Postprandial lipemia and cardiovascular disease

Polyphenols mediated attenuation of diabetes associated cardiovascular complications: A comprehensive review

Background

Diabetes mellitus is a common chronic metabolic disorder that is characterized by increased levels of glucose for prolonged periods of time. Incessant hyperglycemia leads to diabetic complications such as retinopathy, nephropathy, and neuropathy, and cardiovascular complications such as ischemic heart disease, peripheral vascular disease, diabetic cardiomyopathy, stroke, etc. There are many studies that suggest that various polyphenols affect glucose homeostasis and can help to attenuate the complications associated with diabetes.

Objective

This review focuses on the possible role of various dietary polyphenols in palliating diabetes-induced cardiovascular complications. This review also aims to give an overview of the interrelationship among ROS production (due to diabetes), inflammation, glycoxidative stress, and cardiovascular complications as well as the anti-hyperglycemic effects of dietary polyphenols.

Methods

Various scientific databases including Scopus, Web of Science, Google Scholar, PubMed, Science Direct, Springer Link, and Wiley Online Library were used for searching articles that complied with the inclusion and exclusion criteria.

Results

This review lists several polyphenols based on various pre-clinical and clinical studies that have anti-hyperglycemic potential as well as a protective function against cardiovascular complications.

Conclusion

Several pre-clinical and clinical studies suggest that various dietary polyphenols can be a promising intervention for the attenuation of diabetes-associated cardiovascular complications.

Directly Measuring Atherogenic Lipoprotein Kinetics in Zebrafish with the Photoconvertible LipoTimer Reporter

Lipoprotein kinetics are a crucial factor in understanding lipoprotein metabolism since a prolonged time in circulation can contribute to the atherogenic character of apolipoprotein-B (ApoB)-containing lipoproteins (B-lps). Here, we report a method to directly measure lipoprotein kinetics in live developing animals. We developed a zebrafish geneticly encoded reporter, LipoTimer, in which endogenous ApoBb.1 is fused to the photoconvertible fluorophore Dendra2 which shift its emission profile from green to red upon UV exposure. By quantifying the red population of ApoB-Dendra2 over time, we found that B-lp turnover in wild-type larvae becomes faster as development proceeds. Mutants with impaired B-lp uptake or lipolysis present with increased B-lp levels and half-life. In contrast, mutants with impaired B-lp triglyceride loading display slightly fewer and smaller-B-lps, which have a significantly shorter B-lp half-life. Further, we showed that chronic high-cholesterol feeding is associated with a longer B-lp half-life in wild-type juveniles but does not lead to changes in B-lp half-life in lipolysis deficient apoC2 mutants. These data support the hypothesis that B-lp lipolysis is suppressed by the flood of intestinal-derived B-lps that follow a high-fat meal.

Effect of Isocaloric Meals on Postprandial Glycemic and Metabolic Markers in Type 1 Diabetes-A Randomized Crossover Trial

The aim of this study was to assess the effect of four isocaloric meals with different macronutrient compositions on postprandial blood glucose, lipids, and glucagon in adults with type 1 diabetes (T1D). Seventeen subjects tested four isocaloric meals in a randomized crossover design. The meal compositions were as follows: high-carbohydrate (HC); high-carbohydrate with extra fiber (HC-fiber); low-carbohydrate high-protein (HP); and low-carbohydrate high-fat (HF). Blood glucose and lipid measurements were collected up to 4 h and glucagon up to 3 h postprandially. Mean postprandial glucose excursions were lower after the HP compared to the HC (p = 0.036) and HC-fiber meals (p = 0.002). There were no differences in mean glucose excursions after the HF meal compared to the HC and HP meals. The HF meal resulted in higher triglyceride excursions compared to the HP meal (p < 0.001) but not compared to the HC or HC-fiber meals. Glucagon excursions were higher at 180 min after the HP meal compared to the HC and HF meals. In conclusion, the low-carbohydrate HP meal showed the most favorable glycemic and metabolic effects during a 4 h postprandial period in subjects with T1D.

Comparison of aspartame- and sugar-sweetened soft drinks on postprandial metabolism

Aim: We compared the impact of artificially- and sugar-sweetened beverages co-ingested with a mixed meal on postprandial fat and carbohydrate oxidation, blood glucose, and plasma insulin and triglyceride concentrations. Methods: Eight college-aged, healthy males completed three randomly assigned trials, which consisted of a mixed macronutrient meal test with 20oz of Diet-Coke (AS), Coca-Cola (NS), or water (CON). One week separated each trial and each participant served as his own control. Resting energy expenditure (REE) via indirect calorimetry, blood pressure, and blood samples were obtained immediately before, 5, 10, 30, 60, 120, and 180 min after meal and beverage ingestion. A two-way (treatment × time) repeated-measures ANOVA was conducted to assess REE, fat and carbohydrate oxidation rates, blood glucose, and plasma insulin and triglyceride concentrations. Results: There was a significant main effect of treatment on total fat oxidation (P = 0.006), fat oxidation was significantly higher after AS (P = 0.006) and CON (P = 0.001) compared to following NS. There was a significant main effect of treatment on total carbohydrate oxidation (P = 0.005), carbohydrate oxidation was significantly lower after AS (P = 0.014) and CON (P = 0.001) compared to following NS. Plasma insulin concentration AUC was significantly lower after AS (P = 0.019) and trended lower in CON (P = 0.054) compared to following NS. Conclusion: Ingestion of a mixed meal with an artificially-sweetened beverage does not impact postprandial metabolism, whereas a sugar-sweetened beverage suppresses fat oxidation and increases carbohydrate oxidation compared to artificially-sweetened beverage and water.

Bioactive Yoghurt Containing Curcumin and Chlorogenic Acid Reduces Inflammation in Postmenopausal Women

Menopause is marked by a gradual and permanent decrease of estrogen from the ovaries, leading to metabolic and physiological changes in the body. Combined with increased body mass index, postmenopausal women have elevated systemic inflammation and metabolic disturbances leading to increased risk of developing chronic diseases. A bioactive coconut yoghurt containing curcumin and chlorogenic acid was developed with the potential to target inflammatory processes. In this randomized crossover study, healthy postmenopausal women with a BMI of 25–40 were recruited to consume 125 g of either the bioactive or placebo yoghurt. Blood samples were collected at baseline, 30 min, and 1, 2, 3 and 4 h postprandially. Plasma inflammatory markers (TNFα and IL6) and metabolic markers (triglycerides, insulin and glucose) were measured. Participants had significantly lower plasma TNFα Cmax after consumption of the bioactive yoghurt compared to placebo (mean difference = 0.3 pg/mL; p = 0.04). Additionally, plasma TNFα was significantly lower postprandially compared to baseline after consumption of the bioactive yogurt but not the placebo. No differences were observed in the metabolic markers measured. Conclusions: The bioactive yoghurt fortified with curcumin and chlorogenic acid has the potential to reduce inflammatory mediators; however, a larger and longer-term study is required to confirm these findings.

Effect of Acute Intake of Fermented Orange Juice on Fasting and Postprandial Glucose Metabolism, Plasma Lipids and Antioxidant Status in Healthy Human

Higher postprandial plasma glucose and lipemia, and oxidative and inflammatory responses, are considered important cardiovascular risk factors. Fermentation of fruits has generated products with high concentrations of bioactive compounds. The aim of this study was to evaluate the potential acute effects that fermented orange juice (FOJ) can exert in healthy humans by modulating postprandial response, and inflammatory/antioxidant status, compared with orange juice (OJ). Nine volunteers were recruited for a randomized, controlled, and crossover study. Participants ingested 500 mL of FOJ. At 4 h post intake, subjects consumed a standardized mixed meal. Blood samples were collected at 0-8 h hours post intake. The subjects repeated the protocol with OJ following a 2-week washout period. Glucose and lipid metabolism, plasma antioxidant capacity (ORAC, FRAP), endogenous antioxidants (albumin, bilirubin, uric acid), C-reactive protein and fibrinogen were measured in plasma samples. There was a trend of a smaller increase in LDL-C after FOJ intake compared with OJ, a significant decrease in apo-B and significant increase in ORAC. The glycemic and triglyceride response of meal was attenuated with FOJ. No differences were obtained in endogenous antioxidants and inflammation status between the treatments. The acute consumption of FOJ could play a protective role against cardiovascular risk factors.

Tomatoes: An Extensive Review of the Associated Health Impacts of Tomatoes and Factors That Can Affect Their Cultivation

Simple Summary

The research outlined in this review paper discusses potential health benefits associated with a diet enriched with tomatoes and tomato products. This includes details of previous studies investigating the anticancer properties of tomatoes, protection against cardiovascular and neurodegenerative diseases and diabetes, maintenance of a healthy gut microbiome, and improved skin health, fertility, immune response, and exercise recovery. The specific parts of a tomato fruit that contribute these health benefits are also outlined. The potential disadvantages to a tomato-rich diet are detailed, especially the consumption of supplements that contain compounds found in tomatoes, such as lycopene. This review also discusses how the cultivation of tomato plants can affect the nutritional value of the fruit harvested. Different environmental growing conditions such as light intensity, growing media, and temperature are explained in terms of the impact they have on the quality of fruit, its nutrient content, and hence the potential health benefits acquired from eating the fruit.

Abstract

This review outlines the health benefits associated with the regular consumption of tomatoes and tomato products. The first section provides a detailed account of the horticultural techniques that can impact the quality of the fruit and its nutritional properties, including water availability, light intensity, temperature, and growing media. The next section provides information on the components of tomato that are likely to contribute to its health effects. The review then details some of the health benefits associated with tomato consumption, including anticancer properties, cardiovascular and neurodegenerative diseases and skin health. This review also discusses the impact tomatoes can have on the gut microbiome and associated health benefits, including reducing the risk of inflammatory bowel diseases. Other health benefits of eating tomatoes are also discussed in relation to effects on diabetes, the immune response, exercise recovery, and fertility. Finally, this review also addresses the negative effects that can occur as a result of overconsumption of tomato products and lycopene supplements.

The Effect of GLP-1 Receptor Agonists on Postprandial Lipaemia

PURPOSE OF REVIEW

To review the currently available data on the effect of Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) on postprandial lipaemia.

RECENT FINDINGS

Out of the available studies that examined the respective lipid parameter, exenatide reduced postprandial triacyglycerol (TAG) in 4/6, apolipoprotein B-48 in 3/3, non-esterified fatty acids in 2/2, and apolipoprotein C-III and very low-density lipoprotein cholesterol (VLDL-C) in 1/1 studies. Liraglutide reduced postprandial TAG in 2/2, apolipoprotein B-48 in 3/3 and apolipoprotein C-III, chylomicron-TAG and VLDL₁-TAG in 1/1 studies. Lixisenatide reduced postprandial chylomicron-TAG and apolipoprotein B-48 in 1 study. Semaglutide reduced postprandial TAG, apolipoprotein B-48 and VLDL in 1 study. Dulaglutide reduced postprandial apolipoprotein B-48 in 1 study. GLP-1 RAs have consistent beneficial effects on postprandial lipaemia with most of the data coming from studies with exenatide and liraglutide. Reduction of postprandial lipaemia might be one of the mechanisms behind the pleiotropic effects of GLP-1 RAs.

Effects of Acute Partial Sleep Deprivation and High-Intensity Interval Exercise on Postprandial Network Interactions

Introduction: High-intensity interval exercise (HIIE) is deemed effective for cardiovascular and autonomic nervous system (ANS) health-related benefits, while ANS disturbance increases the risk for cardiovascular disease (CVD). Postprandial lipemia and acute-partial sleep deprivation (APSD) are considered as CVD risk factors due to their respective changes in ANS. Exercising in the morning hours after APSD and have a high-fat breakfast afterwards may alter the interactions of the cardiovascular, autonomic regulation, and postprandial lipemic systems threatening individuals' health. This study examined postprandial network interactions between autonomic regulation through heart rate variability (HRV) and lipemia via low-density lipoprotein (LDL) cholesterol in response to APSD and HIIE. Methods: Fifteen apparently healthy and habitually good sleepers (age 31 ± 5.2 SD yrs) completed an acute bout of an isocaloric HIIE (in form of 3:2 work-to-rest ratio at 90 and 40% of VO₂ reserve) after both a reference sleep (RSX) and 3-3.5 h of acute-partial sleep deprivation (SSX) conditions. HRV time and frequency domains and LDL were evaluated in six and seven time points surrounding sleep and exercise, respectively. To identify postprandial network interactions, we constructed one correlation analysis and one physiological network for each experimental condition. To quantify the interactions within the physiological networks, we also computed the number of links (i.e., number of significant correlations). Results: We observed an irruption of negative links (i.e., negative correlations) between HRV and LDL in the SSX physiological network compared to RSX. Discussion: We recognize that a correlation analysis does not constitute a true network analysis due to the absence of analysis of a time series of the original examined physiological variables. Nonetheless, the presence of negative links in SSX reflected the impact of sleep deprivation on the autonomic regulation and lipemia and, thus, revealed the inability of HIIE to remain cardioprotective under APSD. These findings underlie the need to further investigate the effects of APSD and HIIE on the interactions among physiological systems.

Emulsion acid colloidal stability and droplet crystallinity modulate postprandial gastric emptying and short-term satiety: a randomized, double-blinded, crossover, controlled trial in healthy adult males

BACKGROUND

Emulsion droplet triacylglycerol (TAG) crystallinity and colloidal stability can alter the postprandial metabolism, although evidence of their interactive effects is limited.

OBJECTIVES

This acute meal crossover study investigated the influences of droplet TAG crystallinity at 37°C and colloidal gastric stability on gastric emptying (GE), acute lipemia, and satiety.

METHODS

We gave 15 healthy adult males (mean ± SD age, 24.9 y ± 4.5 y; BMI, 26.0 kg/m2 ± 2.0 kg/m2; fasting TAG, 0.9 mmol/L  ± 0.3 mmol/L) 250 mL of four 20% palm stearin or palm olein emulsions with similar particle size distributions and containing partially crystalline droplets that remained stable (SS) or destabilized (SU) or containing liquid droplets that remained stable (LS) or destabilized (LU) when exposed to simulated gastric conditions. Baseline and 6-h postprandial ultrasound gastric antrum measurements, satiety visual analogue scales (VAS), and blood samples for analyses of plasma TAG, peptide YY (PYY), glucagon-like peptide-1 (GLP-1), ghrelin, leptin, glucose-dependent insulinotropic polypeptide, insulin, and glucose were collected. Changes from baseline and incremental area under the curve (iAUC) values were analyzed by repeated-measures ANOVA.

RESULTS

TAG responses did not differ significantly. The gastric antrum area decreased faster (P ≤ 0.01) after treatment with the acid-unstable emulsions (SU and LU), and satiety VAS ratings and plasma endpoints differed between treatments. After LS treatment, participants had 65% and 59% lower 3-h iAUC values for hunger (P = 0.021) and desire to eat (P = 0.031), respectively, compared to after SU treatment. LS treatment resulted in higher 6-h iAUC values for ghrelin (141%; P = 0.023) and PYY (150%; P = 0.043) compared to SU treatment, and LS treatment also resulted in higher GLP-1 values compared to SU (38%; P = 0.016) and LU (76%; P = 0.001) treatment.

CONCLUSION

Emulsion acid colloidal stability, independent of TAG physical state, delayed GE, and satiety was enhanced after consuming acid stable emulsions containing TAG in the liquid state. The study was registered at clinicaltrials.gov as NCT03990246.

The Mediterranean and Nordic Diet: A Review of Differences and Similarities of Two Sustainable, Health-Promoting Dietary Patterns

The Mediterranean diet (MD) and the Nordic diet (ND) share more similarities than differences. Both diets are based on typical local and seasonal foods, share similar nutritional recommendations based on plant-based dietary principles, and are both now orienting toward environmental protection and sustainability. The main difference between the two diets is the primary fat source. Olive oil is the synonym for MD while the ND uses more rapeseed/canola oil. While longitudinal epidemiological studies support adherence to MD as a way to prevent chronic diseases, ND still needs more such studies because the current results are discrepant. Notably, studies that assessed the association between both diets and lower risks of chronic diseases, disability, and mortality from specific and all causes, implied that ND could also have an advantageous effect as MD. Hopefully, there will be more longitudinal and large prospective studies in the future that will provide more evidence-based recommendations.

The Effect of Partly Replacing Vegetable Fat with Bovine Milk Fat in Infant Formula on Postprandial Lipid and Energy Metabolism: A Proof-of-principle Study in Healthy Young Male Adults

SCOPE

Infant formula (IF) uses besides vegetable fats also bovine milk fat, which differs in triacylglycerol (TAG) structure. Furthermore, it differs in fatty acid (FA) composition. Whether changing fat source in IF affects postprandial energy metabolism, lipemic response, and blood lipid profile is unknown.

METHODS AND RESULTS

A proof-of-principle study, with a randomized controlled double-blind cross-over design, is conducted. Twenty healthy male adults consumed drinks with either 100% vegetable fat (VEG) or 67% bovine milk fat and 33% vegetable fat (BOV), on 2 separate days. For a detailed insight in the postprandial responses, indirect calorimetry is performed continuously, and venous blood samples are taken every 30 min, until 5 h postprandially. No differences in postprandial energy metabolism, serum lipids, lipoprotein, or chylomicron concentrations are observed between drinks. After consumption of VEG-drink, C18:2n-6 in serum increased. Observed differences in chylomicron FA profile reflect differences in initial FA profile of test drinks. Serum ketone bodies concentrations increase following consumption of BOV-drink.

CONCLUSIONS

The use of bovine milk fat in IF does neither affect postprandial energy metabolism nor lipemic response in healthy adults, but alters postprandial FA profiles and ketone metabolism. Whether the exact same effects occur in infants requires experimental verification.

Postprandial Metabolism and Vascular Function: Impact of Aging and Physical Activity Level

The consumption of a high-fat meal can induce postprandial lipemia and endothelial dysfunction. The authors assessed the impact of age and physical activity on metabolic and vascular outcomes following meal consumption in healthy adults. The authors recruited four groups: younger active (age 22.1 ± 1.4 years; n = 9), younger inactive (age 22.6 ± 3.7 years; n = 8), older active (age 68.4 ± 7.7 years; n = 8), and older inactive (age 67.7 ± 7.2 years; n = 7). The metabolic outcomes were measured at the baseline and hourly for 6 hr post high-fat meal consumption (12 kcal/kg; 63% fat). Flow-mediated dilation was measured at the baseline, 2 hr, and 4 hr postmeal. The total area under the curve for triglycerides was significantly lower in the more active groups, but did not differ based on age (younger active = 6.5 ± 1.4 mmol/L × 6 hr, younger inactive = 11.7 ± 4.8, older active = 6.8 ± 2.7, older inactive = 12.1 ± 1.7; p = .0004). After adjusting for artery diameter, flow-mediated dilation differed between groups at the baseline (younger active = 4.8 ± 1.6%, younger inactive = 2.5 ± 0.5, older active = 3.4 ± 0.9, older inactive = 2.2 ± 0.4; p < .001) and decreased significantly across groups 4 hr postmeal (mean difference = 0.82; 95% CI [0.02, 1.6]; p = .04). These findings highlight the beneficial effect of regular physical activity on postprandial lipemia, independent of age.

Evaluation of circulating miR-122, miR-30c and miR-33a levels and their association with lipids, lipoproteins in postprandial lipemia

AIMS

Postprandial lipemia is characterized by an increase in triglyceride-rich lipoproteins after fatty meals. MicroRNAs (miRs) play important roles in lipid and lipoprotein metabolism. The aim of this study was to determine relationship between levels of plasma miR expression and lipoprotein metabolism-related proteins in subjects with normal (NPR) and high postprandial response (HPR) in postprandial period.

MATERIALS AND METHODS

The oral fat tolerance test was applied to 22 individuals with NPR and 22 with HPR.

KEY FINDINGS

Increased expressions of miR-122 and miR-33a and miR-122/30c ratio and decreased miR-30c expression were observed in fasting and postprandial period of HPR compared with NPR. ROC curve analysis showed that miR-122/30c ratio is a good biomarker for postprandial lipemia (AUC: 0.97, p < 0.001). Levels of TG, MTTP, and Apo B-48 and chylomicron (CM) particle size were significantly higher in HPR than in NPR (p < 0.05). The miR-122/30c ratio at 2 h was positively correlated with CM particle size, and with TG, MTTP and Apo B-48 levels at 4th hour. miR-33a expression decreased in HPR and was negatively correlated with ABCA1 and Apo A-1 levels at 4th hour of the postprandial period in both groups.

SIGNIFICANCE

Increased miR-122 and decreased miR-30c expression levels in HPR may play critical roles in elevated or prolonged postprandial lipemia. The miR122/30c ratio exhibited good association with MTTP, Apo B-48 and TG levels, and with CM particle size, and may be a reliable marker for evaluating postprandial lipemia. miR-33a may also play a key role in decreased HDL-C in postprandial lipemia.

Acute Resistance Exercise Reduces Postprandial Lipemia and Oxidative Stress in Resistance-Trained Men

McAllister, MJ, Steadman, KS, Renteria, LI, Case, MJ, Butawan, MB, Bloomer, RJ, and McCurdy, KW. Acute resistance exercise reduces postprandial lipemia and oxidative stress in resistance-trained men. J Strength Cond Res XX(X): 000-000, 2020-Acute ingestion of a high-fat meal (HFM) results in significant increases in postprandial triacylglycerols (TAG) and markers of oxidative stress (OS). Combined aerobic and resistance exercise can attenuate postprandial lipemia; however, it is not clear if acute resistance exercise alone can reduce postprandial OS. The purpose of this study was to determine if acute resistance exercise can attenuate postprandial OS and to compare the effects of moderate versus high-intensity resistance exercise in this regard. Nine (n = 9) moderately resistance-trained individuals completed 3 testing conditions in a randomized order as follows: (a) rest (no exercise), (b) moderate intensity (3 sets of 10 repetitions at 68% 1 repetition maximum [RM]), and (c) high-intensity resistance exercise (4 sets of 6 repetitions at 85% 1RM). Exercises included barbell back squat, bench press, straight leg deadlift, lat pull-down, upright row, and sit-ups. A HFM was ingested 12 hours after each condition. Blood samples were collected immediately before as well as 2 and 4 hours after ingestion and analyzed for TAG, cholesterol (CHOL), insulin, malondialdehyde (MDA), total nitrate/nitrite (NOx), glutathione (GSH), and advanced oxidation protein products (AOPP). When comparing 4 hour area under curve (AUC) data between conditions, AOPP demonstrated a significantly lower AUC after the moderate-intensity condition compared with resting condition. In addition, resistance exercise resulted in significantly higher plasma NOx concentrations as well as lower TAG and CHOL concentrations after HFM ingestion. Resistance exercise also prevented a decline in GSH that was induced by the HFM. These results demonstrate that acute resistance exercise can attenuate postprandial OS.

Postprandial lipaemia following consumption of a meal enriched with medium chain saturated and/or long chain omega-3 polyunsaturated fatty acids. A randomised cross-over study

BACKGROUND & AIMS

Postprandial lipaemic response has emerged as a risk factor for cardiovascular disease. Dietary fats such as medium-chain saturated fatty acids (MCSFA) and long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) are known to reduce postprandial lipaemic responses. The combination of the two could potentially have complementary and/or synergistic effects for optimising cardiovascular health. This study aims to investigate the effects of MCSFA (coconut oil) with or without LCn-3PUFA (fish oil) inclusion in the test meal on postprandial blood lipids in healthy adults.

METHODS

In a randomised, double-blinded, placebo-controlled, 2 × 2 factorial cross-over study, participants (n = 15) were randomised to receive four standardised isocaloric test meals. Test meals include: placebo [PL, containing no fish oil (0 g EPA & DHA) or coconut oil (0 g MCSFA)], fish oil [FO, 6 g fish oil (3.85 g EPA & DHA), containing no coconut oil (0 g MCSFA)], coconut oil [CO, 18.65 g coconut oil (15 g MCSFA), containing no fish oil (0 g EPA & DHA)] and coconut oil + fish oil [COFO, 18.65 g coconut oil (15 g MCSFA) + 6 g fish oil (3.85 g EPA & DHA)]; all providing a total fat content of 33.5 g. Participants received all four treatments on four separate test days with at least 3 days washout in between. Blood parameters were measured by finger pricks at 7 timepoints between 0 and 300min. The primary outcome of this study was the change in postprandial triglycerides (TG) concentrations with secondary outcomes as total cholesterol, high-density lipoprotein cholesterol and blood glucose concentrations.

RESULTS

TG area under the curve (AUC) (mmol/L/min) was significantly lower for FO (383.67, p = 0.0125) and COFO (299.12, p = 0.0186) in comparison to PL (409.17) only. TG incremental area under the curve (iAUC) (mmol/L/min) was significantly lower with COFO (59.67) in comparison to CO (99.86), (p = 0.0480). Compared to PL, the change in absolute TG concentrations (mmol/L) from baseline to post TG peak time (180min) after FO were significantly less at 240min (0.39 vs 0.15), 270min (0.2 vs 0.1), and 300min (0.28 vs 0.06), and after COFO was significantly less at 300min (0.28 vs 0.16) (p < 0.05). No significant differences in postprandial AUC and iAUC for any other blood parameters were reported.

CONCLUSIONS

Our study demonstrated that LCn-3PUFA with or without MCSFA but not MCSFA alone are effective in reducing postprandial TG in healthy individuals.

The Influence of Different Foods and Food Ingredients on Acute Postprandial Triglyceride Response: A Systematic Literature Review and Meta-Analysis of Randomized Controlled Trials

The use of postprandial triglyceride (ppTG) as a cardiovascular disease risk indicator has gained recent popularity. However, the influence of different foods or food ingredients on the ppTG response has not been comprehensively characterized. A systematic literature review and meta-analysis was conducted to assess the effects of foods or food ingredients on the ppTG response. PubMed, MEDLINE, Cochrane, and CINAHL databases were searched for relevant acute (<24-h) randomized controlled trials published up to September 2018. Based on our selection criteria, 179 relevant trials (366 comparisons) were identified and systematically compiled into distinct food or food ingredient categories. A ppTG-lowering effect was noted for soluble fiber (Hedges' giAUC = -0.72; 95% CI: -1.33, -0.11), sodium bicarbonate mineral water (Hedges' gAUC = -0.42; 95% CI: -0.79, -0.04), diacylglycerol oil (Hedges' giAUC = -0.38; 95% CI: -0.75, -0.00), and whey protein when it was contrasted with other proteins. The fats group showed significant but opposite effects depending on the outcome measure used (Hedges' giAUC = -0.32; 95% CI: -0.61, -0.03; and Hedges' gAUC = 0.16; 95% CI: 0.06, 0.26). Data for other important food groups (nuts, vegetables, and polyphenols) were also assessed but of limited availability. Assessing for oral fat tolerance test (OFTT) recommendation compliance, most trials were ≥4 h long but lacked a sufficiently high fat challenge. iAUC and AUC were more common measures of ppTG. Overall, our analyses indicate that the effects on ppTG by different food groups are diverse, largely influenced by the type of food or food ingredient within the same group. The type of ppTG measurement can also influence the response.

Acute exercise effects on postprandial fat oxidation: meta-analysis and systematic review

The purpose of this systematic review was to synthesize and evaluate current literature examining the effects of exercise on postprandial fat oxidation, as well as to provide future direction. A quantitative review was performed using meta-analytic methods. A moderator analysis was performed to investigate potential variables that could influence the effect of exercise on postprandial fat oxidation. Fifty-six effects from 26 studies were retrieved. There was a moderate effect of exercise on postprandial fat oxidation (Cohen's d = 0.58 (95% CI, 0.39 to 0.78)). Moderator analysis revealed that sex, age, weight status, training status, exercise type, exercise intensity, timing of exercise, and composition of the meal challenge significantly affected the impact of prior exercise on postprandial fat oxidation. The moderator analysis also indicated that most previous studies have investigated the impact of prior moderate-intensity endurance exercise on postprandial fat oxidation in young, healthy, lean men. Suggested priorities for future research in this area include (i) an examination of sex differences in and/or female-specific aspects of postprandial metabolism; (ii) a comprehensive evaluation of exercise modalities, intensities, and durations; and (iii) a wider variety of test meal compositions, especially those with higher fat content. Novelty A systematic review of the impact of exercise on postprandial fat oxidation was performed using meta-analytic methods. Analysis revealed a moderate effect of exercise on postprandial fat oxidation. The presented data support a need for future studies to investigate sex differences and to include comprehensive evaluations of exercise modalities, intensities, and duration.

Effect of high-carbohydrate or high-monounsaturated fatty acid diets on blood pressure: a systematic review and meta-analysis of randomized controlled trials

Context

Current dietary guidelines for cardiovascular disease risk management recommend restricting intake of saturated fatty acids (SFAs). However, the optimal macronutrient profile, in the context of a low-SFA diet, remains controversial. The blood-pressure effect of replacing SFAs in diets with monounsaturated fatty acids (MUFAs) compared with carbohydrate has not been quantified to date.

Objective

To synthesize the evidence for the effect of substituting a high-carbohydrate (high-CHO) diet for a high-monounsaturated fatty acid (high-MUFA) diet on blood pressure, a systematic review and meta-analysis of randomized clinical trials in a population without health restrictions was conducted.

Data Sources

MEDLINE, EMBASE, and Cochrane Central Register of Controlled Clinical Trials were searched through June 7, 2017. Randomized controlled trials of > 3 weeks duration that assessed the effect of high-MUFA diets in isocaloric substitution for high-CHO diets on systolic blood pressure (SBP) and diastolic blood pressure (DBP) were included.

Data Extraction

Data were pooled using the generic-inverse variance method with random effects models and expressed as mean differences (MDs) with 95% confidence intervals (CIs). Heterogeneity was assessed by Cochran Q statistic and quantified by the I2 statistic. The quality of the evidence was assessed with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

Results

Fourteen trials (n = 980 participants) were included in the analysis. Comparatively, the high-MUFA diets in isocaloric substitution for high-CHO diets did not demonstrate a greater reduction in blood pressure (SBP: MD, -0.08 mmHg [95%CI, -1.01 to 0.84], P = 0.86; DBP: MD = 0.01 mmHg [95%CI, -0.73 to 0.75], P = 0.98). The overall quality of the evidence was assessed as moderate.

Conclusions

In the context of low SFAs, high-MUFA diets in isocaloric substitution for high-CHO diets did not affect blood pressure in individuals with and without hypertension. Large-scale trials achieving higher MUFA targets are required to support these findings.

ClinicalTrials.gov ID

NCT02626325.

MicroRNAs as Therapeutic Targets and Clinical Biomarkers in Atherosclerosis

Atherosclerotic cardiovascular disease remains the leading cause of morbidity and mortality worldwide. Atherosclerosis develops over several decades and is mediated by a complex interplay of cellular mechanisms that drive a chronic inflammatory milieu and cell-to-cell interactions between endothelial cells, smooth muscle cells and macrophages that promote plaque development and progression. While there has been significant therapeutic advancement, there remains a gap where novel therapeutic approaches can complement current therapies to provide a holistic approach for treating atherosclerosis to orchestrate the regulation of complex signalling networks across multiple cell types and different stages of disease progression. MicroRNAs (miRNAs) are emerging as important post-transcriptional regulators of a suite of molecular signalling pathways and pathophysiological cellular effects. Furthermore, circulating miRNAs have emerged as a new class of disease biomarkers to better inform clinical diagnosis and provide new avenues for personalised therapies. This review focusses on recent insights into the potential role of miRNAs both as therapeutic targets in the regulation of the most influential processes that govern atherosclerosis and as clinical biomarkers that may be reflective of disease severity, highlighting the potential theranostic (therapeutic and diagnostic) properties of miRNAs in the management of cardiovascular disease.

Impact of proprotein convertase subtilisin/kexin type 9 inhibition with evolocumab on the postprandial responses of triglyceride-rich lipoproteins in type II diabetic subjects

BACKGROUND

Monoclonal antibodies to proprotein convertase subtilisin/kexin type 9 (PCSK9) significantly lower the levels of low-density lipoprotein and very-low-density lipoproteins (VLDL), but their effect on postprandial lipoprotein metabolism in dyslipidemic subjects is unclear.

OBJECTIVE

This study aimed to investigate the effects of evolocumab on postprandial lipid responses, ectopic fat depots, whole-body cholesterol synthesis, hepatic lipogenesis, and fat oxidation in patients with type II diabetes.

METHODS

The trial was a single-phase, nonrandomized study of 12-week treatment with evolocumab 140 mg subcutaneously every 2 weeks in 15 patients with type II diabetes on background statin therapy. Cardiometabolic responses to a high-fat mixed meal were assessed before and at the end of the intervention period.

RESULTS

Evolocumab treatment reduced significantly postprandial rises in plasma total triglyceride (by 21%; P < .0001) and VLDL₁ triglyceride (by 15%; P = .018), but the increase in chylomicron triglyceride after the meal was not significantly perturbed (P = .053). There were reduced postprandial responses in plasma total apolipoprotein C-III (by 14%; P < .0001) and apolipoprotein B-48 concentration (by 17%; P = .0046) and in "remnant-like particles" cholesterol (by 29%; P < .0001) on the PCSK9 inhibitor. Treatment reduced the steady-state (ie, fasting and postprandial) concentrations of VLDL₂ cholesterol by 50% (P < .0001) and VLDL₂ triglyceride by 29% (P < .0001), in addition to the 78% reduction of low-density lipoprotein cholesterol (P < .001). The changes in apolipoprotein C-III associated significantly with reduction in postprandial responses of remnant-like particles cholesterol and triglyceride-rich lipoprotein cholesterol. Evolocumab therapy did not influence liver fat accumulation, hepatic de novo lipogenesis, or fasting β-hydroxybutyrate but did increase total body cholesterol synthesis (P < .01).

CONCLUSION

Evolocumab treatment improved postprandial responses of triglyceride-rich lipoproteins and measures of cholesterol-enriched remnant particles in type II diabetic subjects. These results indicate that postprandial phenomena need to be taken into account in assessing the full range of actions of PCSK9 inhibitors in dyslipidemic individuals.

Chronic effects of high-intensity interval training on postprandial lipemia in healthy men

The aim of this study was to determine the chronic (≥72 h postexercise) effects of high-intensity interval training (HIIT) on postprandial lipemia and metabolic markers in healthy volunteers. Eight physically active young men (mean ± SD: age 22 ± 3 yr, height 1.77 ± 0.07 m, body mass 67.7 ± 6.2 kg) underwent two 6-h mixed-meal tolerance tests and resting vastus lateralis muscle biopsies before the first session and ≥72 h after the final session of 4 wk of HIIT [16 sessions in total; 10 × 60-s bouts of cycling at 90% maximal oxygen uptake (V̇o_2max), interspersed with 60-s intervals at 45% V̇o_2max]. Arterialized and deep venous blood samples from across the forearm, brachial artery blood flow measurements, and whole-body indirect calorimetry data were obtained before, and at regular intervals for 6 h after, consumption of a standardized mixed meal. The main findings revealed that, when assessed ≥72 h postexercise, postprandial free fatty acid (FFA) uptake across the forearm was increased in response to exercise training (P = 0.025). However, 4 wk of HIIT did not alter fasting or postprandial circulating triglyceride concentrations or their tissue uptake, despite a 10.2% ± 7.7% improvement in V̇o_2max (P = 0.004). Protein content of adipose triglyceride lipase in the vastus lateralis at rest was reduced by 25% ± 21% (P = 0.01). Collectively, these findings suggest that 4 wk of HIIT enhances postprandial clearance of FFA when assessed ≥72 h postexercise but does not confer persisting (training) adaptations in postprandial triglyceridemia.NEW & NOTEWORTHY When assessed ≥72 h after the last exercise session, 4 wk of high-intensity interval training (HIIT) did not improve triglyceridemia but enhanced free fatty acid uptake into muscle with a concurrent reduction in skeletal muscle adipose triglyceride lipase protein content. This suggests that previously reported acute reductions in postprandial triglyceridemia following a single bout of HIIT do not translate to sustained improvements after 4 wk of HIIT, supporting the concept of frequent exercise for the maintenance of lipemic control.

Comparison of diets enriched in stearic, oleic, and palmitic acids on inflammation, immune response, cardiometabolic risk factors, and fecal bile acid concentrations in mildly hypercholesterolemic postmenopausal women-randomized crossover trial

BACKGROUND

Direct comparisons between SFAs varying in chain length, specifically palmitic acid (16:0) and stearic acid (18:0), relative to the latter's metabolic product, oleic acid (18:1), on cardiometabolic risk factors are limited.

OBJECTIVE

The aim of this study was to determine the relative comparability of diets enriched in palmitic acid, stearic acid, and oleic acid on inflammation and coagulation markers, T lymphocyte proliferation/ex-vivo cytokine secretion, plasma cardiometabolic risk factors, and fecal bile acid concentrations.

METHODS

Hypercholesterolemic postmenopausal women (n = 20, mean ± SD age 64 ± 7 y, BMI 26.4 ± 3.4 kg/m2, LDL cholesterol ≥ 2.8 mmol/L) were provided with each of 3 diets [55% energy (%E) carbohydrate, 15%E protein, 30%E fat, with ∼50% fat contributed by palmitic acid, stearic acid, or oleic acid in each diet; 5 wk/diet phase] using a randomized crossover design with 2-wk washouts between phases. Outcome measures were assessed at the end of each phase.

RESULTS

Fasting LDL-cholesterol and non-HDL-cholesterol concentrations were lower after the stearic acid and oleic acid diets than the palmitic acid diet (all P < 0.01). Fasting HDL-cholesterol concentrations were lower after the stearic acid diet than the palmitic acid and oleic acid diets (P < 0.01). The stearic acid diet resulted in lower lithocholic acid (P = 0.01) and total secondary bile acid (SBA) concentrations (P = 0.04) than the oleic acid diet. All other outcome measures were similar between diets. Lithocholic acid concentrations were positively correlated with fasting LDL-cholesterol concentrations (r = 0.33; P = 0.011). Total SBA, lithocholic acid, and deoxycholic acid concentrations were negatively correlated with fasting HDL cholesterol (r = -0.51 to -0.44; P < 0.01) concentrations and positively correlated with LDL cholesterol:HDL cholesterol (r = 0.37-0.54; P < 0.01) ratios.

CONCLUSIONS

Dietary stearic acid and oleic acid had similar effects on fasting LDL-cholesterol and non-HDL-cholesterol concentrations and more favorable ones than palmitic acid. Unlike oleic acid, the hypocholesterolemic effect of stearic acid may be mediated by inhibition of intestinal hydrophobic SBA synthesis. These findings add to the data suggesting there should be a reassessment of current SFA dietary guidance and Nutrient Facts panel labeling.This trial was registered at clinicaltrials.gov as NCT02145936.

Effects of a diet naturally rich in polyphenols on lipid composition of postprandial lipoproteins in high cardiometabolic risk individuals: an ancillary analysis of a randomized controlled trial

BACKGROUND/OBJECTIVES

Plasma lipoprotein composition, especially in the postprandial state, could be relevant for cardiovascular risk and could be influenced by eating habits. This study evaluated the effects of a polyphenol-rich diet on postprandial lipoprotein composition in individuals at high cardiometabolic risk.

SUBJECTS/METHODS

Seventy-eight individuals with high waist circumference and at least another component of the metabolic syndrome were randomized to either a high-polyphenol (HighP) or low-polyphenol (LowP) diet. Before and after the 8-week intervention, chylomicrons, VLDL1, VLDL2, IDL, LDL, HDL particles, and their lipid concentrations were determined over a 6-h high-fat test meal with high or low-polyphenol content, according to the diet assigned.

RESULTS

VLDL1 postprandial areas under the curve (AUCs) were lower for cholesterol (Chol) (1.48 ± 0.98 vs. 1.91 ± 1.13 mmol/L × 6 h, M ± SD, p = 0.014) and triglycerides (Tg) (4.70 ± 2.70 vs. 6.02 ± 3.07 mmol/L × 6 h, p = 0.005) after the HighP than after the LowP diet, with no changes in Chol/Tg ratio. IDL Chol AUCs were higher after the HighP than after the LowP diet (1.29 ± 0.77 vs. 1.01 ± 0.51 mmol/L × 6 h, p = 0.037). LDL Tg AUCs were higher after the HighP than after the LowP diet (1.15 ± 0.33 vs. 1.02 ± 0.35 mmol/L × 6 h, p < 0.001), with a lower Chol/Tg ratio (14.6 ± 4.0 vs. 16.0 ± 3.8, p = 0.007). HDL Tg AUCs were lower after the HighP than after the LowP diet (1.20 ± 0.41 vs. 1.34 ± 0.37 mmol/L × 6 h, p = 0.013).

CONCLUSIONS

A high-polyphenol diet reduces the postprandial lipid content of large VLDL and increases IDL cholesterol; it modifies the composition of LDL particles-which become richer in triglycerides, and of HDL-which become instead triglyceride poor. The overall changes in atherogenicity by these effects warrant further investigation on clinical cardiovascular outcomes.

Postprandial Circulating miRNAs in Response to a Dietary Fat Challenge

Postprandial lipemia has many physiopathological effects, some of which increase the risk of cardiovascular disease. MicroRNAs (miRNAs) can be found in almost all biological fluids, but their postprandial kinetics are poorly described. We aimed to profile circulating miRNAs in response to a fat challenge. In total, 641 circulating miRNAs were assessed by real-time PCR in plasmas from mice two hours after lipid gavage. Mice with intestine-specific loss of Dicer were screened to identify potential miRNAs released by the intestine. A total of 68 miRNAs were selected for further validation. Ten circulating miRNAs were finally validated as responsive to postprandial lipemia, including miR-206-3p, miR-543-3p, miR-466c-5p, miR-27b-5p, miR-409-3p, miR-340-3p, miR-1941-3p, miR-10a-3p, miR-125a-3p, and miR-468-3p. Analysis of their possible tissues of origin/target showed an enrichment of selected miRNAs in liver, intestine, brain, or skeletal muscle. miR-206, miR-27b-5p, and miR-409-3p were validated in healthy humans. Analysis of their predicted target genes revealed their potential involvement in insulin/insulin like growth factor (insulin/IGF), angiogenesis, cholecystokinin B receptor signaling pathway (CCKR), inflammation or Wnt pathways for mice, and in platelet derived growth factor (PDGF) and CCKR signaling pathways for humans. Therefore, the current study shows that certain miRNAs are released in the circulation in response to fatty meals, proposing them as potential novel therapeutic targets of lipid metabolism.

Postprandial Lipemic Responses to Various Sources of Saturated and Monounsaturated Fat in Adults

Background: Postprandial lipemia (PPL) is a cardiovascular disease risk factor. However, the effects of different fat sources on PPL remain unclear. We aimed to determine the postprandial response in triglycerides (TG) to four dietary fat sources in adults. Methods: Participants completed four randomized meal trials. For each meal trial, participants (n = 10; 5M/5F) consumed a high-fat meal (HFM) (13 kcal/kg; 61% of total kcal from fat) with the fat source derived from butter, coconut oil, olive oil, or canola oil. Blood was drawn hourly for 6 h post-meal to quantify PPL. Results: Two-way ANOVA of TG revealed a time effect (p < 0.0001), but no time–meal interaction (p = 0.56), or meal effect (p = 0.35). Meal trials did not differ with regard to TG total (p = 0.33) or incremental (p = 0.14) area-under-the-curve. When stratified by sex and the TG response was averaged across meals, two-way ANOVA revealed a time effect (p < 0.0001), time–group interaction (p = 0.0001), and group effect (p = 0.048), with men exhibiting a greater response than women, although this difference could be attributed to the pronounced difference in BMI between men and women within the sample. Conclusion: In our sample of young adults, postprandial TG responses to a single HFM comprised of different fat sources did not differ.

Chronotropic, Inotropic and Dromotropic Parameters of the Heart and Oxidative Stress in Rats Receiving High Doses of Fructose

Background:

Many risk factors, including nutritional ones, contribute to cardiovascular diseases (CVDs). Increased fructose consumption, for example, can lead to an increase in CVD risk factors, i.e. an increase in blood lipids and the development of insulin resistance.

Materials and Methods:

In the present study, Sprague Dawley rats were divided into two groups: control group (free access to tap drinking water for seven weeks), and a group that received fructose 10% in drinking water for seven weeks, (n═8 per each group). In all groups, before starting the test period and seven weeks after it, electrocardiogram was recorded by Power lab system. Unpaired t-test and two-way ANOVA were used for data analysis. Also, oxidative stress parameters were measured.

Results:

In the group received high doses of fructose, a significant reduction (P <0.05) was observed in the PR interval (P<0.001) and a significant increase (P<0.05) in the QTc interval. However, there was no significant change in the RR interval and the voltage of the QRS complex. A significant decrease in catalase, superoxide dismutase and glutathione peroxidase (P<0.05) and a significant increase (P<0.05) in malondialdehyde and lactate dehydrogenase were observed in the group that received fructose in comparison with the control group at the end of the experiment.

Conclusion:

According to our results, the chance of arrhythmias in the rats receiving high doses of fructose was possibly due to the increased oxidative stress in the healthy rats.

Delayed postprandial TAG peak after intake of SFA compared with PUFA in subjects with and without familial hypercholesterolaemia: a randomised controlled trial

Postprandial hypertriacylglycerolaemia is associated with an increased risk of developing CVD. How fat quality influences postprandial lipid response is scarcely explored in subjects with familial hypercholesterolaemia (FH). The aim of this study was to investigate the postprandial response of TAG and lipid sub-classes after consumption of high-fat meals with different fat quality in subjects with FH compared with normolipidaemic controls. A randomised controlled double-blind cross-over study with two meals and two groups was performed. A total of thirteen hypercholesterolaemic subjects with FH who discontinued lipid-lowering treatment 4 weeks before and during the study, and fourteen normolipidaemic controls, were included. Subjects were aged 18-30 years and had a BMI of 18·5-30·0 kg/m2. Each meal consisted of a muffin containing 60 g (70 E%) of fat, either mainly SFA (40 E%) or PUFA (40 E%), eaten in a random order with a wash-out period of 3-5 weeks between the meals. Blood samples were collected at baseline (fasting) and 2, 4 and 6 h after intake of the meals. In both FH and control subjects, the level of TAG and the largest VLDL sub-classes peaked at 2 h after intake of PUFA and at 4 h after intake of SFA. No significant differences were found in TAG levels between meals or between groups (0·25≤P≤0·72). The distinct TAG peaks may reflect differences in the postprandial lipid metabolism after intake of fatty acids with different chain lengths and degrees of saturation. The clinical impact of these findings remains to be determined.

Validity of an Abbreviated, Clinically Feasible Test for Postprandial Lipemia in Healthy Adults: A Randomized Cross-Over Study

BACKGROUND

A large post-meal triglyceride (TG) response is an independent risk factor for cardiovascular disease, but postprandial lipemia assessments are not clinically practical in their current form. Therefore, we assessed the validity of an abbreviated, clinically feasible protocol in measuring postprandial lipemia.

METHOD

Eighteen healthy adults (8 male and 10 female) completed 3 high-fat meal trials in random order: (1) a Standard in Lab (SL) protocol wherein blood draws (to determine TG) were made from a catheter at baseline and hourly for 6 h; (2) an Abbreviated in Lab (AL) protocol in which participants remained in the laboratory but blood draws were only made at baseline and 4 h post-meal; and (3) an Abbreviated with Freedom (AF) protocol in which participants vacated the laboratory between the meal and the 4-h blood draw.

RESULTS

TG increase from baseline was very similar (p = 0.93) across the 3 trials (SL: 68.5 ± 62.7 mg/dL; AL: 71.1 ± 58.0 mg/dL; AF: 66.7 ± 46.4 mg/dL), as were 4-h TG levels (SL: 144.6 ± 84.2 mg/dL; AL: 171.4 ± 88.2 mg/dL; AF: 157.7 ± 76.7 mg/dL; p = 0.49). Similarly, total and incremental area under the curve (AUC) were not significantly different across the trials (p = 0.12 and 0.91, respectively).

CONCLUSION

The TG results of the clinically feasible, abbreviated protocol were similar to those of the more exhaustive standard protocol. The AF protocol could be a valid and feasible clinical tool for measurement of postprandial lipemia and assessment of cardiovascular risk, although studies in larger and more diverse cohorts are needed.

Liraglutide Reduces Postprandial Hyperlipidemia by Increasing ApoB48 (Apolipoprotein B48) Catabolism and by Reducing ApoB48 Production in Patients With Type 2 Diabetes Mellitus

Objective—

Treatment with liraglutide, a GLP-1 (glucagon-like peptide-1) agonist, has been shown to reduce postprandial lipidemia, an important feature of diabetic dyslipidemia. However, the underlying mechanisms for this effect remain unknown. This prompted us to study the effect of liraglutide on the metabolism of ApoB48 (apolipoprotein B48).

Approach and Results—

We performed an in vivo kinetic study with stable isotopes (D 8 -valine) in the fed state in 10 patients with type 2 diabetes mellitus before treatment and 6 months after the initiation of treatment with liraglutide (1.2 mg/d). We also evaluated, in mice, the effect of a 1-week liraglutide treatment on postload triglycerides and analysed in vitro on jejunum, the direct effect of liraglutide on the expression of genes involved in the biosynthesis of chylomicron. In diabetic patients, liraglutide treatment induced a dramatic reduction of ApoB48 pool (65±38 versus 162±87 mg; P =0.005) because of a significant decrease in ApoB48 production rate (3.02±1.33 versus 6.14±4.27 mg kg -1 d -1 ; P =0.009) and a significant increase in ApoB48 fractional catabolic rate (5.12±1.35 versus 3.69±0.75 pool d -1 ; P =0.005). One-week treatment with liraglutide significantly reduced postload plasma triglycerides in mice and liraglutide, in vitro, reduced the expression of ApoB48, DGAT1 (diacylglycerol O-acyltransferase 1), and MTP (microsomal transfer protein) genes.

Conclusions—

We show that treatment with liraglutide induces a significant reduction of the ApoB48 pool because of both a reduction of ApoB48 production and an increase in ApoB48 catabolism. In vitro, liraglutide reduces the expression of genes involved in chylomicron synthesis. These effects might benefit cardiovascular health.

Clinical Trial Registration—

URL: https://www.clinicaltrials.gov . Unique identifier: NCT02721888.

Platycodi radix beverage ameliorates postprandial lipemia response through lipid clearance of triglyceride-rich lipoprotein: A randomized controlled study in healthy subjects with a high-fat load

BACKGROUND/OBJECTIVES

Elevation of postprandial lipemia characterized by a rise in triglyceride (TG)-rich lipoproteins can increase the risk of atherogenesis. The objective of this study was to investigate postprandial lipemia response to a single dietary fat/sugar load test and monitor beneficial changes induced by the consumption of Platycodi radix (AP) beverage in healthy subjects.

SUBJECTS/METHODS

A total of 52 subjects were randomly assigned to either placebo or AP beverage group with a high-fat shake in a randomized controlled crossover trial. Postprandial blood was collected at 0, 1, 2, 4, and 6 h and analyzed for TG and lipoprotein lipase mass. Inhibition of pancreatic lipase was determined in vitro.

RESULTS

AP inhibited pancreatic lipase activity in vitro (IC₅₀ = 5 mg/mL). Compared to placebo beverage, AP beverage consumption with a high-fat shake induced significant increase of plasma lipoprotein lipase mass (P = 0.0111, β estimate = 4.2948) with significant reduction in very low-density lipoprotein (VLDL) TG concentration (P = 0.038, β estimate = −52.69) at 6 h. Based on significant correlation between high-fat dietary scores MEDFICTS and postprandial TG responses in VLDL (P = 0.0395, r = 0.2127), subgroup analysis revealed that 6 h-postprandial VLDL TG response was significantly decreased by AP consumption in subjects with MEDFICTS ≥ 40 (P = 0.0291, β estimate = −7214).

CONCLUSIONS

AP beverage might have potential to alleviate postprandial lipemia through inhibiting pancreatic lipase activity and elevating lipoprotein lipase mass. Subgroup analysis revealed that subjects with high-fat dietary pattern could be classified as responders to AP beverage among all subjects.

After the LEADER trial and SUSTAIN-6, how do we explain the cardiovascular benefits of some GLP-1 receptor agonists?

Recent cardiovascular outcome trials - the LEADER with liragutide and SUSTAIN-6 with semaglutide - have shown significant reductions of major cardiovascular (CV) events with these glucagon-like peptide (GLP)-1 receptor agonists. Progressive separation of the treatment and placebo curves, starting clearly between 12 and 18 months of the trial period, and significant reductions in the risk of myocardial infarction and stroke, indicate that the beneficial CV effects observed with GLP-1 receptor agonists could be due to an antiatherogenic effect. So far, the reasons for such an effect of GLP-1 receptor agonists have not been entirely clear, although several hypotheses may be proposed. As the reductions in glycated haemoglobin and systolic blood pressure (SBP) in these trials were modest, and both trials lasted only a short period of time, reductions in hyperglycaemia and SBP are unlikely to be involved in the beneficial CV effects of GLP-1 receptor agonists. On the other hand, their effect on lipids and, in particular, the dramatic decrease in postprandial hypertriglyceridaemia may explain their beneficial CV actions. Reduction of body weight, including a significant decrease in visceral fat in patients using GLP-1 receptor agonists, may also have beneficial CV effects by reducing chronic proatherogenic inflammation. In addition, there are in-vitro data showing a direct anti-inflammatory effect with these agents that could also be involved in their beneficial CV effects. Moreover, studies in humans have shown significant beneficial effects on ischaemic myocardium after a very short treatment period, suggesting a direct effect of GLP-1 receptor agonists on myocardium, although the precise mechanism remains unclear. Finally, as a reduction in insulin resistance has been associated with a decrease in CV risk, it cannot be ruled out that the lowering of insulin resistance induced by GLP-1 receptor agonists might also be involved in their beneficial CV actions.

Metabolic and inflammatory biomarkers are associated with epigenetic aging acceleration estimates in the GOLDN study

Background

Recently, epigenetic age acceleration-or older epigenetic age in comparison to chronological age-has been robustly associated with mortality and various morbidities. However, accelerated epigenetic aging has not been widely investigated in relation to inflammatory or metabolic markers, including postprandial lipids.

Methods

We estimated measures of epigenetic age acceleration in 830 Caucasian participants from the Genetics Of Lipid Lowering Drugs and diet Network (GOLDN) considering two epigenetic age calculations based on differing sets of 5'-Cytosine-phosphate-guanine-3' genomic site, derived from the Horvath and Hannum DNA methylation age calculators, respectively. GOLDN participants underwent a standardized high-fat meal challenge after fasting for at least 8 h followed by timed blood draws, the last being 6 h postmeal. We used adjusted linear mixed models to examine the association of the epigenetic age acceleration estimate with fasting and postprandial (0- and 6-h time points) low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglyceride (TG) levels as well as five fasting inflammatory markers plus adiponectin.

Results

Both DNA methylation age estimates were highly correlated with chronological age (r > 0.90). We found that the Horvath and Hannum measures of epigenetic age acceleration were moderately correlated (r = 0.50). The regression models revealed that the Horvath age acceleration measure exhibited marginal associations with increased postprandial HDL (p = 0.05), increased postprandial total cholesterol (p = 0.06), and decreased soluble interleukin 2 receptor subunit alpha (IL2sRα, p = 0.02). The Hannum measure of epigenetic age acceleration was inversely associated with fasting HDL (p = 0.02) and positively associated with postprandial TG (p = 0.02), interleukin-6 (IL6, p = 0.007), C-reactive protein (C-reactive protein, p = 0.0001), and tumor necrosis factor alpha (TNFα, p = 0.0001). Overall, the observed effect sizes were small and the association of the Hannum residual with inflammatory markers was attenuated by adjustment for estimated T cell type percentages.

Conclusions

Our study demonstrates that epigenetic age acceleration in blood relates to inflammatory biomarkers and certain lipid classes in Caucasian individuals of the GOLDN study. Future studies should consider epigenetic age acceleration in other tissues and extend the analysis to other ethnic groups.

Evidence for increased chylomicron remnants in rheumatoid arthritis

BACKGROUND

Levels of apolipoprotein (apo) B48 may be increased in conditions associated with systemic inflammation and increased cardiovascular disease (CVD) risk such as rheumatoid arthritis (RA). We aimed to evaluate apo B48 levels in patients with RA in relation to subclinical atherosclerosis.

METHODS

Patients with RA (without CVD) and controls without RA but with high CVD risk (based on the presence of diabetes mellitus or a history of CVD) and healthy controls were included in this cross-sectional study. Carotid intima-media thickness (cIMT) was measured as a surrogate for vascular damage.

RESULTS

In total, 312 patients with RA, 65 controls with high CVD risk and 36 healthy controls were included. Patients with RA had the highest mean apo B48 (10.00 ± 6.65 mg/L) compared to controls with high CVD risk and healthy controls (8.37 ± 5.16 and 5.22 ± 2.46, P < .001). Triglycerides levels were comparable with controls. In RA, apo B48 correlated positively with triglycerides (r = .645; P < .001) but not with cIMT. However, in RA subjects not using lipid or blood pressure lowering medication, a weak correlation was found with cIMT (r = .157; P = .014). RA patients in the highest apo B48 tertile were more often rheumatoid factor positive and anti-CCP positive compared to the lowest tertile.

CONCLUSION

Rheumatoid arthritis patients have higher levels of apo B48 compared to controls with high CVD risk and healthy controls, with normal levels of triglycerides. This accumulation of atherogenic chylomicron remnants may contribute to the elevated CVD risk in RA patients.

The suprachiasmatic nucleus drives day-night variations in postprandial triglyceride uptake into skeletal muscle and brown adipose tissue

NEW FINDINGS

What is the central question of this study? What are the factors influencing day-night variations in postprandial triglycerides? What is the main finding and its importance? Rats show low postprandial plasma triglyceride concentrations early in the active period that are attributable to a higher uptake by skeletal muscle and brown adipose tissue. We show that these day-night variations in uptake are driven by the suprachiasmatic nucleus, probably via a Rev-erbα-mediated mechanism and independent of locomotor activity. These findings highlight that the suprachiasmatic nucleus has a major role in day-night variations in plasma triglycerides and that disturbances in our biological clock might be an important risk factor contributing to development of postprandial hyperlipidaemia. Energy metabolism follows a diurnal pattern, mainly driven by the suprachiasmatic nucleus (SCN), and disruption of circadian regulation has been linked to metabolic abnormalities. Indeed, epidemiological evidence shows that night work is a risk factor for cardiovascular disease, and postprandial hyperlipidaemia is an important contributor. Therefore, the aim of this work was to investigate the factors that drive day-night variations in postprandial triglycerides (TGs). Intact and SCN-lesioned male Wistar rats were subjected to an oral fat challenge during the beginning of the rest phase (day) or the beginning of the active phase (night). The plasma TG profile was evaluated and tissue TG uptake assayed. After the fat challenge, intact rats showed lower postprandial plasma TG concentrations early in the night when compared with the day. However, no differences were observed in the rate of intestinal TG secretion between day and night. Instead, there was a higher uptake of TG by skeletal muscle and brown adipose tissue early in the active phase (night) when compared with the rest phase (day), and these variations were abolished in rats bearing bilateral SCN lesions. Rev-erbα gene expression suggests this as a possible mediator of the mechanism linking the SCN and day-night variations in TG uptake. These findings show that the SCN has a major role in day-night variations in plasma TGs by promoting TG uptake into skeletal muscle and brown adipose tissue. Consequently, disturbance of the biological clock might be an important risk factor contributing to the development of hyperlipidaemia.

Invited review: The anti-inflammatory properties of dairy lipids

Dairy product consumption is often associated with negative effects because of its naturally high levels of saturated fatty acids. However, recent research has shown that dairy lipids possess putative bioactivity against chronic inflammation. Inflammation triggers the onset of several chronic diseases, including cardiovascular disease, type 2 diabetes mellitus, obesity, and cancer. This review discusses the anti-inflammatory properties of dairy lipids found in milk, yogurt, and cheese, and it examines them in relation to their implications for human health: their protective effects and their role in pathology. We also consider the effect of lipid profile alteration in dairy products-by using ruminant dietary strategies to enrich the milk, or by lipid fortification in the products. We critically review the in vivo, in vitro, ex vivo, and epidemiological studies associated with these dairy lipids and their role in various inflammatory conditions. Finally, we discuss some suggestions for future research in the study of bioactive lipids and dairy products, with reference to the novel field of metabolomics and epidemiological studies.

Bioavailability of n-3 fatty acids from n-3-enriched foods and fish oil with different oxidative quality in healthy human subjects: a randomised single-meal cross-over study

Regular consumption of long-chain n-3 fatty acids (LC n-3 FA) reduces postprandial triacylglycerolaemia. Functional foods and supplements are alternative sources of LC n-3 FA; however, emulsification technologies, food matrices and altered lipid oxidation levels affect their bioavailability. Moreover, which functional foods are optimal LC n-3 FA carriers is unknown. The aim of the study was to determine the bioavailability of LC n-3 FA and the postprandial TAG response after the intake of oxidised or non-oxidised cod liver oil and after the intake of emulsified or non-emulsified LC n-3 FA using novel functional food items as LC n-3 FA carriers in a randomised cross-over acute study. A total of twenty-four healthy subjects completed the study in which subjects consumed one of four different test meals containing 1·5 g LC n-3 FA, or a control meal with no LC n-3 FA. Postprandial TAG-rich lipoproteins were isolated and their fatty acid composition was measured. The LC n-3 FA from emulsified foods were more rapidly incorporated into TAG-rich lipoproteins compared with non-emulsified foods. The incorporation of LC n-3 FA was similar for oils emulsified in yogurt or juice and was unaffected by the oxidative status of the oil. Postprandial TAG levels did not differ among the various test meals. In conclusion, emulsification increases the bioavailability of LC n-3 FA through a more rapid incorporation into TAG-rich lipoproteins, and juice and yogurt are equally suited as LC n-3 FA carriers. The acute intake of oxidised cod liver oil does not influence the incorporation of LC n-3 FA into TAG-rich lipoproteins.

Proprietary tomato extract improves metabolic response to high-fat meal in healthy normal weight subjects

BACKGROUND

Low-density lipoprotein (LDL) oxidation is a risk factor for atherosclerosis. Lycopene and tomato-based products have been described as potent inhibitors of LDL oxidation.

OBJECTIVES

To evaluate the effect of a 2-week supplementation with a carotenoid-rich tomato extract (CRTE) standardized for a 1:1 ratio of lycopene and phytosterols, on post-prandial LDL oxidation after a high-fat meal.

DESIGN

In a randomized, double-blind, parallel-groups, placebo-controlled study, 146 healthy normal weight individuals were randomly assigned to a daily dose of CRTE standardized for tomato phytonutrients or placebo during 2 weeks. Oxidized LDL (OxLDL), glucose, insulin, and triglyceride (TG) responses were measured for 8 h after ingestion of a high-fat meal before and at the end of intervention.

RESULTS

Plasma lycopene, phytofluene, and phytoene were increased throughout the study period in the CRTE group compared to placebo. CRTE ingestion significantly improved changes in OxLDL response to high-fat meal compared to placebo after 2 weeks (p<0.0001). Changes observed in glucose, insulin, and TG responses were not statistically significant after 2 weeks of supplementation, although together they may suggest a trend of favorable effect on metabolic outcomes after a high-fat meal.

CONCLUSIONS

Two-week supplementation with CRTE increased carotenoids levels in plasma and improved oxidized LDL response to a high-fat meal in healthy normal weight individuals.

Consumption of a high-fat meal was associated with an increase in monocyte adhesion molecules, scavenger receptors, and Propensity to Form Foam Cells

BACKGROUND

Macrophage-derived foam cells are the predominant component of arterial plaques in the early stages of atherosclerosis. One factor that poses a major risk for plaque development is high levels of plasma low-density lipoprotein (LDL) as a result of a high-fat meal. In order to better understand how an individuals' diet affects arterial plaque deposition via the process of foam cell formation, we measured the acute circulating monocyte activity response after consuming a high-fat meal (85% of daily fat allowance).

MATERIALS AND METHODS

Venous blood samples from 17 participants were acquired on a FlowSight. Samples were analyzed to identify nonclassical (CD14+/16+) and classical (CD14+/16-) monocytes. We measured monocyte concentration, adhesion molecule expression, CD36 expression, and oxidized LDL (oxLDL) endocytosis for preprandial 1, 3, and 5 h postprandial.

RESULTS

Consuming a high-fat meal caused increases in oxLDL uptake, adhesion molecule expression, and CD36 expression in both classical and nonclassical monocytes, with the nonclassical monocytes responding with larger increases than the classical monocytes.

CONCLUSION

These results suggest that consumption of a high-fat meal increased the potential of monocytes to become foam cells, and implicates nonclassical monocytes as having greater potential than classical monocytes to become foam cells. © 2016 International Clinical Cytometry Society.

Genetic variation of the intestinal fatty acid-binding protein 2 gene in carotid atherosclerosis

The alanine (A) to threonine (T) substitution at codon 54 of the intestinal fatty acid-binding protein 2 (FABP2) has been associated with dyslipidaemia and other characteristics of the metabolic syndrome, which in turn is a risk factor for cerebrovascular disease. The aim of this study was to investigate whether the A54T polymorphism in the FABP2 gene is associated with internal carotid artery (ICA) stenosis in stroke patients. Swedish subjects initially diagnosed with acute cerebrovascular disease (n = 196) that had been assessed with ultrasound of the carotid arteries were identified and grouped depending on whether a stenosis was found. The subjects were genotyped for the A54T polymorphism using a PCR-RFLP method. In a multivariate logistic-regression analysis, where known risk factors for atherosclerosis were fixed (diabetes, systolic blood pressure, age and smoking), having the FABP2 T allele was a significant risk factor for ICA stenosis (odds ratio 2.9; 95% confidence interval, 1.1-7.7; p = 0.04) together with diabetes (odds ratio 4.9; 95% confidence interval, 1.8-14; p < 0.01). Age, smoking and blood pressure did not reach statistical significance. In conclusion, our result supports the hypothesis that the FABP2 A54T polymorphism is associated with ICA stenosis.

Blood glucose and lipid concentrations after overload are not associated with the risk of alcohol relapse

AIMS

There is evidence for the functioning of feedback between alcohol consumption and fat (positive) and carbohydrate (negative) intake. We tried to verify the hypothesis that blood glucose and lipid concentration in a fasting state and after loading may affect the risk of relapse in alcohol-dependent male patients during withdrawal therapy.

METHODS

Blood glucose, total cholesterol (TC) and triglycerides (TG) were determined at the beginning of the study, and again after 4 weeks and 6 months of observation in 54 alcohol-dependent male patients treated against drinking relapse. Glucose concentration was checked after fasting and 2h after loading with a 75 g water solution of glucose, and blood lipids were determined on an empty stomach and 5h after butter loading (0.5 g of butter per kilogram of body mass).

RESULTS

Patients who relapsed compared to subjects who remained abstinent during the 6-month observation did not differ significantly in relation to blood glucose, TC or TG blood concentrations, either in a fasting state or after loading. Patients with an initial above-median increase in TG blood concentration after butter loading (>38%) before the beginning of the study, and who smoked cigarettes with a greater content of nicotine and tar, preferred vodka and had lower values of aminotransferases.

CONCLUSION

Fasting and postprandial blood glucose, TC and TG concentrations had no relationship with the outcome of anti-relapse treatment. However, they presented some associations with the pathomechanism of addiction to nicotine.

Brief Communication: Discordant ability of the triglyceride to apolipoprotein B ratio to predict triglyceride-rich lipoprotein particle size in normal-weight and obese men

The atherogenicity of triglyceride-rich lipoproteins (TRLs) is dependent of their particle size as it determines their metabolic fate. Since TRL possess a single apolipoprotein B (Apo B) molecule per particle, the triglyceride (TG)/Apo B ratio has been used as a convenient method to estimate TRL size. The aim of this study was to validate this approach by correlating the serum TG/Apo B ratio, and the TRL particle size measured by dynamic light scattering (DLS). Twenty-four male volunteers (12 normal-weight and 12 obese individuals) received a high-fat meal. Preprandial (0 h) and postprandial (2 and 4 h) serum samples were collected after meal ingestion, and TRLs were isolated. Serum TG and Apo B levels were quantified, and the TG/Apo B ratio was plotted against TRL particle size measured by DLS for correlation. A strong association between TRL particle size and serum TG/Apo B ratio for normal-weight subjects (P ≤ 0.001) was observed but not for obese subjects (P = 0.6116). TG/Apo B ratio correlates with particle size in healthy normal-weight males but not in obese individuals. Whether this ratio is useful to estimate TRL size in females and in other dyslipidemic patients should be subject of future investigations.

Tomato Sauce Enriched with Olive Oil Exerts Greater Effects on Cardiovascular Disease Risk Factors than Raw Tomato and Tomato Sauce: A Randomized Trial

Epidemiological studies have observed a negative association between tomato intake and the incidence of cardiovascular disease. As tomato sauces are usually cooked with the addition of oil, some studies have pointed out that both processes may increase the bioavailability of the bioactive compounds. However, the effect of consumption of raw tomatoes and tomato sauces on inflammation biomarkers and adhesion molecules related to atherosclerosis remains unknown. The aim of this study was to test the postprandial effects of a single dose of raw tomatoes (RT), tomato sauce (TS) and tomato sauce with refined olive oil (TSOO) on cardiovascular disease risk factors. We performed an open, prospective, randomized, cross-over, controlled feeding trial in 40 healthy subjects who randomly received: 7.0 g of RT/kg of body weight (BW), 3.5 g of TS/kg BW, 3.5 g of TSOO/Kg BW and 0.25 g of sugar solved in water/kg BW on a single occasion on four different days. Biochemical parameters and cellular and circulating inflammatory biomarkers were assessed at baseline and 6 h after each intervention. The results indicate that, compared to control intervention, a single tomato intake in any form decreased plasma total cholesterol, triglycerides and several cellular and plasma inflammatory biomarkers, and increased plasma high density lipoproteins (HDL) cholesterol and interleukine (IL) 10 concentrations. However, the changes of plasma IL-6 and vascular cell adhesion molecule-1 (VCAM-1), and lymphocyte function-associated antigen-1 (LFA-1) from T-lymphocytes and CD36 from monocytes were significantly greater after TSOO than after RT and TS interventions. We concluded that tomato intake has beneficial effects on cardiovascular risk factors, especially cooked and enriched with oil.

Investigation into the acute effects of total and partial energy restriction on postprandial metabolism among overweight/obese participants

The intermittent energy restriction (IER) approach to weight loss involves short periods of substantial (75-100 %) energy restriction (ER) interspersed with normal eating. This study aimed to characterise the early metabolic response to these varying degrees of ER, which occurs acutely and prior to weight loss. Ten (three female) healthy, overweight/obese participants (36 (SEM 5) years; 29·0 (sem 1·1) kg/m2) took part in this acute three-way cross-over study. Participants completed three 1-d dietary interventions in a randomised order with a 1-week washout period: isoenergetic intake, partial 75 % ER and total 100 % ER. Fasting and postprandial (6-h) metabolic responses to a liquid test meal were assessed the following morning via serial blood sampling and indirect calorimetry. Food intake was also recorded for two subsequent days of ad libitum intake. Relative to the isoenergetic control, postprandial glucose responses were increased following total ER (+142 %; P=0·015) and to a lesser extent after partial ER (+76 %; P=0·051). There was also a delay in the glucose time to peak after total ER only (P=0·024). Both total and partial ER interventions produced comparable reductions in postprandial TAG responses (-75 and -59 %, respectively; both P<0·05) and 3-d energy intake deficits of approximately 30 % (both P=0·015). Resting and meal-induced thermogenesis were not significantly affected by either ER intervention. In conclusion, our data demonstrate the ability of substantial ER to acutely alter postprandial glucose-lipid metabolism (with partial ER producing the more favourable overall response), as well as incomplete energy-intake compensation amongst overweight/obese participants. Further investigations are required to establish how metabolism adapts over time to the repeated perturbations experienced during IER, as well as the implications for long-term health.

Modulation of the lipidomic profile due to a lipid challenge and fitness level: a postprandial study

Background

The lipid composition of plasma is known to vary due to both phenotypic factors such as age, gender and BMI as well as with various diseases including cancer and neurological disorders. However, there is little investigation into the variation in the lipidome due to exercise and/ or metabolic challenges. The objectives of this present study were (i) To identify the glycerophospholipid, sphingolipids and ceramide changes in response to an oral lipid tolerance test (OLTT) in healthy adults and (ii) To identify the effect of aerobic fitness level on lipidomic profiles.

Methods

214 healthy adults aged 18–60 years were recruited as part of a metabolic challenge study. A sub-group of 40 volunteers were selected for lipidomic analysis based on their aerobic fitness level. Ceramides, glycerophospholipids and sphingomyelins were quantified in baseline fasting plasma samples as well as at 60, 120, 180, 240 and 300 min following a lipid challenge using high-throughput flow injection ESI-MS/MS.

Results

Mixed model repeated measures analysis identified lipids which were significantly changing over the time course of the lipid challenge. Included in these lipids were lysophosphoethanolamines (LPE), phosphoethanolamines (PE), phosphoglycerides (PG) and ceramides (Cer). Five lipids (LPE a C18:2, LPE a C18:1, PE aa C36:2, PE aa C36:3 and N-C16:1-Cer) had a fold change > 1.5 at 120 min following the challenge and these lipids remained elevated. Furthermore, three of these lipids (LPE a C18:2, PE aa C36:2 and PE aa C36:3) were predictive of fasting and peak plasma TAG concentrations following the OLTT. Further analysis revealed that fitness level has a significant impact on the response to the OLTT: in particular significant differences between fitness groups were observed for phosphatidylcholines (PC), sphingomyelins (SM) and ceramides.

Conclusion

This study identified specific lipids which were modulated by an acute lipid challenge. Furthermore, it identified a series of lipids which were modulated by fitness level. Future lipidomic studies should take into account environmental factors such as diet and fitness level during biomarker discovery work.

Trial registration

Data, clinicaltrials.gov, NCT01172951

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-015-0062-x) contains supplementary material, which is available to authorized users.