Small Dense Low-Density Lipoprotein Cholesterol and the Risk of Coronary Heart Disease in a Japanese Community

Estimated small dense low-density lipoprotein-cholesterol and the risk of kidney and cardiovascular outcomes in diabetic kidney disease

AIMS

This study aimed to investigate the correlations between estimated small dense low-density lipoprotein-cholesterol (esd-LDL-c) and the development of end-stage kidney disease (ESKD), cardiovascular mortality, and all-cause mortality in individuals with diabetic kidney disease (DKD) or diabetes mellitus (DM) concomitant chronic kidney disease (CKD).

METHODS

We analyzed the data from a biopsy-proven DKD cohort conducted at West China Hospital of Sichuan University between 2009 and 2021 (the DKD cohort) and participants with DM and CKD in the National Health and Nutrition Examination Survey (NHANES) 2011-2014 (the NHANES DM-CKD cohort). Cox regression analysis was also used to estimate associations between esd-LDL-c and the incidence of ESKD, cardiovascular mortality, and all-cause mortality.

RESULTS

There were 175 ESKD events among 338 participants in the DKD cohort. Patients were divided into three groups based on esd-LDL-c tertiles (T1 < 33.7 mg/dL, T2 ≥ 33.7 mg/dL to <45.9 mg/dL, T3 ≥ 45.9 mg/dL). The highest tertile of esd-LDL-c was associated with ESKD (adjusted HR 2.016, 95% CI 1.144-3.554, p = .015). Furthermore, there were 99 deaths (39 cardiovascular) among 293 participants in the NHANES DM-CKD cohort. Participants were classified into three groups in line with the tertile values of esd-LDL-c in the DKD cohort. The highest tertile of esd-LDL-c was associated with cardiovascular mortality (adjusted HR 3.95, 95% CI 1.3-12, p = .016) and all-cause mortality (adjusted HR 2.37, 95% CI 1.06-5.32, p = .036).

CONCLUSIONS

Higher esd-LDL-c was associated with increased risk of ESKD in people with biopsy-proven DKD, and higher cardiovascular and all-cause mortality risk among those with DM-CKD.

Impact of Direct Measurement of Small Dense Low-Density Lipoprotein Cholesterol for Long-Term Secondary Prevention in Patients with Stable Coronary Artery Disease

BACKGROUND

This study investigated whether directly measured small dense low-density lipoprotein cholesterol (D-sdLDL-C) can predict long-term coronary artery disease (CAD) events compared with low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein B (apoB), and estimated small dense low-density lipoprotein cholesterol (E-sdLDL-C) determined by the Sampson equation in patients with stable CAD.

METHODS

D-sdLDL-C measured at Showa University between 2010 and 2022, and E-sdLDL-C were evaluated in 790 male and 244 female patients with stable CAD. CAD events, defined as sudden cardiac death, onset of acute coronary syndrome, and/or need for coronary revascularization, were monitored for 12 years. Cutoff lipid levels were determined by receiver operating characteristic curves.

RESULTS

CAD events were observed in 238 male and 67 female patients. The Kaplan-Meier event-free survival curves showed that patients with D-sdLDL-C ≥32.1 mg/dL (0.83 mmol/L) had an increased risk for CAD events (P = 0.007), whereas risk in patients with E-sdLDL-C ≥36.2 mg/dL (0.94 mmol/L) was not increased. In the group with high D-sdLDL-C, the multivariable-adjusted hazard ratio (HR) was 1.47 (95% CI, 1.15-1.89), and it remained significant after adjustment for LDL-C, non-HDL-C, or apoB and in patients treated with statins. HRs for high LDL-C, non-HDL-C, or apoB were not statistically significant after adjustment for high D-sdLDL-C. Higher D-sdLDL-C was associated with enhanced risk of high LDL-C, non-HDL-C, and apoB (HR 1.73; 95% CI, 1.27-2.37).

CONCLUSIONS

Higher D-sdLDL-C can predict long-term recurrence of CAD in stable CAD patients independently of apoB and non-HDL-C. D-sdLDL-C is an independent risk enhancer for secondary CAD prevention, whereas E-sdLDL-C is not.UMIN-CTR Clinical Trial Number: UMIN000027504.

Validation of Estimated Small Dense Low-Density Lipoprotein Cholesterol Concentration in a Japanese General Population

AIM

A high level of directly measured small dense low-density lipoprotein cholesterol (sdLDL-C) is a strong risk factor for atherosclerotic cardiovascular disease. A method for estimating sdLDL-C by using Sampson's equation that includes levels of total cholesterol, high-density lipoprotein cholesterol (HDL-C), non-HDL-C and triglycerides (TG) has recently been proposed. We investigated the validation and exploration of estimated sdLDL-C level.

METHODS

The associations between measured and estimated sdLDL-C levels were investigated in 605 Japanese subjects (men/women: 280/325; mean age: 65±15 years) who received annual health check-ups in the Tanno-Sobetsu Study, a population-based cohort.

RESULTS

Estimated sdLDL-C level was highly correlated with measured sdLDL-C level in all subjects (R2=0.701), nondiabetic subjects without any medication (n=254, R2=0.686) and subjects with diabetes mellitus (n=128, R2=0.721). Multivariable regression analysis showed that levels of non-HDL-C, TG and γ-glutamyl transpeptidase (γGTP) were independent predictors of measured sdLDL-C level. In a stratification of the LDL window, all of the subjects with a combination of high non-HDL-C (≥ 170 mg/dL) and high TG (≥ 150 mg/dL) had high levels of measured and estimated sdLDL-C (≥ 35 mg/dL). Furthermore, machine learning-based estimation of sdLDL-C level by artificial intelligence software, Prediction One, was substantially improved by using components of Sampson's equation (R2=0.803) and by using those components with the addition of γGTP and deletion of TC (R2=0.929).

CONCLUSIONS

sdLDL-C level estimated by Sampson's equation can be used instead of measured sdLDL-C level in general practice. By building multiple machine learning models of artificial intelligence, a more accurate and practical estimation of sdLDL-C level might be possible.

Calculated Small Dense Low-Density Lipoprotein Cholesterol Level is A Predominant Predictor for New Onset of Ischemic Heart Disease

AIM

A high level of directly measured small dense low-density lipoprotein cholesterol (sdLDL-C) is a strong risk factor for ischemic heart disease (IHD). However, it remains unclear whether estimated sdLDL-C level is a predictor for IHD. We investigated the associations of new onset of IHD with levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides (TG), LDL-C and calculated sdLDL-C by Sampson's equation.

METHODS

After exclusion of subjects with IHD or those with TG ≥ 800 mg/dL, a total of 18,176 subjects (men/women: 11,712/6,464, mean age: 46 years) were recruited among 28,990 Japanese individuals who received annual health checkups.

RESULTS

During the 10-year follow-up period, 456 men (3.9%) and 121 women (1.9%) newly developed IHD. Multivariable Cox proportional hazard analyses after adjustment of age, sex, obesity, smoking habit, family history of IHD, estimated glomerular filtration rate, hypertension and diabetes mellitus at baseline showed that the hazard ratio (HR) (1.38 [95% confidence interval: 1.03-1.85]) for new onset of IHD in subjects with the 4th quartile (Q4) of sdLDL-C (≥ 42 mg/dL) was significantly higher than that in subjects with the 1st quartile (Q1) (≤ 24 mg/dL) as the reference, though the adjusted HRs in subjects with Q2-Q4 of TC, HDL-C, non-HDL-C, LDL-C and TG were comparable with those in subjects with Q1 of the respective lipid fractions. The adjusted HR with a restricted cubic spline increased with a higher level of calculated sdLDL-C as a continuous value at baseline.

CONCLUSIONS

sdLDL-C level calculated by Sampson's equation is a predominant predictor for the development of IHD in a general Japanese population.

Specific Increase in Small Dense Low-Density Lipoprotein-Cholesterol Levels beyond Triglycerides in Patients with Diabetes: Implications for Cardiovascular Risk of MAFLD

AIMS

Small dense (sd) low-density lipoprotein (LDL)-cholesterol (C) is the most powerful predictor of cardiovascular (CV) disease among lipid biomarkers and is generated by hypertriglyceridemia and insulin resistance. Metabolic dysfunction-associated fatty liver disease (MAFLD) is a newly proposed liver disease with a high CV risk. We investigated the specific association of sdLDL-C with MAFLD beyond triglycerides (TG) and obesityMethods: Participants were 839 non-alcoholic drinkers with type 2 diabetes enrolled in a regional diabetes cohort. Fatty liver (FL) and visceral fat area (VFA) was detected by computed tomography scan. sdLDL-C and LDL-TG were measured by our established homogeneous assay. TG rich lipoprotein (TRL) was calculated by subtracting LDL-C plus HDL-C from total-C. Grade of sdLDL-C (≤ 24, 25-34, 35-44, and ≥ 45 mg/dL) was classified according to the Hisayama study.

RESULTS

Compared to non-FL counterparts, FL subjects were younger, predominantly male and smokers; and had higher body mass index (BMI), VFA, hemoglobin A1c, C-peptide, TG, and sdLDL-C, while had similar levels of LDL-C, LDL-TG, and TRL-C. Multivariate logistic analysis revealed that sdLDL-C was the most powerful lipid parameter for identifying FL, independent of TG, HDL-C, BMI, and VFA. The independent association between TG and FL was lost when sdLDL-C was added to the analysis. These results remained the same when lipid-lowering drug users were excluded. After adjustment for confounders, the odds ratio for FL was 2.4-2.7 at sdLDL ≥ 35 mg/dL based on sdLDL ≤ 24 mg/dL.

CONCLUSIONS

sdLDL-C levels are specifically elevated in patients with diabetes and MAFLD, independent of TG and VFA, suggesting liver-centered metabolic abnormalities.

Effect of PCSK9 inhibition on plasma levels of small dense low density lipoprotein-cholesterol and 7-ketocholesterol

BACKGROUND

Oxidized forms of cholesterol (oxysterols) are implicated in atherogenesis and can accumulate in the body via direct absorption from food or through oxidative reactions of endogenous cholesterol, inducing the formation of LDL particles loaded with oxidized cholesterol. It remains unknown whether drastic reductions in LDL-cholesterol (LDL-C) are associated with changes in circulating oxysterols and whether small dense LDL (sdLDL) are more likely to carry these oxysterols and susceptible to the effects of PCSK9 inhibition (PCSK9i).

OBJECTIVE

We investigate the effect of LDL-C reduction accomplished via PCSK9i on changes in plasma levels of sdLDL-cholesterol (sdLDL-C) and a common, stable oxysterol, 7-ketocholesterol (7-KC), among 134 patients referred to our Preventive Cardiology clinic.

METHODS

Plasma lipid panel, sdLDL-C, and 7-KC measurements were obtained from patients before and after initiation of PCSK9i.

RESULTS

The intervention caused a significant lowering of LDL-C (-55.4 %). The changes in sdLDL-C levels (mean reduction 51.4 %) were highly correlated with the reductions in LDL-C levels (R = 0.829, p < 0.001). Interestingly, whereas changes in plasma free 7-KC levels with PCSK9i treatment were much smaller than (-6.6 %) and did not parallel those of LDL-C and sdLDL-C levels, they did significantly correlate with changes in triglycerides and very low-density lipoprotein-cholesterol (VLDL-C) levels (R = 0.219, p = 0.025).

CONCLUSION

Our findings suggest a non-preferential clearance of LDL subparticles as a consequence of LDL receptor upregulation caused by PCSK9 inhibition. Moreover, the lack of significant reduction in 7-KC with PCSK9i suggests that 7-KC may be in part carried by VLDL and lost during lipoprotein processing leading to LDL formation.

An increase in calculated small dense low-density lipoprotein cholesterol predicts new onset of hypertension in a Japanese cohort

A disorder of lipid metabolism is involved in cardiovascular diseases including hypertension. A high level of small dense low-density lipoprotein cholesterol (sdLDL-C) is a strong risk factor for atherosclerotic cardiovascular disease. However, the association between sdLDL-C and hypertension has not been fully investigated. We investigated the associations between the development of hypertension during a 10-year period and levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides (TG), and LDL-C and sdLDL-C calculated by using the Sampson equations in 28,990 Japanese subjects who received annual health examinations. After exclusion of subjects with missing data, those with hypertension, and those with TG ≥ 800 mg/dL at baseline, a total of 15,177 subjects (men/women: 9374/5803, mean age: 46 years) were recruited. During the 10-year period, 2379 men (25.4%) and 724 women (12.5%) had new onset of hypertension. Multivariable Cox proportional hazard model analyses showed that levels of HDL-C, non-HDL-C, TG and sdLDL-C, but not levels of TC and LDL-C, were independent risk factors for the development of hypertension after adjustment of age, sex, family history of hypertension, systolic blood pressure, obesity, current smoking habit, alcohol drinking habit, estimated glomerular filtration rate, diagnosis of diabetes mellitus and use of lipid-lowering drugs and that the adjusted risk of sdLDL-C (per 1-standard deviation) was highest (hazard ratio [95% confidence interval: 1.09 [1.05-1.13]). The addition of sdLDL-C to traditional risk factors for hypertension significantly improved the discriminatory capability, which was better than that of other lipid fractions. In conclusion, a high level of calculated sdLDL-C predicts the development of hypertension.

How to Handle Elevated Triglycerides: Life after PROMINENT

PURPOSE OF REVIEW

Hypertriglyceridaemia (HTG) is a common condition characterised by elevated levels of plasma triglycerides (TG), which are transported in the blood mainly by TG-rich lipoproteins (TRL). Elevated TG levels (150-400 mg/dL) are associated with increased cardiovascular risk. Severe HTG (>880 mg/dL) is associated with a risk of acute pancreatitis only. Randomised clinical trials investigating the clinical benefit of TG-lowering drugs in patients with elevated TG levels have provided conflicting results.

RECENT FINDINGS

Elevated TG levels are only one marker of altered lipid/lipoprotein metabolism and indeed reflect altered concentrations of one or more classes or subfractions of TRL, which in turn may have a different association with CV risk. Fibrates, the drugs most commonly used to treat HTG, provide cardiovascular benefits to only a specific subgroup of patients. The lack of clinical benefit from pemafibrate has emphasised the concept that lowering TG levels is not sufficient to reduce the CV risk unless it is accompanied by a reduction in the number of circulating atherogenic lipoproteins, which can be assessed by determining apolipoprotein B levels. Treatment with omega-3 fatty acids was also ineffective in reducing CV risk, with the exception of icosapent ethyl, which, however, appears to have beneficial effects beyond lipids. New drugs are currently being developed that aim to lower TG levels by targeting apolipoprotein C-III or angiopoietin-like-3, both of which are involved in the metabolism of TGs. TG reduction can be achieved by various drugs, but most of them are ineffective in reducing CV risk. The results of outcome studies on new TG-lowering drugs will clarify whether lowering apoB levels is critical to achieve clinical benefit.

Prospective randomized comparative study of the effect of pemafibrate add-on or double statin dose on small dense low-density lipoprotein-cholesterol in patients with type 2 diabetes and hypertriglyceridemia on statin therapy

AIMS/INTRODUCTION

Small dense low-density lipoprotein (sdLDL) is a more potent atherogenic lipoprotein than LDL. As sdLDL-cholesterol (C) levels are determined by triglyceride and LDL-C levels, pemafibrate and statins can reduce sdLDL-C levels. However, it remains unclear whether adding pemafibrate or increasing statin doses would more effectively reduce sdLDL-C levels in patients receiving statin therapy.

MATERIALS AND METHODS

A total of 97 patients with type 2 diabetes and hypertriglyceridemia who were treated with statins were randomly assigned to the pemafibrate 0.2 mg/day addition or statin dose doubled, and followed for 12 weeks. sdLDL-C was measured by our established homogenous assay.

RESULTS

The percentage and absolute reductions of sdLDL-C levels were significantly greater in the pemafibrate add-on group than the statin doubling group (-32.8 vs -8.1%; -16 vs -3 mg/dL, respectively). Triglyceride levels were reduced only in the pemafibrate add-on group (-44%), and LDL-C levels were reduced only in the statin doubling group (-8%), whereas levels of non-high-density lipoprotein-C and apolipoprotein B were similarly decreased (7-9%) in both groups. The absolute reductions of sdLDL-C levels were closely associated with decreased triglyceride, LDL-C, non-high-density lipoprotein-C and apolipoprotein B. In the subgroup analysis, the effect of pemafibrate add-on on sdLDL-C reductions was observed irrespective of baseline lipid parameters or statin type. No serious adverse effects were observed in both groups.

CONCLUSIONS

In patients with type 2 diabetes and hypertriglyceridemia, the addition of pemafibrate to a statin is superior to doubling a statin in reducing sdLDL-C without increasing adverse effects.

Association of atherogenic index of plasma with early neurological deterioration in patients with acute ischemic stroke

PURPOSE

To explore the correlation between Atherogenic Index of Plasma (AIP) and early neurological deterioration (END) in patients with acute ischemic stroke (AIS).

METHODS

A retrospective analysis of 334 patients diagnosed with AIS between January 2021 and May 2023 at the Affiliated Huai'an Hospital of Xuzhou Medical University. Patients were divided into END and non-END groups based on changes in National Institutes of Health Stroke Scale scores (NIHSS) within 7 days of admission, and the differences in the indicators between the two groups were examined using univariate analysis. The patients were then divided into three groups based on the tertile of the AIP (T1: AIP≤ -0.01; T2: 0 ≤AIP≤0.16; AIP≥0.17), and logistic regression analysis was used to examine the association between the AIP and END. Finally, the predictive ability of the AIP was evaluated using the receiver operating characteristic (ROC) curve.

RESULTS

A total of 334 patients were included, of which 64 (19.20%) had END. The results of the analysis showed that the AIP was significantly higher in the END group compared to the non-END group. Multivariable logistic regression analysis showed that higher AIP was associated with END in AIS patients (OR=3.259, 95%CI, 1.490-7.125, P = 0.003), especially in large-artery atherosclerosis (LAA) subtype (OR=4.240, 95%CI,1.30-13.87, P = 0.017). ROC analysis revealed that the best predictive cutoff value of AIP was 0.115, and the area under the ROC curves for AIP was 0.681(0.604-0.758).

CONCLUSION

Our study uncovered that higher AIP levels were associated with END development in AIS patients.

Association of Lipoprotein Subfractions With Presence and Severity of Coronary Artery Disease in Patients Referred for Coronary Angiography

Lipoprotein subfractions (LS) can be used for better risk stratification in subjects deemed not at high risk for coronary artery disease (CAD). In this study, we evaluated the correlation between LS with CAD presence and severity. This is a prospective case-control study of 157 patients referred for coronary angiography who were not on lipid-lowering therapy and had LS measured by nuclear magnetic resonance spectroscopy. Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) scores were calculated to estimate CAD severity. Univariate and multivariable regression analysis was performed to determine correlation of LS with CAD presence and severity and acute coronary syndrome (ACS). There was significant association of certain LS (positive for total low-density lipoprotein particle [LDL-P], small LDL-P and apolipoprotein B, negative for large high-density lipoprotein particle [HDL-P] and apolipoprotein A1 [ApoA1]) with the presence of obstructive CAD and CAD severity. Small LDL-P and HDL-P were still predictive for obstructive CAD after adjusting for traditional risk factors, 10-year atherosclerotic cardiovascular disease risk score and in those with low-density lipoprotein cholesterol <100 mg/100 ml. Total LDL-P and ApoA1 were predictive of CAD severity on multivariable analysis. Higher small LDL-P and lower large HDL-P were associated with ACS presence, although only large HDL-P had a significant inverse correlation with ACS on adjusted analysis (odds ratio 0.74 95% confidence interval 0.58, 0.95) In conclusion, in our cohort of patients referred for coronary angiography, total LDL-P, small LDL-P, and apolipoprotein B had significant direct correlation, and large HDL-P and ApoA1 had significant inverse correlation with obstructive CAD and CAD severity.

Accuracy of Small Dense Low-density Lipoprotein-cholesterol Concentration Estimated via Sampson's Equation in Healthy Subjects and Patients with Diabetes

AIM

Sampson et al. proposed a method to calculate small dense low-density lipoprotein-cholesterol (sdLDL-C) concentrations using common lipid measurements, but its accuracy remains unresolved. We examined the difference between Sampson's equation and direct measurement in patients with diabetes.

METHODS

sdLDL-C was measured directly by our established homogeneous assay and estimated by Sampson's equation in patients with diabetes (n=1542) and healthy control subjects (n=673). Large-buoyant (lb)LDL-C was estimated using triglycerides and LDL-C, and sdLDL-C was obtained by subtracting lbLDL-C from LDL-C. The effect of fasting/nonfasting state or lipid-lowering drug therapy on sdLDL-C values was also examined in 30 and 43 patients with diabetes, respectively.

RESULTS

The coefficient of determination (R2) between calculated sdLDL-C and direct measurement was 0.73 and 0.61 for healthy controls and patients with diabetes, respectively. The R2 between calculated sdLDL-C and nonHDL-C or apolipoprotein B was 0.64 and 0.65, respectively. Calculated sdLDL-C was 4-5 mg/dl or 17%-18% higher than the direct measurement. The lower the plasma lipids, especially sdLDL-C, the greater the dissociation between the two methods. Sampson sdLDL-C was also found to give a positive bias when calculated for the nonfasting samples. Statins and pemafibrate significantly reduced sdLDL-C, but their therapeutic effect was underestimated by 5 mg/dl (24%) via Sampson's equation.

CONCLUSIONS

The correlation between Sampson's equation and direct measurements of sdLDL-C was reduced in patients with diabetes. Furthermore, the correlations with nonHDL-C and apolipoprotein B were even higher than those with direct sdLDL-C. The accuracy of Sampson's equation decreased with lower sdLDL-C concentrations and was also influenced by diet.

Hypertriglyceridemia contributes significantly to high prevalence of small dense LDL-cholesterol in patients with type 2 diabetes, even when LDL-C targets are achieved

Background

Small-dense (sd)LDL-cholesterol (C) is a potent risk factor for atherosclerotic cardiovascular disease (ASCVD) beyond LDL-C, and 35 mg/dL has been proposed as a cut-off value for high-sdLDL-C. sdLDL-C levels are strongly regulated by triglycerides (TG) and LDL-C levels. LDL-C has detailed targets for the prevention of ASCVD, while TG is only defined as abnormal at  ≥ 150 mg/dL. We investigated the effect of hypertriglyceridemia on the prevalence of high-sdLDL-C in patients with type 2 diabetes and explored the optimal TG levels that would suppress high-sdLDL-C.

Methods

Fasting plasma was obtained from 1569 patients with type 2 diabetes who were enrolled in the regional cohort study. sdLDL-C concentrations were measured by the homogeneous assay established by us. High-sdLDL-C was defined as ≤ 35 mg/dL according to the Hisayama Study. Hypertriglyceridemia was defined as ≥ 150 mg/dL.

Results

All lipid parameters except HDL-C were higher in the high-sdLDL-C group than in the normal-sdLDL-C group. The receiver operating characteristic (ROC) curves revealed that high sdLDL-C was identified sensitively by TG and LDL-C, with cut-off values of 115 mg/dL for TG and 110 mg/dL for LDL-C. The presence of hypertriglyceridemia increased the prevalence of high-sdLDL-C sixfold more than the normotriglyceridemic counterpart, regardless of statin use. This substantial influence of hypertriglyceridemia was found even within the control target of LDL-C levels (70-120 mg/dL) for diabetic subjects.

Conclusions

The TG cut-off for high-sdLDL-C was well below 150 mg/dL in a diabetic population. Amelioration of hypertriglyceridemia is needed even when LDL-C targets for diabetes are achieved.

Small Dense LDL Level and LDL/HDL Distribution in Acute Coronary Syndrome Patients

This study aimed to determine the size and distribution of LDL and HDL particles in North African acute coronary syndrome (ACS) patients and to compare the level of small dense LDL (sdLDL) to other markers used in cardiovascular risk prediction.

METHODS

A total of 205 ACS patients and 100 healthy control subjects were enrolled. LDL particle size and LDL and HDL subclass distributions were measured using Quantimetric Lipoprint^® linear polyacrylamide gel electrophoresis. Lipid ratios (total cholesterol, LDL cholesterol, non-HDL cholesterol, and HDL cholesterol) were determined to calculate the atherogenic index of plasma (AIP), the atherogenic coefficient (AC), Castelli's Risk-I (CR-I), and Castelli's Risk-II (CR-II). Receiver operating characteristic (ROC) curve analyses and area under the curve (AUC) were used to assess the predictive value of sdLDL as a marker for cardiovascular disease.

RESULTS

The ACS patients, compared to the healthy control subjects, displayed an alteration of LDL particle distribution, with a significant increase in sdLDL serum concentrations (0.303 ± 0.478 mmol/L vs. 0.0225 ± 0.043 mmol/L, respectively, p < 0.001). The sdLDL levels had a high discrimination accuracy [AUC = 0.847 ± 0.0353 (95% CI 0.778 to 0.916, p < 0.0001)]. The best predictive cutoff value of ACS determined with the maximum Youden index (J) [(sensitivity + specificity) - 1 = 0.60] was 0.038 mmol/L. A Spearman correlation analysis showed that sdLDL levels were moderately but significantly and positively correlated with AC and CR-I (r = 0.37, p < 0.001) and weakly but significantly correlated with PAI and CR-II; r = 0.32 (p < 0.001) and r = 0.30 (p < 0.008), respectively. The subclass distribution of HDL particles from ACS patients was also altered, with a decrease in large HDL particles and an increase in small HDL particles compared to HDL from healthy control subjects.

CONCLUSION

Due to their high atherogenicity, sdLDL levels could be used as a valuable marker for the prediction cardiovascular events.

Prognostic Implication of Small Dense LDL-Cholesterol Levels following Acute Coronary Syndrome

Background and Objectives: Small dense LDL cholesterol is a strong risk factor for atherosclerosis. However, few studies have investigated the impacts of this specific lipid profile on the incident risk of adverse cardiovascular events in patients with acute coronary syndrome. Materials and Methods: Patients with acute coronary syndrome, who underwent revascularization, were included and followed for 2 years. The levels of small dense LDL cholesterol were measured at index discharge (day 0) in the setting of newly administered therapies for secondary prevention, including aspirin and statins, during the index hospitalization. The prognostic impact of small dense LDL-cholesterol levels on the risk of a primary composite endpoint, including cardiac death, non-fatal myocardial infarction, unstable angina pectoris, stroke, and heart failure, was investigated. Results: In total, 46 patients (median 75 (59, 83) years old, 63% men) were included. Median small dense LDL cholesterol was 19.4 (13.5, 23.8) mg/dL at index discharge. All patients initiated statin treatment before the index discharge, with a median LDL-cholesterol level of 77 (64, 109) mg/dL. Small dense LDL-cholesterol level was independently associated with an incremental risk for the primary endpoint (p < 0.05 by adjusting for several potential risk factors, including LDL cholesterol) with a cutoff of 32.6 mg/dL. Conclusions: Small dense LDL-cholesterol level was a significant risk factor for cardiovascular events following presentations of acute coronary syndrome.

Circadian Rhythm of Subspecies of Low-Density Lipoprotein-Cholesterol and High-Density Lipoprotein-Cholesterol in Healthy Subjects and Patients with Type 2 Diabetes

AIMS

We established automated assay kits for quantifying small dense low-density lipoprotein (sdLDL)-cholesterol (C), LDL-triglyceride (TG), and high-density lipoprotein (HDL)3-C, and apolipoprotein (apo)E-rich HDL-C, and these have been recognized as sensitive biomarkers for predicting coronary artery disease. We investigated the circadian rhythms of these novel lipids to determine if fasting is required to determine basal levels.

METHODS

Forty-eight inpatients with type 2 diabetes and 19 healthy volunteers were studied. Blood samples were collected at seven time points, which were obtained after an overnight fast, before and 2 h after each meal, and before the next breakfast. sdLDL-C, LDL-TG, remnant-like particle (RLP)-C, TG-rich lipoprotein (TRL-C), HDL3-C, and apoE-rich HDL-C were measured by the homogeneous methods. NonHDL-C, large buoyant (lb)LDL-C and HDL2-C were calculated by subtracting sdLDL-C from LDL-C or HDL3-C from HDL-C, respectively.

RESULTS

Serum TG levels were significantly increased after meals in both healthy participants and patients with diabetes. RLP-C and TRL-C were also increased postprandially. LDL-TG, LDL-C, nonHDL-C, HDL2,3-C, and apoE-rich HDL-C did not exhibit significant fluctuation during the day in healthy participants and patients with diabetes. sdLDL-C was slightly increased postprandially in subjects with diabetes (1-2 mg/dl, 3%-9%), though its increase was not significant compared to the baseline (fasting) level. Significant postprandial reduction was observed with LDL-C and lbLDL-C. There was no influence of statin therapy or oral anti-diabetes drugs on the circadian rhythm of LDL-C subspecies.

CONCLUSIONS

Subtle postprandial increase in sdLDL-C is considered a negligible level in general clinical practice. Fasting is not mandatory to measure basal concentrations of LDL and HDL subspecies.

Small dense low-density lipoprotein cholesterol compared to other lipoprotein biomarkers for predicting coronary heart disease among individuals with normal fasting glucose: The Multi-Ethnic Study of Atherosclerosis

Objective

This study compared small dense low-density lipoprotein cholesterol (sdLDL-C) with apolipoprotein B (apo B), and low-density lipoprotein particles (LDL-P) in predicting CHD risk in generally healthy adults with normal fasting glucose (NFG).

Methods

This study was conducted among participants with NFG in the Multi-Ethnic Study of Atherosclerosis (MESA) prospective cohort with measurements of sdLDL-C, LDL-P, and apo B available at baseline (2000-2002) and follow-up CHD data (through 2015) (N = 3,258). Biomarkers were evaluated as quartiles, and in categories using clinically and 75th percentile-defined cut-points. Discordance/concordance of sdLDL-C relative to other biomarkers was calculated using 75th percentile cut-points and linear regression residuals. Associations between individual biomarkers, sdLDL-C discordance and CHD incidence were evaluated using Cox proportional hazards regression.

Results

There were 241 incident CHD events in this population through 2015. Higher sdLDL-C, apo B, LDL-P were similarly associated with increased CHD in individuals with NFG. Discordance of sdLDL-C with apo B or LDL-P by 75th percentiles was not significantly associated with CHD. Residuals discordantly higher/lower sdLDL-C relative to apo B (discordant high HR=1.26, 95% CI: 0.89, 1.78; discordant low HR=0.94, 95% CI: 0.68, 1.29) and LDL-P (discordant high HR=1.25, 95% CI: 0.88, 1.75; discordant low HR=0.84, 95% CI:0.60, 1.16), compared to those with concordant measures, had non-statistically significant higher/lower risk of CHD.

Conclusions

Results suggest sdLDL-C, apo B and LDL-P are generally comparable for predicting CHD events in normoglycemic individuals. Larger studies are needed to confirm findings and to investigate whether measurement of sdLDL-C may be beneficial to evaluate as an additional risk-enhancing factor.

Development of Machine Learning Tools for Predicting Coronary Artery Disease in the Chinese Population

Purpose. Coronary artery disease (CAD) is one of the major cardiovascular diseases and the leading cause of death globally. Blood lipid profile is associated with CAD early risk. Therefore, we aim to establish machine learning models utilizing blood lipid profile to predict CAD risk. Methods. In this study, 193 non-CAD controls and 2001 newly-diagnosed CAD patients (1647 CAD patients who received lipid-lowering therapy and 354 who did not) were recruited. Clinical data and the result of routine blood lipids tests were collected. Moreover, low-density lipoprotein cholesterol (LDL-C) subfractions (LDLC-1 to LDLC-7) were classified and quantified using the Lipoprint system. Six predictive models (k-nearest neighbor classifier (KNN), logistic regression (LR), support vector machine (SVM), decision tree (DT), multilayer perceptron (MLP), and extreme gradient boosting (XGBoost)) were established and evaluated by the confusion matrix, area under the receiver operating characteristic (ROC) curve (AUC), recall (sensitivity), accuracy, precision, and F1 score. The selected features were analyzed and ranked. Results. While predicting the CAD development risk of the CAD patients without lipid-lowering therapy in the test set, all models obtained AUC values above 0.94, and the accuracy, precision, recall, and F1 score were above 0.84, 0.85, 0.92, and 0.88, respectively. While predicting the CAD development risk of all CAD patients in the test set, all models obtained AUC values above 0.91, and the accuracy, precision, recall, and F1 score were above 0.87, 0.94, 0.87, and 0.92, respectively. Importantly, small dense LDL-C (sdLDL-C) and LDLC-4 play pivotal roles in predicting CAD risk. Conclusions. In the present study, machine learning tools combining both clinical data and blood lipid profile showed excellent overall predictive power. It suggests that machine learning tools are suitable for predicting the risk of CAD development in the near future.

Approach to risk stratification of atherosclerotic cardiovascular disease: Use of biomarkers and imaging in a Canadian context

OBJECTIVE

To outline the 2021 Canadian Cardiovascular Society (CCS) dyslipidemia guidelines and to present the current approaches to cardiovascular risk stratification, including the incorporation of biomarkers and imaging tests.

SOURCES OF INFORMATION

Current guidelines were reviewed and an Ovid MEDLINE literature search was performed.

MAIN MESSAGE

Cardiovascular disease (CVD) is the leading cause of global mortality, with ischemic heart disease contributing to nearly half of these deaths. Risk stratification is undertaken to identify patients who would benefit from primary prevention for atherosclerotic CVD (ASCVD), but commonly used methods for risk stratification are imperfect. The CCS guidelines endorse that the presence of risk modifiers (family history of premature ASCVD, high-sensitivity C-reactive protein level ≥2.0 mg/L, lipoprotein[a] level ≥500 mg/L [≥50 mg/dL], or coronary artery calcium >0) supports the use of statin therapy in those at intermediate risk (Framingham risk score 10% to 19.9%) who do not otherwise meet the recommendations for statin use. The CCS guidelines recommend statin therapy in patients at intermediate risk when cholesterol levels are elevated (low-density lipoprotein cholesterol level ≥3.5 mmol/L, non-high-density lipoprotein cholesterol level ≥4.2 mmol/L, or apolipoprotein B level ≥1.05 g/L). In addition, statin therapy should be considered for patients at low risk (Framingham risk score 5% to 9.9%) with elevated cholesterol levels, especially if risk modifiers are present. When cholesterol levels are not elevated, evidence still favours the use of statins in intermediate-risk patients when risk modifiers are present and in men 50 years and older and women 60 years and older with 1 additional risk factor.

CONCLUSION

Biomarkers and imaging tests have the potential to improve ASCVD risk stratification by reclassifying any patient whose risk has been inaccurately estimated by traditional methods. Recently published guidelines by the CCS suggest the use of biomarkers and imaging in certain patient groups.

Approche de la stratification du risque de maladies cardiovasculaires athéroscléreuses

Objectif

Donner un aperçu des lignes directrices de la Société canadienne de cardiologie (SCC) de 2021 sur la dyslipidémie et présenter les approches actuelles relatives à la stratification du risque cardiovasculaire, y compris l’intégration de la mesure des biomarqueurs et de l’imagerie.

Sources de l’information

Les lignes directrices actuelles ont été passées en revue, et une recherche documentaire dans Ovid MEDLINE a été effectuée.

Message principal

Les maladies cardiovasculaires (MCV) sont la principale cause de mortalité dans le monde, et les cardiopathies ischémiques contribuent à près de la moitié de ces décès. Une stratification du risque est entreprise pour identifier les patients susceptibles de bénéficier d’une prévention primaire de la MCV athéroscléreuse (MCVAS), mais les méthodes habituellement utilisées pour la stratification du risque sont imparfaites. Les lignes directrices de la SCC soutiennent que la présence de modificateurs du risque (antécédents familiaux de MCVAS prématurée, dosage de la protéine C réactive hypersensible ≥2,0 mg/L, dosage de la lipoprotéine [a] ≥500 mg/L [≥50 mg/dL] ou score calcique coronarien >0) justifie le recours à une thérapie aux statines chez les personnes à risque moyen (score de risque de Framingham de 10 à 19,9 %) qui ne sont pas autrement visées par les recommandations en faveur de l’utilisation de statines. Les lignes directrices de la SCC recommandent une thérapie aux statines chez les patients à risque modéré, lorsque leurs taux de cholestérol sont élevés (taux de cholestérol à lipoprotéines de basse densité ≥3,5 mmol/L, taux de cholestérol lié aux lipoprotéines autres que celles de haute densité ≥4,2 mmol/L ou taux d’apolipoprotéines B ≥1,05 g/L). De plus, une thérapie aux statines devrait être envisagée pour les patients à faible risque (score de risque de Framingham de 5 à 9,9 %) dont les taux de cholestérol sont élevés, surtout en présence de modificateurs du risque. Lorsque les taux de cholestérol ne sont pas élevés, des données probantes favorisent quand même le recours aux statines chez les patients à risque modéré lorsque des modificateurs du risque sont présents, de même que chez les hommes de 50 ans et plus et chez les femmes de 60 ans et plus ayant 1 facteur de risque additionnel.

Conclusion

La mesure des biomarqueurs et l’imagerie ont le potentiel d’améliorer la stratification du risque de MCVAS en reclassant les patients dont le risque avait été estimé de manière inexacte par les méthodes traditionnelles. Les lignes directrices récemment publiées par la SCC suggèrent de se servir des biomarqueurs et de l’imagerie chez certains groupes de patients.

The correlation of atherosclerosis and triglyceride glucose index: a secondary analysis of a national cross-sectional study of Japanese

BACKGROUND

Few studies examined the relationship between triglyceride/glucose index (TyG index) and atherosclerosis in Japanese adults. Therefore, this study evaluated their relationship, as measured based on the brachial-ankle pulse wave velocity (baPWV) in Japanese adults.

METHODS

A total of 912 participants was selected from the NAGALA (NAFLD in Gifu Area, Longitudinal Analysis) study conducted from 2004 to 2012. The relationship between the TyG index and baPWV was estimated through a logistic model. Subgroup analyses by sex, age, body mass index (BMI), total cholesterol, low-density lipoprotein cholesterol, estimated glomerular filtration rate (eGFR), and fatty liver was performed. The formula for TyG index was ln (½fasting triglyceride level [mg/dL] × fasting plasma glucose level [mg/dL]).

RESULTS

A linear relationship between TyG and baPWV was discovered after adjusting for underlying confounders. An increased risk of baPWV was observed after adjusting for sex, age, BMI, systolic blood pressure, diastolic blood pressure, high-density lipoprotein cholesterol, fatty liver, eGFR, and TyG as a continuous variable (adjusted odds ratio [adj OR], 1.57; 95% confidence interval [95% CI], 1.14-2.18). Compared with the TyG index in the first tertile, the probabilities of subjects in the third tertile that developed to baPWV were 1.78-fold higher (adj OR 1.78, 95% CI 1.08-2.95: P for trend 0.024). Moreover, stable associations were observed between the TyG index and baPWV in different variables through subgroup analyses.

CONCLUSIONS

The highest tertile (above 8.57) of the TyG index was positively and linearly related to subclinical atherosclerosis in Japanese adults and may be valuable as a predicted marker.

Metabolic Properties of Lowdensity Lipoprotein (LDL) Triglycerides in Patients with Type 2 Diabetes, Comparison with Small Dense LDL-Cholesterol

AIMS

Abnormal compositional changes in low-density lipoprotein (LDL) particles, such as triglyceride (TG) enrichment and size reduction, are common in patients with diabetes. Several cohort studies have demonstrated that LDL-TG and sdLDL-cholesterol (C) are sensitive biomarkers for predicting atherosclerotic cardiovascular diseases beyond LDL-C. Although sdLDL has been extensively studied, little is known about the properties of LDL-TG. We investigated similarities or differences between LDL-TG and sdLDL-C.

METHODS

Fasting plasma was obtained from 1,085 patients with type 2 diabetes who were enrolled in the diabetes regional cohort study (ViNA Cohort). LDL-TG and sdLDL-C concentrations were measured using a homogeneous assay established by us. In a subset of subjects, LDL-TG and sdLDL-C levels were measured postprandially or after treatment with lipid-lowering drugs.

RESULTS

In a quartile analysis, higher LDL-TG quartiles were associated with higher frequency of female and fibrate users, whereas sdLDL-C quartiles were associated with frequency of men, drinking, and metabolic syndrome-related measurements. Higher quartiles of LDL-TG/LDL-C were associated with smoking, drinking, fibrate users, and statin users. LDL-TG was significantly correlated with TG, LDL-C, sdLDL-C, and apolipoprotein (apo) B, with apoB being the primary determinant. LDL-TG correlated to high sensitive C-reactive protein (CRP) independently of other lipids. Mean LDL-TG did not change with fasting/non-fasting. Statin treatment reduced LDL-TG, whereas fibrates increased it, but these drugs reduced sdLDL-C equally.

CONCLUSIONS

LDL-TG levels were more tightly regulated by the number of LDL particles than plasma TG levels were. SdLDL-C was closely associated with metabolic syndrome-related factors, whereas LDL-TG was associated with low-grade systemic inflammation.

Small Dense LDL: Scientific Background, Clinical Relevance, and Recent Evidence Still a Risk Even with ‘Normal’ LDL-C Levels

Residual cardiovascular disease event risk, following statin use and low-density lipoprotein cholesterol (LDL-C) reduction, remains an important and common medical conundrum. Identifying patients with significant residual risk, despite statin drug use, is an unmet clinical need. One pathophysiologic disorder that contributes to residual risk is abnormal distribution in lipoprotein size and density, which is referred to as lipoprotein heterogeneity. Differences in low density lipoprotein (LDL) composition and size have been linked to coronary heart disease (CHD) risk and arteriographic disease progression. The clinical relevance has been investigated in numerous trials since the 1950s. Despite this long history, controversy remains regarding the clinical utility of LDL heterogeneity measurement. Recent clinical trial evidence reinforces the relevance of LDL heterogeneity measurement and the impact on CHD risk prediction and outcomes. The determination of LDL subclass distribution improves CHD risk prediction and guides appropriate treatment.

Reference interval for serum concentration of small dense low-density lipoprotein cholesterol in the healthy Japanese population

BACKGROUND

Small dense low-density lipoprotein a smaller and denser subfraction among whole low density lipoprotein particles is known to be highly atherogenic. The reference interval (RI) is not strictly defined for serum concentration of sdLDL-cholesterol (sdLDL-C) in Japan. The purpose of this study is to set the reference interval for sdLDL-C in healthy subjects.

METHODS

The population of this cross-sectional study was consisted of 40,862 individuals who had annual health checkups, and healthy subjects were extracted based on exclusion criteria such as medical history, social history, and blood sampling test results. Their serum sdLDL-C values were statistically analyzed and the RIs were set in men, premenopausal women, and postmenopausal women separately.

RESULTS

The mean values of serum sdLDL-C in healthy subjects were 23.9 mg/dL in men, 20.0 mg/dL in premenopausal women and 23.7 mg/dL in postmenopausal women, and the RIs were 12.6-45.3 mg/dL in men, 11.4-35.1 mg/dL in premenopausal women and 14.6-38.6 mg/dL in postmenopausal women. Serum sdLDL-C values were significantly higher in men than in women. Besides, sdLDL-C values were significantly higher in postmenopausal women than in premenopausal women. In both genders, sdLDL-C values tended to increase with age.

CONCLUSION

These results suggest that the RIs for sdLDL-C are recommended as follows: 13-45 mg/dL in men, 11-35 mg/dL in premenopausal women, and 15-39 mg/dL in postmenopausal women, respectively. Aside from these RIs, it is also necessary to define clinical cutoff values graded according to individual risk levels for atherosclerotic cardiovascular diseases.

Atherosclerosis Development and Progression: The Role of Atherogenic Small, Dense LDL

Atherosclerosis is responsible for large cardiovascular mortality in many countries globally. It has been shown over the last decades that the reduction of atherosclerotic progression is a critical factor for preventing future cardiovascular events. Low-density lipoproteins (LDL) have been successfully targeted, and their reduction is one of the key preventing measures in patients with atherosclerotic disease. LDL particles are pivotal for the formation and progression of atherosclerotic plaques; yet, they are quite heterogeneous, and smaller, denser LDL species are the most atherogenic. These particles have greater arterial entry and retention, higher susceptibility to oxidation, as well as reduced affinity for the LDL receptor. Increased proportion of small, dense LDL particles is an integral part of the atherogenic lipoprotein phenotype, the most common form of dyslipidemia associated with insulin resistance. Recent data suggest that both genetic and epigenetic factors might induce expression of this specific lipid pattern. In addition, a typical finding of increased small, dense LDL particles was confirmed in different categories of patients with elevated cardiovascular risk. Small, dense LDL is an independent risk factor for cardiovascular diseases, which emphasizes the clinical importance of both the quality and the quantity of LDL. An effective management of atherosclerotic disease should take into account the presence of small, dense LDL in order to prevent cardiovascular complications.

Increased Concentrations of Atherogenic Proteins in Aneurysm Sac Are Associated with Wall Enhancement of Unruptured Intracranial Aneurysm

Current MR-vessel wall imaging (VWI) of unruptured intracranial aneurysms (UIAs) permits the visualization of wall structures. Aneurysm wall enhancement (AWE) was associated with atherosclerotic remodeling of the aneurysm wall accompanied by infiltration of inflammatory cells, potentially contributing to rupture. This study sought to investigate whether the luminal concentrations of atherosclerotic proteins in the aneurysm sac were associated with increased wall enhancement of UIAs in VWI. Subjects undergoing endovascular treatment for UIAs were prospectively recruited. All subjects underwent evaluation using 3 T-MRI including pre/post contrast VWI of the UIAs. Blood samples were collected from the aneurysm sac and the parent artery during endovascular procedures. The presence of AWE was correlated with the delta difference in concentration between the aneurysm sac and the parent artery for each atherosclerotic protein. A total of consecutive 45 patients with 50 UIAs were enrolled. The delta differences of anti-oxidized low-density lipoprotein (LDL) antibody, small dense LDL, and lipoprotein(a) [Lp(a)] were significantly higher in UIAs with AWE compared with those without AWE (767.6 ± 1957.1 versus - 442.4 ± 1676.3 mIU/mL, p = 0.02, 114.8 ± 397.7 versus - 518.5 ± 1344.4 μg/mL, p = 0.04, and - 5.6 ± 11.3 versus - 28.7 ± 38.5 μg/mL, p = 0.01, respectively). In multivariate logistic regression analysis, the delta Lp(a) was significantly associated with AWE (p = 0.04). Increased concentrations of atherogenic proteins in the aneurysm sac were significantly associated with wall enhancement of UIAs. Future studies examining the effect of medications for atherosclerosis on the atherogenic proteins within the aneurysm sac and hence the wall enhancement are warranted.

Small Dense Low-Density Lipoprotein Cholesterol and Cardiovascular Risk in Statin-Treated Patients with Coronary Artery Disease

Aim: We investigated the relationship between small dense low-density cholesterol (sdLDL-C) and risk of major adverse cardiovascular events (MACE) in patients treated with high- or low-dose statin therapy.

Methods: This was a prospective case-cohort study within the Randomized Evaluation of Aggressive or Moderate Lipid-Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) study, a randomized trial of high- or low-dose (4 or 1 mg/d pitavastatin, respectively) statin therapy, in patients with stable coronary artery disease (CAD). Serum sdLDL-C was determined using an automated homogenous assay at baseline (randomization after a rule-in period, ＞1 month with 1 mg/d pitavastatin) and 6 months after randomization, in 497 MACE cases, and 1543 participants randomly selected from the REAL-CAD study population.

Results: High-dose pitavastatin reduced sdLDL-C by 20% than low-dose pitavastatin (p for interaction ＜0.001). Among patients receiving low-dose pitavastatin, baseline sdLDL-C demonstrated higher MACE risk independent of LDL-C (hazard ratio [95% confidence interval], 4th versus 1st quartile, 1.67 [1.04–2.68];p for trend=0.034). High-dose (versus low-dose) pitavastatin reduced MACE risk by 46% in patients in the highest baseline sdLDL-C quartile (＞34.3 mg/dL; 0.54 [0.36–0.81];p=0.003), but increased relative risk by 40% in patients with 1st quartile (≤ 19.5 mg/dL; 1.40 [0.94–2.09];p=0.099) and did not alter risk in those in 2nd and 3rd quartiles (p for interaction=0.002).

Conclusions: These findings associate sdLDL-C and cardiovascular risk, independent of LDL-C, in statin-treated CAD patients. Notably, high-dose statin therapy reduces this risk in those with the highest baseline sdLDL-C.

Association of serum 25-Hydroxy Vitamin D level with lipid, lipoprotein, and apolipoprotein level

Introduction 25-Hydroxy vitamin D (Vit D3) deficiency was found to be associated with vascular dysfunction, arterial stiffening, extent of coronary artery disease and cardiovascular mortality. Previous studies showed positive correlation between serum Vit D3 and HDL-C and negative correlation between Vit D3 and LDL-C. The aim of this study is to investigate more details about the possible association of serum Vit D3 level with lipid, lipoprotein and apolipoprotein level. Methods Totally 101 patients were included in this study and Vit D3, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), High-density lipoprotein cholesterol (HDL-C), total triglyceride (TG), non-high-density lipoprotein cholesterol (Non-HDL-C), low-density lipoprotein particle (LDL-P), small dense low-density lipoprotein particle (sLDL-P), small dense low-density lipoprotein cholesterol (sdLDL-C), High-density lipoprotein cholesterol particles (HDL-P), High-density lipoprotein 2-cholesterol (HDL2-C), Apolipoprotein B(ApoB), Apolipoprotein A1 (Apo A1) and Apolipoprotein B/Apolipoprotein A1 ratio (ApoB/A ratio) were tested. Results Our results show that patients with Vit D3 deficiency (Vit D3 < 30 ng/ml) have significantly higher level of LDL-C, TG, Non-HDL-C, LDL-P, sLDL-P, sdLDL-C, ApoB and ApoB/A ratio compare with patients have normal Vit D3 level (Vit D3 > 30 ng/ml). Patients with normal Vit D3 level have significantly higher level of HDL-C and HDL2-C. Correlation study shows that Vit D3 level is negative correlated with TC, LDL-C, TG, Non-HDL-C, LDL-P, sLDL-P, sdLDL-C, ApoB and ApoB/A ratio and positive correlated with HDL2-C level. Conclusion Our results show that Vit D3 deficiency links to an increased risk for dyslipidemia and that may be the reason that patients with vitamin D deficiency tend to have higher risk of coronary artery disease.

Dyslipidemia in diabetic kidney disease classified by proteinuria and renal dysfunction: A cross-sectional study from a regional diabetes cohort

AIMS/INTRODUCTION

Diabetic kidney disease (DKD) exacerbates dyslipidemia and increases the incidence of atherosclerotic cardiovascular disease. DKD is a concept that includes typical diabetic nephropathy and an atypical phenotype without proteinuria. We investigated dyslipidemia in different DKD phenotypes that have not been fully studied.

MATERIALS AND METHODS

Fasting plasma was obtained from 1,073 diabetes patients enrolled in the regional diabetes cohort (ViNA cohort). Non-proteinuric and proteinuric DKD were defined as an estimated glomerular filtration rate <60 mL/min/1.73 m² in the absence or presence of urinary albumin-to-creatinine ratio >300 mg/g. Novel lipid risk factors, low-density lipoprotein (LDL) triglyceride (TG) and small dense LDL cholesterol were measured using our established homologous assay.

RESULTS

The proportion of atherosclerotic cardiovascular disease patients was higher in non-proteinuric DKD and even higher in proteinuric DKD than in non-DKD. Increased estimated glomerular filtration rate grade and albuminuric stage were independently correlated with higher TG, TG-rich lipoprotein cholesterol and apolipoprotein CIII. Therefore, proteinuric DKD had the highest of these levels. Small dense LDL cholesterol and LDL-TG were higher in the proteinuria without renal dysfunction group in the lipid-lowering drug-free subset. Lipoprotein(a) was higher in DKD regardless of proteinuria.

CONCLUSIONS

Proteinuria was associated with an atherogenic subspecies of LDL, whereas renal dysfunction was associated with increased lipoprotein(a). Proteinuria and renal dysfunction independently exacerbated TG-rich lipoprotein-related dyslipidemia. This is in good agreement with the results of large-scale clinical studies in which proteinuria and renal dysfunction synergistically increased the risk of atherosclerotic cardiovascular disease in populations with diabetes.

Efficacy and Safety of Xue-Fu-Zhu-Yu Decoction for Patients with Coronary Heart Disease: A Systematic Review and Meta-Analysis

Objective

To systematically evaluate the efficacy and safety of XFZYD for coronary heart disease (CHD).

Methods

A comprehensive literature search of randomized controlled trials using XFZYD for CHD was conducted in 10 electronic databases from their establishment to December 20, 2020. The researchers screened the relevant trials in NoteExpress, extracted the data in duplicate independently, assessed the risk of bias in the trials using the Cochrane collaboration tool, and then used Rev Man 5.3 for data analysis.

Results

30 trials with 3126 participants were included for meta-analysis. The results showed that the clinical effects of XFZYD and its combination with chemical drugs (CD) were 1.13 (RR; 1.13; 95% CI, 1.03 to 1.24) and 1.26 (RR; 1.26; 95% CI, 1.20 to 1.32) times those of CD, respectively. And, it could also improve electrocardiogram effect, which was 1.63 (RR; 1.63; 95% CI, 1.04 to 2.53) times that of CD. XFZYD could not only decrease duration of angina pectoris and improve vascular endothelial function but also obviously reduce the TCM syndrome score. When used in combination with CD, it could also lower AF, correct the dyslipidemia, and reduce the blood viscosity.

Conclusion

These results demonstrated that XFZYD had great advantages in treating CHD with no obvious adverse reactions. Therefore, it is believed that XFZYD is more suitable for CHD patients with clinical indicators of dyslipidemia, high blood viscosity, or vascular endothelial dysfunction. This study is the first systematic review and meta-analysis with some unique ways, including its comprehensiveness, large-scale search, the novelty of findings, and transparent approach.

Main differences between two highly effective lipid-lowering therapies in subclasses of lipoproteins in patients with acute myocardial infarction

Background

Large observational studies have shown that small, dense LDL subfractions are related to atherosclerotic cardiovascular disease. This study assessed the effects of two highly effective lipid-lowering therapies in the atherogenic subclasses of lipoproteins in subjects with ST-segment elevation myocardial infarction (STEMI).

Methods

Patients of both sexes admitted with their first myocardial infarction and submitted to pharmacoinvasive strategy (N = 101) were included and randomized using a central computerized system to receive a daily dose of simvastatin 40 mg plus ezetimibe 10 mg or rosuvastatin 20 mg for 30 days. Intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) subfractions were analysed by polyacrylamide gel electrophoresis (Lipoprint System) on the first (D1) and 30th days (D30) of lipid-lowering therapy. Changes in LDL and IDL subfractions between D1 and D30 were compared between the lipid-lowering therapies (Mann-Whitney U test).

Results

The classic lipid profile was similar in both therapy arms at D1 and D30. At D30, the achievement of lipid goals was comparable between lipid-lowering therapies. Cholesterol content in atherogenic subclasses of LDL (p = 0.043) and IDL (p = 0.047) decreased more efficiently with simvastatin plus ezetimibe than with rosuvastatin.

Conclusions

Lipid-lowering therapy with simvastatin plus ezetimibe was associated with a better pattern of lipoprotein subfractions than rosuvastatin monotherapy. This finding was noted despite similar effects in the classic lipid profile and may contribute to residual cardiovascular risk.

Trial registration

ClinicalTrials.gov, NCT02428374, registered on 28/09/2014.

Relationship between small dense low-density lipoprotein cholesterol with carotid plaque in Chinese individuals with abnormal carotid artery intima-media thickness

Aim

To investigate the relationship of small dense low-density lipoprotein cholesterol (sdLDL-C) to carotid artery intima-media thickness (CA-IMT) and carotid plaque (CAP) in Chinese general population, and to evaluate whether sdLDL-C could be an independent risk factor for individuals with subclinical atherosclerosis.

Methods

A total of 729 subjects were randomly collected from consecutive individuals from April 2019 to April 2020 for an annual health checkup. CA-IMT > 1.0 mm was defined as abnormal IMT. Plaque stability was measured by ultrasound examination based on the property of the echo. And sdLDL-C levels were detected by LipoPrint system. Multivariate logistic regression analysis was performed to identify factors associated with CA-IMT and carotid plaque.

Results

The abnormal IMT group had significantly higher sdLDL-C levels than control group (p < 0.0001). And sdLDL-C levels were significantly positively correlated with IMT value (r = 0.1396, p = 0.0021) and presence of carotid plaque (r = 0.14, p = 0.002) in the subjects with abnormal IMT. In addition, subjects with higher levels of sdLDL-C (r = 0.11, p = 0.035) tended to have unstable CAP. After adjustment for age, gender and blood glucose, sdLDL-C level was an independent risk factor of the presence of CAP (OR = 1.59, 95% CI: 1.02–1.83, p = 0.034) in subjects with abnormal IMT.

Conclusion

SdLDL-C is an independent risk factor of the occurrence of CAP in the Chinese subjects with abnormal IMT. Our findings provide supporting evidence that sdLDL-C might be an alternative way to predict CVD in early stage.

Association between Vitamin D Deficiency and High Serum Levels of Small Dense LDL in Middle-Aged Adults

Recent studies suggested a potential link between vitamin D deficiency and cardiovascular risk factors, including dyslipidemia. This study aimed to investigate the association between serum 25(OH)D levels and atherogenic lipid profiles, specifically, that of small dense low-density lipoprotein-cholesterol (sdLDL-C). From 2009 to 2011, a total of 715 individuals aged 35–65 without evident cardiovascular disease (CVD) were enrolled. Their levels of serum 25(OH)D and lipid profiles were measured. Vitamin D deficiency was found to be more common in females, smokers, alcohol drinkers, individuals at a younger age, and those who do not exercise regularly. The analysis of lipid profiles revealed that high sdLDL-C levels were associated with low serum vitamin D levels and were more common among cigarette smokers; alcohol drinkers; individuals with hypertension; individuals with high BMI; and those with high levels of fasting blood glucose, triglycerides, LDL-C, and VLDL-C. The use of multivariate logistic regression verified a strong negative correlation between low vitamin D status (serum 25(OH)D < 15 ng/mL) and the three identified biomarkers of atherogenic dyslipidemia: high serum levels of sdLDL-C, triglycerides, and VLDL-C. This study provides strong evidence that vitamin D deficiency is associated with atherogenic dyslipidemia, and in particular, high sdLDL-C levels in middle-aged adults without CVD.

Relationship between small dense low density lipoprotein and cardiovascular events in patients with acute coronary syndrome undergoing percutaneous coronary intervention

BACKGROUND

Residual risk remained significant despite effective low density lipoprotein cholesterol (LDL-C) lowering treatment. Small dense low density lipoprotein cholesterol (sdLDL-C) as part of LDL-C has been found to be predictor of coronary heart disease (CHD) and cardiovascular (CV) events in patients with stable CHD independently of LDL-C. However, to date, few studies have explored the role of sdLDL-C in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI). Accordingly, this study aimed to evaluate the association of sdLDL-C with CV events in patients with ACS undergoing PCI.

METHODS

Patients hospitalized with ACS undergoing PCI were enrolled and followed up for 18 months. The risk of sdLDL-C for CV events was compared according to sdLDL-C quartiles. The primary outcome was major cardiovascular and cerebrovascular adverse events (MACCE), which was the composite of all cause of death, nonfatal myocardial infarction (MI), nonfatal stroke or unplanned repeat revascularization. A Cox proportional hazards regression model was performed to estimate the risk of CV events. Subgroup analysis according to diabetes status and LDL-C were performed separately for MACCE.

RESULTS

A total of 6092 patients were included in the analysis (age: 60.2 ± 10.13 years, male: 75.3%, BMI: 25.9 ± 3.33 kg/m², dyslipidemia: 74.1% and diabetes: 44.5%). During 18 months of follow-up, 320 (5.2%) incident CV events occurred. Compared to the lowest sdLDL-C quartile group, patients in the highest quartile had a greater risk of CV events after multivariable adjustment (HR 1.92; 95% CI 1.37-2.70). In addition, it was mainly due to the increase of unplanned repeat revascularization. In the subgroup analyses, significant association was observed regardless of level of LDL-C and diabetes status.

CONCLUSIONS

Patients with elevated sdLDL-C have a higher risk of CV events in Chinese patients with ACS undergoing PCI, providing additional value for better risk assessment.

Physicochemical Properties of Lipoproteins Assessed by Nuclear Magnetic Resonance as a Predictor of Premature Cardiovascular Disease. PRESARV-SEA Study

Some lipoprotein disorders related to the residual risk of premature cardiovascular disease (PCVD) are not detected by the conventional lipid profile. In this case-control study, the predictive power of PCVD of serum sdLDL-C, measured using a lipoprotein precipitation method, and of the physicochemical properties of serum lipoproteins, analyzed by nuclear magnetic resonance (NMR) techniques, were evaluated. We studied a group of patients with a first PCVD event (n = 125) and a group of control subjects (n = 190). Conventional lipid profile, the size and number of Very Low Density Lipoproteins (VLDL), Low Density Lipoproteins (LDL), High Density Lipoproteins (HDL) particles, and the number of particles of their subclasses (large, medium, and small) were measured. Compared to controls, PCVD patients had lower concentrations of all LDL particles, and smaller and larger diameter of LDL and HDL particles, respectively. PCVD patients also showed higher concentrations of small dense LDL-cholesterol (sdLDL), and triglycerides (Tg) in LDL and HDL particles (HDL-Tg), and higher concentrations of large VLDL particles. Multivariate logistic regression showed that sdLDL-C, HDL-Tg, and large concentrations of LDL particles were the most powerful predictors of PCVD. A strong relationship was observed between increased HDL-Tg concentrations and PCVD. This study demonstrates that beyond the conventional lipid profile, PCVD patients have other atherogenic lipoprotein alterations that are detected by magnetic resonance imaging (MRI) analysis.

Small Dense Low-Density Lipoprotein Cholesterol: A Residual Risk for Rapid Progression of Non-Culprit Coronary Lesion in Patients with Acute Coronary Syndrome

Aim: This study investigated whether the small dense low-density lipoprotein cholesterol (sd-LDL-c) level is associated with the rapid progression (RP) of non-culprit coronary artery lesions and cardiovascular events (CE) after acute coronary syndrome (ACS).

Methods: In 142 consecutive patients with ACS who underwent primary percutaneous coronary intervention for the culprit lesion, the sd-LDL-c level was measured using a direct homogeneous assay on admission for ACS and at the 10-month follow-up coronary angiography. RP was defined as a progression of any pre-existing coronary stenosis and/or stenosis development in the initially normal coronary artery. CEs were defined as cardiac death, myocardial infarction, stroke, or coronary revascularization.

Results: Patients were divided into two groups based on the presence ( n =29) or absence ( n =113) of RP after 10 months. The LDL-c and sd-LDL-c levels at baseline were equivalent in both the groups. However, the sd-LDL-c, triglyceride, remnant lipoprotein cholesterol (RL-c), and apoC3 levels at follow-up were significantly higher in the RP group than in the non-RP group. The optimal threshold values of sd-LDL-c, triglyceride, RL-c, and apoC3 for predicting RP according to receiver operating characteristics analysis were 20.9, 113, 5.5, and 9.7 mg/dL, respectively. Only the sd-LDL-c level (≥ 20.9 mg/dL) was significantly associated with incident CEs at 31±17 months (log-rank: 4.123, p =0.043).

Conclusions: The sd-LDL-c level on treatment was significantly associated with RP of non-culprit lesions, resulting in CEs in ACS patients. On-treatment sd-LDL-c is a residual risk and aggressive reduction of sd-LDL-c might be needed to prevent CEs.

The Association of Small Dense Low-Density Lipoprotein Cholesterol and Coronary Heart Disease in Subjects at High Cardiovascular Risk

AIM

The present study aims to investigate the association between serum small dense low-density lipoprotein (sdLDL) cholesterol level and the development of coronary heart disease (CHD) in subjects at high cardiovascular risk.

METHODS

A total of 3,080 participants without prior cardiovascular disease (CVD), aged ≥ 40 years, were followed up for a median of 8.3 years, which were divided into two groups, those with serum sdLDL cholesterol levels of ＜35 mg/dL or ≥ 35 mg/dL. Then, subjects were stratified by the status of diabetes, CVD-related comorbidities (defined as the presence of diabetes, chronic kidney disease, or peripheral artery disease), and the CVD risk assessment according to the Japan Atherosclerosis Society Guidelines. The hazard ratios (HRs) and 95% confidence intervals (CIs) were computed using a Cox proportional hazards model.

RESULTS

During the follow-up, 79 subjects developed CHD. The risk for incident CHD was higher in subjects with serum sdLDL cholesterol of ≥ 35 mg/dL than those with sdLDL cholesterol of ＜35 mg/dL (HR 2.09, 95%CI 1.26-3.45) after adjusting for traditional risk factors. In the subgroup analyses, the multivariable-adjusted HR for incident CHD increased significantly in those with serum sdLDL cholesterol of ≥ 35 mg/dL among subjects with diabetes (HR 2.76, 95%CI 1.09-7.01), subjects with CVD-related comorbidities (HR 2.60, 95%CI 1.21-5.58), and high-risk category defined as the presence of CVD-related comorbidities or a Suita score of ≥ 56 points (HR 1.93, 95%CI 1.02-3.65).

CONCLUSIONS

Elevated serum sdLDL cholesterol was associated with the development of CHD even in subjects at high cardiovascular risk.

Treatment of Hepatitis C Virus Infection with Direct-acting Antiviral Agents Elevates the Serum Small-dense Low-density Lipoprotein Cholesterol Level

Objective The low-density lipoprotein cholesterol (LDL) level is known to increase following the treatment of hepatitis C virus (HCV) infection using direct-acting antiviral agents (DAAs). This study aimed to investigate the changes in the lipid profiles, including small-dense LDL cholesterol (sdLDL), in HCV patients treated with DAAs. Patients We retrospectively assessed 67 HCV patients who achieved sustained virological response with DAA administration and were observed for more than 2 years, of whom 32 were on daclatasvir/asunaprevir, 14 were on sofosbuvir/ledipasvir, and 21 were on sofosbuvir/ribavirin. Methods We evaluated the lipid profiles, including sdLDL, every 6 months until 2 years after the start of treatment and analyzed the factors related to changes in the sdLDL level. Results The median sdLDL value at baseline was 12.8 mg/dL, which increased to 19.5 mg/dL at 6 months (p<0.001) and remained elevated at 25.4 mg/dL at 2 years later (p<0.001). The Kaplan-Meier curve indicated that patients with high values of LDL, albumin, muscle attenuation and visceral to subcutaneous adipose tissue area ratio were at increased risk for elevation of sdLDL over 35 mg/dL (log-rank test: p<0.001; p=0.008, p=0.002 and p=0.042, respectively). A multivariate analysis performed on the factors contributing to elevation of sdLDL 2 years after DAA treatment (≥35.0 mg/dL) revealed pretreatment LDL (≥91.0 mg/dL) and muscle attenuation (≥33.7 HU) as significant factors (p=0.007 and p=0.032, respectively). Conclusion SdLDL increased continuously after DAA treatment, and high LDL levels and low intramuscular fat deposition before treatment contributed to elevated sdLDL levels after treatment.

Comparison of seven different reagents of peroxidase method for small and dense low density lipoprotein cholesterol (sdLDL-C) measurement

Background

We validated the performance of seven different reagents of peroxidase method for sdLDL‐C in two automatic analyzers that are common in Chinese laboratories.

Methods

Seven commercially available sdLDL‐C assays were analyzed with the Beckman AU5400 and Mindray BS2000 automatic analyzers. A total of 336 blood samples were collected and the reference interval was also validated in 298 apparently healthy individuals. Serum samples were used for method comparison of precision, recovery, lower limit of detection, comparison and concurrence analysis, as well as reference interval for the Mindray reagent.

Results

The repeatability CV% of the seven sdLDL‐C assays were 0.81%~3.66% for Mindray BS2000 and 0.76%~3.91% for Beckman AU5400, while Total CVs for Mindray BS2000 sdLDL‐C assay were 1.34%~4.81%, and that of Beckman AU5400 were 2.25%~10.33%. The measured recovery rates of sdLDL‐C assays were within the allowable ±10% deviation range. There was no obvious difference between the reagents in the lower limit detection. There was a difference between the validation results of the reference range and the manufacturer's.BSBE, Mindray, and Dongou had a high degree of association with DENKA SEIKEN on Mindray BS2000, while BSBE, Mindray, Dongou and Merit Choice had a high degree of association with DENKA SEIKEN on Beckman AU5400. Passing–Bablok regression showed excellent linear correlation between BSBE and Mindray and DENKA SEIKEN and on Beckman AU5400.

Conclusions

Our results indicate that the basic performance can meet the testing requirements, but the comparability between them is still insufficient.

Association of small dense LDL-cholesterol with disease severity, hypertension status and clinical outcome in patients with coronary artery disease

OBJECTIVE

Previous studies have demonstrated that small dense LDL-cholesterol (sdLDL-C) is related to the pathogenesis of coronary artery disease (CAD). However, its prognostic role in hypertensive patients with CAD has been undetermined. The aim of the study was to investigate the association between sdLDL-C with disease severity, hypertensive status and clinical outcome in patients with CAD.

METHODS

A total of 4594 patients with angiography-proven CAD were consecutively enrolled and categorized into subgroups according to blood pressure status. Serum sdLDL-C levels were measured by direct quantitative measurement using automated chemistry analyzers. The severity of coronary artery lesions were determined by Gensini score, Syntax score and the number of lesion vessels. The associations of sdLDL-C with disease severity, hypertensive status and cardiovascular events (CVEs) were evaluated.

RESULTS

Patients with hypertension had higher sdLDL-C levels than ones without (P = 0.010). In hypertensive patients, sdLDL-C was positively associated with the severity of CAD (P < 0.05). In addition, hypertensive patients with poorly controlled hypertension had higher sdLDL-C levels than those with well controlled (P < 0.05). Moreover, 149 CVEs occurred in patients with poorly controlled hypertension and Cox regression analysis indicated that elevated sdLDL-C levels were independently associated with CVEs in hypertensive patients with poorly controlled hypertension (adjusted hazard ratio: 1.673, 95% confidence interval: 1.105-2.535, P = 0.015).

CONCLUSION

The current data, for the first time, showed that serum sdLDL-C levels were correlated with hypertension control, disease severity and worse outcomes in hypertensive patients with CAD, suggesting that paying more attention on sdLDL-C in these patients were warranted.

Association of small, dense LDL-cholesterol concentration and lipoprotein particle characteristics with coronary heart disease: A systematic review and meta-analysis

OBJECTIVES

The aim of this study was to systematically collate and appraise the available evidence regarding the associations between small, dense low-density lipoprotein (sdLDL) and incident coronary heart disease (CHD), focusing on cholesterol concentration (sdLDL-C) and sdLDL particle characteristics (presence, density, and size).

BACKGROUND

Coronary heart disease (CHD) is the leading cause of death worldwide. Small, dense low-density lipoprotein (sdLDL) has been hypothesized to induce atherosclerosis and subsequent coronary heart disease (CHD). However, the etiological relevance of lipoprotein particle size (sdLDL) versus cholesterol content (sdLDL-C) remains unclear.

METHODS

PubMed, MEDLINE, Web of Science, and EMBASE were systematically searched for studies published before February 2020. CHD associations were based on quartile comparisons in eight studies of sdLDL-C and were based on binary categorization in fourteen studies of sdLDL particle size. Reported hazards ratios (HR) and odds ratios (OR) with 95% confidence interval (CI) were standardized and pooled using a random-effects meta-analysis model.

RESULTS

Data were collated from 21 studies with a total of 30,628 subjects and 5,693 incident CHD events. The average age was 67 years, and 53% were men. Higher sdLDL and sdLDL-C levels were both significantly associated with higher risk of CHD. The pooled estimate for the high vs. low categorization of sdLDL was 1.36 (95% CI: 1.21, 1.52) and 1.07 (95% CI: 1.01, 1.12) for comparing the top quartiles versus the bottom of sdLDL-C. Several studies suggested a dose response relationship.

CONCLUSIONS

The findings show a positive association between sdLDL or sdLDL-C levels and CHD, which is supported by an increasing body of genetic evidence in favor of its causality as an etiological risk factor. Thus, the results support sdLDL and sdLDL-C as a risk marker, but further research is required to establish sdLDL or sdLDL-C as a potential therapeutic marker for incident CHD risk reduction.