Postprandial lipemia as a cardiometabolic risk factor

The effects of sleep disruption on metabolism, hunger, and satiety, and the influence of psychosocial stress and exercise: A narrative review

Sleep deficiency is a ubiquitous phenomenon among Americans. In fact, in the United States, ∼78% of teens and 35% of adults currently get less sleep than recommended for their age-group, and the quality of sleep appears to be getting worse for many. The consequences of sleep disruption manifest in a myriad of ways, including insulin resistance and disrupted nutrient metabolism, dysregulation of hunger and satiety, and potentially increased body weight and adiposity. Consequently, inadequate sleep is related to an increased risk of various cardiometabolic diseases, including obesity, diabetes, and heart disease. Exercise has the potential to be an effective therapeutic to counteract the deleterious effects of sleep disruption listed above, whereas chronic psychosocial stress may causally promote sleep disruption and cardiometabolic risk. Here, we provide a narrative review of the current evidence on the consequences of short sleep duration and poor sleep quality on substrate metabolism, circulating appetite hormones, hunger and satiety, and weight gain. Secondly, we provide a brief overview of chronic psychosocial stress and its impact on sleep and metabolic health. Finally, we summarise the current evidence regarding the ability of exercise to counteract the adverse metabolic health effects of sleep disruption. Throughout the review, we highlight areas where additional interrogation and future exploration are necessary.

Differential Effects of Two Isocaloric Healthy Diets on Postprandial Lipid Responses in Individuals with Type 2 Diabetes

BACKGROUND

High blood concentrations of triglycerides (TG) in the postprandial period have been shown to be more closely associated with the risk of cardiovascular disease (CVD) than fasting values in individuals with type 2 diabetes (T2D). Dietary changes are the primary determinants of postprandial lipid responses.

METHODS

We investigated the effects of an isocaloric multifactorial diet, rich in n-3 PUFA, MUFA, fiber, polyphenols, and vitamins, compared to an isocaloric diet, containing the same amount of MUFA, on the postprandial lipid response in T2D individuals. Following a randomized, controlled, parallel group design, 43 (25 male/18 female) T2D individuals were assigned to an isocaloric multifactorial (n = 21) or a MUFA-rich diet (n = 22). At the beginning and after the 8 weeks of dietary intervention, the concentrations of plasma triglycerides, total cholesterol, HDL cholesterol, and non-HDL cholesterol were detected at fasting and over a 4-h test meal with the same composition as the prescribed diet.

RESULTS

The concentrations of fasting plasma triglycerides, total cholesterol, HDL cholesterol, and non-HDL cholesterol did not change after both diets. Compared with the MUFA diet, the 8-week multifactorial diet significantly lowered the postprandial response, which was evaluated as the incremental area under the curve (iAUC), of triglycerides by 33% (64 ± 68 vs. 96 ± 50 mmol/L·240 min, mean ± SD, respectively, p = 0.018), total cholesterol by 105% (-51 ± 33 vs. -25 ± 29, p = 0.013), and non-HDL cholesterol by 206% (-39 ± 33 vs. -13 ± 23, p = 0.013).

CONCLUSIONS

In T2D individuals, a multifactorial diet, characterized by several beneficial components, improved the postprandial lipid response compared to a MUFA diet, generally considered a healthy diet being reduced in saturated fat, and probably contributed to the reduction of cardiovascular risk.

The chylomicron saga: time to focus on postprandial metabolism

Since statins have had such tremendous therapeutic success over the last three decades, the field of atherosclerosis has become somewhat LDL-centric, dismissing the relevance of triglycerides (TG), particularly chylomicrons, in atherogenesis. Nonetheless, 50% of patients who take statins are at risk of developing atherosclerotic cardiovascular disease (ASCVD) and are unable to achieve their goal LDL-C levels. This residual risk is mediated, in part by triglyceride rich lipoproteins (TRL) and their remnants. Following his seminal investigation on the subject, Zilversmit proposed that atherosclerosis is a postprandial event in 1979 (1-4). In essence, the concept suggests that remnant cholesterol-rich chylomicron (CM) and very-low density lipoprotein (VLDL) particles play a role in atherogenesis. Given the foregoing, this narrative review addresses the most recent improvements in our understanding of postprandial dyslipidemia. The primary metabolic pathways of chylomicrons are discussed, emphasizing the critical physiological role of lipoprotein lipase and apoCIII, the importance of these particles' fluxes in the postprandial period, their catabolic rate, the complexities of testing postprandial metabolism, and the role of angiopoietin-like proteins in the partition of CM during the fed cycle. The narrative is rounded out by the dysregulation of postprandial lipid metabolism in insulin resistance states and consequent CVD risk, the clinical evaluation of postprandial dyslipidemia, current research limits, and potential future study directions.

Discovery of lipid profiles in plasma-derived extracellular vesicles as biomarkers for breast cancer diagnosis

Lipids are a major component of extracellular vesicles; however, their significance in tumorigenesis and progression has not been well elucidated. As we previously found that lipid profiles drastically changed in breast tumors upon progression, we hypothesized that lipid profiles of plasma-derived extracellular vesicles could be utilized as breast cancer biomarkers. Here, we adopted modified sucrose cushion ultracentrifugation to isolate plasma-derived extracellular vesicles from breast cancer (n = 105), benign (n = 11), and healthy individuals (n = 43) in two independent cohorts (n = 126 and n = 33) and conducted targeted lipidomic analysis. We established a breast cancer diagnostic model comprising three lipids that showed favorable performance with the area under the receiver operating characteristic curve of 0.759, 0.743, and 0.804 in the training, internal validation, and external test sets, respectively. Moreover, we identified several lipids that could effectively discriminate breast cancer progression and subtypes: phosphatidylethanolamines and phosphatidylserines were relatively higher in Stage III, whereas phosphatidylcholines and sphingomyelins were higher in Stage IV; phosphatidylcholines and ceramides were correspondingly concentrated in HER2-positive patients, while lysophosphatidylcholines and polyunsaturated triglycerides were concentrated in the triple-negative breast cancer subtype. Lipid profiling of plasma-derived extracellular vesicles is a non-invasive and promising approach for diagnosing, staging, and subtyping breast cancer.

San-wei-tan-xiang capsule attenuates atherosclerosis by increasing lysosomal activity in adipose tissue macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Dyslipidemia is the leading risk factor of atherosclerosis (AS). Adipose tissue macrophages (ATMs) can regulate postprandial cholesterol levels via uptake and hydrolyzation of lipids and regulation of macrophage cholesterol efflux (MCE). San-wei-tan-xiang (SWTX) capsule, a Traditional Chinese medicine, exerts clinical benefits in patients with atherosclerotic cardiovascular diseases.

AIM OF THE STUDY

This work is aimed to evaluate the chemical ingredients and mechanisms of SWTX in anti-AS.

MATERIALS AND METHODS

The chemical ingredients of SWTX identified by liquid chromatography coupled with tandem mass spectrometry were used for network pharmacological analysis. The atheroprotective function of SWTX was evaluated in ApoE^-/- mice fed a cholesterol-enriched diet.

RESULTS

The chemical ingredients identified in SWTX were predicated to be important for lipid metabolism and AS. Animals studies suggested that SWTX effectively attenuated the atherosclerotic plaque growth, elevated postprandial HDL cholesterol levels, elevated the proportion of Tim4 and CD36-expressed ATMs, and upregulated the uptake of lipid and lysosomal activity in ATMs. SWTX-induced elevation of postprandial HDL cholesterol levels was dependent on increased lysosomal activity, since chloroquine, an inhibitor of lysosomal function, blocked the effect of SWTX. Lastly, some predicated bioactive compounds in SWTX can elevate lysosomal activity in vitro.

CONCLUSION

SWTX could attenuate atherosclerotic plaque formation by elevating lysosomal activity and enhancing MCE in ATMs.

From NAFLD to MAFLD: Definition, Pathophysiological Basis and Cardiovascular Implications

Non-alcoholic fatty liver disease (NAFLD) is defined as a chronic liver disease characterized by excessive fat accumulation in the liver without another obvious cause (no excessive alcohol consumption, hepatotoxic medications, toxins, viral infections, genetic hepatic diseases), therefore it is an exclusion diagnosis. The term NAFLD literally refers to non-alcohol related hepatopathy and does not adequately correlate with metabolic dysfunction and related cardiovascular risks. Therefore, researchers and scientific societies have moved towards changing the terminology. The novel nomenclature for a metabolic-associated fatty liver disease (MAFLD) has been proposed in 2020 by a group of experts to overcome the issues related to the old terminology. The diagnosis of MAFLD is based on the presence of hepatic steatosis and at least one between these three conditions: type 2 diabetes mellitus (T2DM), obesity or metabolic dysregulation. MAFLD has been shown to be an independent risk factor for cardiovascular diseases and atherosclerosis. It is better related to the main risk factors for atherosclerosis and cardiovascular diseases than NAFLD, such as dyslipidemia, T2DM and hypertension. The aim of this review is to highlight the reasons why the term NAFLD is moving to the term MAFLD, what are the conceptual basis of this choice and its clinical implications, particularly in the cardiovascular field.

APOC-III: a Gatekeeper in Controlling Triglyceride Metabolism

PURPOSE OF REVIEW

Apolipoprotein C-III (ApoC-III) is a widely known player in triglyceride metabolism, and it has been recently recognized as a polyhedric factor which may regulate several pathways beyond lipid metabolism by influencing cardiovascular, metabolic, and neurological disease risk. This review summarizes the different functions of ApoC-III and underlines the recent findings related to its multifaceted pathophysiological role.

RECENT FINDINGS

The role of ApoC-III has been implicated in HDL metabolism and in the development of atherosclerosis, inflammation, and ER stress in endothelial cells. ApoC-III has been recently considered an important player in insulin resistance mechanisms, lipodystrophy, diabetic dyslipidemia, and postprandial hypertriglyceridemia (PPT). The emerging evidence of the involvement of ApoC-III in the in the pathogenesis of Alzheimer's disease open the way to further study if modification of ApoC-III level slows disease progression. Furthermore, ApoC-III is clearly linked to cardiovascular disease (CVD) risk, and progression of coronary artery disease (CAD) as well as the calcification of aortic valve and recent clinical trials has pointed out the inhibition of ApoC-III as a promising approach to manage hypertriglyceridemia and prevent CVD. Several evidences highlight the role of ApoC-III not only in triglyceride metabolism but also in several cardio-metabolic pathways. Results from recent clinical trials underline that the inhibition of ApoC-III is a promising therapeutical strategy for the management of severe hypertriglyceridemia and in CVD prevention.

SCD1 is nutritionally and spatially regulated in the intestine and influences systemic postprandial lipid homeostasis and gut-liver crosstalk

Stearoyl-CoA desaturase-1 is an endoplasmic reticulum (ER)-membrane resident protein that inserts a double bond into saturated fatty acids, converting them into their monounsaturated counterparts. Previous studies have demonstrated an important role for SCD1 in modulating tissue and systemic health. Specifically, lack of hepatic or cutaneous SCD1 results in significant reductions in tissue esterified lipids. While the intestine is an important site of lipid esterification and assimilation into the body, the regulation of intestinal SCD1 or its impact on lipid composition in the intestine and other tissues has not been investigated. Here we report that unlike other lipogenic enzymes, SCD1 is enriched in the distal small intestine and in the colon of chow-fed mice and is robustly upregulated by acute refeeding of a high-sucrose diet. We generated a mouse model lacking SCD1 specifically in the intestine (iKO mice). These mice have significant reductions not only in intestinal lipids, but also in plasma triacylglycerols, diacylglycerols, cholesterol esters, and free cholesterol. Additionally, hepatic accumulation of diacylglycerols is significantly reduced in iKO mice. Comprehensive targeted lipidomic profiling revealed a consistent reduction in the myristoleic (14:1) to myristic (14:0) acid ratios in intestine, liver, and plasma of iKO mice. Consistent with the reduction of the monounsaturated fatty acid myristoleic acid in hepatic lipids of chow fed iKO mice, hepatic expression of Pgc-1α, Sirt1, and related fatty acid oxidation genes were reduced in chow-fed iKO mice. Further, lack of intestinal SCD1 reduced expression of de novo lipogenic genes in distal intestine of chow-fed mice and in the livers of mice fed a lipogenic high-sucrose diet. Taken together, these studies reveal a novel pattern of expression of SCD1 in the intestine. They also demonstrate that intestinal SCD1 modulates lipid content and composition of not only intestinal tissues, but also that of plasma and liver. Further, these data point to intestinal SCD1 as a modulator of gut-liver crosstalk, potentially through the production of novel signaling lipids such as myristoleic acid. These data have important implications to understanding how intestinal SCD1 may modulate risk for post-prandial lipemia, hepatic steatosis, and related pathologies.

Angiopoietin-Like Protein Responses to Pecan-Enriched Diets Versus a Nut-Excluded Diet

Daily pecan consumption improves fasting and postprandial triglycerides, but its effect on angiopoietin-like proteins (ANGPTLs) is unknown. The objective of this study was to investigate the impact of daily pecan consumption for 8 weeks on fasting and postprandial ANGPTL3, -8, and -4. This was an 8-week, randomized, controlled trial with three treatments: two pecan groups and a nut-free control group (n = 16). The ADD group (n = 15) consumed pecans (68 g) as part of a free-living diet, and the SUB group (n = 16) substituted the pecans (68 g) for isocaloric foods from their habitual diet. Fifty-six participants were randomized but nine subjects did not begin or finish the 8-week intervention and/or testing visits. At pre- and post-intervention, a high saturated fat meal was consumed with 3.5 h postprandial blood draws to determine changes in ANGPTL3, -8, and -4. There was a significant suppression in postprandial ANGPTL3 from pre- to post-intervention within ADD and SUB (P = .004 and P = .002, respectively) but not control (ns). There were no other changes within or between groups for fasting and postprandial outcomes. Daily pecan consumption improved postprandial ANGPTL3, which may mediate improvements in lipid metabolism.

Triglyceride and Triglyceride-Rich Lipoproteins in Atherosclerosis

Cardiovascular disease (CVD) is still the leading cause of death globally, and atherosclerosis is the main pathological basis of CVDs. Low-density lipoprotein cholesterol (LDL-C) is a strong causal factor of atherosclerosis. However, the first-line lipid-lowering drugs, statins, only reduce approximately 30% of the CVD risk. Of note, atherosclerotic CVD (ASCVD) cannot be eliminated in a great number of patients even their LDL-C levels meet the recommended clinical goals. Previously, whether the elevated plasma level of triglyceride is causally associated with ASCVD has been controversial. Recent genetic and epidemiological studies have demonstrated that triglyceride and triglyceride-rich lipoprotein (TGRL) are the main causal risk factors of the residual ASCVD. TGRLs and their metabolites can promote atherosclerosis via modulating inflammation, oxidative stress, and formation of foam cells. In this article, we will make a short review of TG and TGRL metabolism, display evidence of association between TG and ASCVD, summarize the atherogenic factors of TGRLs and their metabolites, and discuss the current findings and advances in TG-lowering therapies. This review provides information useful for the researchers in the field of CVD as well as for pharmacologists and clinicians.

Causes, clinical findings and therapeutic options in chylomicronemia syndrome, a special form of hypertriglyceridemia

The prevalence of hypertriglyceridemia has been increasing worldwide. Attention is drawn to the fact that the frequency of a special hypertriglyceridemia entity, named chylomicronemia syndrome, is variable among its different forms. The monogenic form, termed familial chylomicronemia syndrome, is rare, occuring in 1 in every 1 million persons. On the other hand, the prevalence of the polygenic form of chylomicronemia syndrome is around 1:600. On the basis of the genetical alterations, other factors, such as obesity, alcohol consumption, uncontrolled diabetes mellitus and certain drugs may significantly contribute to the development of the multifactorial form. In this review, we aimed to highlight the recent findings about the clinical and laboratory features, differential diagnosis, as well as the epidemiology of the monogenic and polygenic forms of chylomicronemias. Regarding the therapy, differentiation between the two types of the chylomicronemia syndrome is essential, as well. Thus, proper treatment options of chylomicronemia and hypertriglyceridemia will be also summarized, emphasizing the newest therapeutic approaches, as novel agents may offer solution for the effective treatment of these conditions.

Compositional, Structural, and Kinetic Aspects of Lipid Digestion and Bioavailability: In Vitro, In Vivo, and Modeling Approaches

Lipid digestion and bioavailability are usually investigated separately, using different approaches (in vitro, modeling, in vivo). However, a few inclusive studies show that their kinetics are closely linked. Lipid bioavailability kinetics is likely involved in the development and evolution of several diseases, so lipid digestion kinetics could be involved as well and can be modulated by food design or combination. To illustrate this possibility, the compositional and structural aspects of lipid digestion kinetics, as investigated using in vitro and modeling approaches, are presented first. Then, in vivo and mixed approaches enabling the study of both kinetics are reviewed and discussed. Finally, disparate modeling approaches are introduced, and a unifying modeling scheme is proposed, opening new perspectives for understanding the role and interactions of various factors (chemical, physical, and biological) involved in lipid metabolism.

Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Late-afternoon endurance exercise is more effective than morning endurance exercise at improving 24-h glucose and blood lipid levels

BACKGROUND

Glucose and lipid tolerance reportedly exhibit diurnal variations, being lower in the evening than in the morning. Therefore, the effects of exercise on glucose and blood lipid levels at different times of the day may differ. This study aimed to investigate the effects of short-term endurance exercise intervention in the morning versus late afternoon on 24-h blood glucose variability and blood lipid levels.

METHODS

Twelve healthy young men participated in a randomized crossover trial. The participants were assigned to morning (09:00-11:00) or late afternoon (16:00-18:00) endurance exercise for a week, consisting of supervised exercise sessions on Mondays, Wednesdays, and Fridays. In the morning and evening trials, the participants walked for 60 min on a treadmill at approximately 60% of maximal oxygen uptake (VO_2max). Following a 2-week wash-out period, the participants performed the exercise training regimen at another time point. Continuous glucose monitoring was used to evaluate blood glucose fluctuations during each 24-h trial period. Blood samples were collected before and after each intervention to examine blood lipid and hormonal responses.

RESULTS

Examination of the area under the curve (AUC) of the glucose level changes for 24 h after the late afternoon versus morning exercise intervention revealed significantly lower values for the former versus the latter (P < 0.01). The AUC of glucose level changes after each meal was also lower after the late afternoon versus morning intervention, and significantly lower values were observed in the late afternoon versus morning trial for breakfast and dinner (P < 0.05, P < 0.01). In addition, a significant decrease in triglycerides (TG) and TG/high-density lipoprotein cholesterol (HDL-C) was noted after versus before the late afternoon intervention (P < 0.05).

CONCLUSIONS

These results suggest that late afternoon endurance exercise is more effective than morning endurance exercise at improving 24-h glucose and triglyceride levels.

Fatty Acid Composition in Local and International Food Products Available in the Maldives

Background:

Consumption of food high in saturated and trans fatty acids is a risk factor associated with non-communicable diseases such as overweight, obesity and cardiovascular diseases. Till to-date, no study has been carried out to analyze fatty acid contents in the food products available in the Maldives markets.

Aims and objectives:

The aim of this study was to assess the fatty acid contents in the food products available in the Maldives supermarkets that are both locally produced and imported into the country. The objective of the study was to collect local and imported food products from the three island markets of the Maldives (Hdh Kulhudhufuish, Naviyani Fuvahmulah and Male’), and analyze the collected food samples for fatty acid composition.

Methods:

A purposive sampling was used to collect fatty food products from the markets of three major islands of the Maldives, Male’, Kulhudhufushi and Fuvahmulah. Total 180 samples were collected and analysed in an accredited laboratory situated in Sri-Lanka, SGS Lanka Laboratory Pvt Ltd.

Results:

The results revealed that 92% of the analyzed products did not detect trans fat and only 7% of the product contained trans fat in the range between <1 to 1.64%. The lowest and highest saturated fatty acids found were in Gulab jamun (0.18 ± 0.03%) and GRB Ghee (62.26 ± 0.68%), respectively. The total fat, mono unsaturated fatty acids, and polyunsaturated fatty acids ranged between 0.45 ± 0.07% to 99.9 ± 0.00%, 0.075 ± 0.01% to 73.58 ± 1.08%, and 0.02 ± 0% to 57.04 ± 0.16%, respectively.

Conclusion:

The food products available in the Maldives supermarkets contained polyunsaturated fatty acids and monounsaturated fatty acids, which are healthy for the human body. However, the food products also contained saturated fatty acids and trans fats, which may contribute to non-communicable diseases in excess consumption. However, the finding of this study did not provide the total intake of trans fat and saturated fatty acids by individuals. Thus, it is recommended to conduct a dietary survey to assess the fatty acid intake level of the population and to develop and regulate the dietary guidelines based on the dietary survey findings. Based on the findings of this study, it is suggested to conduct awareness programs on the importance of reducing the consumption of trans fats and saturated fatty acids.

Molecular Immune-Inflammatory Connections between Dietary Fats and Atherosclerotic Cardiovascular Disease: Which Translation into Clinics?

Current guidelines recommend reducing the daily intake of dietary fats for the prevention of ischemic cardiovascular diseases (CVDs). Avoiding saturated fats while increasing the intake of mono- or polyunsaturated fatty acids has been for long time the cornerstone of dietary approaches in cardiovascular prevention, mainly due to the metabolic effects of these molecules. However, recently, this approach has been critically revised. The experimental evidence, in fact, supports the concept that the pro- or anti-inflammatory potential of different dietary fats contributes to atherogenic or anti-atherogenic cellular and molecular processes beyond (or in addition to) their metabolic effects. All these aspects are hardly translatable into clinics when trying to find connections between the pro-/anti-inflammatory potential of dietary lipids and their effects on CVD outcomes. Interventional trials, although providing stronger potential for causal inference, are typically small sample-sized, and they have short follow-up, noncompliance, and high attrition rates. Besides, observational studies are confounded by a number of variables and the quantification of dietary intakes is far from optimal. A better understanding of the anatomic and physiological barriers for the absorption and the players involved in the metabolism of dietary lipids (e.g., gut microbiota) might be an alternative strategy in the attempt to provide a first step towards a personalized dietary approach in CVD prevention.

Biophysical insights into modulating lipid digestion in food emulsions

During the last decade, major scientific advances on understanding the mechanisms of lipid digestion and metabolism have been made, with a view to addressing health issues (such as obesity) associated with overconsumption of lipid-rich and sucrose-rich foods. As lipids in common foods exist in the form of emulsions, the structuring of emulsions has been one the main strategies for controlling the rate of lipid digestion and absorption, at least from a colloid science viewpoint. Modulating the kinetics of lipid digestion and absorption offers interesting possibilities for developing foods that can provide control of postprandial lipaemia and control the release of lipophilic compounds. Food emulsions can be designed to achieve considerable differences in the kinetics of lipid digestion but most research has been applied to relatively simple model systems and in in vitro digestion models. Further research to translate this knowledge into more complex food systems and to validate the results in human studies is required. One promising approach to delay/control lipid digestion is to alter the stomach emptying rate of lipids, which is largely affected by interactions of emulsion droplets with the food matrices. Food matrices with different responses to the gastric environment and with different interactions between oil droplets and the food matrix can be designed to influence lipid digestion. This review focuses on key scientific advances made during the last decade on understanding the physicochemical and structural modifications of emulsified lipids, mainly from a biophysical science perspective. The review specifically explores different approaches by which the structure and stability of emulsions may be altered to achieve specific lipid digestion kinetics.

Determination of the Optimal Cutoff Value of Triglyceride That Corresponds to Fasting Levels in Chinese Subjects With Marked Hypertriglyceridemia

The level of triglyceride (TG) ≥ 2. 3 mmol/L is suggestive of marked hypertriglyceridemia (HTG) and requires treatment with a triglyceride-lowering agent in high-risk and very high-risk patients as recommended by the 2019 ESC/EAS guidelines for the management of dyslipidemia. However, the optimal cutoff value required to diagnose non-fasting HTG that corresponds to the fasting goal level of 2.3 mmol/L in Chinese subjects is unknown. This study enrolled 602 cardiology inpatients. Blood lipid levels, including calculated non-high-density lipoprotein cholesterol (non-HDL-C) and remnant cholesterol (RC), were measured at 0, 2, and 4 h after a daily Chinese breakfast. Of these, 482 inpatients had TG levels of <2.3 mmol/L (CON group) and 120 inpatients had TG levels of ≥2.3 mmol/L (HTG group). Receiver operating characteristic (ROC) curve analysis was used to determine the cutoff values for postprandial HTG that corresponded to a target fasting level of 2.3 mmol/L. Marked hypertriglyceridemia (≥2.3 mmol/L) was found in 120 (19.9%) patients in this study population. The levels of non-fasting TG and RC increased significantly in both groups and reached the peak at 4 h after a daily meal, especially in the HTG group (p < 0.05). The optimal cutoff value of TG at 4 h, which corresponds to fasting TG of ≥2.3 mmol/L, that can be used to predict HTG, was 2.66 mmol/L. According to the new non-fasting cutoff value, the incidence of non-fasting HTG is close to its fasting level. In summary, this is the first study to determine the non-fasting cutoff value that corresponds to a fasting TG of ≥2.3 mmol/L in Chinese patients. Additionally, 2.66 mmol/l at 4 h after a daily meal could be an appropriate cutoff value that can be used to detect non-fasting marked HTG in Chinese subjects.

Volanesorsen for treatment of familial chylomicronemia syndrome

INTRODUCTION

Familial chylomicronemia syndrome (FCS) is a rare subtype of severe hypertriglyceridemia that affects ~1 in 100, 000 to 1,000,000 individuals. The major risk to health is acute pancreatitis. FCS is defined by biallelic loss-of-function mutations in one of five canonical genes that encode proteins critical to lipolysis of large triglyceride-rich lipoprotein particles. Unlike the vast majority of patients with severe hypertriglyceridemia, FCS patients lack any lipolytic capacity and are thus resistant to standard medications.

AREAS COVERED

This review focuses on a mechanism that effectively reduces elevated triglyceride levels in FCS, namely interference of synthesis of apolipoprotein (apo) C-III. Volanesorsen is an antisense RNA drug administered subcutaneously that knocks down apo C-III, resulting in dramatic reductions in triglyceride levels both in FCS patients and in the wider population of subjects with severe hypertriglyceridemia.

EXPERT OPINION

Volanesorsen is a highly effective treatment to reduce elevated triglycerides in FCS patients, providing proof-of-concept of the validity of targeting apo C-III. However, off target effects of volanesorsen, including thrombocytopenia, may ultimately limit its use. Nonetheless, building on the knowledge derived from the volanesorsen experience, there is intensified interest in promising newer agents that also target apo C-III but have technical modifications that limit potential off target adverse effects.

Does four-week consecutive, dawn-to-sunset intermittent fasting during Ramadan affect cardiometabolic risk factors in healthy adults? A systematic review, meta-analysis, and meta-regression

AIMS

This study aimed to evaluate the effects of Ramadan diurnal intermittent fasting (RDIF; 29-30 days) on cardiometabolic risk factors (CMRF) in healthy adults, and examine the effect of various cofactors on the outcomes using sub-group meta-regression.

DATA SYNTHESIS

We conducted a systematic review and meta-analysis to measure the effect sizes of changes in CMRF in healthy adult Muslims observing RDIF. Ten scientific databases (EBSCOhost, CINAHL, Cochrane, EMBASE, PubMed/MEDLINE, Scopus, Google Scholar, ProQuest Medical, ScienceDirect, and Web of Science) were searched from the date of inception (1950) to the end of November 2020. The CMRF searched and analyzed were total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), diastolic blood pressure (DBP), and heart rate (HR). We identified 91 studies (4431 adults aged 18-85 years) conducted between 1982 and 2020 in 23 countries distributed over four continents. RDIF-induced effect sizes for CMRF were: TC (no. of studies K = 77, number of subjects N = 3705, Hedge's g = -0.092, 95% confidence interval (CI): -0.168, 0.016); TG (K = 74, N = 3591, Hedge's g = -0.127, 95% CI: -0.203, 0.051); HDL-C (K = 68, N = 3528, Hedge's g = 0.138, 95% CI: 0.051, 0.224); LDL-C (K = 65, N = 3354, Hedge's g = -0.115, 95% CI: -0.197, -0.034); VLDL-C (K = 13, N = 648, Hedge's g = -0.252, 95% CI: -0.431, 0.073), DBP (K = 32, N = 1716, Hedge's g = -0.255, 95% CI: -0.363, 0.147), and HR (K = 12, N = 674, Hedge's g = -0.082, 95% CI: -0.300, 0.136). Meta-regression revealed that the age of fasting people was a significant moderator of changes in both HDL-C (P = 0.02) and VLDL-C (P = 0.01). Male sex was the only significant moderator of changes in LDL-C (P = 0.055). Fasting time duration was the only significant moderator of HDL-C (P = 0.001) at the end of Ramadan.

CONCLUSIONS

RDIF positively impacts CMRF, which may confer short-term transient protection against cardiovascular disease among healthy people.

Acute consumption of pecans decreases angiopoietin-like protein-3 in healthy males: a secondary analysis of randomized controlled trials

Angiopoietin-like proteins (ANGPTL)-3 and -4 regulate lipid metabolism, but the effect of tree nuts of varying fatty acid composition on post-meal responses is unknown. The purpose of the study was to conduct a secondary analysis of two studies on ANGPTL3 and -4 responses to meals containing different tree nuts. We hypothesized that the pecan-containing meal would mitigate postprandial rises in ANGPTL3 compared to the traditional meal without nuts in males, but not females. In addition, we hypothesized that there would be no other differences between any other treatments in ANGPTL3 or -4 responses. The two studies were double-blind, randomized crossover trials. Twenty-two adults (10=male, 12=female) completed study 1, which compared meals containing pecans vs. no nuts (control), and thirty adults (14=male, 16=female) completed study 2, which compared meals containing black walnuts, English walnuts (EW), or no nuts (control). Blood was collected at fasting, 30, 60, 120, and 180min postprandially. In study 1, ANGPTL3 was suppressed more in pecan vs. control in males (iAUC: -579.4±219.4 vs. -128.4±87.1pg/mL/3h, P<.05). In study 2, there was no difference in ANGPTL3 between black walnuts vs. EW, but ANGPTL3 was suppressed more in control vs. black walnuts in females only (iAUC: -196.4±138.4 vs. 102.1±90.1pg/mL/3h, P<.05). There were no differences in ANGPTL4 between treatments. In conclusion, adding pecans to a meal decreased ANGPTL3 in males, but not females. These data highlight the importance of investigating the impact of nutrients and sex on postprandial ANGPTL3 ad -4 responses to better understand their ability to reduce cardiovascular disease risk.

Changes in the profile of circulating HDL subfractions in severe obese adolescents following a weight reduction program

BACKGROUND AND AIMS

Epidemiological studies show that obese adolescents are candidates to suffer cardiovascular pathologies in adulthood. In order to detect subfractions with a diagnostic value for future cardiovascular disorders, we analyzed the complete lipoprotein profile of severely obese adolescents.

METHODS AND RESULTS

Twenty-eight obese adolescents free from comorbidities were admitted into a weight reduction program. Anthropometric parameters were monitored. The circulating lipoproteins and glycemia were measured at the beginning and at the end of the study by conventional blood analysis as well as by using lipoprotein electrophoresis. Twenty-one puberty-matched normal-weight adolescents were recruited as controls. After 4 months, participants improved anthropometric parameters. Blood analysis indicated that circulating lipoproteins were in the healthy range during intervention. Nevertheless, results obtained from lipoprotein electrophoresis showed a significant increase in the large high-density lipoprotein subfraction in the obese population at the end of intervention, but significantly lower than normal-weight counterparts. In addition, intermediate- and low-density lipoprotein subfractions were in the healthy range in controls and in obese adolescents during intervention.

CONCLUSIONS

Altogether, it seems that the obese adolescents with no comorbidities do not develop a clear dyslipidemia. However, low values of large high-density lipoprotein subfractions could be considered as candidate predictors to develop cardiovascular disease in the future. For this reason, diet and exercise are key tools to fight against this pathology.

REGISTRATION NUMBER FOR CLINICAL TRIALS

ISRCTN99414527.

Genetic basis of hypertriglyceridemies

Diagnosis and treatment of triglyceride metabolism disorders: from pathophysiology to clinical practice. Hypertriglyceridaemia (HTG) affects 15%-20% of the world's population, and is frequently discovered as an incidental finding in a laboratory test. Disorders of triglyceride (TG) metabolism have a complex genetic basis. New genetic tools that allow a more precise approach to the disorders have made it possible to redefine and classify HTG into two groups: monogenic HTG (TG>10 mmol/L) and polygenic HTG (2 mmol/L<TG<10 mmol/L) with a milder phenotype, but with a clear genetic influence. In approximately 50% of patients with severe HTG a genetic cause has not yet been found. In addition to the inclusion of ever more genes in studies, statistical models are now also being examined that consider complex gene-environment interactions that could explain why the presence of a set of apparently benign variants may cause HTG in the presence of a triggering factor such as adiposity. Knowledge of the genetic nature of HTG has also helped identify targets for pharmacological treatments, thus avoiding a strict diet with a fat content of less than 20%, which is difficult to maintain. Accurate diagnosis of these disorders is essential for correct treatment according to the inherent risk of each HTG, since, as has been shown in multiple studies, high fasting and postprandial TG concentrations are an independent risk factor for cardiovascular disease.

Mechanisms of Atherosclerosis Induced by Postprandial Lipemia

Postprandial lipemia plays an important role in the formation, occurrence, and development of atherosclerosis, and it is closely related to coronary heart disease and other diseases involving endothelial dysfunction, oxidative stress, inflammation, and other mechanisms. Therefore, it has become a focus area for further research. The studies on postprandial lipemia mainly include TG, TRL, VLDL, CM, and remnant cholesterol. Diurnal triglyceride patterns and postprandial hyperlipidemia are very relevant and are now insufficiently covered. The possible mechanisms between postprandial lipemia and cardiovascular disease have been reviewed in this article by referring to relevant literature in recent years. The research progress on the effects of postprandial lipemia on endothelial function, oxidative stress, and inflammation is highlighted. The intervention of postprandial lipemia is discussed. Non-medicinal intervention such as diet and exercise improves postprandial lipemia. As medicinal intervention, statin, fibrate, ezetimibe, omega-3 fatty acids, and niacin have been found to improve postprandial lipid levels. Novel medications such as pemafibrate, PCSK9, and apoCIII inhibitors have been the focus of research in recent years. Gut microbiota is closely related to lipid metabolism, and some studies have indicated that intestinal microorganisms may affect lipid metabolism as environmental factors. Whether intervention of gut microbiota can reduce postprandial lipemia, and therefore against AS, may be worthy of further study.

Food Matrix and Macronutrient Digestion

Food digestion may be regarded as a physiological interface between food and health. During digestion, the food matrix is broken down and the component nutrients and bioactive compounds are absorbed through a synergy of mechanical, chemical, and biochemical processes. The food matrix modulates the extent and kinetics to which nutrients and bioactive compounds make themselves available for absorption, hence regulating their concentration profile in the blood and their utilization in peripheral tissues. In this review, we discuss the structural and compositional aspects of food that modulate macronutrient digestibility in each step of digestion. We also discuss in silico modeling approaches to describe the effect of the food matrix on macronutrient digestion. The detailed knowledge of how the food matrix is digested can provide a mechanistic basis to elucidate the complex effect of food on human health and design food with improved functionality.

Effects of two consecutive mixed meals high in palmitic acid or stearic acid on 8-h postprandial lipemia and glycemia in healthy-weight and overweight men and postmenopausal women: a randomized controlled trial

Purpose

Palmitic and stearic acids have different effects on fasting serum lipoproteins. However, the effects on postprandial lipemia and glycemia are less clear. Also, the effects of a second meal may differ from those of the first meal. Therefore, we studied the effects of two consecutive mixed meals high in palmitic acid- or stearic acid-rich fat blends on postprandial lipemia and glycemia.

Methods

In a randomized, crossover study, 32 participants followed 4-week diets rich in palmitic or stearic acids, At the end of each dietary period, participants consumed two consecutive meals each containing ± 50 g of the corresponding fat blend.

Results

Postprandial concentrations of triacylglycerol (diet-effect: − 0.18 mmol/L; p = 0.001) and apolipoprotein B48 (diet-effect: − 0.68 mg/L; p = 0.002) were lower after stearic-acid than after palmitic-acid intake. Consequently, total (iAUC_0–8 h) and first meal (iAUC_0–4 h) responses were lower after stearic-acid intake (p ≤ 0.01). Second meal responses (iAUC_4–8 h) were not different. Postprandial changes between the diets in non-esterified fatty acids (NEFA) and C-peptide differed significantly over time (p < 0.001 and p = 0.020 for diet*time effects, respectively), while those for glucose and insulin did not. The dAUC_0–8 h, dAUC_0–4 h, and dAUC_4–8 h for NEFA were larger after stearic-acid intake (p ≤ 0.05). No differences were observed in the iAUCs of C-peptide, glucose, and insulin. However, second meal responses for glucose and insulin (iAUC_4–8 h) tended to be lower after stearic-acid intake (p < 0.10).

Conclusion

Consumption of the stearic acid-rich meals lowered postprandial lipemia as compared with palmitic acid. After the second stearic acid-rich meal, concentrations of C-peptide peaked earlier and those of NEFA decreased more.

Clinical trial registry This trial was registered at clinicaltrials.gov as NCT02835651 on July 18, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02530-2.

Palmitic acid-rich oils with and without interesterification lower postprandial lipemia and increase atherogenic lipoproteins compared with a MUFA-rich oil: A randomized controlled trial

BACKGROUND

Interesterified (IE) fats are widely used in place of trans fats; however, little is known about their metabolism.

OBJECTIVES

To test the impact of a commonly consumed IE compared with a non-IE equivalent fat on in vivo postprandial and in vitro lipid metabolism, compared with a reference oil [rapeseed oil (RO)].

METHODS

A double-blinded, 3-phase crossover, randomized controlled trial was performed in healthy adults (n = 20) aged 45-75 y. Postprandial plasma triacylglycerol and lipoprotein responses (including stable isotope tracing) to a test meal (50 g fat) were evaluated over 8 h. The test fats were IE 80:20 palm stearin/palm kernel fat, an identical non-IE fat, and RO (control). In vitro, mechanisms of digestion were explored using a dynamic gastric model (DGM).

RESULTS

Plasma triacylglycerol 8-h incremental area under the curves were lower following non-IE compared with RO [-1.7 mmol/L⋅h (95% CI: -3.3, -0.0)], but there were no differences between IE and RO or IE and non-IE. LDL particles were smaller following IE and non-IE compared with RO (P = 0.005). Extra extra large, extra large, and large VLDL particle concentrations were higher following IE and non-IE compared with RO at 6-8 h (P < 0.05). No differences in the appearance of [13C]palmitic acid in plasma triacylglycerol were observed between IE and non-IE fats. DGM revealed differences in phase separation of the IE and non-IE meals and delayed release of SFAs compared with RO.

CONCLUSIONS

Interesterification did not modify fat digestion, postprandial lipemia, or lipid metabolism measured by stable isotope and DGM analysis. Despite the lower lipemia following the SFA-rich fats, increased proatherogenic large triacylglycerol-rich lipoprotein remnant and small LDL particles following the SFA-rich fats relative to RO adds a new postprandial dimension to the mechanistic evidence linking SFAs to cardiovascular disease risk.

Elevated Levels of Apolipoprotein CIII Increase the Risk of Postprandial Hypertriglyceridemia

BACKGROUND

To investigate possible mechanisms of postprandial hypertriglyceridemia (PPT), we analyzed serum lipid and apolipoprotein (Apo) AI, B, CII and CIII levels before and after a high-fat meal.

METHODS

The study has been registered with the China Clinical Trial Registry (registration number:ChiCTR1800019514; URL: http://www.chictr.org.cn/index.aspx). We recruited 143 volunteers with normal fasting triglyceride (TG) levels. All subjects consumed a high-fat test meal. Venous blood samples were obtained during fasting and at 2, 4, and 6 hours after the high-fat meal. PPT was defined as TG ≥2.5 mmol/L any time after the meal. Subjects were divided into two groups according to the high-fat meal test results: postprandial normal triglyceride (PNT) and PPT. We compared the fasting and postprandial lipid and ApoAI, ApoB, ApoCII and ApoCIII levels between the two groups.

RESULTS

Significant differences were found between the groups in fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), TG, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), TG-rich lipoprotein remnants (TRLRs), ApoB, ApoCIII, ApoAI/ApoB and ApoCII/ApoCIII. The insulin, HOMA-IR, TG, TC, LDL-C, non-HDL-C, TRLRs, ApoB, ApoCIII and ApoCII/ApoCIII values were higher in the PPT group, while the ApoAI/ApoB ratio was higher in the PNT group. The postprandial TG level peaked in the PNT group 2 hours after the meal but was significantly higher in the PPT group and peaked at 4 hours. TRLRs gradually increased within 6 hours after the high-fat meal in both groups. The area under the curve (AUC) of TG and TRLRs and the AUC increment were higher in the PPT group (P < 0.001). ApoCIII peaked in the PNT group 2 hours after the meal and gradually decreased. ApoCIII gradually increased in the PPT group within 6 hours after the meal, exhibiting a greater AUC increment (P < 0.001). Fasting ApoCIII was positively correlated with age, systolic and diastolic blood pressure, body mass index (BMI), waist circumference, TC, TG, LDL-C, non-HDL-C, TRLRs, and ApoB (P<0.05). ApoCIII was an independent risk factor of PPT after adjustment for BMI, waist circumference, TC, LDL-C, and ApoB (P < 0.001, OR=1.188).

CONCLUSIONS

Elevated ApoCIII levels may cause PPT.

Evaluating the appropriate oral lipid tolerance test model for investigating plasma triglyceride elevation in mice

The oral lipid tolerance test (OLTT) has been known to assess intestinal fat metabolism and whole-body lipid metabolism, but rodent models for OLTT are not yet established. Differences in OLTT methodology preclude the generation of definitive results, which may cause some confusion about the anti-hypertriglyceridemia effects of the test materials. To standardize and generate more appropriate methodology for the OLTT, we examined the effects of mice strain, dietary lipid sources, fasting period, and gender on lipid-induced hypertriglyceridemia in mice. First, lipid-induced hypertriglyceridemia was more strongly observed in male ddY mice than in C57BL/6N or ICR mice. Second, the administration of olive and soybean oils remarkably represented lipid-induced hypertriglyceridemia. Third, fasting period before the OLTT largely affected the plasma triglyceride elevation. Fasting for 12 h, but less than 48 h, provoked lipid-induced hypertriglyceridemia. Fourth, we explored the suppressive effects of epigallocatechin gallate (EGCG), a green tea polyphenol, on lipid-induced hypertriglyceridemia. The administration of 100 mg/kg of EGCG suppressed lipid-induced hypertriglyceridemia and intestinal lipase activity. Fifth, EGCG-induced suppressive effects were observed after lipid-induced hypertriglyceridemia was observed in male mice, but not in female mice. Lastly, lipid-induced hypertriglyceridemia could be more effectively induced in mice fed a high-fat diet for 1 week before the OLTT. These findings indicate that male ddY mice after 12 h fasting displayed marked lipid-induced hypertriglyceridemia in response to soybean oil. Hence, the defined experiment condition may be a more appropriate OLTT model for evaluating lipid-induced hypertriglyceridemia.

The Impact of Dietary Glycemic Index and Glycemic Load on Postprandial Lipid Kinetics, Dyslipidemia and Cardiovascular Risk

Many recent studies have acknowledged postprandial hypetriglyceridemia as a distinct risk factor for cardiovascular disease. This dysmetabolic state is the result of the hepatic overproduction of very low-density lipoproteins (VLDLs) and intestinal secretion of chylomicrons (CMs), which leads to highly atherogenic particles and endothelial inflammation. Postprandial lipid metabolism does not only depend on consumed fat but also on the other classes of nutrients that a meal contains. Various mechanisms through which carbohydrates exacerbate lipidemia have been identified, especially for fructose, which stimulates de novo lipogenesis. Glycemic index and glycemic load, despite their intrinsic limitations, have been used as markers of the postprandial glucose and insulin response, and their association with metabolic health and cardiovascular events has been extensively studied with contradictory results. This review aims to discuss the importance and pathogenesis of postprandial hypertriglyceridemia and its association with cardiovascular disease. Then, we describe the mechanisms through which carbohydrates influence lipidemia and, through a brief presentation of the available clinical studies on glycemic index/glycemic load, we discuss the association of these indices with atherogenic dyslipidemia and address possible concerns and implications for everyday practice.

Genome-Wide Association Study of the Postprandial Triglyceride Response Yields Common Genetic Variation in LIPC (Hepatic Lipase)

BACKGROUND

The increase in serum triglyceride (TG) concentrations in response to a meal is considered a risk factor for cardiovascular disease. We aimed to elucidate the genetics of the postprandial TG response through genome-wide association studies (GWAS).

METHODS

Participants of the NEO (Netherlands Epidemiology of Obesity) study (n=5630) consumed a liquid mixed meal after an overnight fast. GWAS of fasting and postprandial serum TG at 150 minutes were performed. To identify genetic variation of postprandial TG independent of fasting TG, we calculated the TG response at 150 minutes by the residuals of a nonlinear regression that predicted TG at 150 minutes as a function of fasting TG. Association analyses were adjusted for age, sex, and principal components in a linear regression model. Next, using the identified variants as determinants, we performed linear regression analyses on the residuals of the postprandial response of 149 nuclear magnetic resonance-based metabolite measures.

RESULTS

GWAS of fasting TG and postprandial serum TG at 150 minutes resulted in completely overlapping loci, replicating previous GWAS. From GWAS of the TG response, we identified rs7350789-A (allele frequency=0.36), mapping to hepatic lipase (LIPC), to be associated with a smaller increase in TG concentrations at 150 minutes (β=-0.11; P-value=5.1×10^-8). Rs7350789-A was associated with responses of 33 metabolite measures (P-value <1.34×10^-3), mainly smaller increases of the TG-component in almost all HDL (high-density lipoprotein) subparticles (HDL-TG), a smaller decrease of HDL diameter and smaller increases of most components of VLDL (very low density lipoprotein) subparticles.

CONCLUSIONS

GWAS of the TG response identified a variant near LIPC as a main contributor to postprandial TG metabolism independent of fasting TG concentrations, resulting in smaller increases of HDL-TG and VLDL subparticles.

Immunometabolic function of cholesterol in cardiovascular disease and beyond

Inflammation represents the driving feature of many diseases, including atherosclerosis, cancer, autoimmunity and infections. It is now established that metabolic processes shape a proper immune response and within this context the alteration in cellular cholesterol homeostasis has emerged as a culprit of many metabolic abnormalities observed in chronic inflammatory diseases. Cholesterol accumulation supports the inflammatory response of myeloid cells (i.e. augmentation of toll-like receptor signalling, inflammasome activation, and production of monocytes and neutrophils) which is beneficial in the response to infections, but worsens diseases associated with chronic metabolic inflammation including atherosclerosis. In addition to the innate immune system, cells of adaptive immunity, upon activation, have also been shown to undergo a reprogramming of cellular cholesterol metabolism, which results in the amplification of inflammatory responses. Aim of this review is to discuss (i) the molecular mechanisms linking cellular cholesterol metabolism to specific immune functions; (ii) how cellular cholesterol accumulation sustains chronic inflammatory diseases such as atherosclerosis; (iii) the immunometabolic profile of patients with defects of genes affecting cholesterol metabolism including familial hypercholesterolaemia, cholesteryl ester storage disease, Niemann-Pick type C, and immunoglobulin D syndrome/mevalonate kinase deficiency. Available data indicate that cholesterol immunometabolism plays a key role in directing immune cells function and set the stage for investigating the repurposing of existing 'metabolic' drugs to modulate the immune response.

Postprandial Hypertriglyceridaemia Revisited in the Era of Non-Fasting Lipid Profile Testing: A 2019 Expert Panel Statement, Main Text

Residual vascular risk exists despite the aggressive lowering of Low-Density Lipoprotein Cholesterol (LDL-C). A contributor to this residual risk may be elevated fasting, or non-fasting, levels of Triglyceride (TG)-rich lipoproteins. Therefore, there is a need to establish whethe a standardised Oral Fat Tolerance Test (OFTT) can improve atherosclerotic Cardiovascular (CV) Disease (ASCVD) risk prediction in addition to a fasting or non-fasting lipid profile. An expert panel considered the role of postprandial hypertriglyceridaemia (as represented by an OFTT) in predicting ASCVD. The panel updated its 2011 statement by considering new studies and various patient categories. The recommendations are based on expert opinion since no strict endpoint trials have been performed. Individuals with fasting TG concentration <1 mmol/L (89 mg/dL) commonly do not have an abnormal response to an OFTT. In contrast, those with fasting TG concentration ≥2 mmol/L (175 mg/dL) or nonfasting ≥2.3 mmol/L (200 mg/dL) will usually have an abnormal response. We recommend considering postprandial hypertriglyceridaemia testing when fasting TG concentrations and non-fasting TG concentrations are 1-2 mmol/L (89-175 mg/dL) and 1.3-2.3 mmol/L (115-200 mg/dL), respectively as an additional investigation for metabolic risk prediction along with other risk factors (obesity, current tobacco abuse, metabolic syndrome, hypertension, and diabetes mellitus). The panel proposes that an abnormal TG response to an OFTT (consisting of 75 g fat, 25 g carbohydrate and 10 g proteins) is >2.5 mmol/L (220 mg/dL). Postprandial hypertriglyceridaemia is an emerging factor that may contribute to residual CV risk. This possibility requires further research. A standardised OFTT will allow comparisons between investigational studies. We acknowledge that the OFTT will be mainly used for research to further clarify the role of TG in relation to CV risk. For routine practice, there is a considerable support for the use of a single non-fasting sample.

Palmitic Acid Versus Stearic Acid: Effects of Interesterification and Intakes on Cardiometabolic Risk Markers - A Systematic Review

Fats that are rich in palmitic or stearic acids can be interesterified to increase their applicability for the production of certain foods. When compared with palmitic acid, stearic acid lowers low-density lipoprotein (LDL)-cholesterol, which is a well-known risk factor for coronary heart disease (CHD), but its effects on other cardiometabolic risk markers have been studied less extensively. In addition, the positional distribution of these two fatty acids within the triacylglycerol molecule may affect their metabolic effects. The objective was to compare the longer-term and postprandial effects of (interesterified) fats that are rich in either palmitic or stearic acids on cardiometabolic risk markers in humans. Two searches in PubMed/Medline, Embase (OVID) and Cochrane Library were performed; one to identify articles that studied effects of the position of palmitic or stearic acids within the triacylglycerol molecule and one to identify articles that compared side-by-side effects of palmitic acid with those of stearic acid. The interesterification of palmitic or stearic acid-rich fats does not seem to affect fasting serum lipids and (apo) lipoproteins. However, substituting palmitic acid with stearic acid lowers LDL-cholesterol concentrations. Postprandial lipemia is attenuated if the solid fat content of a fat blend at body temperature is increased. How (the interesterification of) palmitic or stearic acid-rich fats affects other cardiometabolic risk markers needs further investigation.

Acute whole apple consumption did not influence postprandial lipaemia: a randomised crossover trial

Whole apples are a source of pectin and polyphenols, both of which show potential to modulate postprandial lipaemia (PPL). The present study aimed to explore the effects of whole apple consumption on PPL, as a risk factor for CVD, in generally healthy but overweight and obese adults. A randomised, crossover acute meal trial was conducted with seventeen women and nine men (mean BMI of 34·1 (sem0·2) kg/m2). Blood samples were collected for 6 h after participants consumed an oral fat tolerance test meal that provided 1 g fat/kg body weight and 1500 mg acetaminophen per meal for estimating gastric emptying, with and without three whole raw Gala apples (approximately 200 g). Plasma TAG (with peak postprandial concentration as the primary outcome), apoB48, chylomicron-rich fraction particle size and fatty acid composition, glucose, insulin and acetaminophen were analysed. Differences between with and without apples were identified by ANCOVA. Apple consumption did not alter postprandial TAG response, chylomicron properties, glucose or acetaminophen (P> 0·05), but did lead to a higher apoB48 peak concentration and exaggerated insulin between 20 and 180 min (P< 0·05). Overall, as a complex food matrix, apples did not modulate postprandial TAG when consumed with a high-fat meal in overweight and obese adults, but did stimulate insulin secretion, potentially contributing to an increased TAG-rich lipoprotein production.

Sex differences in postprandial responses to different dairy products on lipoprotein subclasses: a randomised controlled cross-over trial

Men have earlier first-time event of CHD and higher postprandial TAG response compared with women. The aim of this exploratory sub-study was to investigate if intake of meals with the same amount of fat from different dairy products affects postprandial lipoprotein subclasses differently in healthy women and men. A total of thirty-three women and fourteen men were recruited to a randomised controlled cross-over study with four dairy meals consisting of butter, cheese, whipped cream or sour cream, corresponding to 45 g of fat (approximately 60 energy percent). Blood samples were taken at 0, 2, 4 and 6 h postprandially. Lipoprotein subclasses were measured using NMR and analysed using a linear mixed model. Sex had a significant impact on the response in M-VLDL (P=0·04), S-LDL (P=0·05), XL-HDL (P=0·009) and L-HDL (P=0·001) particle concentration (P), with women having an overall smaller increase in M-VLDL-P, a larger decrease in S-LDL-P and a larger increase in XL- and L-HDL-P compared with men, independent of meal. Men showed a decrease in XS-VLDL-P compared with women after intake of sour cream (P<0·01). In men only, XS-VLDL-P decreased after intake of sour cream compared with all other meals (v. butter: P=0·001; v. cheese: P=0·04; v. whipped cream: P=0·006). Meals with the same amount of fat from different dairy products induce different postprandial effects on lipoprotein subclass concentrations in men and women.

Four nights of sleep restriction suppress the postprandial lipemic response and decrease satiety

Chronic sleep restriction, or inadequate sleep, is associated with increased risk of cardiometabolic disease. Laboratory studies demonstrate that sleep restriction causes impaired whole-body insulin sensitivity and glucose disposal. Evidence suggests that inadequate sleep also impairs adipose tissue insulin sensitivity and the NEFA rebound during intravenous glucose tolerance tests, yet no studies have examined the effects of sleep restriction on high-fat meal lipemia. We assessed the effect of 5 h time in bed (TIB) per night for four consecutive nights on postprandial lipemia following a standardized high-fat dinner (HFD). Furthermore, we assessed whether one night of recovery sleep (10 h TIB) was sufficient to restore postprandial metabolism to baseline. We found that postprandial triglyceride (TG) area under the curve was suppressed by sleep restriction (P = 0.01), but returned to baseline values following one night of recovery. Sleep restriction decreased NEFAs throughout the HFD (P = 0.02) and NEFAs remained suppressed in the recovery condition (P = 0.04). Sleep restriction also decreased participant-reported fullness or satiety (P = 0.03), and decreased postprandial interleukin-6 (P < 0.01). Our findings indicate that four nights of 5 h TIB per night impair postprandial lipemia and that one night of recovery sleep may be adequate for recovery of TG metabolism, but not for markers of adipocyte function.

Single Triglyceride-Rich Meal Destabilizes Barrier Functions and Initiates Inflammatory Processes of Endothelial Cells

Postprandial hypertriglyceridemia is an independent risk factor for cardiovascular disease. The aim of this study was to assess the effects of a single fat-rich meal on barrier functions and inflammatory status on human umbilical vascular endothelial cells (HUVECs), furthermore we assess the effects of mixture of palmitic acid and 25-hydroxycholesterol (PA +25OHCH) on integrity of endothelial cells and their inflammatory properties. HUVECs were induced with serum of healthy volunteers taken before, and 3 h after, the consumption of a meal with a standardized daily required dose of fats. In addition, endothelial cells were induced with PA +25OHCH (800 μM/L+10 μg/mL). Total cholesterol, triglycerides (TGs), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, high sensitivity c-reactive protein, and glucose were measured at fasting and postprandially. HUVEC integrity was measured in the RTCA-DP xCELLigence system. mRNA expression of interleukin (IL)-33, IL-32, intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1), CX3C-chemokine, vascular endothelial growth factor (VEGF) occludin, and VE-cadherin was analyzed by real-time polymerase chain reaction. Viability and apoptosis were assessed in flow cytometry. The level of VEGF and IL-33 in fasting and postprandial serum was assessed by enzyme-linked immunosorbent assay (ELISA). Three hours after consumption of a fatty meal, all patients displayed increased levels of TGs and Toll-like receptors (110 ± 37 mg/dL versus 182 ± 64 mg/dL P < 0.05) (24 ± 11 mg/dL versus 42 ± 14 mg/dL P < 0.05). Postprandial serum and PA +25OHCH caused >20% decrease of HUVEC integrity than fasting serum (P < 0.001). HUVEC disintegration was accompanied by a decrease of occludin mRNA expression as compared with fasting serum (P < 0.05). The fatty meal affected neither VE-cadherin mRNA expression nor its apoptosis (P > 0.05). Mixture of PA +25OHCH caused decrease of VE-cadherin mRNA expression as compared with fasting serum (P < 0.01). PA +25OHCH did not affect HUVEC apoptosis (P > 0.05). Postprandial serum and PA +25OHCH caused increase of IL-33, MCP-1, ICAM-1, IL-32, VEGF, and CX3C-chemokine mRNA expression as compared with fasting serum (P < 0.05). Moreover, level of VEGF in fatty serum was significantly higher (P < 0.001). Postprandial lipemia after a single fatty meal may destabilize the endothelial barrier and initiate inflammatory processes.

Association of oxytocin levels and oxytocin receptor gene polymorphism (rs2254298) with cardiovascular risk factors in Brazilian elderly from Primary Health Care

BACKGROUND

Morbidity and mortality from cardiovascular disease is a typical phenomenon in the elderly, and are related to unfavorable genetic, hormonal and environmental (lifestyle) interactions. In this context, oxytocin (OT) seems plays a key role in the development of CVD by performing important actions in metabolism energy and hemodynamic variables.

OBJECTIVE

To verify if there is an association between (OT) levels and the oxytocin receptor gene (OXTR) polymorphism (rs2254298) with cardiovascular risk factors (CRF) in the elderly.

METHODS

This was a cross-sectional study in community-dwelling elderly attending primary health care. The genotyping was done using the polymerase chain reaction technique. The CRF factors investigated included hypertension, diabetes mellitus, dyslipidemia, sedentary lifestyle, and obesity. Levels of triglycerides (TGC) postprandial and glucose were measured in capillary blood. OT and cortisol levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The sample comprised 177 elderly individuals. OT levels showed a significant negative correlation with postprandial triglycerides (p = 0.030) and BMI (p = 0.019). OT levels were also associated with leanness (p = 0.005). On Poisson regression analysis, OT remained a predictor for leanness (p = 0.010). No significant associations were observed between the OXTR polymorphism and CRF.

CONCLUSION

The results suggest that Postprandial TGC levels are increased, while OT levels are decreased, and this hormone was significantly elevated in lean elderly. Future studies are needed to confirm these findings, and the role of OT in metabolic parameters.

Measuring phenotypic flexibility by transcriptome time-course analyses during challenge tests before and after energy restriction

Metabolic challenge tests may be a valuable tool to magnify the effects of diet on health. The use of transcriptomics enables a more extensive characterization of the effects of diet. The question remains whether transcriptome time-course analyses during challenge tests will deliver more information on the effect of diet than a static fasting measurement. A dietary intervention known to improve health is energy restriction (ER). Seventy-two healthy, overweight men and women aged 50-65 were subjected to an oral glucose tolerance test (OGTT) and a mixed-meal test (MMT) before and after 12 wk of a 20% ER diet or control diet. Whole-genome gene expression of peripheral blood mononuclear cells was performed before and after the intervention. This was done during fasting, during the OGTT at 30, 60, and 120 min, and during the MMT at 60, 120, 240, and 360 min. Upon ER, the OGTT resulted in a faster and more pronounced down-regulation in gene expression of oxidative phosphorylation, cell adhesion, and DNA replication compared with the control. The MMT showed less-consistent effects. The OGTT combined with transcriptomics can be used to measure dynamic cellular adaptation upon an intervention that cannot be determined with a static fasting measurement.-Van Bussel, I. P. G., Fazelzadeh, P., Frost, G. S., Rundle, M., Afman, L. A. Measuring phenotypic flexibility by transcriptome time-course analyses during challenge tests before and after energy restriction.

Effect of the food form and structure on lipid digestion and postprandial lipaemic response

As the food matrix is a determinant of the rate of fat digestion and absorption, it is important for the modulation of postprandial triglyceridaemia. High postprandial triglyceride levels are associated with an increase in inflammation, oxidative stress, an imbalance in the lipoprotein profile and an increase in the risk of developing chronic diseases. This study was designed to assess the in vitro digestion patterns and the postprandial lipaemic responses to test foods with the same nutrient composition but differing in the form and structure. A liquid, a semi-solid and a solid test food with the same nutrient and energy composition were designed. The digestion profiles of the three foods were assessed using a dynamic in vitro model. The foods were also consumed by healthy young adults who donated blood samples after an overnight fast and again 0.5, 1, 2, 3, 4 and 6 h after consuming each of the test foods and who were also assessed for appetite sensations. The solid food showed phase separation during gastric digestion and a lower release of fatty acids during intestinal digestion than the liquid and semi-solid foods. During the postprandial feeding experiments, the solid food caused a lower increase in serum triglycerides than the liquid food and produced higher fullness and satisfaction. In conclusion, the food form and structure modulated fat release, postprandial triglyceridaemia and appetite sensations independent of the nutrient and energy content. Thus, manipulation of the food structure and form may be used in designing strategies for improving metabolic markers and satiety.

Efectos agudos del ejercicio resistido en la lipemia postprandial de mujeres postmenopáusicas con sobrepeso

Introducción. La magnitud de la lipemia postprandial es un indicador de riesgo cardiovascular, en especial en mujeres con actividad hormonal reducida. Los ejercicios resistidos (ER) podrían ser un factor que influencie las concentraciones de lípidos después de consumir alimentos.Objetivo. Determinar los efectos agudos sobre la lipemia postprandial de mujeres postmenopáusicas que tiene la realización de sesiones de ER de alto y bajo volumen, en comparación a un grupo control.Materiales y métodos. Después de una evaluación inicial (antropometría, perfil lipídico y fitness muscular), 32 mujeres fueron divididas aleatoriamente en tres grupos: uno con ER de alto volumen (n=11), otro con ER de bajo volumen (n=11) y un grupo control sin ER (n=10). 12 horas después de los ejercicios se suministró un compuesto nutricional hiperlipídico y se analizó la lipemia postprandial cada hora durante 5 horas.Resultados. Los diferentes volúmenes de ER no redujeron de manera importante los marcadores lipémicos (colesterol total, triglicéridos, LDL y VLDL) (p>0.05) ni aumentaron las concentraciones plasmáticas de HDL (p>0.05).Conclusiones. Las sesiones de ER no afectaron los marcadores lipémicos postprandiales, aunque sí mostraron resultados clínicos relevantes en los grupos experimentales (reducción de LDL-VLDL y aumento de HDL en momentos específicos).

Medium-chain fatty acids lower postprandial lipemia: A randomized crossover trial

Epidemiological and interventional studies have linked saturated fatty acids (SFA) with elevated levels of low-density lipoprotein cholesterol (LDL-C) and increased CVD risk. However, the effects of the SFA chain length on postprandial lipemia in humans are not well elucidated. The aim of this study was to investigate the impact of short, medium and long-chain SFA on postprandial blood lipids in healthy volunteers. Sixteen healthy volunteers consumed test biscuits containing 40 g of either butter (BB), coconut oil (CB) or lard (LB) in a single-blinded, randomized crossover design. Blood samples were collected fasting and 2, 3, 4, and 6 hours postprandially and assessed for blood lipids (total cholesterol, TC; high-density lipoprotein cholesterol, HDL-C; LDL-C and triglyceride, TG). The postprandial TG response following CB was 59.8% lower than following BB (p < 0.01) and 58.8% lower than LB (p < 0.01), although no difference was observed between the BB and the LB responses. The net area under the LDL-C concentration curve was significantly larger after consumption of the CB compared to the BB, despite no significant differences in postprandial net area under the TC and HDL-C concentration curves. Consumption of medium-chain SFA as CB resulted in lower postprandial TG excursions compared to short-chain SFA as BB and long-chain SFA as LB, despite their identical fat and caloric content. These results suggest that SFA differ in their potential to elevate postprandial lipid levels, and that coconut oil, a rich source of medium-chain SFA may not be as hyperlipidemic as animal fats rich in long chain SFA. ANZCTR IDENTIFIER: 12617000903381. CLINICAL TRIAL REGISTRY NUMBER: The study was registered with the Australia New Zealand Trial registry as ACTRN12617000903381.

Changes in non-fasting concentrations of blood lipids after a daily Chinese breakfast in overweight subjects without fasting hypertriglyceridemia

BACKGROUND

Overweight is always accompanied by hypertriglyceridemia (HTG), but the change in non-fasting triglyceride (TG) concentration in overweight subjects without postprandial hypertriglyceridemia was unknown.

METHODS

Concentrations of serum lipids were measured at 2 and 4 h in matched overweight (OW group, n = 54) and control subjects (CON group, n = 55) after a daily meal. Concentrations of remnant cholesterol and non-HDL cholesterol were calculated according to the formulas. The diagnostic criteria for non-fasting HTG were based on 2 different consensus statement. ROC curve was used to determine the pointcut of postprandial HTG.

RESULTS

OW group had higher fasting concentrations of RC and non-HDL-C than CON group. Non-fasting concentrations of triglyceride and RC significantly increased in 2 groups while were higher in OW group (p < .05). The proportion of non-fasting HTG increased after a daily meal in OW group was significantly higher than the percentage of fasting HTG (p < .05). There was a significant correlation between the postprandial concentrations of TG and RC.

CONCLUSIONS

Overweight subjects were more likely to develop non-fasting hypertriglyceridemia and higher concentrations of RC and non-HDL-C. Additionally, 2.0 mmol/l at 4 h after breakfast could be a pointcut value to detect changes in lipid profile of Chinese overweight people.

Long-term consumption of a Mediterranean diet improves postprandial lipemia in patients with type 2 diabetes: the Cordioprev randomized trial

Background

Patients with type 2 diabetes (T2D) have an elevated postprandial lipemia (PPL) that has been associated with increased cardiovascular risk.

Objective

We aimed to analyze whether the long-term consumption of 2 healthy dietary patterns is associated with an improvement in PPL and remnant cholesterol (RC) concentrations in patients with T2D.

Design

We selected patients from the Cordioprev study who underwent oral fat load tests (FLTs) at baseline and the 3-y follow-up (241 patients with and 316 patients without T2D). Subjects were randomly assigned to receive either a Mediterranean diet rich in olive oil (MedDiet; 35% of calories from fat [22% monounsaturated fatty acids (MUFAs)] and 50% from carbohydrates) or a low-fat (LF) diet [<30% fat (12-14% MUFAs) and 55% of calories from carbohydrates]. Lipids were measured in serial bloods drawn at 0, 1, 2, 3, and 4 h after the FLT.

Results

After 3 y of dietary intervention, patients with T2D showed an improvement in their PPL measured as postprandial triglycerides (TGs) (P < 0.0001), TG area under the curve (AUC) (P = 0.001), and TG-rich lipoproteins (TRLs-TG; P = 0.001) compared with baseline. Subgroup analysis, based on the type of dietary intervention, showed that those T2D patients randomly assigned to the MedDiet presented a reduction in the TG AUC of 17.3% compared with baseline (P = 0.003). However, there were no differences for T2D patients randomly assigned to the LF diet (P > 0.05) or in patients without T2D (P > 0.05) regardless of the dietary intervention. In addition, the MedDiet induced a significant improvement in the RC AUC in patients with T2D (P = 0.04). However, there was no significant improvement in those following the LF diet.

Conclusions

Our findings show that the long-term consumption of a MedDiet rich in olive oil improves PPL and RC concentrations mainly in patients with T2D. This trial was registered at clinicaltrials.gov as NCT00924937.