All Low-Density Lipoprotein Particles Are Not Created Equal

Efficacy and Safety of Long-term Ketogenic Diet Therapy in a Patient With Type 1 Diabetes

Fewer than 1% of patients with type 1 diabetes achieve normal glycemic control (glycated hemoglobin [HbA1c] < 5.7%/ < 39 mmol/mol). Additionally, exogenous insulin administration often causes "iatrogenic hyperinsulinemia," leading to whole-body insulin resistance and increased risk of cardiovascular complications. We present data on the clinical efficacy and safety of a long-term (10-year) ketogenic diet (≤50 g carbohydrates/day) therapy in a patient with type 1 diabetes. The use of a ketogenic diet resulted in successful glycemic control, assessed by HbA1c (5.5%; 36.6 mmol/mol), continuous glucose monitoring median glucose (98 mg/dL; 5.4 mmol/L), and glucose time-in-range of 70 to 180 mg/dL (90%) without acute glycemic complications. In conjunction, there was a 43% decrease in daily insulin requirements. Low-density lipoprotein cholesterol increased, whereas small-dense low-density lipoprotein was in the normal range (<90 nmol/L). No adverse effects were observed on thyroid function, kidney function, or bone mineral density. This case report demonstrates that a long-term ketogenic diet in a person with type 1 diabetes has considerable therapeutic benefits.

Increased low-density lipoprotein cholesterol on a low-carbohydrate diet in adults with normal but not high body weight: A meta-analysis

BACKGROUND

Low-density lipoprotein (LDL) cholesterol change with consumption of a low-carbohydrate diet (LCD) is highly variable. Identifying the source of this heterogeneity could guide clinical decision-making.

OBJECTIVES

To evaluate LDL cholesterol change in randomized controlled trials involving LCDs, with a focus on body mass index (BMI) in kg/m2.

METHODS

Three electronic indexes (Pubmed, EBSCO, and Scielo) were searched for studies between 1 January, 2003 and 20 December, 2022. Two independent reviewers identified randomized controlled trials involving adults consuming <130 g/d carbohydrate and reporting BMI and LDL cholesterol change or equivalent data. Two investigators extracted relevant data, which were validated by other investigators. Data were analyzed using a random-effects model and contrasted with results of pooled individual participant data.

RESULTS

Forty-one trials with 1379 participants and a mean intervention duration of 19.4 wk were included. In a meta-regression accounting for 51.4% of the observed variability on LCDs, mean baseline BMI had a strong inverse association with LDL cholesterol change [β = -2.5 mg/dL/BMI unit, 95% confidence interval (CI): -3.7, -1.4], whereas saturated fat amount was not significantly associated with LDL cholesterol change. For trials with mean baseline BMI <25, LDL cholesterol increased by 41 mg/dL (95% CI: 19.6, 63.3) on the LCD. By contrast, for trials with a mean of BMI 25-<35, LDL cholesterol did not change, and for trials with a mean BMI ≥35, LDL cholesterol decreased by 7 mg/dL (95% CI: -12.1, -1.3). Using individual participant data, the relationship between BMI and LDL cholesterol change was not observed on higher-carbohydrate diets.

CONCLUSIONS

A substantial increase in LDL cholesterol is likely for individuals with low but not high BMI with consumption of an LCD, findings that may help guide individualized nutritional management of cardiovascular disease risk. As carbohydrate restriction tends to improve other lipid and nonlipid risk factors, the clinical significance of isolated LDL cholesterol elevation in this context warrants investigation. This trial was registered at PROSPERO as CRD42022299278.

Effects of a low-carbohydrate diet in adults with type 1 diabetes management: A single arm non-randomised clinical trial

Public interest in low-carbohydrate (LC) diets for type 1 diabetes (T1D) management has increased. This study compared the effects of a healthcare professional delivered LC diet compared to habitual diets higher in carbohydrates on clinical outcomes in adults with T1D. Twenty adults (18-70 yrs) with T1D (≥6 months duration) with suboptimal glycaemic control (HbA1c>7.0% or >53 mmol/mol) participated in a 16-week single arm within-participant, controlled intervention study involving a 4-week control period following their habitual diets (>150 g/day of carbohydrates) and a 12-week intervention period following a LC diet (25-75 g/day of carbohydrates) delivered remotely by a registered dietitian. Glycated haemoglobin (HbA1c -primary outcome), time in range (blood glucose: 3.5-10.0 mmol/L), frequency of hypoglycaemia (<3.5 mmol/L), total daily insulin, and quality of life were assessed before and after the control and intervention periods. Sixteen participants completed the study. During the intervention period, there were reductions in total dietary carbohydrate intake (214 to 63 g/day; P<0.001), HbA1c (7.7 to 7.1% or 61 to 54 mmol/mol; P = 0.003) and total daily insulin use (65 to 49 U/day; P<0.001), increased time spent in range (59 to 74%; P<0.001), and improved quality of life (P = 0.015), with no significant changes observed during the control period. Frequency of hypoglycaemia episodes did not differ across timepoints, and no episodes of ketoacidosis or other adverse events were reported during the intervention period. These preliminary findings suggest that a professionally supported LC diet may lead to improvements in markers of blood glucose control and quality of life with reduced exogenous insulin requirements and no evidence of increased hypoglycaemia or ketoacidosis risk in adults with T1D. Given the potential benefits of this intervention, larger, longer-term randomised controlled trials are warranted to confirm these findings. Trial Registration: https://www.anzctr.org.au/ACTRN12621000764831.aspx.

Exploring the Association between Low-Density Lipoprotein Subfractions and Major Adverse Cardiovascular Outcomes—A Comprehensive Review

Cardiovascular disease (CVD) impacts hundreds of millions of people each year and is the main cause of death worldwide, with atherosclerosis being its most frequent form of manifestation. Low-density lipoproteins (LDL) have already been established as a significant cardiovascular risk factor, but more recent studies have shown that small, dense LDLs are the ones more frequently associated with a higher overall risk for developing atherosclerotic cardiovascular disease. Ever since atherogenic phenotypes were defined for the first time, LDL subfractions have been continuously analyzed in order to identify those with a higher atherogenic profile that could further become not only high-accuracy, effective prognostic biomarkers, but also treatment targets for novel lipid-lowering molecules. This review sets out to comprehensively evaluate the association between various LDL-subfractions and the risk of further developing major adverse cardiovascular events, by assessing both genetical and clinical features and focusing on their physiopathological characteristics, chemical composition, and global ability to predict long-term cardiovascular risk within the general population. Further research is required in order to establish the most beneficial range of LDL-C levels for both primary and secondary prevention, as well as to implement LDL subfraction testing as a routine protocol, separately from the general assessment of the other traditional cardiovascular risk factors.

Mechanism of the Regulation of Plasma Cholesterol Levels by PI(4,5)P2

Elevated low-density lipoprotein (LDL) cholesterol (LDLc) is one of the most well-established risk factors for cardiovascular disease, while high levels of high-density lipoprotein (HDL) cholesterol (HDLc) have been associated with protection from cardiovascular disease. Cardiovascular disease remains one of the leading causes of death worldwide; thus it is important to understand mechanisms that impact LDLc and HDLc metabolism. In this chapter, we will discuss molecular processes by which phosphatidylinositol-(4,5)-bisphosphate, PI(4,5)P₂, is thought to modulate LDLc or HDLc. Section 1 will provide an overview of cholesterol in the circulation, discussing processes that modulate the various forms of lipoproteins (LDL and HDL) carrying cholesterol. Section 2 will describe how a PI(4,5)P₂ phosphatase, transmembrane protein 55B (TMEM55B), impacts circulating LDLc levels through its ability to regulate lysosomal decay of the low-density lipoprotein receptor (LDLR), the primary receptor for hepatic LDL uptake. Section 3 will discuss how PI(4,5)P₂ interacts with apolipoprotein A-I (apoA1), the key apolipoprotein on HDL. In addition to direct mechanisms of PI(4,5)P₂ action on circulating cholesterol, Sect. 4 will review how PI(4,5)P₂ may indirectly impact LDLc and HDLc by affecting insulin action. Last, as cholesterol is controlled through intricate negative feedback loops, Sect. 5 will describe how PI(4,5)P₂ is regulated by cholesterol.

A Health Care Professional Delivered Low Carbohydrate Diet Program Reduces Body Weight, Haemoglobin A1c, Diabetes Medication Use and Cardiovascular Risk Markers-A Single-Arm Intervention Analysis

This study examined the effectiveness of a health care professional delivered low-carbohydrate diet program (Diversa Health Program) aiming to improve obesity/type-2-diabetes management for people living in Australia. 511 adults (Age:57.1 ± 13.7 [SD] yrs) who participated between January 2017−August 2021 for ≥30 days with pre-post data collected for ≥1 key outcome variable (body weight and HbA1c) were included in the analysis. Average participation duration was 218 ± 207 days with 5.4 ± 3.9 reported consultation visits. Body weight reduced from 92.3 ± 23.0 to 86.3 ± 21.1 kg (n = 506, p < 0.001). Weight loss was 0.9 ± 2.8 kg (1.3%), 4.5 ± 4.3 kg (5.7%) and 7.9 ± 7.2 kg (7.5%), respectively, for those with a classification of normal weight (n = 67), overweight (n = 122) and obese (n = 307) at commencement. HbA1c reduced from 6.0 ± 1.2 to 5.6 ± 0.7% (n = 212, p < 0.001). For members with a commencing HbA1c of <5.7% (n = 110), 5.7−6.4% (n = 55), and ≥6.5% (n = 48), HbA1c reduced −0.1 ± 0.2%, −0.3 ± 0.3%, and −1.4 ± 1.3%, respectively. For members with a commencing HbA1c ≥6.5%, 90% experienced a HbA1c reduction and 54% achieved a final HbA1c < 6.5%. With inclusion and exclusion of metformin, respectively, 124 and 82 diabetes medications were prescribed to 63 and 42 members that reduced to 82 and 35 medications prescribed to 51 and 26 members at final visit. A health care professional delivered low-carbohydrate diet program can facilitate weight loss and improve glycaemic control with greatest improvements and clinical relevance in individuals with worse baseline parameters.

Lipoprotein subfractions and subclinical vascular health in middle aged women: does menopause status matter?

OBJECTIVE

During midlife, women experience changes in lipoprotein profiles and deterioration in vascular health measures. We analyzed the associations of groups of lipoprotein subfractions as determined by principal component analysis (PCA) with subclinical vascular health measures in midlife women and tested if these associations were modified by menopause status.

METHODS

PCA was used to generate principal components (PCs) from 12 lipoprotein subfractions quantified among 545 midlife women. The associations of the identified PCs and concurrent vascular health measures were assessed using linear or logistic regressions among participants with carotid intima-media thickness (cIMT; n = 259), coronary artery calcium (n = 249), or aortic calcium (n = 248) scores.

RESULTS

PCA generated four PCs representing groups of (1) small, medium, and large very low-density lipoproteins subclasses-very low-density lipoprotein PC; (2) very small, small, and medium low-density lipoprotein (LDL) subclasses-small-medium LDL-PC; (3) large and small high-density lipoproteins subclasses and midzone particles-high-density lipoprotein PC; and (4) large LDL and small intermediate-density lipoproteins-large LDL-PC. Small-medium LDL-PC was positively associated with cIMT, coronary artery calcium, and aortic calcium in unadjusted but not in adjusted models. Menopause status modified the positive association of the small-medium LDL-PC with cIMT (interaction P = 0.02) such that this association was stronger after versus before menopause (P = 0.01).

CONCLUSIONS

Carotid intimal medial thickening is positively and independently associated with small- and medium-sized LDL particles after menopause. Monitoring levels of specific lipoprotein fractions may have value in identifying midlife women at risk for developing atherosclerotic vascular disease.

Small dense low-density lipoprotein particles: clinically relevant?

PURPOSE OF REVIEW

Levels of small, dense low-density lipoprotein (LDL) (sdLDL) particles determined by several analytic procedures have been associated with risk of atherosclerotic cardiovascular disease (ASCVD). This review focuses on the clinical significance of sdLDL measurement.

RECENT FINDINGS

Results of multiple prospective studies have supported earlier evidence that higher levels of sdLDL are significantly associated with greater ASCVD risk, in many cases independent of other lipid and ASCVD risk factors as well as levels of larger LDL particles. A number of properties of sdLDL vs. larger LDL, including reduced LDL receptor affinity and prolonged plasma residence time as well as greater oxidative susceptibility and affinity for arterial proteoglycans, are consistent with their heightened atherogenic potential. Nevertheless, determination of the extent to which sdLDL can preferentially impact ASCVD risk compared with other apoprotein B-containing lipoproteins has been confounded by their metabolic interrelationships and statistical collinearity, as well as differences in analytic procedures and definitions of sdLDL.

SUMMARY

A growing body of data points to sdLDL concentration as a significant determinant of ASCVD risk. Although future studies should be aimed at determining the clinical benefit of reducing sdLDL levels, there is sufficient evidence to warrant consideration of sdLDL measurement in assessing and managing risk of cardiovascular disease.

VIDEO ABSTRACT

https://www.dropbox.com/s/lioohr2ead7yx2p/zoom_0.mp4?dl=0.

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.

Impact of Dietary Palmitic Acid on Lipid Metabolism

Palmitic acid (PA) is ubiquitously present in dietary fat guaranteeing an average intake of about 20 g/d. The relative high requirement and relative content in the human body, which accounts for 20–30% of total fatty acids (FAs), is justified by its relevant nutritional role. In particular physiological conditions, such as in the fetal stage or in the developing brain, the respectively inefficient placental and brain blood–barrier transfer of PA strongly induces its endogenous biosynthesis from glucose via de novo lipogenesis (DNL) to secure a tight homeostatic control of PA tissue concentration required to exert its multiple physiological activities. However, pathophysiological conditions (insulin resistance) are characterized by a sustained DNL in the liver and aimed at preventing the excess accumulation of glucose, which result in increased tissue content of PA and disrupted homeostatic control of its tissue concentration. This leads to an overaccumulation of tissue PA, which results in dyslipidemia, increased ectopic fat accumulation, and inflammatory tone via toll-like receptor 4. Any change in dietary saturated FAs (SFAs) usually reflects a complementary change in polyunsaturated FA (PUFA) intake. Since PUFA particularly n-3 highly PUFA, suppress lipogenic gene expression, their reduction in intake rather than excess of dietary SFA may promote endogenous PA production via DNL. Thereby, the increase in tissue PA and its deleterious consequences from dysregulated DNL can be mistakenly attributed to dietary intake of PA.

Dietary Saturated Fats and Health: Are the U.S. Guidelines Evidence-Based?

The last decade has seen nearly 20 papers reviewing the totality of the data on saturated fats and cardiovascular outcomes, which, altogether, have demonstrated a lack of rigorous evidence to support continued recommendations either to limit the consumption of saturated fatty acids or to replace them with polyunsaturated fatty acids. These papers were unfortunately not considered by the process leading to the most recent U.S. Dietary Guidelines for Americans, the country's national nutrition policy, which recently reconfirmed its recommendation to limit saturated fats to 10% or less of total energy intake, based on insufficient and inconsistent evidence. Continuation of a cap on saturated fat intake also fails to consider the important effects of the food matrix and the overall dietary pattern in which saturated fatty acids are consumed.

Alternative Dietary Patterns for Americans: Low-Carbohydrate Diets

The decades-long dietary experiment embodied in the Dietary Guidelines for Americans (DGA) focused on limiting fat, especially saturated fat, and higher carbohydrate intake has coincided with rapidly escalating epidemics of obesity and type 2 diabetes (T2D) that are contributing to the progression of cardiovascular disease (CVD) and other diet-related chronic diseases. Moreover, the lack of flexibility in the DGA as it pertains to low carbohydrate approaches does not align with the contemporary trend toward precision nutrition. We argue that personalizing the level of dietary carbohydrate should be a high priority based on evidence that Americans have a wide spectrum of metabolic variability in their tolerance to high carbohydrate loads. Obesity, metabolic syndrome, and T2D are conditions strongly associated with insulin resistance, a condition exacerbated by increased dietary carbohydrate and improved by restricting carbohydrate. Low-carbohydrate diets are grounded across the time-span of human evolution, have well-established biochemical principles, and are now supported by multiple clinical trials in humans that demonstrate consistent improvements in multiple established risk factors associated with insulin resistance and cardiovascular disease. The American Diabetes Association (ADA) recently recognized a low carbohydrate eating pattern as an effective approach for patients with diabetes. Despite this evidence base, low-carbohydrate diets are not reflected in the DGA. As the DGA Dietary Patterns have not been demonstrated to be universally effective in addressing the needs of many Americans and recognizing the lack of widely available treatments for obesity, metabolic syndrome, and T2D that are safe, effective, and sustainable, the argument for an alternative, low-carbohydrate Dietary Pattern is all the more compelling.

Changes in lipoprotein particle subclasses, standard lipids, and apolipoproteins after supplementation with n-3 or n-6 PUFAs in abdominal obesity: A randomized double-blind crossover study

BACKGROUND & AIMS

Marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), lower circulating levels of triacylglycerols (TAGs), and the plant-derived omega-6 (n-6) PUFA linoleic acid (LA) may reduce cholesterol levels. Clinical studies on effects of these dietary or supplemental PUFAs on other blood fat fractions are few and have shown conflicting results. This study aimed to determine effects of high-dose supplemental n-3 (EPA + DHA) and n-6 (LA) PUFAs from high-quality oils on circulating lipoprotein subfractions and standard lipids (primary outcomes), as well as apolipoproteins, fatty acids, and glycemic control (secondary outcomes), in females and males with abdominal obesity.

METHODS

This was a randomized double-blind crossover study with two 7-wk intervention periods separated by a 9-wk washout phase. Females (n = 16) were supplemented with 3 g/d of EPA + DHA (TAG fish oil) or 15 g/d of LA (safflower oil), while males (n = 23) received a dose of 4 g/d of EPA + DHA or 20 g/d of LA. In fasting blood samples, we investigated lipoprotein particle subclasses by nuclear magnetic resonance spectroscopy, as well as standard lipids, apolipoproteins, fatty acid profiles, and glucose and insulin. Data were analyzed by linear mixed-effects modeling with 'subjects' as the random factor.

RESULTS

The difference between interventions in relative change scores was among the lipoprotein subfractions significant for total very-low-density lipoproteins (VLDLs) (n-3 vs. n-6: -38%∗ vs. +16%, p < 0.001; ∗: significant within-treatment change score), large VLDLs (-58%∗ vs. -0.91%, p < 0.001), small VLDLs (-57%∗ vs. +41%∗, p < 0.001), total low-density lipoproteins (LDLs) (+5.8%∗ vs. -4.3%∗, p = 0.002), large LDLs (+23%∗ vs. -2.1%, p = 0.004), total high-density lipoproteins (HDLs) (-6.0%∗ vs. +3.7%, p < 0.001), large HDLs (+11%∗ vs. -5.3%, p = 0.001), medium HDLs (-24%∗ vs. +6.2%, p = 0.030), and small HDLs (-9.9%∗ vs. +9.6%∗, p = 0.002), and among standard lipids for TAGs (-16%∗ vs. -2.6%, p = 0.014), non-esterified fatty acids (-19%∗ vs. +5.5%, p = 0.033), and total cholesterol (-0.28% vs. -4.4%∗, p = 0.042). A differential response in relative change scores was also found for apolipoprotein (apo)B (+0.40% vs. -6.0%∗, p = 0.008), apoA-II (-6.0%∗ vs. +1.5%, p = 0.001), apoC-II (-11%∗ vs. -1.7%, p = 0.025), and apoE (+3.3% vs. -3.8%, p = 0.028).

CONCLUSIONS

High-dose supplementation of high-quality oils with n-3 (EPA + DHA) or n-6 (LA) PUFAs was followed by reductions in primarily TAG- or cholesterol-related markers, respectively. The responses after both interventions point to changes in the lipoprotein-lipid-apolipoprotein profile that have been associated with reduced cardiometabolic risk, also among people with TAG or LDL-C levels within the normal range.

REGISTRATION

Registered under ClinicalTrials.gov Identifier: NCT02647333.

CLINICAL TRIAL REGISTRATION

Registered at https://clinicaltrials.gov/ct2/show/NCT02647333.

Effect of PCSK9 inhibitor on lipoprotein particles in patients with acute coronary syndromes

Background

To assess the effects of proprotein convertase subtilisin/kexin type 9 inhibitor (evolocumab) on lipoprotein particles subfractions with Nuclear Magnetic Resonance spectroscopy in patients with acute coronary syndromes.

Methods

A total of 99 consecutive patients with ACS were enrolled and assigned to either the experimental group (n = 54) or the control group (n = 45). The combination therapy of PCSK9 inhibitor (Repatha®, 140 mg, q2w) and moderate statin (Rosuvastatin, 10 mg, qn) was administered in the experimental group, with statin monotherapy (Rosuvastatin, 10 mg, qn) in the control group. The therapeutic effects on lipoprotein particle subfractions were assessed with NMR spectroscopy after 8 weeks treatment, and the achievement of LDL-C therapeutic target in both groups were analyzed.

Results

In the experimental group, after 8 weeks of evolocumab combination treatment, the concentrations of blood lipids (TC, LDL-C and its subfractions [LDL-1 to 6], VLDL-C and its subfractions [VLDL-1 to 5], IDL-C, and HDL-C), lipoprotein particles, and their subfractions [VLDL-P, IDL-P, LDL-P, and its subfractions [LDL-P1 to 6], apoB, and LP(a)] demonstrated therapeutic benefits with statistical significance (P < 0.05). The decrease in total LDL-P concentrations was mainly due to a decreased concentration of small-sized LDL particles (LDL-P 5 + 6), which was significantly more prominent than the decrease in medium-sized LDL-P (LDL-P3 + 4) and large-sized LDL-P (LDL-P1 + 2) (P < 0.001). According to lipid control target recommended by the latest China Cholesterol Education Program Expert Consensus in 2019, after 8 weeks treatment, 96.3% patients in the experimental group and 13.3% in the control group had achieved the LDL-C therapeutic target (P < 0.01).

Conclusions

Evolocumab combination treatment for 8 weeks significantly improves the plasma lipid profiles in ACS patients, and significantly decrease the concentration of lipoprotein particles which might contribute to the pathonesis of atherosclerosis.

Coconuts and Health: Different Chain Lengths of Saturated Fats Require Different Consideration

The diet heart hypothesis has driven nutrition recommendations and policy for decades. Recent studies have questioned the hypothesis and sparked great controversy over the assumed connection between saturated fat intake and heart disease. Recent evidence suggests that dietary patterns should be the focus of dietary recommendations, not any one food or nutrient. Furthermore, to classify foods as simply saturated fat, polyunsaturated or monounsaturated fats is to ignore the many other potential nutrients and health benefits. Coconut is classified as a saturated fat and therefore listed as a food to limit to reduce heart disease risk. However, different saturated fats, medium-chain or long-chain, act differently metabolically and thus have different health effects. The medium-chain fatty acids predominate in coconut are absorbed differently and have been associated with several health benefits, including improvements in cognitive function and a more favorable lipid profile compared to longer chain fatty acids. Coconuts provide a healthful source of saturated fats and should not be considered the same as foods with longer chain saturated fats. Future recommendations should take this research into consideration. It is the purpose of this review to discuss the research regarding the connection between saturated fat intake, specifically coconut consumption, and health, while focusing on dietary patterns and lifestyle behaviors.

Impact of a 2-year trial of nutritional ketosis on indices of cardiovascular disease risk in patients with type 2 diabetes

BACKGROUND

We have previously reported that in patients with type 2 diabetes (T2D) consumption of a very low carbohydrate diet capable of inducing nutritional ketosis over 2 years (continuous care intervention, CCI) resulted in improved body weight, glycemic control, and multiple risk factors for cardiovascular disease (CVD) with the exception of an increase in low density lipoprotein cholesterol (LDL-C). In the present study, we report the impact of this intervention on markers of risk for atherosclerotic cardiovascular disease (CVD), with a focus on lipoprotein subfraction particle concentrations as well as carotid-artery intima-media thickness (CIMT).

METHODS

Analyses were performed in patients with T2D who completed 2 years of this study (CCI; n = 194; usual care (UC): n = 68). Lipoprotein subfraction particle concentrations were measured by ion mobility at baseline, 1, and 2 years and CIMT was measured at baseline and 2 years. Principal component analysis (PCA) was used to assess changes in independent clusters of lipoprotein particles.

RESULTS

At 2 years, CCI resulted in a 23% decrease of small LDL IIIb and a 29% increase of large LDL I with no change in total LDL particle concentration or ApoB. The change in proportion of smaller and larger LDL was reflected by reversal of the small LDL subclass phenotype B in a high proportion of CCI participants (48.1%) and a shift in the principal component (PC) representing the atherogenic lipoprotein phenotype characteristic of T2D from a major to a secondary component of the total variance. The increase in LDL-C in the CCI group was mainly attributed to larger cholesterol-enriched LDL particles. CIMT showed no change in either the CCI or UC group.

CONCLUSION

Consumption of a very low carbohydrate diet with nutritional ketosis for 2 years in patients with type 2 diabetes lowered levels of small LDL particles that are commonly increased in diabetic dyslipidemia and are a marker for heightened CVD risk. A corresponding increase in concentrations of larger LDL particles was responsible for higher levels of plasma LDL-C. The lack of increase in total LDL particles, ApoB, and in progression of CIMT, provide supporting evidence that this dietary intervention did not adversely affect risk of CVD.

Low carbohydrate diet: are concerns with saturated fat, lipids, and cardiovascular disease risk justified?

PURPOSE OF REVIEW

There is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss, and in the improvement of markers of the insulin-resistant phenotype, including a reduction in inflammation, atherogenic dyslipidemia, hypertension, and hyperglycemia. However, critics have expressed concerns that the LCD promotes unrestricted consumption of saturated fat, which may increase low-density lipoprotein (LDL-C) levels. In theory, the diet-induced increase in LDL-C increases the risk of cardiovascular disease (CVD). The present review provides an assessment of concerns with the LCD, which have focused almost entirely on LDL-C, a poor marker of CVD risk. We discuss how critics of the LCD have ignored the literature demonstrating that the LCD improves the most reliable CVD risk factors.

RECENT FINDINGS

Multiple longitudinal clinical trials in recent years have extended the duration of observations on the safety and effectiveness of the LCD to 2-3 years, and in one study on epileptics, for 10 years.

SUMMARY

The present review integrates a historical perspective on the LCD with a critical assessment of the persistent concerns that consumption of saturated fat, in the context of an LCD, will increase risk for CVD.

Effect of low-carbohydrate diets on cardiometabolic risk, insulin resistance, and metabolic syndrome

PURPOSE OF REVIEW

An obesity epidemic has resulted in increasing prevalence of insulin resistance, hyperinsulinemia, metabolic syndrome (MetS), and cardiovascular disease (CVD). The Diet-Heart Hypothesis posited that dietary fat is the culprit. Yet dietary fat reduction has contributed to the problem, not resolved it. The role of hyperinsulinemia, the genesis of its atherogenic dyslipidemia and systemic inflammation in CVD and its reversal is reviewed.

RECENT FINDINGS

Overnutrition leads to weight gain and carbohydrate intolerance creating a vicious cycle of insulin resistance/hyperinsulinemia inhibiting fat utilization and encouraging fat storage leading to an atherogenic dyslipidemia characterized by hypertriglyceridemia, low HDL, and small dense LDL. The carbohydrate-insulin model better accounts for the pathogenesis of obesity, MetS, and ultimately type 2 diabetes (T2DM) and CVD. Ketogenic Diets reduce visceral obesity, increase insulin sensitivity, reverse the atherogenic dyslipidemia and the inflammatory biomarkers of overnutrition. Recent trials show very high adherence to ketogenic diet for up to 2 years in individuals with T2DM, reversing their metabolic, inflammatory and dysglycemic biomarkers as well as the 10-year estimated atherosclerotic risk. Diabetes reversal occurred in over 50% and complete remission in nearly 8%.

SUMMARY

Therapeutic carbohydrate-restricted can prevent or reverse the components of MetS and T2DM.

Public health guidelines should recommend reducing saturated fat consumption as much as possible: NO

The proposition that dietary SFAs should be restricted to the maximal extent possible (e.g., to achieve approximately half of current consumption) is based primarily on observational and clinical trial data that are interpreted as indicating a benefit of such limitation on cardiovascular disease (CVD) risk. Further support is believed to derive from the capacity of SFAs to raise LDL cholesterol, and the evidence that LDL-cholesterol lowering reduces CVD incidence. Despite their apparent merit, these arguments are flawed. In fact, although it is possible that dietary intake of SFAs has a causal role in CVD, the evidence to support this contention is inconclusive. Moreover, other considerations argue against a guideline focused primarily on limiting SFA intake, including the heterogeneity of individual SFAs, the likelihood of clinically meaningful interindividual variation in response to SFA reduction, the potential for unintended health consequences of population-wide promotion of severe restriction, and the critical differences in health impacts among individual SFA-containing foods.

Saturated Fats and Health: A Reassessment and Proposal for Food-Based Recommendations: JACC State-of-the-Art Review

The recommendation to limit dietary saturated fatty acid (SFA) intake has persisted despite mounting evidence to the contrary. Most recent meta-analyses of randomized trials and observational studies found no beneficial effects of reducing SFA intake on cardiovascular disease (CVD) and total mortality, and instead found protective effects against stroke. Although SFAs increase low-density lipoprotein (LDL) cholesterol, in most individuals, this is not due to increasing levels of small, dense LDL particles, but rather larger LDL particles, which are much less strongly related to CVD risk. It is also apparent that the health effects of foods cannot be predicted by their content in any nutrient group without considering the overall macronutrient distribution. Whole-fat dairy, unprocessed meat, and dark chocolate are SFA-rich foods with a complex matrix that are not associated with increased risk of CVD. The totality of available evidence does not support further limiting the intake of such foods.

High-Risk Atherosclerosis and Metabolic Phenotype: The Roles of Ectopic Adiposity, Atherogenic Dyslipidemia, and Inflammation

Current algorithms for assessing risk of atherosclerotic cardiovascular disease (ASCVD) and, in particular, the reliance on low-density lipoprotein (LDL) cholesterol in conditions where this measurement is discordant with apoB and LDL-particle concentrations fail to identify a sizeable part of the population at high risk for adverse cardiovascular events. This results in missed opportunities for ASCVD prevention, most notably in those with metabolic syndrome, prediabetes, and diabetes. There is substantial evidence that accumulation of ectopic fat and associated metabolic traits are markers for and pathogenic components of high-risk atherosclerosis. Conceptually, the subset of advanced lesions in high-risk atherosclerosis that triggers vascular complications is closely related to a set of coordinated high-risk traits clustering around a distinct metabolic phenotype. A key feature of this phenotype is accumulation of ectopic fat, which, coupled with age-related muscle loss, creates a milieu conducive for the development of ASCVD: atherogenic dyslipidemia, nonresolving inflammation, endothelial dysfunction, hyperinsulinemia, and impaired fibrinolysis. Sustained vascular inflammation, a hallmark of high-risk atherosclerosis, impairs plaque stabilization in this phenotype. This review describes how metabolic and inflammatory processes that are promoted in large measure by ectopic adiposity, as opposed to subcutaneous adipose tissue, relate to the pathogenesis of high-risk atherosclerosis. Clinical biomarkers indicative of these processes provide incremental information to standard risk factor algorithms and advanced lipid testing identifies atherogenic lipoprotein patterns that are below the discrimination level of standard lipid testing. This has the potential to enable improved identification of high-risk patients who are candidates for therapeutic interventions aimed at prevention of ASCVD.

The Atherogenic Role of Circulating Modified Lipids in Atherosclerosis

Lipid accumulation in the arterial wall is a crucial event in the development of atherosclerotic lesions. Circulating low-density lipoprotein (LDL) is the major source of lipids that accumulate in the atherosclerotic plaques. It was discovered that not all LDL is atherogenic. In the blood plasma of atherosclerotic patients, LDL particles are the subject of multiple enzymatic and non-enzymatic modifications that determine their atherogenicity. Desialylation is the primary and the most important atherogenic LDL modification followed by a cascade of other modifications that also increase blood atherogenicity. The enzyme trans-sialidase is responsible for the desialylation of LDL, therefore, its activity plays an important role in atherosclerosis development. Moreover, circulating modified LDL is associated with immune complexes that also have a strong atherogenic potential. Moreover, it was shown that antibodies to modified LDL are also atherogenic. The properties of modified LDL were described, and the strong evidence indicating that it is capable of inducing intracellular accumulation of lipids was presented. The accumulated evidence indicated that the molecular properties of modified LDL, including LDL-containing immune complexes can serve as the prognostic/diagnostic biomarkers and molecular targets for the development of anti-atherosclerotic drugs.

Effects of red meat, white meat, and nonmeat protein sources on atherogenic lipoprotein measures in the context of low compared with high saturated fat intake: a randomized controlled trial

BACKGROUND

Dietary recommendations to limit red meat are based on observational studies linking intake to cardiovascular disease (CVD) risk together with the potential of its saturated fatty acid (SFA) content to raise low-density lipoprotein (LDL) cholesterol. However, the relation of white meat to CVD risk, and the effects of dietary protein source on lipoprotein particle subfractions, have not been extensively evaluated.

OBJECTIVE

We tested whether levels of atherogenic lipids and lipoproteins differed significantly following consumption of diets with high red meat content compared with diets with similar amounts of protein derived from white meat or nonmeat sources, and whether these effects were modified by concomitant intake of high compared with low SFAs.

METHODS

Generally healthy men and women, 21-65 y, body mass index 20-35 kg/m2, were randomly assigned to 1 of 2 parallel arms (high or low SFA) and within each, allocated to red meat, white meat, and nonmeat protein diets consumed for 4 wk each in random order. The primary outcomes were LDL cholesterol, apolipoprotein B (apoB), small + medium LDL particles, and total/high-density lipoprotein cholesterol.

RESULTS

Analysis included participants who completed all 3 dietary protein assignments (61 for high SFA; 52 for low SFA). LDL cholesterol and apoB were higher with red and white meat than with nonmeat, independent of SFA content (P < 0.0001 for all, except apoB: red meat compared with nonmeat [P = 0.0004]). This was due primarily to increases in large LDL particles, whereas small + medium LDL and total/high-density lipoprotein cholesterol were unaffected by protein source (P = 0.10 and P = 0.51, respectively). Primary outcomes did not differ significantly between red and white meat. Independent of protein source, high compared with low SFA increased LDL cholesterol (P = 0.0003), apoB (P = 0.0002), and large LDL (P = 0.0002).

CONCLUSIONS

The findings are in keeping with recommendations promoting diets with a high proportion of plant-based food but, based on lipid and lipoprotein effects, do not provide evidence for choosing white over red meat for reducing CVD risk. This trial was registered at Clinicaltrials.gov as NCT01427855.

Consumption of regular-fat vs reduced-fat cheese reveals gender-specific changes in LDL particle size - a randomized controlled trial

Background

Regular-fat cheese does not seem to increase low density lipoprotein cholesterol (LDL-C) concentrations compared to reduced-fat cheese. However, plasma LDL-C concentrations do not reflect levels and size of LDL particles, which might be a better predictor of cardiovascular risk.

Methods

The aim was to compare the effects of regular-fat cheese vs reduced-fat cheese and carbohydrate-rich foods on LDL particle size distribution in adults with ≥ 2 metabolic syndrome (MetS) risk factors. The study was part of a 12 weeks’ randomized controlled trial in which subjects had been randomly allocated to 1 of 3 intervention groups; regular-fat cheese (REG), reduced-fat cheese (RED) or a no-cheese/carbohydrate (CHO) group. Subjects in the REG and RED groups consumed 80 g cheese/d per 10 MJ, whereas subjects in the CHO consumed bread and jam corresponding to 90 g/d and 25 g/d per 10 MJ, respectively. Fasting blood samples at wk. 0 (baseline) and wk. 12 were analyzed for LDL particle size distribution and cholesterol content using nuclear magnetic resonance (NMR) spectroscopy.

Results

A total of 85 subjects [mean ± SD age: 54.0 ± 12.8 y; BMI: 28.7 ± 3.6 kg/m²] completed the study. Overall, regular-fat cheese did not impact lipoprotein particle number and size differently than reduced-fat cheese. In men (n = 23), the REG diet decreased total LDL particle number (LDL-P, − 223.2 ± 91.1 nmol/l, P = 0.01) compared with the RED diet. The reduction was primarily in the medium-sized LDL fraction (− 128.5 ± 51.8 nmol/l, P = 0.01). In women (n = 62), the REG diet increased the concentration of cholesterol in the small high density lipoprotein (HDL) particles compared with the CHO diet (2.9 ± 1.0 mg/dl, P = 0.006).

Conclusion

Overall, regular-fat cheese did not alter LDL particle size distribution compared to reduced-fat cheese after a 12 wk. intervention in subjects with ≥2 MetS risk factors. However, our results suggest that lipoprotein response to cheese intake is gender-specific. This warrants further investigation.

Trial registration

This trial was registered at Clinicaltrials.gov as NCT0261471. Registered 30 November 2015 - Retrospectively registered.

Pathways and mechanisms linking dietary components to cardiometabolic disease: thinking beyond calories

Calories from any food have the potential to increase risk for obesity and cardiometabolic disease because all calories can directly contribute to positive energy balance and fat gain. However, various dietary components or patterns may promote obesity and cardiometabolic disease by additional mechanisms that are not mediated solely by caloric content. Researchers explored this topic at the 2017 CrossFit Foundation Academic Conference 'Diet and Cardiometabolic Health - Beyond Calories', and this paper summarizes the presentations and follow-up discussions. Regarding the health effects of dietary fat, sugar and non-nutritive sweeteners, it is concluded that food-specific saturated fatty acids and sugar-sweetened beverages promote cardiometabolic diseases by mechanisms that are additional to their contribution of calories to positive energy balance and that aspartame does not promote weight gain. The challenges involved in conducting and interpreting clinical nutritional research, which preclude more extensive conclusions, are detailed. Emerging research is presented exploring the possibility that responses to certain dietary components/patterns are influenced by the metabolic status, developmental period or genotype of the individual; by the responsiveness of brain regions associated with reward to food cues; or by the microbiome. More research regarding these potential 'beyond calories' mechanisms may lead to new strategies for attenuating the obesity crisis.

Pathophysiology of Diabetic Dyslipidemia

Accumulating clinical evidence has suggested serum triglyceride (TG) is a leading predictor of atherosclerotic cardiovascular disease, comparable to low-density lipoprotein (LDL)-cholesterol (C) in populations with type 2 diabetes, which exceeds the predictive power of hemoglobinA1c. Atherogenic dyslipidemia in diabetes consists of elevated serum concentrations of TG-rich lipoproteins (TRLs), a high prevalence of small dense low-density lipoprotein (LDL), and low concentrations of cholesterol-rich high-density lipoprotein (HDL)2-C. A central lipoprotein abnormality is an increase in large TG-rich very-low-density lipoprotein (VLDL)1, and other lipoprotein abnormalities are metabolically linked to increased TRLs. Insulin critically regulates serum VLDL concentrations by suppressing hepatic VLDL production and stimulating VLDL removal by activation of lipoprotein lipase. It is still debated whether hyperinsulinemia compensatory for insulin resistance is causally associated with the overproduction of VLDL. This review introduces experimental and clinical observations revealing that insulin resistance, but not hyperinsulinemia stimulates hepatic VLDL production. LDL and HDL consist of heterogeneous particles with different size and density. Cholesterol-depleted small dense LDL and cholesterol-rich HDL2 subspecies are particularly affected by insulin resistance and can be named “Metabolic LDL and HDL,” respectively. We established the direct assays for quantifying small dense LDL-C and small dense HDL(HDL3)-C, respectively. Subtracting HDL3-C from HDL-C gives HDL2-C. I will explain clinical relevance of measurements of LDL and HDL subspecies determined by our assays. Diabetic kidney disease (DKD) substantially worsens plasma lipid profile thereby potentiated atherogenic risk. Finally, I briefly overview pathophysiology of dyslipidemia associated with DKD, which has not been so much taken up by other review articles.

Organic cation transporter 1 (OCT1) modulates multiple cardiometabolic traits through effects on hepatic thiamine content

A constellation of metabolic disorders, including obesity, dysregulated lipids, and elevations in blood glucose levels, has been associated with cardiovascular disease and diabetes. Analysis of data from recently published genome-wide association studies (GWAS) demonstrated that reduced-function polymorphisms in the organic cation transporter, OCT1 (SLC22A1), are significantly associated with higher total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride (TG) levels and an increased risk for type 2 diabetes mellitus, yet the mechanism linking OCT1 to these metabolic traits remains puzzling. Here, we show that OCT1, widely characterized as a drug transporter, plays a key role in modulating hepatic glucose and lipid metabolism, potentially by mediating thiamine (vitamin B1) uptake and hence its levels in the liver. Deletion of Oct1 in mice resulted in reduced activity of thiamine-dependent enzymes, including pyruvate dehydrogenase (PDH), which disrupted the hepatic glucose–fatty acid cycle and shifted the source of energy production from glucose to fatty acids, leading to a reduction in glucose utilization, increased gluconeogenesis, and altered lipid metabolism. In turn, these effects resulted in increased total body adiposity and systemic levels of glucose and lipids. Importantly, wild-type mice on thiamine deficient diets (TDs) exhibited impaired glucose metabolism that phenocopied Oct1 deficient mice. Collectively, our study reveals a critical role of hepatic thiamine deficiency through OCT1 deficiency in promoting the metabolic inflexibility that leads to the pathogenesis of cardiometabolic disease.

The liver is the major organ for glucose and lipid metabolism; impairment in liver energy metabolism is often found in metabolic disorders. Traditionally, excesses in macronutrients (fat and glucose) are linked to the development of metabolic disorders. Our study provides evidence that imbalances in a micronutrient, vitamin B1 (thiamine), can serve as an etiological cause of lipid and glucose disorders and implicates the organic cation transporter, OCT1, in these disorders. OCT1 is a key determinant of thiamine levels in the liver. In humans, reduced-function polymorphisms of OCT1 significantly associate with high LDL cholesterol levels. Using Oct1 knockout mice, we show that reduced OCT1-mediated thiamine uptake in the liver leads to reduced levels of TPP—the active metabolite of thiamine—and decreased activity of key TPP-dependent enzymes. As a result, a shift from glucose to fatty acid oxidation occurs, leading to imbalances in key metabolic intermediates, alterations in metabolic flux pathways, and disruptions of various metabolic regulatory mechanisms. The extensive characterization of Oct1 knockout mice provides evidence for the molecular mechanisms responsible for various metabolic traits and indicates an important role for imbalances in micronutrients in cardiometabolic disorders.

Saturated Fat Consumption and Risk of Coronary Heart Disease and Ischemic Stroke: A Science Update

At a workshop to update the science linking saturated fatty acid (SAFA) consumption with the risk of coronary heart disease (CHD) and ischemic stroke, invited participants presented data on the consumption and bioavailability of SAFA and their functions in the body and food technology. Epidemiological methods and outcomes were related to the association between SAFA consumption and disease events and mortality. Participants reviewed the effects of SAFA on CHD, causal risk factors, and surrogate risk markers. Higher intakes of SAFA were not associated with higher risks of CHD or stroke apparently, but studies did not take macronutrient replacement into account. Replacing SAFA by cis-polyunsaturated fatty acids was associated with significant CHD risk reduction, which was confirmed by randomized controlled trials. SAFA reduction had little direct effect on stroke risk. Cohort studies suggest that the food matrix and source of SAFA have important health effects.

Changes in low-density lipoprotein size phenotypes associate with changes in apolipoprotein C-III glycoforms after dietary interventions

BACKGROUND

The presence of small dense low-density lipoprotein (LDL) is associated with obesity, type II diabetes, and an increased risk for cardiovascular disease. Apolipoprotein C-III (apoC-III) is involved in the formation of small dense LDL, but the exact mechanisms are still not well defined. ApoC-III is a glycosylated apolipoprotein, with 3 major glycoforms: apoC-III₀, apoC-III₁, and apoC-III₂ that contain 0, 1, or 2 molecules of sialic acid, respectively. In our previous work, we reported an association among apoC-III₀ and apoC-III₁, but not apoC-III₂ with fasting plasma triglyceride levels in obesity and type II diabetes.

OBJECTIVE

The goal of this study was to determine the relationship between changes in the major apoC-III glycoforms and small dense LDL levels after dietary interventions.

METHODS

Mass spectrometric immunoassay was performed on fasting plasma samples from 61 subjects who underwent either a high-carbohydrate diet (n = 34) or a weight loss intervention (n = 27).

RESULTS

After both dietary interventions, changes in total apoC-III concentrations were associated with changes in LDL peak particle diameter (r = -0.58, P < .0001). Increases in total apoC-III concentrations after the high-carbohydrate diet were associated with decreases in LDL size (r = -0.53, P = .001), and decreases in apoC-III concentrations after weight loss were associated with increases in LDL peak particle diameter (r = -0.54, P = .004). Changes in concentrations of apoC-III₁ and apoC-III₀, but not apoC-III₂, were associated with changes in LDL peak particle diameter in both the weight loss and high-carbohydrate interventions.

CONCLUSIONS

We conclude that apoC-III₀ and apoC-III₁, but not apoC-III₂ are associated with the formation of small dense LDL.

Use of low density lipoprotein particle number levels as an aid in statin treatment decisions for intermediate risk patients: a cost-effectiveness analysis

Background

The 2013 ACC/AHA guideline recommended either no statin therapy or moderate-intensity statin therapy (MST) for intermediate risk patients—those with 5–7.5% 10-year risk and without cardiovascular disease (CVD), hypercholesterolemia or diabetes. The guideline further suggested that the therapy choice be based on patient-clinician discussions of risks and benefits. Since low-density lipoprotein particle (LDL-P) levels were reported to be associated with CVD independently of traditional risk factors in intermediate and low risk patients, we investigated the cost-effectiveness of using LDL-P levels to identify intermediate risk patients likely to benefit from initiating or intensifying statin therapy.

Methods

We evaluated 5 care strategies for intermediate risk patients. These included the strategies suggested by the guideline: no-statin therapy and MST. We compared each of these strategies to a related strategy that incorporated LDL-P testing. No-statin therapy was compared with the strategy of MST for those with high LDL-P levels and no statin therapy for all other patients (test-and-MST). MST was compared with the strategy of high-intensity statin therapy (HST) for those with high LDL-P levels and MST for all other patients (test-and-HST). We also evaluated the strategy of HST for all. Costs (payer perspective) and utilities were assessed over a 5-year time horizon in a Markov model of 100,000 hypothetical intermediate risk patients.

Results

HST dominated all other strategies, costing less and—despite causing 739 more cases of diabetes than did MST—resulting in more quality adjusted life-years (QALYs). For patient-clinician discussions that would otherwise lead to the MST strategy, we found the test-and-HST strategy reduced costs by $4.67 MM and resulted in 134 fewer CVD events and 115 additional QALYs. For patient-clinician discussions that would otherwise lead to no statin therapy, we found that the test-and-MST strategy reduced costs by $3.25 MM, resulted in 97 fewer CVD events and 44 additional QALYs.

Conclusions

The HST strategy was cost saving and improved outcomes in intermediate risk patients. For patient and clinicians concerned about the adverse events associated with HST, using LDL-P levels to target intensified statin therapy could improve outcomes and reduce costs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0429-6) contains supplementary material, which is available to authorized users.

Diet, lipids, and cardiovascular disease

PURPOSE OF REVIEW

Modulation of diet is the primary lifestyle approach for reducing cardiovascular disease (CVD) risk, with a major focus of current guidelines being to lower LDL cholesterol by reducing intake of saturated fatty acids. However, dietary effects on lipid-related CVD risk factors extend beyond LDL cholesterol, with growing emphasis on the prevention and management of atherogenic dyslipidemia, which includes elevated triglyceride, small dense LDL, and reduced HDL cholesterol, and which is associated with excess adiposity and insulin resistance. We here review recent studies of dietary macronutrient effects on CVD risk that may act through effects on plasma lipid and lipoprotein metabolism.

RECENT FINDINGS

Effects of reducing saturated fatty acids on CVD risk have been evaluated both in terms of the replacement macronutrient(s) and the food and dietary context in which the macronutrients are consumed. Although weight loss remains the most important goal for reducing cardiometabolic risk among overweight and obese individuals, a variety of lines of evidence support limitation of added sugars and processed starches for improving features of atherogenic dyslipidemia.

SUMMARY

Increasing understanding of the complexity of nutrient-disease relationships has shifted the framework for CVD prevention from a focus on macronutrient content of diets to foods and dietary patterns.

Prepregnancy Adverse Lipid Profile and Subsequent Risk of Gestational Diabetes

CONTEXT

Lower low-density lipoprotein (LDL) peak diameter and a predominance of small, dense LDL are associated with type 2 diabetes, but it is unclear whether they are a risk factor for gestational diabetes mellitus (GDM).

OBJECTIVE

To evaluate whether prepregnancy lipid profile predicts the development of GDM during pregnancy.

DESIGN

A nested case-control study among women who participated in a multiphasic health exam, where blood was collected and stored between 1984 and 1996, and who then had a subsequent pregnancy between 1984 and 2009.

SETTING

Kaiser Permanente Northern California.

PARTICIPANTS

Cases were 254 women who developed GDM. Two controls were selected for each case and matched for year of blood draw, age at baseline, age at pregnancy, and number of intervening pregnancies.

MAIN OUTCOME MEASURES

Prepregnancy LDL peak diameter and prepregnancy lipid subfraction concentrations grouped according to size, and the odds of developing GDM.

RESULTS

Women in the lowest quartiles of LDL peak diameter and high-density lipoprotein had increased odds of GDM compared with women in the highest quartiles (odds ratio [95% CI], 2.60 [1.37-4.94] and 1.98 [1.01-3.86], respectively), in multivariable adjusted models. Being in the highest quartile of small and very small LDL subfractions also increased the odds of GDM (2.61 [1.35-5.03] and 2.44 [1.22-4.85], respectively).

CONCLUSIONS

Lower LDL peak diameter size and high-density lipoprotein levels and higher levels of small and very small LDL subfraction groups were present years before pregnancy in women who developed GDM. A prepregnancy atherogenic lipid profile may help identify women at risk of GDM to target for prevention.

Twice weekly intake of farmed Atlantic salmon (Salmo salar) positively influences lipoprotein concentration and particle size in overweight men and women

The US Dietary Guidelines for Americans recommend twice weekly fish intake. Farmed Atlantic salmon is a good source of omega-3 (n-3) fatty acids which have positive lipid modifying effects; however, it is unknown whether these responses are dose-dependent. Our primary research objective was to determine the effect of dose-dependent intake of farmed Atlantic salmon on lipoprotein particle (P) size and concentration. We hypothesized that low-density lipoprotein (LDL)-P and high-density lipoprotein (HDL)-P size and concentration would increase with salmon intake in a dose-dependent manner. Overweight, adult participants (n = 19) were enrolled in a cross-over designed clinical trial evaluating intake of farmed Atlantic salmon. In random order, participants were assigned to 90, 180, or 270 g of salmon twice weekly for 4-week dietary treatments. Following a 4- to 8-week washout, participants crossed over to another dose of fish intake until all treatments were completed. Plasma lipid concentrations were determined and serum lipoprotein concentrations and particle size were determined by nuclear magnetic resonance. Intake of salmon reduced plasma and serum triglyceride (TG) concentrations and increased plasma HDL-C concentrations. The concentrations of large very low-density lipoprotein (VLDL)-P and chylomicron (CM)-P were reduced. Large LDL-P concentrations were increased in a dose-dependent manner. The mean size of VLDL-P was reduced and that of LDL was increased. Total TG was reduced as was the TG content of VLDL-P and CM-P. Twice weekly intake of farmed Atlantic salmon portions influences lipoprotein particle size and concentration in a manner associated with cardiovascular disease risk reduction.

A multicomponent nutrient bar promotes weight loss and improves dyslipidemia and insulin resistance in the overweight/obese: chronic inflammation blunts these improvements

This study determined if twice-daily consumption of a nutrient-dense bar intended to fill gaps in Western diets, without other dietary/lifestyle requirements, favorably shifted metabolic/anthropometric indicators of dysregulation in a healthy direction. Three 8-wk clinical trials in 43 healthy lean and overweight/obese (OW/OB) adults, who served as their own controls, were pooled for analysis. In less inflamed OW/OB [high-sensitivity C-reactive protein (hsCRP) <1.5], statistically significant decreases occurred in weight (-1.1 ± 0.5 kg), waist circumference (-3.1 ± 1.4 cm), diastolic blood pressure (-4.1 ± 1.6 mmHg), heart rate [HR; -4.0 ± 1.7 beats per minute (bpm)], triglycerides (-72 ± 38.2 mg/dl), insulin resistance (homeostatic model of insulin resistance) (-0.72 ± 0.3), and insulin (-2.8 ± 1.3 mU/L); an increase in HDL-2b (+303 ± 116 nM) and realignment of LDL lipid subfractions toward a less atherogenic profile [decreased small LDL IIIb (-44 ± 23.5 nM), LDL IIIa (-99 ± 43.7 nM), and increased large LDL I (+66 ± 28.0 nM)]. In the more inflamed OW/OB (hsCRP >1.5), inflammation was reduced at 2 wk (-0.66 mg/L), and HR at 8 wk (-3.4 ± 1.3 bpm). The large HDL subfraction (10.5-14.5 nm) increased at 8 wk (+346 ± 126 nM). Metabolic improvements were also observed in lean participants. Thus, favorable changes in measures of cardiovascular health, insulin resistance, inflammation, and obesity were initiated within 8 wk in the OW/OB by replacing deficiencies in Western diets without requiring other dietary or lifestyle modifications; chronic inflammation blunted most improvements.

Saturated Fats Versus Polyunsaturated Fats Versus Carbohydrates for Cardiovascular Disease Prevention and Treatment

The effects of saturated fatty acids (SFAs) on cardiovascular disease (CVD) risk are modulated by the nutrients that replace them and their food matrices. Replacement of SFAs with polyunsaturated fatty acids has been associated with reduced CVD risk, although there is heterogeneity in both fatty acid categories. In contrast, replacement of SFAs with carbohydrates, particularly sugar, has been associated with no improvement or even a worsening of CVD risk, at least in part through effects on atherogenic dyslipidemia, a cluster of traits including small, dense low-density lipoprotein particles. The effects of dietary SFAs on insulin sensitivity, inflammation, vascular function, and thrombosis are less clear. There is growing evidence that SFAs in the context of dairy foods, particularly fermented dairy products, have neutral or inverse associations with CVD. Overall dietary patterns emphasizing vegetables, fish, nuts, and whole versus processed grains form the basis of heart-healthy eating and should supersede a focus on macronutrient composition.