Exercise and dietary-mediated reductions in postprandial lipemia

A 4-Week Pecan-Enriched Diet Improves Postprandial Lipid Peroxidation in Aging Adults

Pecans are rich in bioactive compounds known to reduce oxidative stress and provide glucoregulatory benefits. Few studies assessing the effect of a pecan-enriched diet on such health outcomes suggest potential improvements to cardiometabolic health; however, this has not been studied in an older adult population. Thus, we aimed to examine the effect of daily pecan consumption for 4-weeks on fasting and postmeal antioxidant status, oxidative stress, and markers of glycemia in healthy aging adults. In this randomized, parallel, controlled trial, 41 healthy adults (50-75 years) either consumed 68 g of pecans/day (pecan; n = 21) or avoided all nuts (control; n = 20). At pre- (V1) and postintervention visits (V2), blood samples were obtained at fasting, and 30, 60, and 120 min following a high saturated fat meal to assess changes in malondialdehyde, which is a measure of lipid peroxidation, total antioxidant capacity (TAC), glucose, and insulin. Across the intervention, there were no differences in fasting or postprandial TAC, glucose, or insulin for pecan versus control. There was a trend for a difference in fasting lipid peroxidation from V1 to V2 by treatment (P = .06) driven by a slight reduction for pecan versus control (Δpecan: -2.0 ± 1.1 vs. Δcontrol: +0.6 ± 0.8 μM). In addition, postprandial lipid peroxidation was suppressed at V2 for pecan, and this was different from control (pecan areas under the curve (AUC): 10.6 ± 1.3 μM/h to 9.1 ± 1.2 μM/h vs. control AUC: 8.9 ± 1.3 μM/h to 9.2 ± 1.1 μM/h; P = .03). These findings suggest that a 1 month, pecan-enriched diet is protective against postmeal oxidative stress. Longer interventions or a diabetic population may be needed to observe glucoregulatory benefits. Clinical Trial Registration: NCT04385537.

Red cells manufactured from lipaemic whole blood donations: Do they have higher haemolysis?

BACKGROUND AND OBJECTIVES

Lipaemia in blood donations is thought to influence haemolysis in stored red blood cell (RBC) components. Higher lipid concentrations are believed to increase red cell fragility, exacerbating haemolysis during collection and subsequent red cell storage. This study aimed to investigate associations between lipoproteins in plasma and haemolysis of red cells stored in saline-adenine-glucose-mannitol (SAGM).

MATERIALS AND METHODS

Fifty-four plasma and matched RBCs were obtained from lipaemic whole blood donations. Plasma was tested for coagulation factors, triglycerides and cholesterol. Haemolysis, glucose, lactate, extracellular potassium, lactate dehydrogenase and adenosine triphosphate (ATP) were measured in RBC on Days 7, 21 and 42 of storage. Additionally, 20 plasma and matched RBCs from non-lipaemic donations were tested as controls.

RESULTS

Lipaemic plasma had significantly higher triglyceride concentrations compared with non-lipaemic plasma. However, there was no significant difference in plasma cholesterol between the two groups. There were no significant differences in glucose, extracellular potassium or ATP concentrations in RBC from either group. There was no significant difference in haemolysis at expiry in lipaemic-derived and control RBC, with a weak correlation between haemolysis and either triglycerides or cholesterol.

CONCLUSION

There was no significant difference in haemolysis in RBC manufactured from lipaemic and non-lipaemic whole blood donations when stored in SAGM; however, the proportion of RBC from lipaemic donations with higher haemolysis was greater than in the controls. There was a weak correlation between red cell haemolysis and plasma triglycerides. Therefore, RBCs derived from lipaemic donations are suitable for blood bank inventories.

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.

Exercise to lower postprandial lipemia: why, when, what and how

We review recent findings on the ability of exercise to lower postprandial lipemia (PPL). Specifically, we answer why exercise is important in lowering PPL, when it is most effective to exercise to achieve this, what the preferred exercise is and how exercise reduces PPL. Most findings confirm the power of exercise to lower PPL, which is an independent risk factor for cardiovascular disease. Exercise is most effective when performed on the day preceding a high- or moderate-fat meal. This effect lasts up to approximately two days; therefore, one should exercise frequently to maintain this benefit. However, the time of exercise relative to a meal is not that important in real-life conditions, since one consumes several meals during the day; thus, an exercise bout will inevitably exert its lowering effect on PPL in one or more of the subsequent meals. Although moderate-intensity continuous exercise, high-intensity intermittent exercise (HIIE), resistance exercise and accumulation of short bouts of exercise throughout the day are all effective in lowering PPL, submaximal, high-volume interval exercise seems to be superior, provided it is tolerable. Finally, exercise reduces PPL by both lowering the rate of appearance and increasing the clearance of triacylglycerol-rich lipoproteins from the circulation.

Pecan-enriched diets decrease postprandial lipid peroxidation and increase total antioxidant capacity in adults at-risk for cardiovascular disease

Pecans are a rich source of antioxidants, but the effect of regular consumption on post-meal responses is unknown. The objective of this study was to examine the impact of daily pecan consumption for 8 weeks on fasting and postprandial lipid peroxidation, total antioxidant capacity (TAC), and tocopherols in adults at higher risk for cardiovascular disease (CVD) (hypercholesterolemia or elevated adiposity). We hypothesized that daily pecan consumption would result in increased fasting γ-tocopherol, increased fasting and postprandial TAC, and decreased fasting and postprandial lipid peroxidation. This was a randomized, parallel, controlled trial with 3 treatments: two pecan groups and a nut free control (n = 16). The ADD group (n = 15) consumed pecans as part of a free-living diet, and the SUB group (n = 16) substituted the pecans for isocaloric foods from their habitual diet. At the pre- and post-intervention, a high saturated fat breakfast shake was consumed with postprandial blood draws over 2h. In the ADD and SUB groups, postprandial lipid peroxidation was suppressed (iAUC: 0.9 ± 1.3 to -2.9 ± 2.0 and 4.5 ± 1.7 to 0.7 ± 1.1 µM/2h, respectively; P <0.05) and TAC was elevated (iAUC: -240.8 ± 110.2 to 130.9 ± 131.7 and -227.6 ± 131.2 to 208.7 ± 145.7 µM Trolox Equivalents/2h, respectively; P <0.01) from pre- to post-intervention. Furthermore, there was an increase in γ-tocopherol from pre- to post-intervention within the ADD (1.4 ± 0.1 to 1.8 ± 0.1 µg/mL; P <0.001) and SUB groups (1.8 ± 0.2 to 2.1 ± 0.2 µg/mL; P <0.05). There were no changes in any variable within the control group. These findings suggest that daily pecan consumption protects against oxidative stress that occurs following a high-fat meal in adults at risk for CVD.

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.

Exercise-A Panacea of Metabolic Dysregulation in Cancer: Physiological and Molecular Insights

Metabolic dysfunction is a comorbidity of many types of cancers. Disruption of glucose metabolism is of concern, as it is associated with higher cancer recurrence rates and reduced survival. Current evidence suggests many health benefits from exercise during and after cancer treatment, yet only a limited number of studies have addressed the effect of exercise on cancer-associated disruption of metabolism. In this review, we draw on studies in cells, rodents, and humans to describe the metabolic dysfunctions observed in cancer and the tissues involved. We discuss how the known effects of acute exercise and exercise training observed in healthy subjects could have a positive outcome on mechanisms in people with cancer, namely: insulin resistance, hyperlipidemia, mitochondrial dysfunction, inflammation, and cachexia. Finally, we compile the current limited knowledge of how exercise corrects metabolic control in cancer and identify unanswered questions for future research.

The Importance of Fatty Acids as Nutrients during Post-Exercise Recovery

It is well recognized that whole-body fatty acid (FA) oxidation remains increased for several hours following aerobic endurance exercise, even despite carbohydrate intake. However, the mechanisms involved herein have hitherto not been subject to a thorough evaluation. In immediate and early recovery (0–4 h), plasma FA availability is high, which seems mainly to be a result of hormonal factors and increased adipose tissue blood flow. The increased circulating availability of adipose-derived FA, coupled with FA from lipoprotein lipase (LPL)-derived very-low density lipoprotein (VLDL)-triacylglycerol (TG) hydrolysis in skeletal muscle capillaries and hydrolysis of TG within the muscle together act as substrates for the increased mitochondrial FA oxidation post-exercise. Within the skeletal muscle cells, increased reliance on FA oxidation likely results from enhanced FA uptake into the mitochondria through the carnitine palmitoyltransferase (CPT) 1 reaction, and concomitant AMP-activated protein kinase (AMPK)-mediated pyruvate dehydrogenase (PDH) inhibition of glucose oxidation. Together this allows glucose taken up by the skeletal muscles to be directed towards the resynthesis of glycogen. Besides being oxidized, FAs also seem to be crucial signaling molecules for peroxisome proliferator-activated receptor (PPAR) signaling post-exercise, and thus for induction of the exercise-induced FA oxidative gene adaptation program in skeletal muscle following exercise. Collectively, a high FA turnover in recovery seems essential to regain whole-body substrate homeostasis.

The Effects of a Single Versus Three Consecutive Sessions of Football Training on Postprandial Lipemia: a Randomized, Controlled Trial in Healthy, Recreationally Active Males

BACKGROUND

Exercise frequency is important for maintaining health; however, its effects on postprandial responses remain largely unknown. Better understanding this during popular sports activities such as football may influence exercise habits. Therefore, the aim of the present study was to examine the effects of playing one single versus three consecutive days of 60-min small-sided football matches on postprandial lipemia.

METHODS

Fifteen males performed either one (1FOOT; n = 7) or three 60-min football (3FOOT; n = 8) sessions across an 8-day trial period. On day 1, a blood sample was collected at fasted (0 min) and 0.75, 2, 4, 6 h after a high-fat meal. Participants were then randomly allocated to the 1FOOT (day 7) or 3FOOT (days 5, 6, 7) condition. On day 8, they repeated the high-fat meal and blood sampling for 6 h following the meal. Postprandial total and incremental area under the curve (AUC, iAUC, respectively) were calculated.

RESULTS

The postprandial triglyceride iAUC was 41% lower from pre- to post-measures for the 1FOOT (p < 0.05; ES = 1.02) and 15.7% lower for the 3FOOT (ns; ES = 0.41). Total triglyceride AUC was lower (26%) post-football matches in the 3FOOT group only (p < 0.01; ES = 1.23). In 3FOOT, insulin concentration was lower for post- compared to pre-measures at 0.75 and 2 h, respectively (p < 0.001).

CONCLUSION

One single 60-min small-sided football match lowered postprandial TG incremental area under the curve while performing three consecutive days of football matches did not result in a greater attenuation.

TRIAL REGISTRATION

ISRCTN17934193 , registered 06 April 2019.

Tart cherry consumption with or without prior exercise increases antioxidant capacity and decreases triglyceride levels following a high-fat meal

Exercise and high-phytonutrient foods may lower oxidative stress and increase antioxidant levels, which could combat the negative effects associated with a high-fat (HF) meal. The objective of this study is to test the effects of Montmorency tart cherry (Prunus cerasus L.) consumption, with or without aerobic exercise, on antioxidant responses to an HF meal. Twelve normal-weight men (aged 22 ± 3 years), participated in a randomized crossover design comprising 4 trials: (i) HF meal with Montmorency tart cherry consumption (MC), (ii) HF meal with placebo (P), (iii) exercise prior to HF meal with MC (E+MC), and (iv) exercise prior to HF meal with P (E+P). The HF meal contained 60 g of fat and was consumed with MC or P. For exercise trials, a 30-min bout of submaximal treadmill exercise was performed the afternoon prior to HF meal consumption. Antioxidant capacity and triglycerides (TG) levels were measured at baseline and at 1, 2, and 3 h postprandially. Postprandial antioxidant capacity as assessed by oxygen radical absorbance capacity was significantly higher after MC and E+MC compared with E+P (incremental area under the curve (iAUC): 2.95 ± 2.19 and 4.87 ± 1.45 vs. -1.02 ± 1.72 mmol Trolox equivalents/L for MC and E+MC vs. E+P, respectively; p < 0.01). Postprandial TG levels were significantly lower after E+MC compared with P (iAUC: 58.99 ± 19.46 vs. 107.46 ± 22.66 mmol Trolox equivalents/L for E+MC vs. P, respectively; p < 0.05). These results indicate that MC consumption alone, and in combination with prior exercise, leads to greater antioxidant capacity following an HF meal compared with prior exercise with placebo. Further, MC consumption with prior exercise led to more favorable postprandial TG levels compared with placebo.

Reduced first-phase insulin secretion increases postprandial lipidemia in subjects with impaired glucose tolerance

OBJECTIVE

It is not clear which phase of insulin secretion is more important to regulate lipoprotein lipase (LPL) activity. After a meal, insulin is released and acts as a major regulator of LPL activity. Postprandial hyperlipidemia is a common comorbidity in subjects with insulin resistance (IR). Therefore this study aimed to evaluate the role of the first-phase insulin secretion (FPIS) on postprandial lipidemia in subjects with IR and impaired glucose tolerance (IGT).

RESEARCH DESIGN AND METHODS

This is a cross-sectional, observational and comparative study. We included male and female subjects between 40 and 60 years with a body mass index (BMI) between 23 and 30 kg/m². Then, patients were divided into three groups. Group 1 consisted of control subjects with normal glucose tolerance and preserved FPIS. Group 2 included patients with IGT and a reduced FPIS. Group 3 consisted of subjects with IGT but normal FPIS. Both groups were paired by age and BMI with subjects in the control group. Subjects underwent an intravenous glucose tolerance test to classify each case, and then a load with a mixed meal load to measure postprandial lipidemia.

RESULTS

A total of 32 subjects were evaluated: 10 were control subjects, 8 subjects with IGT with a reduced FPIS and 14 subjects with IGT and preserved FPIS. After administration of a standardized meal, group 2 showed a greater glucose area under the curve (AUC) at 30 and 120 min (p=0.001, for both). This group also showed a statistically significant increase (p<0.001) in triglyceride AUC.

CONCLUSIONS

A reduced FPIS is significantly and independently associated with a larger postprandial hyperlipidemia in subjects with IGT.

Postprandial lipids accelerate and redirect nitric oxide consumption in plasma

Nitric oxide (NO) and O2 are both three-to four-fold more soluble in biological lipids than in aqueous solutions. Their higher concentration within plasma lipids accelerates NO autoxidation to an extent that may be of importance to overall NO bioactivity. This study was undertaken to test the hypothesis that increased plasma lipids after a high-fat meal appreciably accelerate NO metabolism and alter the byproducts formed. We found that plasma collected from subjects after consumption of a single high-fat meal had a higher capacity for NO consumption and consumed NO more rapidly compared to fasting plasma. This increased NO consumption showed a direct correlation with plasma triglyceride concentrations (p = 0.006). The accelerated NO consumption in postprandial plasma was reversed by removal of the lipids from the plasma, was mimicked by the addition of hydrophobic micelles to aqueous buffer, and could not be explained by the presence of either free hemoglobin or ceruloplasmin. The products of NO consumption were shifted in postprandial plasma, with 55% more nitrite (n = 12, p = 0.002) but 50% less SNO (n = 12, p = 0.03) production compared to matched fasted plasma. Modeling calculations indicated that NO autoxidation was accelerated by about 48-fold in the presence of plasma lipids. We conclude that postprandial triglyceride-rich lipoproteins exert a significant influence on NO metabolism in plasma.

The Effect of Diet and Exercise on Intestinal Integrity and Microbial Diversity in Mice

BACKGROUND

The gut microbiota is now known to play an important role contributing to inflammatory-based chronic diseases. This study examined intestinal integrity/inflammation and the gut microbial communities in sedentary and exercising mice presented with a normal or high-fat diet.

METHODS

Thirty-six, 6-week old C57BL/6NTac male mice were fed a normal or high-fat diet for 12-weeks and randomly assigned to exercise or sedentary groups. After 12 weeks animals were sacrificed and duodenum/ileum tissues were fixed for immunohistochemistry for occludin, E-cadherin, and cyclooxygenase-2 (COX-2). The bacterial communities were assayed in fecal samples using terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of 16S rRNA gene amplicons.

RESULTS

Lean sedentary (LS) mice presented normal histologic villi while obese sedentary (OS) mice had similar villi height with more than twice the width of the LS animals. Both lean (LX) and obese exercise (OX) mice duodenum and ileum were histologically normal. COX-2 expression was the greatest in the OS group, followed by LS, LX and OX. The TRFLP and pyrosequencing indicated that members of the Clostridiales order were predominant in all diet groups. Specific phylotypes were observed with exercise, including Faecalibacterium prausnitzi, Clostridium spp., and Allobaculum spp.

CONCLUSION

These data suggest that exercise has a strong influence on gut integrity and host microbiome which points to the necessity for more mechanistic studies of the interactions between specific bacteria in the gut and its host.

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.

The beneficial roles of Lupineus luteus and lifestyle changes in management of metabolic syndrome: A case study

Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors including obesity, hypertension, dyslipidemia and hyperuricemia. Here, we report a 43-year-old man with obesity, hypertension, hypercholesterolemia, hyperuricemia and mild liver dysfunctions. Lupid (Lupineus luteus) and therapeutic lifestyle change (TLC) were suggested as therapeutic intervention for the present case for 6 months. The body weight, body mass index (BMI), blood pressure, total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), triacylglycerol (TAG), uric acid (UA) and alanine transaminase (ALT) were markedly decreased by 26.85%, 26.95%, 13%, 53.84%, 57.84%, 36.14%, 47.58% and 61.62% respectively, compared to those at baselines. However, high density lipoprotein cholesterol (HDL-C) value was markedly increased by 30.77%. The present results concluded that administration of lupin with TLC is good intervention for prevention and treatment of MetS.

Treatment of Hypertriglyceridemia: a Review of Current Options

Hypertriglyceridemia is an important marker of increased levels of highly atherogenic remnant-like particles. The importance of lowering plasma levels of triglycerides (TG) has been called into question many times, but currently it is considered an integral part of residual cardiovascular risk reduction strategies. Lifestyle changes (improved diet and increased physical activity) are effective TG lowering measures. Pharmacological treatment usually starts with statins, although associated TG reductions are typically modest. Fibrates are currently the drugs of choice for hyperTG, frequently in combination with statins. Niacin and omega-3 fatty acids improve control of triglyceride levels when the above measures are inadequately effective. Some novel therapies including anti-sense oligonucleotides and inhibitors of microsomal triglyceride transfer protein have shown significant TG lowering efficacy. The current approach to the management of hypertriglyceridemia is based on lifestyle changes and, usually, drug combinations (statin and fibrate and/or omega-3 fatty acids or niacin).