The effect of upper- and lower-body exercise on next-day postprandial triglycerides in healthy young men.

Aims: High non-fasting triglycerides (TG) concentration is linked to the development of atherosclerosis, and physical activity is commonly recommended to reduce postprandial TG concentration and cardiovascular diseases. Previous studies have demonstrated that acute whole-body (walking and running) or lower-body (leg cycling) aerobic exercise reduces postprandial TG. However, it is unclear whether upper-body exercise (i.e. arm-cranking) with sufficient energy expenditure lowers postprandial TG. Therefore, this study aimed to evaluate the effects of energy-matched upper- and lower-body exercises on postprandial TG concentrations the next day in healthy young men. Method and Materials: Fifteen healthy young men (age 22.5 ± 1.7 years, height 173.8 ± 5.7 cm, body mass 68.2 ± 8.5 kg, peak oxygen uptake 48.0 ± 5.5 mL/min/kg and physically active) participated in a three-arm crossover trials: 1) arm-cranking, 2) leg-cycling exercise at 70% of mode-specific peak oxygen uptake to induce a net energy expenditure of 1,255 kJ, or 3) rested between 16:00 and 17:00 h on day 1 and consumed two standardised meals for breakfast (10:00 h) and lunch (13:00 h) on day 2. The mean macronutrient content of the breakfast was 44.9 ± 5.6 g fat, 104.8 ± 13.0 g carbohydrate, and 29.4 ± 3.6 g protein, which provided 3.95 ± 0.49 MJ energy (43% fat, 45% carbohydrate, and 12% protein), and that of the lunch was 45.2 ± 5.6 g fat, 106.7 ± 13.2 g carbohydrate, and 33.9 ± 4.2 g protein, which provided 4.06 ± 0.50 MJ energy (42% fat, 44% carbohydrate, and 14% protein). Results: Time-averaged postprandial serum TG concentrations over 8 h differed among trials (main effect of trial p < 0.001) and were lower in the upper- and lower-body exercise trials than in the control trial (1.46 ± 0.54 vs. 1.50 ± 0.69 vs. 1.79 ± 0.83 mmol/L, respectively). The incremental TG area under the curve (AUC) (main effect of trial, p = 0.012) was 39% and 37% higher in the control trial than in the upper- and lower-body exercise trials (p = 0.025 and p = 0.033, respectively). There were no significant differences in incremental TG AUC between the upper- and lower-body exercise trials. Conclusion: An acute bout of energy-matched upper- and lower-body exercises similarly lowered postprandial TG concentrations the following day in healthy young men.Trial registration number: UMIN000045449.Date of registration: 10 September 2021.

Plasma protein N-glycome composition associates with postprandial lipaemic response.

BACKGROUND: A dysregulated postprandial metabolic response is a risk factor for chronic diseases, including type 2 diabetes mellitus (T2DM). The plasma protein N-glycome is implicated in both lipid metabolism and T2DM risk. Hence, we first investigate the relationship between the N-glycome and postprandial metabolism and then explore the mediatory role of the plasma N-glycome in the relationship between postprandial lipaemia and T2DM. METHODS: We included 995 individuals from the ZOE-PREDICT 1 study with plasma N-glycans measured by ultra-performance liquid chromatography at fasting and triglyceride, insulin, and glucose levels measured at fasting and following a mixed-meal challenge. Linear mixed models were used to investigate the associations between plasma protein N-glycosylation and metabolic response (fasting, postprandial (Cmax), or change from fasting). A mediation analysis was used to further explore the relationship of the N-glycome in the prediabetes (HbA1c = 39-47 mmol/mol (5.7-6.5%))-postprandial lipaemia association. RESULTS: We identified 36 out of 55 glycans significantly associated with postprandial triglycerides (Cmax ß ranging from -0.28 for low-branched glycans to 0.30 for GP26) after adjusting for covariates and multiple testing (padjusted < 0.05). N-glycome composition explained 12.6% of the variance in postprandial triglycerides not already explained by traditional risk factors. Twenty-seven glycans were also associated with postprandial glucose and 12 with postprandial insulin. Additionally, 3 of the postprandial triglyceride-associated glycans (GP9, GP11, and GP32) also correlate with prediabetes and partially mediate the relationship between prediabetes and postprandial triglycerides. CONCLUSIONS: This study provides a comprehensive overview of the interconnections between plasma protein N-glycosylation and postprandial responses, demonstrating the incremental predictive benefit of N-glycans. We also suggest a considerable proportion of the effect of prediabetes on postprandial triglycerides is mediated by some plasma N-glycans.

Instructions on appropriate fasting prior to phlebotomy; effects on patient awareness, preparation, and biochemical parameters.

OBJECTIVES: This study investigated the effect of appropriate pre-phlebotomy instructions on patients' awareness of the need to fast, their fasting status at phlebotomy, and the measurement of specific biochemical analytes and indices. METHODS: While booking their phlebotomy appointments, two-hundred outpatients, with a wide range of pre-existing medical conditions, were recruited and randomly assigned to either control or intervention groups. The control group received no instructions while the intervention group was verbally instructed to fast for precisely 12 h prior to their appointment. Serum samples were collected from participants to quantify common biochemical analytes and serum indices, some of which were known to be influenced by fasting status, such as triglyceride and the lipaemic index. At the same appointment, participants completed a survey assessing their perception of, and adherence to, fasting requirements. RESULTS: In the intervention group, 99% responded that they had fasted before phlebotomy vs. 16% of controls. Subjects stated they fasted for 12 h in 51% of the intervention group and 7% of the controls. Median concentrations for potassium and total bilirubin were statistically, but not clinically, significantly different. In the study, a single patient in the intervention group was found to have a lipaemic sample. CONCLUSIONS: Without instruction, it appears few patients will fast appropriately prior to blood collection. This study suggests that most patients recall and adhere to verbal instructions regarding fasting. Though many in the control group stated they did not fast, triglyceride concentration and lipaemia were not significantly different from the intervention group, and biochemical analyses appear unaffected by fasting status.

Elimination of lipaemic interference by high-speed centrifugation.

Introduction: In order to deliver high quality results, detection and elimination of possible analytical interferences, such as lipaemia, is crucial. The aim of this study is to evaluate the efficacy of high-speed centrifugation in eliminating lipaemic interference and to define own lipaemic index (LI) for the studied biochemical analytes. Materials and methods: Evaluated analytes were: albumin, alkaline phosphatase, alanine-aminotransferase (ALT), aspartate-aminotransferase (AST), calcium, creatinine, gamma-glutamyltransferase (GGT), glucose, phosphates, total proteins, urea and total bilirubin. Those analytes and LIs have been analysed in duplicate in the Roche Diagnostics-c8000 analyser in samples centrifuged at 3000 rpm/10 minutes in the SL16 (Thermo Scientific, Waltham, USA) centrifuge and according to an own high-speed centrifugation protocol (12,900 rpm/15 minutes) in the MicroCL17R (Thermo Scientific, Waltham, USA) centrifuge. Lipaemia has been measured in each sample. The efficiency of high-speed centrifugation is verified by the Wilcoxon test (P < 0.05). In cases where significant differences are observed, our own LI is calculated. For ALT and AST, it is verified by McNemar test (P < 0.05). For creatinine, both Wilcoxon and McNemar test were applied. Results: There were statistically significant differences in analyte concentration before and after high-speed centrifugation for: albumin, creatinine, GGT, glucose, phosphates, urea and total bilirrubin. Own LI is calculated. McNemar test shows statistically significant diferences in the proportion of delivered results before and after high-speed centrifugation in ALT, AST and creatinine. Conclusions: This study confirms the efficacy of high-speed centrifugation protocol for all the considered analytes, excepting calcium, alkaline phosphatase and total proteins.

Investigating the effects of endogenous lipaemia on the measurement of sodium by indirect ion specific electrode potentiometry.

BACKGROUND: The widely automated method using indirect ion specific electrodes (ISE) potentiometry for determination of sodium concentration is prone to interference from lipaemia. Manufacturer-specified lipaemic (L)-index cut offs may underestimate the effects of endogenous lipaemia. METHODS: We assessed the interference on sodium concentration caused by endogenous lipaemia in 32 residual samples (from 13 patients) using indirect ISE (Cobas® 8000 modular analyser with c702 module, Roche diagnostics) and direct ISE (GEM 4000 premier, Werfen) potentiometric methods. Regression analysis (linear and non-linear) was used to determine a reliable (L)-index cut off for reporting sodium concentration. RESULTS: There was a poor correlation observed between triglyceride concentration and (L)-index. There was significant negative interference caused by endogenous lipaemia within analysed samples. Non-linear regression demonstrated a negative interference of approximately 5% at an (L)-index of 250. CONCLUSION: At present, the manufacturer advises not to report sodium concentration by indirect ISE on the Cobas® 8000 modular analyser if the (L)-index is >2000. However, this has been determined by the addition of exogenous lipids (Intralipid®) and it is clear that this is not comparable to endogenous lipaemia. To ensure patient safety, clinical laboratories should consider lowering the cut off for (L)-index that they use for reporting sodium concentration.

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.

A survey of practice in the management of haemolysis, icterus and lipaemia in blood specimens in the United Kingdom and Republic of Ireland.

BACKGROUND: Haemolysis, icterus and lipaemia (HIL) are common interferants in laboratory medicine, potentially impacting patient care. This survey investigates HIL management in medical laboratories across the UK and Republic of Ireland (ROI). METHODS: A survey was sent to members of key professional organisations for laboratory medicine in the UK and ROI. Questions related to the detection, monitoring, quality control, and management of HIL. RESULTS: In total, responses from 124 laboratories were analysed, predominantly from England (52%) and ROI (36%). Most responses were from public hospitals with biochemistry services (90%), serving primary care (91%), inpatients (91%), and outpatients (89%). Most laboratories monitored H (98%), I (88%), and L (96%) using automated indices (93%), alone or in combination with visual inspection.Manufacturer-stated cut-offs were used by 83% and were applied to general chemistries in 79%, and immunoassays in 50%. Where HIL cut-offs are breached, 64% withheld results, while 96% reported interference to users. HIL were defined using numeric scales (70%) and ordinal scales (26%). HIL targets exist in 35% of laboratories, and 54% have attempted to reduce HIL. Internal Quality Control for HIL was lacking in 62% of laboratories, and just 18% of respondents have participated in External Quality Assurance. Laboratories agree manufacturers should: standardise HIL reporting (94%), ensure comparability between platforms (94%), and provide information on HIL cross-reactivity (99%). Respondents (99%) showed interest in evidence-based, standardised HIL cut-offs. CONCLUSIONS: Most respondents monitor HIL, although the wide variation in practice may differentially affect clinical care. Laboratories seem receptive to education and advice on HIL management.

Biophysical insights into modulating lipid digestion in food emulsions.

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

Acute exercise improves glucose and TAG metabolism in young and older adults following high-fat, high-carbohydrate meal intake.

A single high-fat, high-carbohydrate meal (HFHC) results in elevated postprandial glucose (GLU), triglycerides (TAG) and metabolic load index (MLI; TAG (mg/dl) + GLU (mg/dl)) that contributes to chronic disease risk. While disease risk is higher in older adults (OA) compared to younger adults (YA), the acute effects of exercise on these outcomes in OA is understudied. Twelve YA (age 23.3 ± 3.9 yrs, n = 5 M/7 F) and 12 OA (age 67·7 ± 6.0 yrs, n = 8 M/4 F) visited the laboratory in random order to complete a HFHC with no exercise (NE) or acute exercise (EX) condition. EX was performed 12 hours prior to HFHC at an intensity of 65 % of maximal heart rate to expend 75 % of the kcals consumed in HFHC (Marie Callender's Chocolate Satin Pie; 12 kcal/kgbw; 57 % fat, 37 % CHO). Blood samples were taken at 0, 30, 60, 90 minutes, and then every hour until 6 hours post-meal. TAG levels increased to a larger magnitude in OA (Δ∼61 ± 31 %) compared to YA (Δ∼37 ± 34 %, P < 0·001), which were attenuated in EX compared to NE (P < 0·05) independent of age. There was no difference in GLU between OA and YA after the HFM, however, EX had attenuated GLU independent of age (NE: Δ∼21 ± 26 %; EX: Δ∼12 ± 18 %, P = 0·027). MLI was significantly lower after EX compared to NE in OA and YA (P < 0·001). Pre-prandial EX reduced TAG, GLU and MLI post-HFHC independent of age.

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.

Effects of statins and exercise on postprandial lipoproteins in metabolic syndrome vs metabolically healthy individuals.

AIMS: To determine if the combination of exercise and statin could normalize postprandial triglyceridaemia (PPTG) in hypercholesteraemic individuals. METHODS: Eight hypercholesteraemic (blood cholesterol 182 ± 38 mg dL-1 ; low-density lipoprotein-cholesterol [LDL-c] 102 ± 32 mg dL-1 ) overweight (body mass index 30 ± 4 kg m-2 ) individuals with metabolic syndrome (MetS) were compared to a group of 8 metabolically healthy (MetH) controls (blood cholesterol 149 ± 23 mg dL-1 ; LDL-c 77 ± 23 mg dL-1 , and body mass index 23 ± 2 kg m-2 ). Each group underwent 2 PPTG tests, either 14 hours after a bout of intense exercise or without previous exercise. Additionally, MetS individuals were tested 96 hours after withdrawal of their habitual statin medication to study medication effects. RESULTS: A bout of exercise before the test meal did not reduce PPTG in MetS (P = .347), but reduced PPTG by 46% in MetH (413 ± 267 to 224 ± 142 mg dL-1 for 5 h incremental area under the curve; P = .02). In both trials (i.e., either after a bout of intense exercise or without previous exercise), statin withdrawal in MetS greatly increased PPTG (average 65%; P < .01), mean LDL-c (average 25%; P < .01), total cholesterol (average 16%; P < .01) and apolipoprotein (Apo) B48 (24%; P < .01), without interference from exercise. However, Apo B100 was not affected by statin withdrawal. CONCLUSION: Hypercholesteraemic MetS individuals (compared to MetH controls) fail to show an effect of exercise on reducing PPTG. However, chronic statin medication blunts the elevations in triglyceride after a fat meal (i.e., incremental area under the curve of PPTG) reducing their cardiovascular risk associated with their atherogenic dyslipidaemia. Statin decreases PPTG by reducing the secretion or accelerating the catabolism of intestinal Apo B48.

Effects of a single bout of walking on postprandial triglycerides in men of Chinese, European and Japanese descent: a multisite randomised crossover trial.

INTRODUCTION: Elevated non-fasting triglyceride (TG) concentrations are a risk factor for cardiovascular diseases but can be reduced after acute exercise. Ethnic-based differences in the magnitude of postprandial lipaemia and the extent that acute exercise reduces postprandial TG are poorly characterised across some ethnicities including those of East Asian origin. This paper describes the protocol of a multisite randomised crossover study comparing the effect of acute walking on postprandial TG in two groups of East Asian men with European men. METHODS AND ANALYSIS: Twenty Japanese, 20 Singaporean Chinese and 20 white British healthy men (21-39 years) recruited from Japan, Singapore and the UK, respectively, will complete two, 2-day trials. Fasted and postprandial venous blood samples and arterial blood pressure measurements will be taken over 6 hours the day after either: (1) 60-min treadmill walking; or (2) a rest day of normal living. The primary outcome is the difference in postprandial TG among ethnic groups after rest and walking. Secondary outcomes include cholesterol, glucose, insulin, ketone bodies, preheparin lipoprotein lipase, C-reactive protein and systolic/diastolic blood pressure. ETHICS AND DISSEMINATION: The study was approved by the Ethics Review Committee on Research with Human Subjects of Waseda University and the Nanyang Technological University Institutional Review Board. Relevant approval will be obtained from the UK site. Research findings will be disseminated through peer-reviewed journal publication and health conferences. TRIAL REGISTRATION NUMBER: UMIN000038625.

Fundoscopic characteristics in three cases of familial hyperchylomicronaemia. / Características fundoscópicas en tres casos de hiperquilomicronemia familiar.

CASES REPORT: Three cases are presented of patients with familial hyperchylomicronaemia and lipaemia retinalis, in whom an analysis is made of the fundoscopic characteristics of each of them. DISCUSSION: The typical appearance of the retinal fundus is pale salmon coloured and corresponds to levels of severe lipaemia retinalis. As regards the findings, the vascular tree tonality is probably the best exploratory evidence to help in the ophthalmological diagnosis.

Gender differences on oxidative stress markers and complement component C3 plasma values after an oral unsaturated fat load test.

OBJECTIVE: Post-prandial lipaemia (PL), oxidative stress (OS), and complement component C3 (C3) values are related to the atherosclerosis process. The post-prandial response of C3 after an oral fat load test (OFLT) using unsaturated fat is poorly addressed. The aim of this study was to analyze and compare the post-prandial response of OS markers and C3 values in men and women after an OFLT using unsaturated fat. METHODS: The study included a total of 22 healthy subjects with normal lipids and normal blood glucose (11 men and 11 pre-menopausal women). An oral unsaturated fat load test (OFLT: 50g fat per m2 body surface) was performed using a commercial liquid preparation of long chain triglycerides (Supracal®). OS markers and C3 were measured using standardized methods at fasting state and every 2h up to 8h after the OFLT. RESULTS: Men showed statistically significant higher C3, oxidized glutathione (GSSG), and oxidized-reduced glutathione (GSSG/GSH) ratio values at fasting state compared to that obtained in women. In addition, post-prandial C3 values and GSSG/GSH ratios were significantly higher in men compared to women. The GSSG value and GSSG/GSH ratio significantly decreased in men after the OFLT compared to fasting values. In contrast, the post-prandial OS markers decrease observed in women was not statistically significant. CONCLUSIONS: In fasting state, men showed higher statistically significant C3 values and OS markers than women. The post-prandial OS markers (GSSG and GSSG/GSH ratio) significantly decrease after the OFLT with unsaturated fat in men compared to women.

Effects of statin therapy and exercise on postprandial triglycerides in overweight individuals with hypercholesterolaemia.

AIMS: To determine the effects of statins on postprandial lipaemia (PPL) and to study if exercise could enhance statin actions. METHODS: Ten hypercholesteraemic (blood cholesterol 204 ± 36 mg dL-1 ; low-density lipoprotein-cholesterol 129 ± 32 36 mg dL-1 ) overweight (body mass index 30 ± 4 kg m-2 ), metabolic syndrome individuals chronically medicated with statins (>6 months) underwent 5-hour PPL tests in 4 occasions in a randomized order: (i) substituting their habitual statin medication by placebo for 96 hours (PLAC trial); (ii) taking their habitual statin medicine (STA trial); (iii) placebo combined with a bout of intense aerobic exercise (EXER+PLAC trial); and (iv) combining exercise and statin medicine (EXER+STA trial). RESULTS: Before the fat meal, statin withdrawal (i.e. PLAC and EXER+PLAC) increased blood triglycerides (TG; 24%), low-density lipoprotein-cholesterol (31%) and total cholesterol (19%; all P < .05) evidencing treatment compliance. After the meal, statin withdrawal increased 5-hour postprandial TG (PPTG) compared to its matched trials (94% higher PLAC vs STA and 45% higher EXER+PLAC vs EXER+STA; P < .05). EXER+PLAC trial did not lower PPTG below PLAC (i.e. incremental AUC of 609 ± 152 vs 826 ± 190 mg dL-1 5 h; P = .09). Adding exercise to statin did not result in larger reductions in PPTG (i.e. EXER+STA vs STA incremental area under the curve of 421 ± 87 vs 421 ± 84 mg dL-1 5 h; P = .99). CONCLUSION: In hypercholesteraemic metabolic syndrome individuals, chronic statin therapy blunts the elevations in TG after a fat meal (i.e. incremental area under the curve of PPTG) reducing the cardiovascular risk associated to their atherogenic dyslipidaemia. However, a single bout of intense aerobic exercise before the high fat meal, does not reduce PPTG but also does not interfere with the effects of statin treatment.

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

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

Pre-meal and postprandial lipaemia in subjects with the metabolic syndrome: effects of timing and protein quality (randomised crossover trial).

Non-fasting TAG - postprandial lipaemia (PPL) - are to a higher degree associated with cardiovascular risk compared with fasting TAG. Dietary protein, especially whey proteins (WP), may lower PPL. We hypothesised that a WP pre-meal (17·6 g protein) consumed 15 v. 30 min before a fat-rich meal reduces the PPL response in subjects with the metabolic syndrome (MetS) and that a WP pre-meal has more potent effects than casein and gluten pre-meals. A total of sixteen subjects with the MetS completed an acute, randomised, crossover trial. WP pre-meals were consumed 15 and 30 min, and casein and gluten 15 min before a fat-rich meal. Blood samples were drawn 360 min postprandially to determine metabolite and hormone responses, S-paracetamol (for assessment of gastric emptying) and amino acids. Insulin and glucagon responses were affected by both timing and protein type (for all P <0·01), with significantly higher concentrations for WP given at -15 min than WP at -30 min and higher responses compared with gluten for the first 30 min after pre-meal consumption (for all P <0·05). The PPL responses changed neither by timing nor by protein type. Glucose-dependent insulinotropic peptide but not glucagon-like peptide 1 responses differed between the three protein types. S-paracetamol concentration was higher for WP (-30 min) than for WP (-15 min) 15 min after the main meal (P = 0·028), and higher for casein and gluten than for WP at time point 30 min (for all P <0·05). In conclusion, the PPL response was not changed by ingestion of a 17·6 g protein pre-meal, whereas both timing and protein quality affected hormone secretion (insulin and glucagon).

A pre-meal of whey proteins induces differential effects on glucose and lipid metabolism in subjects with the metabolic syndrome: a randomised cross-over trial.

PURPOSE: Postprandial lipaemia (PPL), an independent risk factor for cardiovascular disease, is affected by composition and timing of meals. We evaluated if whey proteins (WP) consumed as a pre-meal before a fat-rich meal reduce postprandial triglyceride (TG) and apolipoprotein B-48 (ApoB-48) responses in subjects with the metabolic syndrome (MeS). METHODS: An acute, randomised, cross-over trial was conducted. 20 subjects with MeS consumed a pre-meal of 0, 10 or 20 g WP 15 min prior to a fat-rich meal. The responses of TG and ApoB-48 were assessed. We also analysed postprandial responses of free fatty acids (FFA), glucose, insulin, glucagon, glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and paracetamol (reflecting gastric emptying rates). RESULTS: WP pre-meal did not alter the TG or ApoB-48 responses. In contrast, the insulin response was more pronounced after a pre-meal of 20 g WP than with 10 g WP (P = 0.0005) and placebo (P < 0.0001). Likewise, the postprandial glucagon response was greater with a pre-meal of 20 g WP than with 10 g WP (P < 0.0001) and 0 g WP (P < 0.0001). A pre-meal with 20 g of WP generated lower glucose (P = 0.0148) and S-paracetamol responses (P = 0.0003) and a higher GLP-1 response (P = 0.0086) than placebo. However, the pre-meal did not influence responses of GIP, FFA or appetite assessed by a Visual Analog Scale. CONCLUSIONS: Consumption of a WP pre-meal prior to a fat-rich meal did not affect TG and chylomicron responses. In contrast, the WP pre-meal stimulates insulin and glucagon secretion and reduces blood glucose as expected, and delays gastric emptying. Consequently, our study points to a differential impact of a WP pre-meal on lipid and glucose metabolism to a fat-rich meal in subjects with MeS.

Roux-en-Y Gastric Bypass Is More Effective than Sleeve Gastrectomy in Improving Postprandial Glycaemia and Lipaemia in Non-diabetic Morbidly Obese Patients: a Short-term Follow-up Analysis.

PURPOSE: We aimed to compare the effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on postprandial glucose and lipid metabolism in addition to weight loss and fasting metabolic profile, in non-diabetic patients undergoing bariatric surgery. METHODS: Seventy-one patients were consecutively recruited and studied preoperatively, 3 and 6 months after surgery. Of these, 28 underwent RYGB (7 males, age 38 ± 9 years, BMI 46.9 ± 5.0 kg/m2), and 43 SG (9 males, age 38 ± 9 years, BMI 50.2 ± 7.0 kg/m2). A semi-liquid mixed meal was consumed, and blood samples were taken before, and every 30 min after meal ingestion up to 180 min postprandially, for measurement of glucose, insulin, and lipids. The overall postprandial response was assessed as area under the concentration-time curve (AUC). RESULTS: Baseline metabolic parameters were similar between RYGB and SG. Both groups experienced comparable weight loss, and a similar improvement in fasting glucose, insulin, and insulin resistance. Total and LDL cholesterol levels were lower at 6 months after RYGB compared to SG, while there was no difference in HDL cholesterol or triglycerides. Glucose AUC was lower after RYGB compared to SG at both 3 (p = 0.008) and 6 months (p = 0.016), without any difference in postprandial insulin response. Triglyceride AUC was also lower in RYGB vs. SG at 3 and 6 months (p ≤ 0.001). CONCLUSIONS: RYGB is superior to SG in improving postprandial glycaemia and lipaemia and cholesterol profile 6 months postoperatively in non-diabetic, severely obese patients. These findings imply procedure-specific effects, such as the malabsorptive nature of RYGB, and less likely a different incretin postoperative response.