-in (~78 % taking statins). ApoB:LDL-C and apoB:non-HDL-C correlations were assessed after randomized (4:3), double-blind ERN/LRPT or placebo for 12 weeks. Pearson correlation coefficients between apoB:LDL-C and apoB:non-HDL-C were computed and simple linear regression models were fitted for apoB:LDL-C and apoB:non-HDL-C at baseline and Week 12, and the correlations between measured apoB and measured vs predicted values of LDL-C and non-HDL-C were studied.

RESULTS

LDL-C and especially non-HDL-C were well correlated with apoB at baseline, and treatment with ERN/LRPT increased these correlations, especially between LDL-C and apoB. Despite the tighter correlations, many patients who achieved non-HDL-C goal, and especially LDL-C goal, remained above apoB goal. There was a trend towards greater increases in these correlations in the higher TG subgroup, non-significant possibly due to the small number of subjects.

CONCLUSIONS

ERN/LRPT treatment increased association of apoB with LDL-C and non-HDL-C in patients with T2DM. Lowering LDL-C, non-HDL-C and apoB with niacin has the potential to reduce coronary risk in patients with T2DM.

Effects of extended-release niacin/laropiprant, simvastatin, and the combination on correlations between apolipoprotein B, LDL cholesterol, and non-HDL cholesterol in patients with dyslipidemia

BACKGROUND

Statins modify correlations between apolipoprotein B (apoB) and low-density lipoprotein cholesterol (LDL-C) and apoB and non-high-density lipoprotein cholesterol (non-HDL-C); however, it is not known whether niacin-based therapies have similar effects.

OBJECTIVE

To evaluate the effects of extended-release niacin (ERN)/laropiprant (LRPT), simvastatin (SIMVA), and ERN/LRPT + SIMVA (pooled ERN/LRPT + SIMVA) on apoB:LDL-C and apoB:non-HDL-C correlations in dyslipidemic patients.

METHODS

This post-hoc analysis of a 12-week study evaluated the apoB:LDL-C and apoB:non-HDL-C correlations in dyslipidemic patients randomized equally to double-blind ERN/LRPT 1 g/20 mg, SIMVA 10, 20, or 40 mg, or ERN/LRPT 1 g/20 mg + SIMVA (10, 20, or 40 mg) once daily for 4 weeks. At week 5, doses were doubled in all groups except SIMVA 40 mg (unchanged) and ERN/LRPT 1 g/20 mg + SIMVA 40 mg (switched to ERN/LRPT 2 g/40 mg + SIMVA 40 mg). Simple linear regression analyses were used to calculate LDL-C and non-HDL-C levels corresponding to known apoB baseline values (ie, in untreated patients) and following treatment.

RESULTS

The apoB:LDL-C and apoB:non-HDL-C correlations were higher and the predicted LDL-C and non-HDL-C levels for a known apoB value were considerably lower following treatment with ERN/LRPT, SIMVA and ERN/LRPT + SIMVA compared with untreated patients at baseline.

CONCLUSION

Greater dissociation of apoB, LDL-C, and non-HDL-C targets occur following treatment with ERN/LRPT, SIMVA, and ERN/LRPT + SIMVA in patients with dyslipidemia. The achievement of more aggressive LDL-C and non-HDL-C goals in patients receiving lipid-modifying therapy may further reduce coronary risk by normalizing apoB-containing atherogenic lipoproteins.

Water extracts of immature Rubus coreanus regulate lipid metabolism in liver cells

Hyperlipidemia is a major contributor for atherosclerosis and hypolipidemic drugs such as statin are highly prescribed to treat elevated lipid level in plasma. Rubus coreanus, which is widely cultivated in south eastern Asia, have been reported to show significant cholesterol lowering action in hyperlipidemic subjects. Our objective was to determine the cellular effect of Rubus coreanus extract (RCE) on cholesterol biosynthesis in human hepatic cells (HepG2) and to elucidate the molecular mechanism by which it causes change in cholesterol metabolism. RCE treatment lowered cholesterol biosynthesis as well as secretion from HepG2 cells. This effect was associated with lowering the release of apolipoproteins from hepatic cells. RCE treatment also showed an increase in phosphorylation of foxhead box protein 01 (FoXo-1) and 5-adenosine monophosphate-activated protein kinase (AMPK), thus lowering expression of phosphoenolpyruvate carboxykinase (PEPCK) and G6Pase, which might be a major pathway for cholesterol biosynthesis inhibition. Apart from this; RCE also lowered sterol regulatory element-binding protein-1 (SREBP-1) expression in HepG2 cells, showing a long term regulation of cholesterol biosynthesis activity. These results indicate that one of the anti-hyperlipidemic actions of RCE is due to inhibition of cholesterol biosynthesis in hepatic cells and provides first documentation of a hypolipidemic bio-molecular action of Rubus coreanus.

Hypertriglyceridemia and residual dyslipidemia in statin-treated, patients with diabetes at the highest risk for cardiovascular disease and achieving very-low low-density lipoprotein-cholesterol levels

BACKGROUND

As the result of the high prevalence of comorbidities and conventional risk factors among patients with type 2 diabetes (T2DM), most patients belong to the highest cardiovascular disease risk category, and have a target low-density lipoprotein cholesterol (LDL-C) of <70 mg/dL. Because substantial residual risk persists at LDL-C <70 mg/dL, a more comprehensive control of non-LDL-C and particles was recommended in the joint 2008 American Diabetes Association/American College of Cardiology Consensus.

OBJECTIVE

To ascertain, in statin-treated T2DM patients belonging to this greatest-risk group, with on-statin LDL-C <70 mg/dL, (1) the proportion of patients meeting all three critical levels (LDL-C <70 mg/dL, non-high-density lipoprotein cholesterol [HDL-C] <100 mg/dL, apoB <80 mg/dL) and (2) the variables associated with target attainment versus nonattainment.

PATIENTS AND METHODS

Among 675 unselected patients with T2DM, 367 were both at very high cardiometabolic risk and taking statins; 118 of these patient had LDL-C levels <70 mg/dL. Patients meeting all three criteria (LDL-C, non-HDL-C, and apoB; n = 79; all three at goal group) were compared with those only reaching LDL-C (n = 49; only LDL-C at goal group).

RESULTS

LDL-C was 54 (12) for the all three at goal group versus 57 (10) mg/dL for the only LDL-C at goal group (NS). The two groups were similar regarding age, gender, diabetes duration, body mass index, waist circumference, blood pressure, renal function and micro-/macroangiopathy prevalence. A statin plus fibrate was given to 16% of patients in the all three at goal group and 32% in the only LDL-C at goal group. The two groups did not differ in baseline (prestatin) LDL-C, HDL-C, and non-HDL-C, except for pre-/post-lipid-lowering drug(s) triglycerides (TG): 177 (95)/118 (56) for all three at goal versus 279 (134)/ 241 (103) mg/dL for only LDL-C at goal (P = .0230 and P = .0001). The only LDL-C at goal group had lower HDL-C (vs. all three at goal): 41 (12) vs. 47 (14) mg/dL (P = .0237), with atherogenic dyslipidemia [hypo-HDL-C + hyper-TG] prevalence of 35% in the all three at goal versus 56% in the only LDL-C at goal group (P < .0001). log(TG)/HDL-C was 0.049 (0.021) for all three at goal versus 0.063 (0.021) for only LDL-C at goal (P < .0001). The LDL-C/apoB ratio was 0.92 (0.24) for all three at goal vs. 0.67 (0.18) for only LDL-C at goal (P < .0001), suggestive of smaller/denser LDL.

CONCLUSION

The presence of atherogenic dyslipidemia was associated with a failure to meet all three critical modifiable targets for hypercholesterolemia, such a nonachievement being found in a large proportion (one-third) of very-high risk T2DM patients with very-low on-statin LDL-C. Attainment of all three targets will require (1) titration/permutation of statins, (2) lifestyle (re)inforcement; and/or (3) statin-fibrate bitherapy.