Diet to Stop Hypertension: Should Fats be Included?

PURPOSE OF REVIEW: International guidelines emphasize advice to incorporate dietary measures for the prevention and in the management of hypertension. Current data show that modest reductions in weight can have an impact on blood pressure. Reducing salt and marine oils have also shown consistent benefit in reducing blood pressure. Whether other dietary constituents, in particular the amount and type of fat that play important roles in cardiovascular prevention, influence blood pressure sufficiently to be included in the management of hypertension is less certain. In this review, we provide a summary of the most recent findings, with a focus on dietary patterns, fats and other nutrients and their impact on blood pressure and hypertension. RECENT FINDINGS: Since reducing salt consumption is an established recommendation only corollary dietary advice is subject to the current review. Population studies that have included reliable evaluation of fat intake have indicated almost consistently blood pressure lowering with consumption of marine oils and fats. Results with vegetable oils are inconclusive. However dietary patterns that included total fat reduction and changes in the nature of vegetable fats/oils have suggested beneficial effects on blood pressure. Plant-based foods, dairy foods and yoghurt particularly, may also lower blood pressure irrespective of fat content. Total fat consumption is not directly associated with blood pressure except when it is part of a weight loss diet. Consumption of marine oils has mostly shown moderate blood pressure lowering and possibly greatest effect with docosahexaenoic acid-rich oil.

Australian Atherosclerosis Society Position Statement on Lipoprotein(a): Clinical and Implementation Recommendations.

This position statement provides guidance to cardiologists and related specialists on the management of adult patients with elevated lipoprotein(a) [Lp(a)]. Elevated Lp(a) is an independent and causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve disease (CAVD). While circulating Lp(a) levels are largely determined by ancestry, they are also influenced by ethnicity, hormones, renal function, and acute inflammatory events, such that measurement should be done after accounting for these factors. Further, circulating Lp(a) concentrations should be estimated using an apo(a)-isoform independent assay that employs appropriate calibrators and reports the results in molar units (nmol/L). Selective screening strategies of high-risk patients are recommended, but universal screening of the population is currently not advised. Testing for elevated Lp(a) is recommended in all patients with premature ASCVD and those considered to be at intermediate-to-high risk of ASCVD. Elevated Lp(a) should be employed to assess and stratify risk and to enable a decision on initiation or intensification of preventative treatments, such as cholesterol lowering therapy. In adult patients with elevated Lp(a) at intermediate-to-high risk of ASCVD, absolute risk should be reduced by addressing all modifiable behavioural, lifestyle, psychosocial and clinical risk factors, including maximising cholesterol-lowering with statin and ezetimibe and, where appropriate, PCSK9 inhibitors. Apheresis should be considered in patients with progressive ASCVD. New ribonucleic acid (RNA)-based therapies which directly lower Lp(a) are undergoing clinical trials.

Dietary patterns, dietary nutrients and cardiovascular disease.

A healthy dietary pattern can benefit multiple cardiovascular disease (CVD) risk factors. In conjunction with current standard-of-care pharmaceutical interventions it can provide an effective strategy for the prevention of CVD. Previous dietary recommendations have focused on targeting macronutrients. However, most of the recent international dietary guidelines now recommend a whole food, dietary pattern approach, whilst avoiding quantitative nutrient advice. The guidelines recommend: (1) increased intake of plant-based foods including complex, fibre-rich carbohydrates such as wholegrains, fruits and vegetables, but restricting the intake of refined starches; (2) substituting saturated fats with polyunsaturated and monounsaturated oils; (3) reducing salt intake; (4) increased fish consumption (or fish oils where applicable); (5) reducing sugar-sweetened drinks and added sugars; (6) avoiding butter and cream particularly in individuals at increased risk of CVD, but encouraging fermented products such as yoghurt; there is no specific advice on cheese and milk; (7) allowing consumption of lean meat in moderation but restricting processed meats; and (8) reducing cholesterol intake and foods rich in cholesterol (e.g., eggs and crustaceans) for those with diabetes and at increased CVD risk. The dietary guidelines should be adhered to in conjunction with low-to-moderate alcohol consumption, regular physical activity, avoiding tobacco and maintaining a healthy weight. This review summarises recently published research, international guidelines and position statements for minimizing CVD risk.

Dairy Foods: Is Its Cardiovascular Risk Profile Changing?

PURPOSE OF REVIEW: The majority of international guidelines for cardiovascular disease (CVD) prevention recommend moderate intake of low fat or fat-free products, and limiting full fat dairy food because of its high saturated fatty acid content. Recent equivocal observational studies and greater understanding of the complex nature of dairy foods has led to reappraisal for some types of dairy foods. RECENT FINDINGS: Current guidelines from major cardiovascular societies have differed; interpretation of major observational studies has been inconsistent. Apart from the adverse effect of butter, consumption of more complex dairy products notably fermented varieties, yogurt in particular, appears to be inversely associated with outcomes of CVD and type 2 diabetes (T2D). Reduced fat in dairy food appears advantageous but is no longer a unanimous view although is preferred for people at increased CVD risk and dyslipidemia. Changed evidence has led to new advice regarding consumption of some dairy foods. The apparent beneficial effects of cheese, fermented milk, and yogurt allow for increased consumption of nutritious staple foods. Reduced fat yogurt may be desirable as part of diets for individuals with CVD or T2D.

Shark liver oil supplementation enriches endogenous plasmalogens and reduces markers of dyslipidemia and inflammation.

Plasmalogens are membrane glycerophospholipids with diverse biological functions. Reduced plasmalogen levels have been observed in metabolic diseases; hence, increasing their levels might be beneficial in ameliorating these conditions. Shark liver oil (SLO) is a rich source of alkylglycerols that can be metabolized into plasmalogens. This study was designed to evaluate the impact of SLO supplementation on endogenous plasmalogen levels in individuals with features of metabolic disease. In this randomized, double-blind, placebo-controlled cross-over study, the participants (10 overweight or obese males) received 4-g Alkyrol® (purified SLO) or placebo (methylcellulose) per day for 3 weeks followed by a 3-week washout phase and were then crossed over to 3 weeks of the alternate placebo/Alkyrol® treatment. SLO supplementation led to significant changes in plasma and circulatory white blood cell lipidomes, notably increased levels of plasmalogens and other ether lipids. In addition, SLO supplementation significantly decreased the plasma levels of total free cholesterol, triglycerides, and C-reactive protein. These findings suggest that SLO supplementation can enrich plasma and cellular plasmalogens and this enrichment may provide protection against obesity-related dyslipidemia and inflammation.

Development and validation of a ceramide- and phospholipid-based cardiovascular risk estimation score for coronary artery disease patients.

AIMS: Distinct ceramide lipids have been shown to predict the risk for cardiovascular disease (CVD) events, especially cardiovascular death. As phospholipids have also been linked with CVD risk, we investigated whether the combination of ceramides with phosphatidylcholines (PCs) would be synergistic in the prediction of CVD events in patients with atherosclerotic coronary heart disease in three independent cohort studies. METHODS AND RESULTS: Ceramides and PCs were analysed using liquid chromatography-mass spectrometry (LC-MS) in three studies: WECAC (The Western Norway Coronary Angiography Cohort) (N = 3789), LIPID (Long-Term Intervention with Pravastatin in Ischaemic Disease) trial (N = 5991), and KAROLA (Langzeiterfolge der KARdiOLogischen Anschlussheilbehandlung) (N = 1023). A simple risk score, based on the ceramides and PCs showing the best prognostic features, was developed in the WECAC study and validated in the two other cohorts. This score was highly significant in predicting CVD mortality [multiadjusted hazard ratios (HRs; 95% confidence interval) per standard deviation were 1.44 (1.28-1.63) in WECAC, 1.47 (1.34-1.61) in the LIPID trial, and 1.69 (1.31-2.17) in KAROLA]. In addition, a combination of the risk score with high-sensitivity troponin T increased the HRs to 1.63 (1.44-1.85) and 2.04 (1.57-2.64) in WECAC and KAROLA cohorts, respectively. The C-statistics in WECAC for the risk score combined with sex and age was 0.76 for CVD death. The ceramide-phospholipid risk score showed comparable and synergistic predictive performance with previously published CVD risk models for secondary prevention. CONCLUSION: A simple ceramide- and phospholipid-based risk score can efficiently predict residual CVD event risk in patients with coronary artery disease.

Practical Guidance for Food Consumption to Prevent Cardiovascular Disease.

This dietary guidance, informed by best contemporary evidence, aims to assist medical practitioners and allied health professionals in advising patients for the primary and secondary prevention of cardiovascular disease (CVD). While differing in some details from other current guidelines, the core messages accord with those published in 2019 by the American College of Cardiology/American Heart Association and the European Society of Cardiology/European Atherosclerosis Society; the National Lipid Association in 2014 and the NH&MRC Australian Dietary Guidelines in 2013. These were assessed through the Appraisal of Guidelines for Research and Evaluation (AGREE II) and the levels of evidence and classes of a recommendation developed using the GRADE system. Recommendations with high levels of evidence include increased consumption of plant based foods comprising mainly complex, fibre enriched carbohydrates (wholegrains, fruits and vegetables) while limiting intake of refined starches; partial replacement of saturated fats with monounsaturated or polyunsaturated fats and oils; reduced salt intake; achievement and maintenance of healthy weight; and low-to-moderate consumption of alcohol. Additional guidance but with moderate levels of evidence includes increased consumption of fish (and fish oils where indicated); reduction in sugar-sweetened beverages and added sugars; avoidance of butter and cream especially in those at increased CVD risk but encouragement of yoghurt; allow moderate consumption of lean meat but limit intake of processed meats; and limit cholesterol-rich foods such as eggs and crustaceans for those at increased CVD risk. Guidance has been formulated qualitatively on food categories of commonly eaten foods while avoiding prescriptive quantitative measures that are less readily translatable. This approach accords with current guidelines such as the American College of Cardiology/American Heart Association 2019 guidelines and is understandable and readily implemented.

Gaps in the Care of Familial Hypercholesterolaemia in Australia: First Report From the National Registry.

BACKGROUND: Familial hypercholesterolaemia (FH) is under-diagnosed and under-treated worldwide, including Australia. National registries play a key role in identifying patients with FH, understanding gaps in care and advancing the science of FH to improve care for these patients. METHODS: The FH Australasia Network has established a national web-based registry to raise awareness of the condition, facilitate service planning and inform best practice and care services in Australia. We conducted a cross-sectional analysis of 1,528 FH adults enrolled in the registry from 28 lipid clinics. RESULTS: The mean age at enrolment was 53.4±15.1 years, 50.5% were male and 54.3% had undergone FH genetic testing, of which 61.8% had a pathogenic FH-causing gene variant. Only 14.0% of the cohort were family members identified through cascade testing. Coronary artery disease (CAD) was reported in 28.0% of patients (age of onset 49.0±10.5 years) and 64.9% had at least one modifiable cardiovascular risk factor. The mean untreated LDL-cholesterol was 7.4±2.5 mmol/L. 80.8% of patients were on lipid-lowering therapy with a mean treated LDL-cholesterol of 3.3±1.7 mmol/L. Among patients receiving lipid-lowering therapies, 25.6% achieved an LDL-cholesterol target of <2.5 mmol/L without CAD or <1.8 mmol/L with CAD. CONCLUSION: Patients in the national FH registry are detected later in life, have a high burden of CAD and risk factors, and do not achieve guideline-recommended LDL-cholesterol targets. Genetic and cascade testing are under-utilised. These deficiencies in care need to be addressed as a public health priority.

Changing dietary approaches to prevent cardiovascular disease.

PURPOSE OF REVIEW: We have focused on recent research relevant to effects of dietary patterns and major food groups on cardiovascular outcomes, taking into account guidelines and position statements from expert authorities, with an emphasis on important changes in recommendations, some of which remain controversial. RECENT FINDINGS: Major findings include: refocusing on qualitative patterns of food consumption replacing quantitative prescriptive advice on nutrients; increasing intake of plant foods; substituting saturated fats with polyunsaturated and monounsaturated oils; reducing salt intake; regular consumption of fish with a focus on omega-3 enrichment; not restricting dairy foods, other than butter and cream, with encouragement of some fermented products; reducing cholesterol intake for those at increased cardiovascular risk and diabetes, allowing 7-eggs weekly; restricting processed meats and allowing moderate lean meat consumption; preference for fiber-rich complex carbohydrates and reduced sugar intake; maintaining healthy bodyweight; and although water is the preferred beverage, allowing moderate alcohol consumption to national guidelines and avoiding alcohol in specific cardiovascular disorders. SUMMARY: The new approach that focuses on healthier patterns of food intake is more readily understood by health practitioners and translatable to consumers and patients.

Cholesterol transport between red blood cells and lipoproteins contributes to cholesterol metabolism in blood.

Lipoproteins play a key role in transport of cholesterol to and from tissues. Recent studies have also demonstrated that red blood cells (RBCs), which carry large quantities of free cholesterol in their membrane, play an important role in reverse cholesterol transport. However, the exact role of RBCs in systemic cholesterol metabolism is poorly understood. RBCs were incubated with autologous plasma or isolated lipoproteins resulting in a significant net amount of cholesterol moved from RBCs to HDL, while cholesterol from LDL moved in the opposite direction. Furthermore, the bi-directional cholesterol transport between RBCs and plasma lipoproteins was saturable and temperature-, energy-, and time-dependent, consistent with an active process. We did not find LDLR, ABCG1, or scavenger receptor class B type 1 in RBCs but found a substantial amount of ABCA1 mRNA and protein. However, specific cholesterol efflux from RBCs to isolated apoA-I was negligible, and ABCA1 silencing with siRNA or inhibition with vanadate and Probucol did not inhibit the efflux to apoA-I, HDL, or plasma. Cholesterol efflux from and cholesterol uptake by RBCs from Abca1+/+ and Abca1-/- mice were similar, arguing against the role of ABCA1 in cholesterol flux between RBCs and lipoproteins. Bioinformatics analysis identified ABCA7, ABCG5, lipoprotein lipase, and mitochondrial translocator protein as possible candidates that may mediate the cholesterol flux. Together, these results suggest that RBCs actively participate in cholesterol transport in the blood, but the role of cholesterol transporters in RBCs remains uncertain.

D-Dimer Predicts Long-Term Cause-Specific Mortality, Cardiovascular Events, and Cancer in Patients With Stable Coronary Heart Disease: LIPID Study.

BACKGROUND: D-dimer, a degradation product of cross-linked fibrin, is a marker for hypercoagulability and thrombotic events. Moderately elevated levels of D-dimer are associated with the risk of venous and arterial events in patients with vascular disease. We assessed the role of D-dimer levels in predicting long-term vascular outcomes, cause-specific mortality, and new cancers in the LIPID trial (Long-Term Intervention with Pravastatin in Ischaemic Disease) in the context of other risk factors. METHODS: LIPID randomized patients to placebo or pravastatin 40 mg/d 5 to 38 months after myocardial infarction or unstable angina. D-dimer levels were measured at baseline and at 1 year. Median follow-up was 6.0 years during the trial and 16 years in total. RESULTS: Baseline D-dimer levels for 7863 patients were grouped by quartile (≤112, 112-173, 173-273, >273 ng/mL). Higher levels were associated with older age, female sex, history of hypertension, poor renal function, and elevated levels of B-natriuretic peptide, high-sensitivity C-reactive protein, and sensitive troponin I (each P<0.001). During the first 6 years, after adjustment for up to 30 additional risk factors, higher D-dimer was associated with a significantly increased risk of a major coronary event (quartile 4 versus 1: hazard ratio [HR], 1.45; 95% confidence interval, 1.21-1.74), major cardiovascular disease (CVD) event (HR, 1.45; 95% confidence interval, 1.23-1.71) and venous thromboembolism (HR, 4.03; 95% confidence interval, 2.31-7.03; each P<0.001). During the 16 years overall, higher D-dimer was an independent predictor of all-cause mortality (HR, 1.59), CVD mortality (HR, 1.61), cancer mortality (HR, 1.54), and non-CVD noncancer mortality (HR, 1.57; each P<0.001), remaining significant for deaths resulting from each cause occurring beyond 10 years of follow-up (each P≤0.01). Higher D-dimer also independently predicted an increase in cancer incidence (HR, 1.16; P=0.02).The D-dimer level increased the net reclassification index for all-cause mortality by 4.0 and venous thromboembolism by 13.6. CONCLUSIONS: D-dimer levels predict long-term risk of arterial and venous events, CVD mortality, and non-CVD noncancer mortality independent of other risk factors. D-dimer is also a significant predictor of cancer incidence and mortality. These results support an association of D-dimer with fatal events across multiple diseases and demonstrate that this link extends beyond 10 years' follow-up.

Baseline and on-statin treatment lipoprotein(a) levels for prediction of cardiovascular events: individual patient-data meta-analysis of statin outcome trials.

BACKGROUND: Elevated lipoprotein(a) is a genetic risk factor for cardiovascular disease in general population studies. However, its contribution to risk for cardiovascular events in patients with established cardiovascular disease or on statin therapy is uncertain. METHODS: Patient-level data from seven randomised, placebo-controlled, statin outcomes trials were collated and harmonised to calculate hazard ratios (HRs) for cardiovascular events, defined as fatal or non-fatal coronary heart disease, stroke, or revascularisation procedures. HRs for cardiovascular events were estimated within each trial across predefined lipoprotein(a) groups (15 to <30 mg/dL, 30 to <50 mg/dL, and ≥50 mg/dL, vs <15 mg/dL), before pooling estimates using multivariate random-effects meta-analysis. FINDINGS: Analyses included data for 29 069 patients with repeat lipoprotein(a) measurements (mean age 62 years [SD 8]; 8064 [28%] women; 5751 events during 95 576 person-years at risk). Initiation of statin therapy reduced LDL cholesterol (mean change -39% [95% CI -43 to -35]) without a significant change in lipoprotein(a). Associations of baseline and on-statin treatment lipoprotein(a) with cardiovascular disease risk were approximately linear, with increased risk at lipoprotein(a) values of 30 mg/dL or greater for baseline lipoprotein(a) and 50 mg/dL or greater for on-statin lipoprotein(a). For baseline lipoprotein(a), HRs adjusted for age and sex (vs <15 mg/dL) were 1·04 (95% CI 0·91-1·18) for 15 mg/dL to less than 30 mg/dL, 1·11 (1·00-1·22) for 30 mg/dL to less than 50 mg/dL, and 1·31 (1·08-1·58) for 50 mg/dL or higher; respective HRs for on-statin lipoprotein(a) were 0·94 (0·81-1·10), 1·06 (0·94-1·21), and 1·43 (1·15-1·76). HRs were almost identical after further adjustment for previous cardiovascular disease, diabetes, smoking, systolic blood pressure, LDL cholesterol, and HDL cholesterol. The association of on-statin lipoprotein(a) with cardiovascular disease risk was stronger than for on-placebo lipoprotein(a) (interaction p=0·010) and was more pronounced at younger ages (interaction p=0·008) without effect-modification by any other patient-level or study-level characteristics. INTERPRETATION: In this individual-patient data meta-analysis of statin-treated patients, elevated baseline and on-statin lipoprotein(a) showed an independent approximately linear relation with cardiovascular disease risk. This study provides a rationale for testing the lipoprotein(a) lowering hypothesis in cardiovascular disease outcomes trials. FUNDING: Novartis Pharma AG.

Dietary Fat and Blood Pressure.

PURPOSE OF REVIEW: Do dietary fats lower blood pressure? This review covers total fats, individual fatty acids and foods that provide specific fats. RECENT FINDINGS: Evidence for blood pressure lowering is stronger for supplements providing individual marine fatty acids than for fish intake since data on fish consumption are scarce. Such effects are more readily apparent in hypertensive than normal subjects. Biological mechanisms to support linkage between dietary fish oils and blood pressure are plausible. Information on other dietary fatty acids (saturates, linoleic acid, alpha-linolenic acid) is mostly less robust and therefore inconclusive. However, findings with respect to consumption of dairy foods especially of the low-fat variety do suggest association with lower blood pressures. Apart from marine fatty acids which have mostly been significantly associated with clinically modest blood pressure-lowering, the effects of other dietary fatty acids are inconsistent or clinically minor. Consumption of dairy especially of yoghurt has been linked with lower blood pressure despite the relatively high saturated fat content but the mechanism is unclear.

Weight Loss and Exercise Alter the High-Density Lipoprotein Lipidome and Improve High-Density Lipoprotein Functionality in Metabolic Syndrome.

OBJECTIVE: High-density lipoprotein (HDL) lipid composition and function may better reflect cardiovascular risk than HDL cholesterol concentration. This study characterized the relationships between HDL composition, metabolism, and function in metabolic syndrome (MetS) patients and how changes in composition after weight loss (WL) and exercise treatments are related to function. APPROACH AND RESULTS: Plasma samples from MetS patients (n=95) and healthy individuals (n=40) were used in this study. Subsets of the MetS group underwent 12 weeks of no treatment (n=17), WL (n=19), or WL plus exercise (WLEX; n=17). HDL was isolated using density-gradient ultracentrifugation. The HDL lipidome was analyzed by mass spectrometry, and particle size determined by nuclear magnetic resonance. Cholesteryl ester transfer protein activity and ex vivo HDL cholesterol efflux capacity (CEC) were assessed. The HDL lipidome in the MetS patients was substantially different from that in healthy individuals, mean particle size was smaller, and CEC was lower. Several HDL phospholipid and sphingolipid species were associated with HDL diameter and CEC. The HDL lipidome and particle size were modified toward the healthy individuals after WL and WLEX treatments, with greater effects observed in the latter group. Cholesteryl ester transfer protein activity was reduced after WL and WLEX, and CEC was improved after WLEX. CONCLUSIONS: WLEX treatment in MetS patients normalizes the HDL lipidome and particle size profile and enhances CEC. HDL lipids associated with diminished CEC may represent novel biomarkers for early prediction of HDL dysfunction and disease risk and may represent potential therapeutic targets for future HDL therapies. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00163943.

Long-Term Effectiveness and Safety of Pravastatin in Patients With Coronary Heart Disease: Sixteen Years of Follow-Up of the LIPID Study.

BACKGROUND: We aimed to assess the long-term effects of treatment with statin therapy on all-cause mortality, cause-specific mortality, and cancer incidence from extended follow-up of the Long-term Intervention with Pravastatin in Ischemic Disease (LIPID) trial. METHODS AND RESULTS: LIPID initially compared pravastatin and placebo over 6 years in 9014 patients with previous coronary heart disease. After the double-blind period, all patients were offered open-label statin therapy. Data were obtained over a further 10 years from 7721 patients, by direct contact for 2 years, by questionnaires thereafter, and from mortality and cancer registries. During extended follow-up, 85% assigned pravastatin and 84% assigned placebo took statin therapy. Patients assigned pravastatin maintained a significantly lower risk of death from coronary heart disease (relative risk [RR] 0.89; 95% confidence interval [CI], 0.81-0.97; P=0.009), from cardiovascular disease (RR, 0.88; 95% CI, 0.81-0.95; P=0.002), and from any cause (RR, 0.91; 95% CI, 0.85-0.97; absolute risk reduction, 2.6%; P=0.003).Cancer incidence was similar by original treatment group during the double-blind period (RR, 0.94; 95% CI, 0.82-1.08; P=0.41), later follow-up (RR, 1.02; 95% CI, 0.91-1.14; P=0.74), and overall (RR, 0.99; 95% CI, 0.91-1.08; P=0.83). There were no significant differences in cancer mortality, or in the incidence of organ-specific cancers. Cancer findings were confirmed in a meta-analysis with other large statin trials with extended follow-up. CONCLUSIONS: In LIPID, the absolute survival benefit from 6 years of pravastatin treatment appeared to be maintained for the next 10 years, with a similar risk of death among survivors in both groups after the initial period. Treatment with statins does not influence cancer or death from noncardiovascular causes during long-term follow-up.

Plasma Lipidomic Profiles Improve on Traditional Risk Factors for the Prediction of Cardiovascular Events in Type 2 Diabetes Mellitus.

BACKGROUND: Clinical lipid measurements do not show the full complexity of the altered lipid metabolism associated with diabetes mellitus or cardiovascular disease. Lipidomics enables the assessment of hundreds of lipid species as potential markers for disease risk. METHODS: Plasma lipid species (310) were measured by a targeted lipidomic analysis with liquid chromatography electrospray ionization-tandem mass spectrometry on a case-cohort (n=3779) subset from the ADVANCE trial (Action in Diabetes and Vascular Disease: Preterax and Diamicron-MR Controlled Evaluation). The case-cohort was 61% male with a mean age of 67 years. All participants had type 2 diabetes mellitus with ≥1 additional cardiovascular risk factors, and 35% had a history of macrovascular disease. Weighted Cox regression was used to identify lipid species associated with future cardiovascular events (nonfatal myocardial infarction, nonfatal stroke, and cardiovascular death) and cardiovascular death during a 5-year follow-up period. Multivariable models combining traditional risk factors with lipid species were optimized with the Akaike information criteria. C statistics and NRIs were calculated within a 5-fold cross-validation framework. RESULTS: Sphingolipids, phospholipids (including lyso- and ether- species), cholesteryl esters, and glycerolipids were associated with future cardiovascular events and cardiovascular death. The addition of 7 lipid species to a base model (14 traditional risk factors and medications) to predict cardiovascular events increased the C statistic from 0.680 (95% confidence interval [CI], 0.678-0.682) to 0.700 (95% CI, 0.698-0.702; P<0.0001) with a corresponding continuous NRI of 0.227 (95% CI, 0.219-0.235). The prediction of cardiovascular death was improved with the incorporation of 4 lipid species into the base model, showing an increase in the C statistic from 0.740 (95% CI, 0.738-0.742) to 0.760 (95% CI, 0.757-0.762; P<0.0001) and a continuous net reclassification index of 0.328 (95% CI, 0.317-0.339). The results were validated in a subcohort with type 2 diabetes mellitus (n=511) from the LIPID trial (Long-Term Intervention With Pravastatin in Ischemic Disease). CONCLUSIONS: The improvement in the prediction of cardiovascular events, above traditional risk factors, demonstrates the potential of plasma lipid species as biomarkers for cardiovascular risk stratification in diabetes mellitus. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier: NCT00145925.

Reduction in peripheral vascular resistance predicts improvement in insulin clearance following weight loss.

BACKGROUND: The hyperinsulinemia of obesity is a function of both increased pancreatic insulin secretion and decreased insulin clearance, and contributes to cardiovascular risk. Whilst weight loss is known to enhance insulin clearance, there is a paucity of data concerning the underlying mechanisms. This study was conducted to examine the inter-relationships between changes in sympathetic nervous system (SNS) activity, vascular function and insulin clearance during a weight loss program. METHODS: Seventeen non-smoking, un-medicated individuals aged 55 ± 1 years (mean ± SEM), body mass index (BMI) 33.9 ± 1.7 kg/m(2), underwent a 4-month hypocaloric diet (HCD), using a modified Dietary Approaches to Stop Hypertension diet, whilst seventeen age- and BMI-matched subjects acted as controls. Insulin sensitivity and insulin clearance were assessed via euglycemic hyperinsulinemic clamp (exogenous insulin clearance); hepatic insulin extraction was calculated as fasting C-peptide to insulin ratio (endogenous insulin clearance); SNS activity was quantified by microneurographic nerve recordings of muscle sympathetic nerve activity (MSNA) and whole-body norepinephrine kinetics; and vascular function by calf venous occlusion plethysmography and finger arterial tonometry. RESULTS: Weight loss averaged -8.3 ± 0.6% of body weight in the HCD group and was accompanied by increased clamp-derived glucose utilization (by 20 ± 9%, P = 0.04) and exogenous insulin clearance (by 12 ± 5%, P = 0.02). Hepatic insulin extraction increased from 6.3 ± 0.8 to 7.1 ± 0.9 (P = 0.09). Arterial norepinephrine concentration decreased by -12 ± 5%, whole-body norepinephrine spillover rate by -14 ± 8%, and MSNA by -9 ± 5 bursts per 100 heartbeats in the HCD group (P all >0.05 versus control group). Step-wise regression analysis revealed a bidirectional relationship between enhanced exogenous insulin clearance post weight loss and reduction in calf vascular resistance (r = -0.63, P = 0.01) which explained 40% of the variance. Increase in hepatic insulin extraction was predicted by enhanced finger reactive hyperaemic response (P = 0.006) and improvement in oral glucose tolerance (P = 0.002) which together explained 64% of the variance. CONCLUSIONS: Insulin clearance is independently and reciprocally associated with changes in vascular function during weight loss intervention. Trial registration ClinicalTrials.gov: NCT01771042 and NCT00408850.

Postprandial Plasma Phospholipids in Men Are Influenced by the Source of Dietary Fat.

BACKGROUND: Postprandial lipemia represents a risk factor for chronic diseases, including type 2 diabetes. Little is known about the effect of dietary fat on the plasma lipidome in the postprandial period. OBJECTIVE: The objective of this study was to assess the effect of dairy fat and soy oil on circulating postprandial lipids in men. METHODS: Men (40-60 y old, nonsmokers; n = 16) were randomly assigned in a crossover design to consume 2 breakfast meals of dairy-based or soy oil-based foods. The changes in the plasma lipidome during the 4-h postprandial period were analyzed with electrospray ionization tandem mass spectrometry and included 316 lipid species in 23 classes and subclasses, representing sphingolipids, phospholipids, glycerolipids, and sterols. RESULTS: Nonparametric Friedman tests showed significant changes in multiple plasma lipid classes, subclasses, and species in the postprandial period after both dairy and soy meals. No difference was found in triglyceridemia after each meal. However, 6 endogenous lipid classes increased after dairy but decreased after soy (P < 0.05), including ether-linked phospholipids and plasmalogens and sphingomyelin (not present in soy), dihexosylceramide, and GM3 ganglioside. Phosphatidylcholine and phosphatidylinositol were not affected by the soy meal but were significantly elevated after the dairy meal (8.3% and 16%, respectively; P < 0.05). CONCLUSIONS: The changes in postprandial plasma phospholipids in men relate to the diet composition and the relative size of the endogenous phospholipid pools. Despite similar lipemic responses as measured by changes in triglyceride concentrations, the differential responses to dairy and soy meals derived through lipidomic analysis of phospholipids suggest differences in the metabolism of soybean oil and dairy fat. The increased concentrations of plasmalogens, with potential antioxidant capacity, in the postprandial period after dairy but not soy meals may represent a further important difference in the response to these sources of fat. The trial was registered at www.anzctr.org.au as ACTRN12610000562077.

Indications for Omega-3 Long Chain Polyunsaturated Fatty Acid in the Prevention and Treatment of Cardiovascular Disease.

BACKGROUND: The National Heart Foundation of Australia (NHFA) 2008 review on omega-3 long-chain polyunsaturated fatty acids (LCPUFA) made recommendations with respect to supplementation for primary and secondary prevention of cardiovascular disease. Since then, new findings have been published regarding the relationship between omega-3 polyunsaturated fatty acids, including supplementation, and cardiovascular health. METHODS: A literature search was undertaken in PubMed and Medline, for literature published between January 1, 2007 and August 31, 2013. RESULTS AND CONCLUSIONS: A total of eight research questions were developed and, using the National Health and Medical Research Council's evidence assessment framework, conclusions were made in relation to dietary intake of fish and omega-3 LCPUFA for cardiovascular health. In the evidence published since 2007, this summary of evidence concludes that dietary intake of fish was found to be mostly consistent with respect to protection from heart disease and stroke. Higher fish intake was associated with lower incident rates of heart failure in addition to lower sudden cardiac death, stroke and myocardial infarction. In relation to omega-3 LCPUFA supplementation, neither a beneficial nor adverse effect was demonstrated in primary or secondary prevention of coronary heart disease (CHD). Although the evidence continues to be positive for the role of omega-3 LCPUFA in the treatment of hypertriglyceridaemia and a modest positive benefit in heart failure. No further evidence was found to support the consumption of 2g alpha-linolenic acid (ALA)/day over the current Australian guidelines for 1 g/day.

Plasma lipoprotein(a) concentration predicts future coronary and cardiovascular events in patients with stable coronary heart disease.

OBJECTIVE: Association between lipoprotein(a) (Lp(a)) level and a first-ever coronary (CHD) event is recognized. Less is evident in patients with overt CHD and stable symptoms in whom we investigated associations between Lp(a) and future events. APPROACH AND RESULTS: Relationships between Lp(a) concentration and CHD and cardiovascular disease outcomes during 6 years' median follow-up were evaluated in the Long-Term Intervention with Pravastatin in Ischaemic Disease (LIPID) study. Lp(a) concentrations were measured in plasma from 7863 patients who had sustained a previous coronary event and been randomized to pravastatin or placebo. Lp(a) levels were categorized by lowest half, third quartile, 75th to 90th percentile, and highest decile. The prognostic value of Lp(a) on outcomes was assessed by fitting a Cox proportional-hazards model after adjustment for other risk factors and baseline cardiovascular disorders. The prognostic value of a change in Lp(a) at year 1 categorized by quartiles was assessed using Cox regression in a landmark model incorporating the above factors and baseline levels. Baseline Lp(a) concentration was associated with total CHD events (P<0.001), total cardiovascular disease events (P=0.002), and coronary events (P=0.03). Greatest risk occurred at >73 mg/dL, upper decile. For events after year 1, an increase in Lp(a) at 1 year was associated with adverse outcomes for total CHD events and total cardiovascular disease events (P=0.002 each). CONCLUSIONS: In the LIPID study, baseline Lp(a) was associated with future cardiovascular disease and CHD events. Increased Lp(a) concentrations after 1 year were also associated with future events, supporting measurement of Lp(a) for risk assessment of patients with known CHD.