Evaluation of Low-Density Lipoprotein Particle Number Distribution in Patients With Type 2 Diabetes Mellitus With Low-Density Lipoprotein Cholesterol <50 mg/dl and Non-High-Density Lipoprotein Cholesterol <80 mg/dl

Many patients with type 2 diabetes mellitus (T2DM) have relatively normal levels of low-density lipoprotein (LDL) cholesterol yet have increased risk for cardiovascular events. Distribution of lipoprotein subclasses in patients with T2DM who have achieved very low levels of LDL cholesterol (<50 mg/dl) or non-high-density lipoprotein (HDL) cholesterol (<80 mg/dl) have not been extensively examined. The aim of this study was to assess variations in lipoprotein particle concentration in patients with diabetes with "very low" LDL cholesterol and non-HDL cholesterol levels to elucidate the drivers of residual cardiovascular risk. Data were selected from a single large clinical laboratory database. Cases were patients with T2DM diagnosis codes (International Classification of Diseases, Ninth Revision, codes 250 to 250.93). Lipoprotein particle concentrations were analyzed using nuclear magnetic resonance spectroscopy. The Friedewald equation was used to calculate LDL cholesterol. Among the 1,970 patients with T2DM, the mean age was 61 years, and approximately 51% were men. At LDL cholesterol concentrations <50 mg/dl (triglyceride <150 mg/dl and HDL cholesterol >40 mg/dl), 16% had LDL particle concentrations <500 nmol/L, 70% had concentrations of 500 to 1,000 nmol/L, and 14% had concentrations >1,001 nmol/L. At non-HDL cholesterol levels <80 mg/dl, 8% had LDL particle concentrations <500 nmol/L, 67% had concentrations of 500 to 1,000 nmol/L, and 25% had concentrations >1,001 nmol/L. In conclusion, despite attainment of LDL cholesterol <50 mg/dl or non-HDL cholesterol <80 mg/dl, patients with diabetes exhibited significant variation in LDL particle levels, with most having LDL particle concentrations >500 nmol/L, suggesting the persistence of potential residual coronary heart disease risk.     

Incremental Lowering of Low-Density Lipoprotein Cholesterol With Ezetimibe 20 mg vs 10 mg Daily in Patients Receiving Concomitant Statin Therapy

Background

Ezetimibe is typically administered at a dose of 10 mg daily, with few reports of use at other doses. We compared plasma concentrations of low-density lipoprotein (LDL) cholesterol and other lipid variables in patients with dyslipidemia who were receiving ezetimibe 10 mg and then 20 mg daily.

Methods

A retrospective chart review identified 27 patients who received ezetimibe 10 mg and then 20 mg daily at different times; 15 participants were receiving stable statin therapy and 12 were not receiving concomitant statins. Plasma concentrations of lipids, creatine kinase (CK), and aspartate transaminase (AST) were determined. Plasma concentrations of ezetimibe and ezetimibe glucuronide were measured in a second group of patients.

Results

Patients taking statins and ezetimibe 20 mg had further reductions in total and LDL cholesterol of 7.1% and 10.3%, respectively (both P < 0.05) than did those receiving the 10-mg dose. No difference between 20-mg and 10-mg dosing was seen among patients not receiving statins. Plasma concentrations of ezetimibe and its active metabolite were about 2-fold higher (P < 0.05) in patients taking ezetimibe 20 mg than in those receiving 10 mg daily. All patients tolerated ezetimibe 20 mg without side effects.

Conclusions

Ezetimibe 20 mg daily reduced total and LDL cholesterol further in patients receiving statin therapy compared with 10 mg daily. Prospective studies are required to show whether the higher plasma levels of ezetimibe and its active metabolite in patients taking the 20-mg dose have any detrimental effects. Increasing the ezetimibe dose to 20 mg daily might be an interesting potential approach for patients who fail to reach lipid targets on ezetimibe 10 mg daily along with maximally tolerated doses of statin.     

Lipoprotein-Associated Phospholipase A2 (Lp-PLA2) in Acute Coronary Syndrome: Relationship With Low-Density Lipoprotein Cholesterol

Background

Lipoprotein-associated phospholipase A₂ (Lp-PLA₂) might play a role in the formation of vulnerable atherosclerotic plaques. Its plasma distribution and mass in subjects with acute coronary syndrome (ACS) has yet to be characterized.

Methods

We compared plasma levels of Lp-PLA₂ in 24 patients within 48 hours of an ACS (acute) and 12 weeks after (recovery), in 26 patients with stable coronary artery disease and in 10 normal healthy control subjects. Lp-PLA₂ mass was determined using enzyme-linked immunosorbent assay.

Results

The ACS patients (mean age 57 ± 8.7 years) had high-sensitivity C-reactive protein (hsCRP) levels of 30.46 ± 57.57 mg/L (ACS acute) vs 1.69 ± 1.32 mg/L (ACS recovery). Plasma Lp-PLA₂ levels were significantly higher in ACS acute subjects than in ACS recovery subjects (143.13 ± 60.88 ng/mL vs 88.74 ± 39.12 ng/mL; P < 0.0001). Interestingly, stable coronary artery disease patients had higher Lp-PLA₂ levels than ACS recovery patients (121.72 ± 31.11 ng/mL vs 88.74 ± 39.12 ng/mL; P = 0.0018). There was a strong correlation between Lp-PLA₂ and low-density lipoprotein (LDL) cholesterol (LDL-C) (r = 0.709; P < 0.0001) or changes in LDL (r = 0.449; P = 0.027), suggesting that the major determinant of plasma Lp-PLA₂ is LDL-C. No significant correlations were observed between Lp-PLA₂ and hsCRP or high-density lipoprotein (HDL) cholesterol. When separated using high-performance liquid chromatography, > 65%-70% of Lp-PLA₂ mass was within the apolipoprotein B-containing lipoprotein fraction, with approximately 30%-35% on HDL fraction, with no significant change in distribution between ACS acute and recovery.

Conclusions

Subjects with an ACS have markedly increased Lp-PLA₂ levels acutely related to LDL-C levels.     

Serum Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) is Independently Associated with Insulin Resistance,Triglycerides, Lipoprotein(a) Levels but not Low-Density Lipoprotein Cholesterol Levels in a General Population

Aim: Proprotein convertase subtilisin/kexin type 9 (PCSK9) has been identified as an important regulator of low-density lipoprotein (LDL) receptor processing. Evolocumab and alirocumab are PCSK9 inhibitors; however, little is known about the association between PCSK9 levels and lipid profiles in a general population. Because PCSK9 inhibitors have LDL-C lowering effects, we investigated whether there is a positive correlation between serum PCSK9 levels and LDL-C or lipoprotein(a) [Lp(a)].Methods: In Uku town, 674 residents (mean age; 69.2 ± 8.3 years) received health check-ups. The participants underwent a physical examination and blood tests, including PCSK9 and Lp(a). Serum PCSK9 and Lp(a) were measured by ELISA and Latex methods, respectively. HOMA-IR was calculated by fasting plasma glucose × insulin levels/405.Results: The mean (range) of PCSK9 and Lp(a) were 211.2 (49–601) ng/mL and 60 (1–107) mg/dL, respectively. Because of a skewed distribution, the log-transformed values were used. With univariate linear regression analysis, PCSK9 levels were associated with Lp(a) (p = 0.028), triglycerides (p < 0.001), and HOMA-IR (p < 0.001), but not with LDL-C (p = 0.138) levels. Multiple stepwise regression analysis revealed that serum PCSK9 levels were independently associated with triglycerides (p < 0.001), Lp(a) (p = 0.033) and HOMA-IR (p = 0.041).Conclusions: PCSK-9 is independently associated with triglycerides, Lp(a) levels, and HOMA-IR, but not LDL-C, in a relatively large general population sample.     

Efficacy and Safety of Alirocumab as Add‐on Therapy in High–Cardiovascular‐Risk Patients With Hypercholesterolemia Not Adequately Controlled With Atorvastatin (20 or 40 mg) or Rosuvastatin (10 or 20 mg): Design and Rationale of the ODYSSEY OPTIONS Studies

The phase 3 ODYSSEY OPTIONS studies (OPTIONS I, NCT01730040; OPTIONS II, NCT01730053) are multicenter, multinational, randomized, double‐blind, active‐comparator, 24‐week studies evaluating the efficacy and safety of alirocumab, a fully human monoclonal antibody targeting proprotein convertase subtilisin/kexin type 9, as add‐on therapy in ～ 650 high‐cardiovascular (CV)‐risk patients whose low‐density lipoprotein cholesterol (LDL‐C) levels are ≥100 mg/dL or ≥70 mg/dL according to the CV‐risk category, high and very high CV risk, respectively, with atorvastatin (20–40 mg/d) or rosuvastatin (10–20 mg/d). Patients are randomized to receive alirocumab 75 mg via a single, subcutaneous, 1‐mL injection by prefilled pen every 2 weeks (Q2W) as add‐on therapy to atorvastatin (20–40 mg) or rosuvastatin (10–20 mg); or to receive ezetimibe 10 mg/d as add‐on therapy to statin; or to receive statin up‐titration; or to switch from atorvastatin to rosuvastatin (OPTIONS I only). At week 12, based on week 8 LDL‐C levels, the alirocumab dose may be increased from 75 mg to 150 mg Q2W if LDL‐C levels remain ≥100 mg/dL or ≥70 mg/dL in patients with high or very high CV risk, respectively. The primary efficacy endpoint in both studies is difference in percent change in calculated LDL‐C from baseline to week 24 in the alirocumab vs control arms. The studies may provide guidance to inform clinical decision‐making when patients with CV risk require additional lipid‐lowering therapy to further reduce LDL‐C levels. The flexibility of the alirocumab dosing regimen allows for individualized therapy based on the degree of LDL‐C reduction required to achieve the desired LDL‐C level.     

Comparison of effectiveness of rosuvastatin versus atorvastatin on the achievement of combined C-reactive protein (<2 mg/L) and low-density lipoprotein cholesterol (< 70 mg/dl) targets in patients with type 2 diabetes mellitus (from the ANDROMEDA study)

Decreasing C-reactive protein (CRP) in addition to decreasing low-density lipoprotein (LDL) cholesterol may further decrease coronary heart disease risk. The effects of rosuvastatin compared with atorvastatin in achieving a combined target of LDL cholesterol <70 mg/dl and CRP <2 mg/L in 509 patients with type 2 diabetes mellitus was evaluated. CRP decreased significantly versus baseline in both treatment groups. Significantly more patients treated with rosuvastatin achieved the combined end point of LDL cholesterol <70 mg/dl and CRP <2 mg/L compared with atorvastatin by the end of the study period (58% vs 37%; p <0.001 vs atorvastatin). In conclusion, CRP was effectively decreased in patients with type 2 diabetes receiving rosuvastatin or atorvastatin, whereas rosuvastatin decreased LDL cholesterol significantly more than atorvastatin.     

Effect of atorvastatin 80 mg on endothelial cell function (forearm blood flow) in patients with pretreatment serum low-density lipoprotein cholesterol levels <130 mg/dl

The effect of 6-week treatment with 80 mg/day atorvastatin on vascular function in the forearm was investigated in 18 patients with mean pretreatment serum low-density lipoprotein cholesterol concentrations of 112 +/- 4 mg/dl in a double-blind, placebo-controlled, randomized study. Statin treatment improved hyperemic forearm blood flow and decreased serum markers of oxidative stress and inflammation.