Evolving concepts of dyslipidemia, atherosclerosis, and cardiovascular disease: the Louis F. Bishop Lecture

Associations between the Genetic Heritability of Dyslipidemia and Dietary Patterns in Korean Adults Based on Sex Differences

Dyslipidemia can be defined as an abnormality in serum lipid levels that is substantially linked to genetic variations and lifestyle factors, such as diet patterns, and has distinct sex-specific characteristics. We aimed to elucidate the genetic impact of dyslipidemia according to sex and explore the associations between genetic variants and dietary patterns in large-scale population-based cohorts. After performing genome-wide association studies (GWASs) in male, female, and entire cohorts, significant single nucleotide polymorphisms (SNPs) were identified in the three groups, and genetic risk scores (GRSs) were calculated by summing the risk alleles from the selected SNPs. After adjusting for confounding variables, the risk of dyslipidemia was 2.013-fold and 2.535-fold higher in the 3rd quartile GRS group in the male and female cohorts, respectively, than in the 1st quartile GRS group. While instant noodle and soft drink intake were significantly associated with GRS related to hyperlipidemia in male cohorts, coffee consumption was substantially related to GRS related to hyperlipidemia in female cohorts. Considering the influence of genetic factors and dietary patterns, the findings of this study suggest the potential for implementing sex-specific strategic interventions to avoid dyslipidemia.

Association of ambient PM10 and PM2.5 with coronary stenosis measured using selective coronary angiography

BACKGROUND

Long-term ambient particulate matter (PM) exposure exerts detrimental effects on cardiovascular health. Evidence on the relation of chronically exposed ambient PM10 and PM2.5 with coronary stenosis remains lacking. Our aim was to investigate the association of PM10 and PM2.5 with coronary stenosis in patients undergoing coronary angiography.

METHODS

We performed a retrospective cohort study consisting of 7513 individuals who underwent coronary angiography in Fujian Province, China, from January 2019 to December 2021. We calculated a modified Gensini score (GS) to represent the degree of stenosis in coronary arteries by selective coronary angiography. We fitted linear regressions and logistic models to assess the association of PM10 and PM2.5 with coronary stenosis. We employed restricted cubic splines to describe the exposure-response curves. We performed mediation analyses to assess the potential mediators.

RESULTS

Long-term ambient PM10 and PM2.5 (prior three years average) exposure was significantly associated with the GS, with a breakpoint concentration of 47.5 μg/m3 and 25.8 μg/m3 for PM10 and PM2.5, respectively, above which we found a linear positive exposure-response relationship of ambient PM with GS. Each 10 µg /m3 increase in PM10 exposure (β: 4.81, 95 % CI: 0.44-9.19) and PM2.5 exposure [β: 10.50, 95 % CI: 3.14-17.86] were positively related to the GS. The adjusted odds ratio (OR) for each 10 µg/m3 increment in PM10 exposure on severe coronary stenosis was 1.33 (95 % CI: 1.04-1.76). Correspondingly, the adjusted OR for PM2.5 was 1.87 (95 % CI: 1.24-2.99). The mediation analysis indicated that the effect of PM10 on coronary stenosis may be partially mediated through total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, serum creatinine and blood urea nitrogen, and the effect of PM2.5 may be mediated in part by hemoglobin A1c.

CONCLUSION

Our study provides the first evidence that chronic ambient PM10 and PM2.5 exposure was associated with coronary stenosis assessed by GS in patients with suspected coronary artery disease and reveals its potential mediators.

Blood Lead and High-Density Lipoprotein Concentrations in Relation to Human Blood Pressure: A Cross Sectional Study

Background

While the relationship between blood pressure and blood lead has been studied more extensively, the effect of high-density lipoprotein (HDL) concentration on this relationship remains uncertain. Therefore, this study aimed to determine the effect of HDL concentration on the relationship between blood lead and blood pressure.

Methods

The research used cross-sectional data from the 2005 to 2014 National Health and Nutrition Examination Survey (NHANES), which included 16,451 participants aged 20–60 years. Multivariable linear regression was used to evaluate the correlation among blood lead, systolic blood pressure (SBP), and diastolic blood pressure (DBP). HDL concentration was determined by low HDL concentration (≤ 49 mg/dl) and high HDL concentration (>49 mg/dl) stratified. The effect of HDL concentration was assessed by an interaction test between blood lead and SBP in multivariable linear regression.

Results

In this cross-sectional research, we identified a positive correlation between blood lead and SBP, but not DBP. The relationship between blood lead and SBP was different in the group with low and high HDL concentrations (β: 0.21 95% Cl:−0.05-0.46 vs. β:0.47 95% Cl: 0.15-0.79). In addition, high HDL significantly altered the positive correlation between blood lead and SBP (P-value of interaction < 0.001).

Conclusion

The study suggests an interaction between HDL and blood lead in elevating SBP, which may have important clinical implications.

Effect of Moderately but Persistently Elevated Lipid Levels on Risks of Stroke and Myocardial Infarction in Young Korean Adults

Background

Identifying predictive markers for future atherosclerotic cardiovascular diseases may be helpful to motivate young adults to promote healthy lifestyle. We sought to determine the association between persistently elevated low‐density lipoprotein‐cholesterol (LDL‐C) and/or triglyceride levels and the atherosclerotic cardiovascular diseases risks in young adults.

Methods and Results

We conducted a nationwide population‐based cohort study of 1 887 853 statin‐naive adults aged 20 to 39 years, with LDL‐C <190 mg/dL, using the Korean National Health Insurance Service database. Persistently elevated LDL‐C and triglyceride levels were defined by ≥3 measurements of ≥160 and ≥175 mg/dL, respectively. The primary outcome was a composite of stroke and myocardial infarction. Among the study population, 11 121 (0.59%) and 167 373 (8.87%) had persistently elevated LDL‐C and triglycerides, respectively. During a median follow‐up of 5.2 years, 2170 and 1537 incidences of stroke (0.16%) and myocardial infarction (0.23%) occurred. Persistently elevated LDL‐C levels were significantly associated with increased risks of the primary outcome, with an adjusted hazard ratio (HR) of 1.396 (95% CI, 1.005–1.940). This association was independent of high‐density lipoprotein cholesterol. Persistently elevated triglycerides were significantly associated with increased risks of the primary outcome (HR, 1.120; 95% CI, 1.015–1.236), but attenuated after adjustment for high‐density lipoprotein cholesterol.

Conclusions

Persistently elevated LDL‐C and triglyceride levels were associated with atherosclerotic cardiovascular diseases risk in young Korean adults without severe hypercholesterolemia. These lipid abnormalities should be considered risk factors in young adults since their effects on lifetime atherosclerotic cardiovascular diseases risk may become more pronounced over the life course.

Health Disparities among Australia's Remote-Dwelling Aboriginal People: A Report from 2020

BACKGROUND

Australia has 2 distinct indigenous groups, Torres Strait Islanders and Aborigines. The Aborigines, described in this report, first colonized the continent 65 millennia ago. Those still living in the Northern Territory (NT) retain much ancestrally derived genetic complement but also are the most health-challenged by environment and lifestyle in 21st century. Reports providing overviews of these disparities are, as yet, rare.

CONTENT

This review defines the studied population and then describes and attempts to explain contemporary clinical findings among Australia's remote-dwelling Aborigines, principally in the NT. The report is structured by life stage and then by organ system. Finally, a brief synthesis is advanced concerning the disparities that Australia's Aboriginals face.

SUMMARY

In 2015-2017, NT aboriginal life expectancy for people then born was 66.6 years for men and 69.9 years for women compared with 78.1 and 82.7 years, respectively, among nonindigenous Territorians. Principal causes of the reduced longevity, with nonindigenous comparisons, include adolescent pregnancy, with maternal use of alcohol and tobacco (each 7-fold greater); fetal alcohol spectrum disorder and attention deficit hyperactivity disorder; skin infections, both scabies and impetigo (50-fold greater); rheumatic heart disease (260-fold greater); premature acute myocardial infarction (9-fold greater); bronchiectasis (40-fold greater); lung cancer (2-fold greater); diabetes mellitus (10-fold greater); renal failure (30-fold greater); and suicide (2-fold greater). Some disease has genetic roots, secondary to prolonged genetic drift. Much arises from avoidable stressors and from contemporary environmental disparities in housing. The Europid diet is also not helpful.

Identifying functional non-coding variants in APOA5/A4/C3/A1 gene cluster associated with coronary heart disease

Recent genome-wide association studies identified several polymorphisms in the APOA5/A4/C3/A1 gene cluster influencing lipids level and risk of coronary heart disease (CHD). However, few studies explored the molecular mechanism. The purposes of this study were to fine-map noncoding region between APOA1 and APOC3 and then explore the clinical relevance in CHD and potential underlying mechanisms. In this study, a 2.7-kb length of the non-coding region between APOA1 and APOC3 was screened and five polymorphisms were investigated in the case-control study. The molecular mechanism was explored. Our data confirmed the association between rs7123454, rs12721030, rs10750098, and rs12721028 with CHD in 828 patients and 828 controls and replicated it in an independent population of 405 patients and 405 controls. In addition, the rs10750098 and rs12721030 are significantly associated with decreased serum APOA1 levels (P = 4.2 × 10^-4 and P = 3.2 × 10^-5, combined analysis), while a significant association was observed between serum APOA1 level and CHD (OR: 0.43, 95% CI: 0.28-0.64, P < .01) with adjustment for clinical covariates and different population sets. In vitro evaluation of potential function of non-coding variants between APOA1 and APOC3 demonstrated that rs10750098 as being the most sufficient to confer the haplotype-specific effect on the regulation of APOs gene transcription. Our results strongly implicate the involvement of common noncoding DNA variants in APOA5/A4/C3/A1 gene cluster in the pathogenesis of dyslipidemia and the risk of CHD.

Mildly Abnormal Lipid Levels, but Not High Lipid Variability, Are Associated With Increased Risk of Myocardial Infarction and Stroke in “Statin-Naive” Young Population A Nationwide Cohort Study

Rationale:

In young adults, the role of mildly abnormal lipid levels and lipid variability in the risk of atherosclerotic cardiovascular diseases remains uncertain.

Objective:

To investigate the association of these abnormalities in lipid profiles with the risk of myocardial infarction (MI) and stroke in young population.

Methods and Results:

From the Korean National Health Insurance Service, a nationwide population-based cohort of 1 934 324 statin-naive adults aged 20 to 39 years, with ≥3 lipid profile measurements and without a history of MI and stroke, were followed-up until the date of MI or stroke, or December 31, 2017. The primary measure of lipid variability was variability independent of the mean. Higher baseline total cholesterol, LDL-C (low-density lipoprotein-cholesterol), and triglycerides and lower HDL-C (high-density lipoprotein-cholesterol) levels were significantly associated with increased MI risk; respective adjusted hazard ratios and 95% CIs comparing the highest versus lowest quartiles were 1.35 (1.20–1.53) for total cholesterol, 1.41 (1.25–1.60) for LDL-C, 1.28 (1.11–1.47) for triglycerides, and 0.82 (0.72–0.94) for HDL-C. Adjusted analyses for deciles of lipid profiles showed that MI risk was significantly elevated among participants with total cholesterol ≥223.4 mg/dL, LDL-C ≥139.5 mg/dL, HDL-C ≤41.8 mg/dL, and triglycerides ≥200.1 mg/dL. The associations between lipid levels and stroke risk were less prominent. Multivariable-adjusted restricted cubic spline analysis demonstrated that the increase in MI risk was not exclusively driven by extreme values of lipid profiles. Similar results were obtained on sensitivity analyses of baseline lipid levels. However, associations between lipid variability and the risk of MI and stroke varied depending on the measure of lipid variability used.

Conclusions:

Mildly abnormal baseline lipid levels were associated with an increased future risk of atherosclerotic cardiovascular disease events, particularly MI, whereas measures of lipid variability were not. Therefore, in young adults, achieving optimal lipid levels could be valuable in the prevention of atherosclerotic cardiovascular disease.

Decline in Cardiovascular Mortality: Possible Causes and Implications

If the control of infectious diseases was the public health success story of the first half of the 20th century, then the decline in mortality from coronary heart disease and stroke has been the success story of the century's past 4 decades. The early phase of this decline in coronary heart disease and stroke was unexpected and controversial when first reported in the mid-1970s, having followed 60 years of gradual increase as the US population aged. However, in 1978, the participants in a conference convened by the National Heart, Lung, and Blood Institute concluded that a significant recent downtick in coronary heart disease and stroke mortality rates had definitely occurred, at least in the US Since 1978, a sharp decline in mortality rates from coronary heart disease and stroke has become unmistakable throughout the industrialized world, with age-adjusted mortality rates having declined to about one third of their 1960s baseline by 2000. Models have shown that this remarkable decline has been fueled by rapid progress in both prevention and treatment, including precipitous declines in cigarette smoking, improvements in hypertension treatment and control, widespread use of statins to lower circulating cholesterol levels, and the development and timely use of thrombolysis and stents in acute coronary syndrome to limit or prevent infarction. However, despite the huge growth in knowledge and advances in prevention and treatment, there remain many questions about this decline. In fact, there is evidence that the rate of decline may have abated and may even be showing early signs of reversal in some population groups. The National Heart, Lung, and Blood Institute, through a request for information, is soliciting input that could inform a follow-up conference on or near the 40th anniversary of the original landmark conference to further explore these trends in cardiovascular mortality in the context of what has come before and what may lie ahead.

Evaluation of Lipid Profile and Apolipoproteins in Essential Hypertensive Patients

INTRODUCTION

Essential hypertension is one of the most common diseases of the Indian population contributing greatly to the morbidity, mortality and economic burden. It has a strong association with cardiovascular disease and abnormal lipid metabolism. Not only the traditional lipid parameters, but also the novel lipid components like Apo A1 and Apo B100 also have been identified to play a role.

AIM

The present study was done to evaluate serum lipid profile and Apo A1, Apo B 100 in essential hypertensive patients and correlate their values with the degree of hypertension.

MATERIALS AND METHODS

Fasting samples from 55 age and sex matched controls and 55 essential hypertensives were tested for plasma glucose, serum urea, creatinine, lipid profile, apo A1 and apo B100. The cases were subclassified based on the severity of hypertension according to JNC criteria.

RESULTS

The study showed a significantly raised value for serum cholesterol, triacylglycerol, Low Density Lipoprotein (LDL), Very Low-Density Lipoprotein (VLDL) in the hypertensive patients than the control group whereas serum High-Density Lipoprotein (HDL) registered a fall in the cases. Apo A1 revealed a non-significant fall in the hypertensive patients. In contrast, there was a rise in the serum apo B100 in the cases. Apo B100/apo A1 ratio was significantly raised in both stage I and stage II hypertensive patients in comparision to the controls. When correlated, serum apo A1 revealed a negative association where as serum apo B 100 showed a positive association with systolic and diastolic bloood pressure. Both LDL/HDL and apoB100/apo A1 and apo B100 revealed a significant positive association with both SBP and DBP. However, apoB100/apo A1 revealed a more positive association in comparision to LDL/HDL ratio (r=0.749, p<0.001, r=0.756, p<0.001 vs r=0.336, p<0.000, r=0.312, p<0.001).

CONCLUSION

Apo B100/apoA1 has emerged as an important complementary parameter in addition to traditional lipid ratio for evaluation of risk for future cardiovascular disease.

Epidemiological aspects of heart diseases

Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide. Coronary heart disease (CHD) is the main cause of mortality in heart patients following stroke, rheumatic heart disease and myocardial infarctions. Approximately 80% of individuals succumb to CVDs, due to poor living conditions in low and middle income families and malnutrition. Infectious diseases, human immunodeficiency, tuberculosis, malaria, high blood pressure or hypertension, obesity and overweight, and nutritional disorders including smoking, excessive alcohol consumption, high salt and sugar intake, as well as other factors are responsible for CVDs and CHDs in young as well as elderly individuals. The focus of the present review are recent epidemiological aspects of CVD and CHD as well as the usefulness of a Mediterranean diet for heart patients and the prevention of heart diseases.

Hepatic Transmembrane 6 Superfamily Member 2 Regulates Cholesterol Metabolism in Mice

BACKGROUND & AIMS

The rs58542926 C>T variant of the transmembrane 6 superfamily member 2 gene (TM6SF2), encoding an E167K amino acid substitution, has been correlated with reduced total cholesterol (TC) and cardiovascular disease. However, little is known about the role of TM6SF2 in metabolism. We investigated the long-term effects of altered TM6SF2 levels in cholesterol metabolism.

METHODS

C57BL/6 mice (controls), mice that expressed TM6SF2 specifically in the liver, and mice with CRISPR/Cas9-mediated knockout of Tm6sf2 were fed chow or high-fat diets. Blood samples were collected from all mice and plasma levels of TC, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol, and triglycerides were measured. Liver tissues were collected and analyzed by histology, real-time polymerase chain reaction, and immunoblot assays. Adenovirus vectors were used to express transgenes in cultured Hep3B hepatocytes.

RESULTS

Liver-specific expression of TM6SF2 increased plasma levels of TC and LDL-c, compared with controls, and altered liver expression of genes that regulate cholesterol metabolism. Tm6sf2-knockout mice had decreased plasma levels of TC and LDL-c, compared with controls, and consistent changes in expression of genes that regulate cholesterol metabolism. Expression of TM6SF2 promoted cholesterol biosynthesis in hepatocytes.

CONCLUSIONS

TM6SF2 regulates cholesterol metabolism in mice and might be a therapeutic target for cardiovascular disease.

Cyclooxygenase 2, toll-like receptor 4 and interleukin 1β mRNA expression in atherosclerotic plaques of type 2 diabetic patients

OBJECTIVES AND DESIGN

Inflammation has a prominent role in the development of atherosclerosis. Type 2 diabetes could contribute to atherosclerosis development by promoting inflammation. This status might accelerate changes in intrinsic vascular wall cells and favor plaque formation. Cyclooxygenase 2 (COX-2) is highly expressed in atherosclerotic plaques. COX-2 gene expression is promoted through activation of toll-like receptor 4 (TLR4) and pro-inflammatory cytokine interleukin 1β (IL1-β). Aim of this study is to investigate whether expression profiles of pro-inflammatory genes such as COX-2, TLR4 and IL1-β in atherosclerotic plaques are altered in type 2 diabetes (T2D).

METHODS

Total RNA was isolated from plaques of atherosclerotic patients and expression of COX-2, TLR4, IL1-β analyzed using real-time PCR. Histological analysis was performed on sections of the plaque to establish the degree of instability.

RESULTS

Statistically significant differences in mRNA expression of COX-2 and IL1-β were found in plaques of T2D compared with non-T2D patients. A multi-variable linear regression model suggests that COX-2 mRNA expression is affected by T2D pathology and IL1-β mRNA expression in atherosclerotic plaques.

CONCLUSIONS

Our results support the hypothesis that T2D pathology contributes in vivo to increase the inflammatory process associated with the atherosclerotic plaque formation, as shown by an increment of COX-2 and IL1-β mRNA expression.

Genetic loci associated with changes in lipid levels leading to constitution-based discrepancy in Koreans

Background

Abnormal lipid concentrations are risk factors for atherosclerosis and cardiovascular disease. The pathological susceptibility to cardiovascular disease risks such as metabolic syndrome, diabetes mellitus, hypertension, insulin resistance, and so on differs between Sasang constitutional types.

Methods

We used multiple regression analyses to study the association between lipid-related traits and genetic variants from several genome-wide association studies according to Sasang constitutional types, considering that the Tae-Eum (TE) has predominant cardiovascular risk.

Results

By analyzing 26 variants of 20 loci in two Korean populations (8,597 subjects), we found that 12 and 5 variants, respectively, were replicably associated with lipid levels and dyslipidemia risk. By analyzing TE and non-TE type (each 2,664 subjects) populations classified on the basis of Sasang constitutional medicine, we found that the minor allele effects of three variants enriched in TE type had a harmful influence on lipid risk (near apolipoprotein A-V (APOA5)-APOA4-APOC3-APOA1 on increased triglyceride: p = 8.90 × 10^-11, in APOE-APOC1-APOC4 on increased low-density lipoprotein cholesterol: p = 1.63 × 10^-5, and near endothelial lipase gene on decreased high-density lipoprotein cholesterol: p = 4.28 × 10^-3), whereas those of three variants (near angiopoietin-like 3 gene, APOA5-APOA4-APOC3-APOA1, and near lipoprotein lipase gene on triglyceride and high-density lipoprotein cholesterol) associated in non-TE type had neutral influences because of a compensating effect.

Conclusions

These results implied that the minor allele effects of lipid-associated variants may predispose TE type subjects to high cardiovascular disease risk because of their genetic susceptibility to lipid-related disorders.

Antihyperlipidemic effects of stilbenoids isolated from Morus alba in rats fed a high-cholesterol diet

Mulberroside A (MUL) was purified from an ethanol extract of Morus alba root, and oxyresveratrol (OXY) was produced by enzymatic conversion of MUL. Normal rats, Triton WR-1339-induced hyperlipidemic rats, and high-cholesterol diet (HCD)-induced hyperlipidemic rats were orally treated with MUL or OXY (1-5mg/kg/day). MUL and OXY were administered 1h prior to concomitant treatment with Triton WR-1339 for a further 24h, whereas the drugs were administered concurrently with HCD for 4weeks. Oral MUL and OXY pre-treatment vs. water pre-treatment of Triton WR-1339-induced hyperlipidemic rats significantly (p<0.05) reduced the levels of serum lipids in a dose-dependent manner, while high-density lipoprotein cholesterol (HDL-C, or "good" cholesterol) levels were increased. Oral MUL and OXY treatment of HCD-fed rats also showed a significant (p<0.05) dose-dependent decrease in serum lipids, coronary artery risk index (CRI), and atherogenic index (AI), but not HDL-C. Furthermore, MUL and OXY treatment of HCD-induced hyperlipidemic rats demonstrated a significant dose-dependent improvement in the histological features of hepatic fatty degeneration. Aspartate aminotransferase and alanine aminotransferase values in OXY-treated normal rats were not significantly different from those in water-treated control rats. These results indicate that MUL and OXY might be developed as novel antihyperlipidemic agents.

Low-density lipoprotein subfraction, carotid artery intima-media thickness, nitric oxide, and tumor necrosis factor alpha are associated with newly diagnosed ischemic stroke

OBJECTIVES

Small dense (sd) low-density lipoprotein (LDL), tumor necrosis factor (TNF) alpha (α), and nitric oxide (NO) have recently emerged as important stroke risk factors. The aim of the study was to investigate the effects of increased levels of small LDL particle size, TNF-α and NO on the developed ischemic stroke and increased carotid artery intima-media thickness (CIMT).

MATERIALS AND METHODS

A total of 29 women and 25 men (a total of 54 ischemic stroke patients) and a similar age group of 50 controls (29 females and 21 males) were included in the study. CIMT, C-reactive protein (CRP), TNF-α, NO, and lipid subfraction test of the two groups were measured.

RESULTS

The mean LDL particle size was smaller in patients with stroke than in the controls (26.8 ± 0.31 nm vs. 27.0 ± 0.31 nm, P = 0.003). sd-LDL, TNF-α, NO, CRP, right CIMT, and left CIMT were higher in patients with stroke than in the controls (respectively; 8.2 ± 7.8 mg/dL vs. 3.3 ± 3.5 mg/dL, P < 0.001;75.6 ± 25.0 pg/mL vs. 65.4 ± 9.1 pg/mL, P = 0.009;76.4 ± 53.3 mmol/L vs. 41.5 ± 27.0 mmol/L, P < 0.001;1.9 ± 2.6 mm vs. 0.4 ± 0.3 mm P < 0.001;0.97 ± 0.38 mm vs. 0.83 ± 0.15 mm, P = 0.007;1.04 ± 0.44 mm vs. 0.87 ± 0.19 mm, P = 0.010).

CONCLUSION

These results show that sd-LDL is independently associated with the incidence of stroke and may be a risk factor in the development of stroke. In addition, TNF-α, NO, right CIMT, and left CIMT may be a risk factor in the development of ischemic stroke.

Low-density lipoprotein subfraction, carotid artery intima-media thickness, nitric oxide, and tumor necrosis factor alpha are associated with newly diagnosed ischemic stroke

OBJECTIVES

Small dense (sd) low-density lipoprotein (LDL), tumor necrosis factor (TNF) alpha (α), and nitric oxide (NO) have recently emerged as important stroke risk factors. The aim of the study was to investigate the effects of increased levels of small LDL particle size, TNF-α and NO on the developed ischemic stroke and increased carotid artery intima-media thickness (CIMT).

MATERIALS AND METHODS

A total of 29 women and 25 men (a total of 54 ischemic stroke patients) and a similar age group of 50 controls (29 females and 21 males) were included in the study. CIMT, C-reactive protein (CRP), TNF-α, NO, and lipid subfraction test of the two groups were measured.

RESULTS

The mean LDL particle size was smaller in patients with stroke than in the controls (26.8 ± 0.31 nm vs. 27.0 ± 0.31 nm, P = 0.003). sd-LDL, TNF-α, NO, CRP, right CIMT, and left CIMT were higher in patients with stroke than in the controls (respectively; 8.2 ± 7.8 mg/dL vs. 3.3 ± 3.5 mg/dL, P < 0.001;75.6 ± 25.0 pg/mL vs. 65.4 ± 9.1 pg/mL, P = 0.009;76.4 ± 53.3 mmol/L vs. 41.5 ± 27.0 mmol/L, P < 0.001;1.9 ± 2.6 mm vs. 0.4 ± 0.3 mm P < 0.001;0.97 ± 0.38 mm vs. 0.83 ± 0.15 mm, P = 0.007;1.04 ± 0.44 mm vs. 0.87 ± 0.19 mm, P = 0.010).

CONCLUSION

These results show that sd-LDL is independently associated with the incidence of stroke and may be a risk factor in the development of stroke. In addition, TNF-α, NO, right CIMT, and left CIMT may be a risk factor in the development of ischemic stroke.

High concentrations of AGE-LDL and oxidized LDL in circulating immune complexes are associated with progression of retinopathy in type 1 diabetes

OBJECTIVE

To determine whether immunocomplexes (ICs) containing advanced glycation end product (AGE)-LDL (AGE-LDL) and oxidized LDL (oxLDL) contribute to the development of retinopathy over a 16-year period in subjects with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Levels of AGE-LDL and oxLDL in ICs were measured in 517 patients of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) cohort. Retinopathy was assessed by stereoscopic fundus photography. Cox proportional hazards models were used to assess the effect of AGE-LDL-ICs and oxLDL-ICs on retinopathy progression.

RESULTS

In unadjusted models, higher baseline levels of AGE-LDL-ICs and oxLDL-ICs significantly predicted progression of diabetic retinopathy outcomes. After adjustment by study-design variables (treatment group, retinopathy cohort, duration of type 1 diabetes, and baseline albumin excretion rate [AER], hemoglobin A(1c) (HbA(1c)), and Early Treatment Diabetic Retinopathy Study [ETDRS] score), one SD increase in IC levels was associated with 47% (hazard ratio [HR] 1.47 [95% CI 1.19-1.81]; AGE-LDL-IC) and 45% (1.45 [1.17-1.80]; oxLDL-IC) increased risk of developing proliferative diabetic retinopathy (PDR) and 37% (1.37 [1.12-1.66]; to both ICs) increased risk of progressing to severe nonproliferative retinopathy. Analyses were stratified by retinopathy cohort because results differed between primary and secondary cohorts. For AGE-LDL-ICs, HR for progression to PDR was 2.38 (95% CI 1.30-4.34) in the primary cohort and attenuated in the secondary cohort (1.29 [1.03-1.62]). Similar results were observed for oxLDL-ICs.

CONCLUSIONS

Increased levels of AGE-LDL and oxLDL in ICs are associated with increased risk for progression to advanced retinopathy in patients with type 1 diabetes, indicating that the antibody response to modified LDL plays a significant role in retinopathy progression.

High levels of remnant lipoprotein cholesterol is a risk factor for large artery atherosclerotic stroke

BACKGROUND AND PURPOSE

Remnant lipoproteins (RLPs) are products of partially catabolized chylomicrons and very-low-density lipoprotein, from which some triglycerides have been removed. These particles are smaller and denser than the parent particles and are believed to be strongly atherogenic. We explored the association between RLP cholesterol (RLP-C) and ischemic stroke, including stroke subtypes.

METHODS

A cohort of 142 ischemic stroke patients (90 men and 52 women; age, 65.2±12.8 years, mean±SD) was enrolled; all had acute infarcts confirmed by diffusion-weighted MRI, and had fasting lipograms. A full stroke-related evaluation was conducted on each patient. An outpatient population of 88 subjects without a history of cerebrovascular or cardiovascular disease served as a control group. Serum RLP fractions were isolated using an immunoaffinity gel containing specific antiapolipoprotein (anti-apo)B-100 and anti-apoA-I antibodies. RLP-C values were considered to be high when they were in the highest quartile of all values in the study.

RESULTS

High RLP-C values were more common in stroke patients than in control patients (31.0% vs. 14.8%, p=0.01), when 5.6 mg/dL (>75th percentile) was used as the cutoff value. Multivariable analyses indicated that RLP-C was a risk factor for stroke, with an odds ratio of 2.54 (p=0.045). The RLP-C level was higher in the large artery atherosclerosis subgroup (5.7±3.9 mg/dL) than in any other stroke subgroup (small vessel occlusion, 4.9±5.9 mg/dL; cardioembolism, 1.8±2.3 mg/dL; stroke of undetermined etiology, 3.1±2.9 mg/dL).

CONCLUSIONS

We have found an association between high RLP-C levels and ischemic stroke, and in particular large artery atherosclerotic stroke.

Antisense therapy and emerging applications for the management of dyslipidemia

BACKGROUND

Because a significant percentage of patients who require high-dose statin therapy for dyslipidemia experience treatment-related muscle symptoms and an inconsistent clinical response, alternative or adjunctive approaches to the management of dyslipidemia are needed. One alternative approach, antisense therapy, may offer an effective and well-tolerated option for patients not satisfactorily responsive to or intolerant to standard pharmacologic dyslipidemia therapies.

OBJECTIVE

This review provides an overview of antisense technology and its potential role in the management of dyslipidemia.

METHODS

Source material was obtained primarily from the published literature identified through a search of the PubMed database.

RESULTS

Antisense technology is an evolving approach to therapy that has gone through a series of refinements to enhance molecular stability, potency, and tolerability. Mipomersen is an antisense molecule capable of producing clinically meaningful reductions in low-density lipoprotein cholesterol in patients with severe familial hypercholesterolemia. Further long-term clinical studies are required to more clearly quantify its impact on risk for cardiovascular events and establish whether it increases risk for hepatosteatosis.

CONCLUSION

Antisense therapy represents a potentially effective and well-tolerated emerging treatment modality for numerous diseases. In the treatment of hypercholesterolemia, the antisense therapy mipomersen may provide a possible treatment option for patients with treatment-resistant dyslipidemia.

Combination therapy with ezetimibe/simvastatin versus statin monotherapy for low-density lipoprotein cholesterol reduction and goal attainment in a real-world clinical setting

BACKGROUND

Randomized studies have demonstrated improved attainment of target low-density lipoprotein cholesterol (LDL-C) values when ezetimibe is combined with statins for the treatment of hypercholesterolemia. However, the efficacy of an intervention in randomized controlled clinical studies may not correlate with its efficacy in a real-world (community practice) setting. Data to support the LDL-C lowering efficacy of ezetimibe/simvastatin (EZE/SMV) outside of controlled clinical studies are currently lacking.

OBJECTIVE

Using patient data from a large, national, administrative claims database, this retrospective observational study evaluated the efficacy of EZE/SMV in lowering LDL-C values and achieving LDL-C target values in newly initiating users and compared the results with those from several statin monotherapies.

METHODS

Patients with hypercholesterolemia who had filled their first prescription for EZE/SMV or statin monotherapy between July 1, 2004, and December 31, 2007, and were ≥18 years old were evaluated. Pertinent data taken from the database included lipid-lowering drug name, date of first prescription, dose, serum lipid levels, and sample dates. Data on cardiovascular history, diabetes, and other concurrent diseases and therapies were also available. Following propensity score matching, multivariate regression models were constructed to estimate the impact of the choice of therapy on key treatment outcomes including the reduction of LDL-C (absolute and percent) as well as the percent of patients achieving goal LDL-C levels as defined by the updated American Heart Association/American College of Cardiology (AHA/ACC) Guidelines for 2006.

RESULTS

In the total population, both the percent decrease and the absolute reduction in LDL-C values were significantly greater with the use of EZE/SMV than with the 3 statin monotherapies (P < 0.005 for all comparisons). A significantly greater percentage of patients achieved AHA/ACC LDL-C goals in the first 3 months of EZE/SMV treatment compared with those using each statin monotherapy (P < 0.05 for all comparisons). Among matched patients with diagnosed diabetes, the percent reduction in LDL-C was also higher with the use of EZE/SMV than with each statin monotherapy (P < 0.005 for all comparisons).

CONCLUSION

In a real-world setting, EZE/SMV appeared to be more effective than simvastatin, atorvastatin, or rosuvastatin monotherapy for attaining therapeutic goals set forth by national and professional societies in patients being initiated on statin-based lipid-lowering therapy.

Hypercholesterolemia and a candidate gene within the 12q24 locus

Background

The 12q24 locus entails at least one gene responsible for hypercholesterolemia. Within the 12q24 locus lies the gene of proteasome modulator 9 (PSMD9). PSMD9 is in linkage with type 2 diabetes (T2D), T2D-nephropathy and macrovascular pathology in Italian families and PSMD9 rare mutations contribute to T2D.

Aims

In the present study, we aimed at determining whether the PSMD9 T2D risk single nucleotide polymorphisms (SNPs) IVS3 + nt460 A > G, IVS3 + nt437 T > C and E197G A > G are linked to hypercholesterolemia in 200 T2D Italian families.

Methods

We characterized 200 Italian families for presence and/or absence of hypercholesterolemia characterized by LDL levels ≥ 100 mg/dl in drug-naïve patients and/or presence of a diagnosis of hypercholesterolemia in a patient treated with statin medication. The phenotypes were described as unknown in all cases in which the diagnosis was either unclear or the data were missing. We tested in the 200 Italians families for evidence of linkage of the PSMD9 SNPs with hypercholesterolemia. The non-parametric linkage analysis was performed for the qualitative phenotype by using the Merlin software; the Lod score and correspondent P-value were calculated. For the significant linkage score, 1000 replicates were performed to calculate the empirical P-value.

Results

The PSMD9 gene SNPs studied show linkage to hypercholesterolemia. The results are not due to random chance.

Conclusions

PSMD9 should be tested in all populations reporting linkage to hypercholesterolemia within the chromosome 12q24 locus. The impact of this gene on hypercholesterolemia and contribution to cardio- and cerebrovascular events may be high.

Dyslipidaemia as a predictor of hypertension in middle-aged men

AIMS

Dyslipidaemia and hypertension are features of the metabolic syndrome, but the role of dyslipidaemia in the development of hypertension is less clear. We assessed the association of dyslipidaemia with incident hypertension during a 7-year follow-up in a population-based cohort of middle-aged men without hypertension at baseline.

METHODS AND RESULTS

In all, 88 of 311 men developed hypertension during the follow-up. A 1-SD increment in triglyceride concentrations was associated with a 1.6-fold [95% CI(confidence interval) 1.2-2.3] increased risk of developing hypertension, independently of features related to the metabolic syndrome. In separate multivariable models, the triglyceride content of high-density lipoprotein (HDL) cholesterol and apolipoprotein B concentrations were also associated with new-onset hypertension. In a stepwise backwards logistic regression model, concentrations of low-density lipoprotein (LDL) cholesterol [odds ratio (OR) 1.3, 95% CI 1.0-1.7 for a 1-SD change] and triglyceride content of HDL cholesterol (OR) 1.5, 95% CI 1.1-1.9) were positively associated with incident hypertension, whereas HDL concentrations (OR 0.7, 95% CI 0.5-0.9) seemed protective. In factor analyses, elevated triglyceride levels and related disturbances in lipid and cholesterol metabolism were associated with new-onset hypertension.

CONCLUSION

Dyslipidaemia characteristic of the metabolic syndrome predicts the development of hypertension during a 7-year follow-up of eastern Finnish men, independently of features related to insulin resistance. The recognition of dyslipidaemia and initiation of lifestyle treatment even in the absence of hypertension is likely to reduce the long-term burden of cardiovascular disease.

Mast cells: multipotent local effector cells in atherothrombosis

Our understanding of the relationship between the proatherogenic activities of arterial mast cells (MCs) and the development of atherosclerotic lesions is advancing. Atherosclerosis is a chronic inflammatory disease in which cholesterol and other lipids of circulating low-density lipoprotein (LDL) particles accumulate both extracellularly and intracellularly in the innermost layer of the arterial wall, the intima. One prerequisite for the proatherogenic activity of the LDL particles is their retention and proteolytic modification within the extracellular matrix of the intima. Experimental studies with activated chymase-secreting MCs have provided us fundamental insights into the molecular mechanisms of these processes. High-density lipoprotein (HDL) particles, again, remove cholesterol from the intracellular stores and carry it back to the circulation. MC chymase and tryptase actively degrade HDL and thus generate functionally defective particles that are unable to initiate cholesterol efflux from the arterial wall. In advanced atherosclerotic plaques, the accumulated lipids are separated from the circulation by a collagenous cap. By inducing apoptosis of endothelial cells (ECs), subendothelial MCs may induce detachment of ECs from the cap (plaque erosion). Moreover, MCs may weaken the cap if they disturb local collagen turnover by inducing apoptosis of the collagen-secreting smooth muscle cells or when they promote collagen degradation by activating matrix metalloproteinases. Plaques with a weak cap are vulnerable to rupture. The exposed subendothelial tissue at eroded and ruptured sites of plaques triggers local development of a platelet-rich thrombus. As regulators of the collagen-induced platelet activation and fibrin formation/fibrinolysis, the MCs may retard or accelerate the growth of the plaque-associated thrombus and ultimately participate in the wound-healing response of the injured plaque. We propose that by promoting cholesterol accumulation and plaque vulnerability and by locally regulating hemostasis, MCs in atherosclerotic lesions have the potential to contribute to the clinical outcomes of atherosclerosis, such as myocardial infarction and stroke.

High Levels of HDL Cholesterol Do Not Predict Protection From Cardiovascular Disease in Women

Elevated levels >or= 60 mg/dL) of high-density lipoprotein cholesterol have been felt to be protective for cardiovascular disease in women. While cardiovascular disease is the leading killer of women in the United States, this is underrecognized, and women's symptoms are often atypical, leading to underdiagnosis. When high-density lipoprotein cholesterol is high, physicians may underestimate a woman's cardiovascular risk. This tendency may have adverse health consequences.

Endothelial dysfunction and arterial abnormalities in childhood obesity

Rates of overweight and obesity in both adults and children have risen sharply during the past 20 years. The reasons for this escalation in obesity are not fully determined, however, sedentary lifestyle and dietary changes in combination with genetic predisposition are probably involved. Clinical cardiovascular disease, including myocardial infarction and stroke, are usually only manifest in the fifth decade of life or beyond. However, the earliest physical signs of atherosclerosis, the underlying disease process that leads to these events, may be present from early childhood. There are now a variety of noninvasive tests used to assess both the structural and functional properties of the vasculature and in vivo changes suggestive of 'early atherosclerosis' have now been characterised. These have allowed not only an increased understanding of the atherosclerotic changes to the vasculature that accompany overweight and obesity in children, but have also allowed serial study of the effects of diet and exercise interventions on early atherosclerosis changes, in childhood obesity.

Niacin-ER/statin combination for the treatment of dyslipidemia: focus on low high-density lipoprotein cholesterol

Statins are effective drugs for lowering low-density lipoprotein cholesterol, and their use has been associated with a significant decrease in cardiovascular morbidity and mortality. However, statins are ineffective in lowering plasma triglycerides and lipoprotein(a), or increasing low high-density lipoprotein cholesterol (HDL-C) plasma levels, which are independent risk factors for coronary heart disease. Niacin, on the other hand, is the most potent drug available for lowering plasma levels of triglycerides and lipoprotein(a) and raising HDL-C levels. It follows, then, that a combination of niacin with a statin might be an effective combination in improving all components of the lipid profile. Previous studies have shown that the use of long-acting niacin with a statin, in dose combinations of niacin-ER/lovastatin 1,000/20 mg or 2,000/40 mg once daily, has been effective in favorably modifying low-density lipoprotein cholesterol, triglycerides, lipoprotein(a), and HDL-C plasma levels. Dyslipidemias often predate the onset of hypertension, and HDL-C has been found to be inversely related to the incidence of hypertension. Normalization of lipid components, including the total cholesterol/HDL-C ratio, is important in the management of hypertensive individuals and patients with the metabolic syndrome or diabetes. Thus, the long-term treatment of dyslipidemias with these two agents may help to modify risk and reduce cardiovascular morbidity and mortality in these patients over and above benefits achieved by lowering blood pressure.