Postprandial State Research Articles

A Standardized Protocol for Measuring Bioelectrical Impedance in Green Turtles (Chelonia mydas).

AbstractBioelectrical impedance analysis (BIA) is gaining popularity in wildlife studies as a portable technology for immediate and nondestructive predictions of body composition components, such as fat-free and fat masses. Successful application of BIA for field-based research requires the identification and control of potential sources of error, as well as the creation of and adherence to a standardized protocol for measurement. The aim of our study was to determine sources of error and to provide a standardization protocol to improve measurement precision of BIA on juvenile green turtles (Chelonia mydas; ). We assessed the effects of altered environmental temperature (20°C-30°C), postprandial state (2-72 h), and time out of the water (2 h) on five impedance parameters (resistance at infinite frequency [Rinf], resistance at zero frequency [R0], resistance at 50 kHz [R50], phase angle at 50 kHz [PhA50], and intracellular resistance [Ri]) using a bioimpedance spectroscopy device. Technical reproducibility of measurements and interanimal variability were also assessed. We found an inverse exponential relationship between change in environmental temperature and impedance parameters Rinf, R0, and R50. Postprandial state significantly increased Rinf and Ri 72 h after feeding. BIA measurements were reproducible within individual juvenile green turtles at temperatures from 20°C to 30°C. Significant variation in impedance values was found between animals at all temperatures, sampling times, and postprandial states, but the relative differences (%) were small in magnitude. Our study suggests that measurement precision is improved by measuring animals at consistent environmental temperatures close to their preferred thermal range. We propose a standardized protocol of measurement conditions to facilitate laboratory and field use of BIA for body composition assessment studies in turtles.

Relationship between psychological stress and ghrelin concentrations in pregnant women with overweight or obesity

Exposure to, perception of, and response to stress have all been shown to influence appetite and dietary behaviors in non-pregnancy human and animal studies, mediated in part by the appetite stimulating hormone ghrelin. Yet, the impact of prenatal stress on biological pathways associated with appetite in the context of pregnancy is not well understood. The objective of this study was to assess the relationship between these layered dimensions of stress with fasting and postprandial plasma ghrelin concentrations among Hispanic pregnant women with overweight or obesity, a population known to experience heightened levels of stress. Thirty-three non-diabetic Hispanic women with pre-pregnancy body mass index of 25.0–34.9 kg/m2 participated in a crossover study at 28–32 weeks’ gestation. At each visit, participants provided fasting blood and saliva samples, consumed a standardized mixed-meal, and completed a 15-minute task: friendly conversation (control) or the Trier Social Stress Test (experimental stress exposure). Six timed blood and saliva samples were collected up to 2 h from baseline and assayed for ghrelin and cortisol, respectively, and area-under-the-curve (AUC) values were computed. Day-to-day stress levels were assessed by the Perceived Stress Scale. Physiological and psychological stress reactivity was determined by cortisol AUC and change in self-reported affect state, respectively, during the experimental stress visit. Maternal perceived stress was positively associated with ghrelin concentrations in the fasted (β = 0.06, p = 0.02) and postprandial state (β = 0.05, p = 0.02). Mean ghrelin AUC was not significantly different following acute stress versus control. Measures of acute stress reactivity were not associated with ghrelin AUC. Contrary to our hypothesis, among Hispanic pregnant women with overweight and obesity, exposure to an acute stress induction task did not alter postprandial ghrelin concentrations, and changes in individual psychological and physiological stress reactivity did not associate with postprandial ghrelin. However, our findings suggest that maternal report of general perceived stress over the last month is associated with higher fasting and postprandial ghrelin concentrations. Differences in the effects of short-term stress exposure versus day-to-day perception of stress on appetite and food intake in pregnancy deserves further investigation.

Monocyte subsets display age-dependent alterations at fasting and undergo non-age-dependent changes following consumption of a meal

BackgroundMonocytes are a heterogenous population of immune cells whose subsets and functions become substantially dysregulated with advanced age. Although much of our current understanding of the age-related changes in monocytes is derived from fasting blood samples, most people are predominately in the postprandial state during waking hours. As hormonal, metabolic, and immunological changes in response to the consumption of a meal are manifested in postprandial blood, it’s unclear how age-dependent changes in peripheral monocytes at fasting are impacted by a dietary challenge.ObjectiveWe investigated the impact of age and meal consumption on circulating monocyte frequencies and subsets defined as classical (CD14 + CD16-), intermediate (CD14 + CD16 +), or non-classical (CD14dim CD16 +) in a cohort of 349 healthy adult volunteers grouped into categories based on their age: young adults (18–33 y, n = 123), middle adults (34–49 y, n = 115), and older adults (50–66 y, n = 111).ResultsFollowing 12-h fast total monocyte counts inversely correlated with subject age. Older adults had significantly fewer circulating monocytes along with elevated levels of TGs, cholesterol, glucose, IL-6, IL-8, TNF, neopterin, and CCL2 compared with young adults. Circulating monocyte pools in older adults consisted of smaller proportions of classical but larger proportions of intermediate and non-classical monocytes. Proportions of classical monocytes were inversely correlated with plasma TNF, IL-8, and neopterin while intermediate monocytes were positively correlated with plasma IL-6, TNF, and neopterin. Three hours after consuming a fat-containing meal postprandial monocyte counts increased in all age groups. Despite age-dependent differences in monocyte subsets at fasting, consumption of a meal induced similar changes in the proportions of classical and non-classical monocytes across age groups. Within the circulating postprandial monocyte pool, percentages of classical monocytes decreased while non-classical monocytes increased. However no change in precursory intermediate monocytes were detected. Our study confirms that ageing is associated with changes in monocyte frequencies and subsets and shows that consuming a fat-containing meal induces temporal changes in monocyte frequency and subsets independently of subject age.Clinical trialRegistered on ClincialTrials.gov (Identifier: NCT02367287)

The vagus nerve mediates the stomach-brain coherence in rats

Interactions between the brain and the stomach shape both cognitive and digestive functions. Recent human studies report spontaneous synchronization between brain activity and gastric slow waves in the resting state. However, this finding has not been replicated in any animal models. The neural pathways underlying this apparent stomach-brain synchrony is also unclear. Here, we performed functional magnetic resonance imaging while simultaneously recording body-surface gastric slow waves from anesthetized rats in the fasted vs. postprandial conditions and performed a bilateral cervical vagotomy to assess the role of the vagus nerve. The coherence between brain fMRI signals and gastric slow waves was found in a distributed “gastric network”, including subcortical and cortical regions in the sensory, motor, and limbic systems. The stomach-brain coherence was largely reduced by the bilateral vagotomy and was different between the fasted and fed states. These findings suggest that the vagus nerve mediates the spontaneous coherence between brain activity and gastric slow waves, which is likely a signature of real-time stomach-brain interactions. However, its functional significance remains to be established.

Role of liver AMPK and GCN2 kinases in the control of postprandial protein metabolism in response to mid-term high or low protein intake in mice.

Protein synthesis and proteolysis are known to be controlled through mammalian target of rapamycin, AMP-activated kinase (AMPK) and general control non-derepressible 2 (GCN2) pathways, depending on the nutritional condition. This study aimed at investigating the contribution of liver AMPK and GCN2 on the adaptation to high variations in protein intake. To evaluate the answer of protein pathways to high- or low-protein diet, male wild-type mice and genetically modified mice from C57BL/6 background with liver-specific AMPK- or GCN2-knockout were fed from day 25 diets differing in their protein level as energy: LP (5%), NP (14%) and HP (54%). Two hours after a 1g test meal, protein synthesis rate was measured after a 13C valine flooding dose. The gene expression of key enzymes involved in proteolysis and GNC2 signaling pathway were quantified. The HP diet but not the LP diet was associated with a decrease in fractional synthesis rate by 29% in the liver compared to NP diet. The expression of mRNA encoding ubiquitin and Cathepsin D was not sensitive to the protein content. The deletion of AMPK or GCN2 in the liver did not affect nor protein synthesis rates and neither proteolysis markers in the liver or in the muscle, whatever the protein intake. In the postprandial state, protein level alters protein synthesis in the liver but not in the muscle. Taken together, these results suggest that liver AMPK and GCN2 are not involved in this adaptation to high- and low-protein diet observed in the postprandial period.

Global landscape of protein complexes in postprandial-state livers from diet-induced obese and lean mice

Obesity is associated with a spectrum of nonalcoholic fatty liver disease (NAFLD) which is characterized by steatosis. Prolonged fat deposition aggravates liver dysfunctions leading to an advanced form of NAFLD such as steatohepatitis and cirrhosis. As liver function in the postprandial state is critical for macronutrient metabolism and energy homeostasis, we sought to determine the differences in protein complex profiles in lean and fatty livers in the postprandial state. Protein complex profiling is of interest as proteins often do not function alone and the information on the interactions may reveal novel etiology of NAFLD, which is currently limited compared with proteome profiles or RNA-sequencing profiles. To this end, we fractionated liver lysates using size-exclusion chromatography (SEC) and analyzed each fraction using untargeted LC-MS/MS. We identified 1172 proteins that were discovered in lean and fatty livers, and their elution profiles were compared. We found that the majority of liver proteins were present as putative complexes. Also, the fatty liver protein elution profile showed great conservations as lean liver despite the metabolic disease state. Yet, we discovered a few proteins that showed different elution patterns in the fatty liver, including Acadm, Aldh1a7, Aldh1a1, Akr1a1, Eif3l, Fkbp2, G6pdx, Gm20441, Hao1, Pcna, Pkm, Ppif, Prdx4, Stmn1, Tagln, Tubb4b, Ubqln2, and Usp14, which may be involved in high fat diet-induced alterations of protein oligomerization and hepatic functions. Overall, our protein complex profiling could expand our understanding of hepatic abnormalities that cannot be uncovered by simple quantitation of protein expression.

Blood Lipid Responses to Diets Enriched with Cottonseed Oil Compared with Olive Oil in Adults with High Cholesterol in a Randomized Trial

BackgroundIncreasing unsaturated fat intake is beneficial for cardiovascular health, but the type of unsaturated fat to recommend remains equivocal. ObjectivesWe investigated the effects of an 8-week diet intervention that was rich in either cottonseed oil (CSO; PUFA rich) or olive oil (OO; MUFA rich) on blood lipids in hypercholesterolemic adults. MethodsForty-three men and women with hypercholesterolemia (53 ± 10 years; BMI, 27.6 ± 4.8 kg/m2) completed this randomized parallel clinical trial consisting of an 8-week partial outpatient feeding intervention. Participants were given meals and snacks accounting for ∼60% of their daily energy needs, with 30% of energy needs from either CSO (n = 21) or OO (n = 22). At pre- and postdiet intervention visits, participants consumed a high-SFA meal (35% of total energy needs; 70% of energy from fat). The primary outcomes of fasting cholesterol profiles and secondary outcomes of postprandial blood lipids and glycemic markers were assessed over a 5-hour period. ResultsThere were greater reductions from baseline to week 8 in fasting serum total cholesterol (TC; −17.0 ± 3.94 mg/dL compared with −2.18 ± 3.72 mg/dL, respectively; P = 0.008), LDL cholesterol (−19.7 ± 3.94 mg/dL compared with −5.72 ± 4.23 mg/dL, respectively; P = 0.018), non–HDL cholesterol (−20.8 mg/dL ± 4.00 compared with −6.61 ± 4.01 mg/dL, respectively; P = 0.014), and apoB (−11.8 mg/dL ± 2.37 compared with −3.10 ± 2.99 mg/dL, respectively; P = 0.05), in CSO compared with OO. There were also visit effects from baseline to week 8 for increases in HDL cholesterol (CSO, 56.5 ± 2.79 mg/dL to 60.2 ± 3.35 mg/dL, respectively; OO: 59.7 ± 2.63 mg/dL to 64.1 ± 2.24 mg/dL, respectively; P < 0.001), and decreases in the TC:HDL-cholesterol ratio (CSO, 4.30 ± 0.27 mg/dL to 3.78 ± 0.27 mg/dL, respectively; OO, 3.94 ± 0.16 mg/dL to 3.57 ± 0.11 mg/dL, respectively; P < 0.001), regardless of group assignment. In response to the high-SFA meal, there were differences in postprandial plasma glucose (P = 0.003) and triglyceride (P = 0.004) responses and a trend in nonesterified fatty acids (P = 0.11) between groups, showing protection in the postprandial state from an occasional high-SFA fat meal with CSO, but not OO, diet enrichment. ConclusionsCSO, but not OO, diet enrichment caused substantial improvements in fasting and postprandial blood lipids and postprandial glycemia in hypercholesterolemic adults. This trial was registered at clinicaltrials.gov as NCT04397055.

The Role and Regulatory Mechanism of Brown Adipose Tissue Activation in Diet-Induced Thermogenesis in Health and Diseases

Brown adipose tissue (BAT) has been considered a vital organ in response to non-shivering adaptive thermogenesis, which could be activated during cold exposure through the sympathetic nervous system (SNS) or under postprandial conditions contributing to diet-induced thermogenesis (DIT). Humans prefer to live within their thermal comfort or neutral zone with minimal energy expenditure created by wearing clothing, making shelters, or using an air conditioner to regulate their ambient temperature; thereby, DIT would become an important mechanism to counter-regulate energy intake and lipid accumulation. In addition, there has been a long interest in the intriguing possibility that a defect in DIT predisposes one to obesity and other metabolic diseases. Due to the recent advances in methodology to evaluate the functional activity of BAT and DIT, this updated review will focus on the role and regulatory mechanism of BAT biology in DIT in health and diseases and whether these mechanisms are applicable to humans.

The accuracy of four formulas for LDL-C calculation at the fasting and postprandial states.

BackgroundElevated level of low-density lipoprotein cholesterol (LDL-C) is concerned as one of the main risk factors for cardiovascular disease, in both the fasting and postprandial states. This study aimed to compare the measured LDL-C with LDL-C calculated by the Friedewald, Martin–Hopkins, Vujovic, and Sampson formulas, and establish which formula could provide the most reliable LDL-C results for Chinese subjects, especially at the postprandial state.MethodsTwenty-six subjects were enrolled in this study. The blood samples were collected from all the subjects before and after taking a daily breakfast. The calculated LDL-C results were compared with LDL-C measured by the vertical auto profile method, at both the fasting and postprandial states. The percentage difference between calculated and measured LDL-C (total error) and the number of results exceeding the total error goal of 12% were established.ResultsThe calculated LDL-CF levels showed no significant difference from LDL-CVAP levels at the fasting state. The calculated LDL-CS were significantly higher than LDL-CVAP at the fasting state (P < 0.05), while the calculated LDL-Cs were very close to LDL-CVAP levels after a daily meal. At the fasting state, the median total error of calculated LDL-CF was 0 (quartile: −3.8 to 6.0), followed by LDL-CS, LDL-CMH, and LDL-CV. At the postprandial states, the median total errors of LDL-CS were the smallest, 1.0 (−7.5, 8.5) and −0.3 (−10.1, 10.9) at 2 and 4 h, respectively. The calculated LDL-CF levels showed the highest correlation to LDL-CVAP and accuracy in evaluating fasting LDL-C levels, while the Sampson formula showed the highest accuracy at the postprandial state.ConclusionThe Friedewald formula was recommended to calculate fasting LDL-C, while the Sampson formula seemed to be a better choice to calculate postprandial LDL-C levels in Chinese subjects.

Modulation of 1,2-Dicarbonyl Compounds in Postprandial Responses Mediated by Food Bioactive Components and Mediterranean Diet.

Glycoxidative stress with the consequent generation of advanced glycation end products has been implied in the etiology of numerous non-communicable chronic diseases. During the postprandial state, the levels of 1,2-dicarbonyl compounds can increase, depending on numerous factors, including characteristics of the subjects mainly related to glucose metabolism disorders and nutritional status, as well as properties related to the chemical composition of meals, including macronutrient composition and the presence of dietary bioactive molecules and macromolecules. In this review, we examine the chemical, biochemical, and physiological pathways that contribute to postprandial generation of 1,2-dicarbonyl compounds. The modulation of postprandial 1,2-dicarbonyl compounds is discussed in terms of biochemical pathways regulating the levels of these compounds, as well as the effect of phenolic compounds, dietary fiber, and dietary patterns, such as Mediterranean and Western diets.

Response of lipoproteins to a meal tolerance test in patients with type 2 diabetes and hypertriglyceridemia

Background and Aims : High fasting TG is a marker of increased postprandial TG-rich lipoproteins and their remnants. Non-fasting TG is said to be 20-25% higher than fasting TG. It remains unclear what determines the non-fasting lipid profile. The aim of this study was to examine lipid parameters in fasting and postprandial states and to explore their relationship in patients with type 2 diabetes (T2D) and hypertriglyceridemia.Methods: This was a post-hoc analysis of a pemafibrate phase 3 clinical trial in Japanese patients with T2D and hypertriglyceridemia who underwent a meal tolerance test (N=68). Baseline data before starting the study drug were analyzed. The blood sampling was conducted at 0, 1, 2, 4.5 and 6.5 h after taking the test meal (592 kcal).Results: After taking the test meal, TG increased from 256.8 mg/dL (0 h) to 274.8 mg/dL (1 h, +11.0%), 330.8 mg/dL (2 h, +36.3%), 341.8 mg/dL (4.5 h, +42.1%) and 285.8 mg/dL (6.5 h, +19.7%). The postprandial apoB48 time course was similar to that of TG, whereas the increase in RemL-C was slower. AUC0-6.5h-TG and AUC0-6.5h-RemL-C were significantly associated with baseline values for TG, RemL-C, apoB48, apoC2, apoC3 and apoE.Conclusions: In patients with T2D and hypertriglyceridemia, plasma TG levels increased up to approximately 1.5-fold after taking the test meal. Postprandial TG and RemL-C increases can be predictable from the baseline values for TG, RemL-C, apoB48, apoC2, apoC3 and apoE. Background and Aims : High fasting TG is a marker of increased postprandial TG-rich lipoproteins and their remnants. Non-fasting TG is said to be 20-25% higher than fasting TG. It remains unclear what determines the non-fasting lipid profile. The aim of this study was to examine lipid parameters in fasting and postprandial states and to explore their relationship in patients with type 2 diabetes (T2D) and hypertriglyceridemia. Methods: This was a post-hoc analysis of a pemafibrate phase 3 clinical trial in Japanese patients with T2D and hypertriglyceridemia who underwent a meal tolerance test (N=68). Baseline data before starting the study drug were analyzed. The blood sampling was conducted at 0, 1, 2, 4.5 and 6.5 h after taking the test meal (592 kcal). Results: After taking the test meal, TG increased from 256.8 mg/dL (0 h) to 274.8 mg/dL (1 h, +11.0%), 330.8 mg/dL (2 h, +36.3%), 341.8 mg/dL (4.5 h, +42.1%) and 285.8 mg/dL (6.5 h, +19.7%). The postprandial apoB48 time course was similar to that of TG, whereas the increase in RemL-C was slower. AUC0-6.5h-TG and AUC0-6.5h-RemL-C were significantly associated with baseline values for TG, RemL-C, apoB48, apoC2, apoC3 and apoE. Conclusions: In patients with T2D and hypertriglyceridemia, plasma TG levels increased up to approximately 1.5-fold after taking the test meal. Postprandial TG and RemL-C increases can be predictable from the baseline values for TG, RemL-C, apoB48, apoC2, apoC3 and apoE.

Methodological considerations for circulating long noncoding RNA quantification.

In the past decade, significant resources have been invested in long noncoding RNA (lncRNA) research. Despite the knowledge available, we are far from incorporation of lncRNA into clinical practice. Here, we emphasize the technical challenges in the field, hoping to provoke a response leading to new consensus and guidelines.

Identification of Intestinal NaCl Absorptive-Anion Secretory Cells: Potential Functional Significance.

Use of human enteroids studied in the undifferentiated and differentiated state that mimic the intestinal crypt and villus, respectively, has allowed studies of multiple enterocyte populations, including a large population of enterocytes that are transitioning from the crypt to the villus. This population expresses NHE3, DRA, and CFTR, representing a combination of Na absorptive and anion secretory functions. In this cell population, these three transporters physically interact, which affects their baseline and regulated activities. A study of this cell population and differentiated Caco-2 cells transduced with NHE3 and endogenously expressing DRA and CFTR has allowed an understanding of previous studies in which cAMP seemed to stimulate and inhibit DRA at the same time. Understanding the contributions of these cells to overall intestinal transport function as part of the fasting and post-prandial state and their contribution to the pathophysiology of diarrheal diseases and some conditions with constipation will allow new approaches to drug development.

A meal rich in palm oil or butter modifies the sphingolipid profile of postprandial triglyceride-rich lipoproteins from type 2 diabetic women

Elevated concentrations of triglyceride-rich lipoproteins (TGRL) in the fasting and postprandial states are risk factors for cardiovascular events, especially in type 2 diabetes (T2D). T2D modifies the lipid composition of plasma and lipoproteins and some sphingolipids (SP) have been validated as potent predictive biomarkers of cardiovascular disease occurrence. The main objectives of the present study were to characterize the plasma SP profile in fasting T2D patients and to determine whether SP are modified in postprandial TGRL from these patients compared to fasting TGRL. In a randomized parallel-group study, 30 T2D women ingested a breakfast including 20g lipids from either hazelnut cocoa palm oil-rich spread (Palm Nut) or Butter. Plasma was collected and TGRL were isolated by ultracentrifugation at fasting and 4h after the meal. Fasting samples of 6 control subjects from another cohort were analyzed for comparison. SP were analyzed by tandem mass spectrometry. Plasma from fasting T2D patients had higher ceramide (Cer) and ganglioside GM3 concentrations, and lower concentrations of sphingosylphosphorylcholine vs healthy subjects. In postprandial TGRL from T2D patients compared to those in the fasting state, Cer concentrations and especially C16:0, C24:1 and C24:0 molecular species, increased after the Palm Nut or Butter breakfast. A positive correlation was observed in the Palm Nut group between changes (Δ4h-fasting) of summed C16:0+C22:0+C24:1+C24:0 Cer concentrations in TGRL, and changes in plasma TG, TGRL-TG and TGRL-C16:0 concentrations. Altogether in T2D, the altered profile of plasma SP and the increased Cer concentrations in postprandial TGRL could contribute to the increased atherogenicity of TGRL.

The Effect of Acute Intermittent and Continuous Hypoxia on Plasma Circulating ßOHB Levels Under Different Feeding Statuses in Humans.

Introduction: Acute hypoxia is known to increase circulating nonesterified fatty acid (NEFA) levels. Adipose tissue lipolysis is a major source of NEFA into circulation and insulin suppresses this process when the tissue is insulin sensitive. NEFA can be esterified to triglycerides and/or completely/partially oxidized, the latter leading to ketogenesis in the liver. To our knowledge, the effect of hypoxia on ketogenesis, more specifically ß-hydroxybutyrate (ßOHB) levels, remains unknown in humans. Therefore, the objective of this study was to determine the effect of acute intermittent and continuous hypoxia on circulating ßOHB levels under different feeding status. Methods: Plasma samples from three different randomized crossover studies were assessed for ßOHB concentrations. In the first study, 14 healthy men (23 ± 3.5 years) were exposed to 6 h of normoxia or intermittent hypoxia (IH-Fed) (15 hypoxic events/hour) following an isocaloric meal. In the second study, 10 healthy men (26 ± 5.6 years) were exposed to 6 h of continuous normobaric hypoxia (CH-Fasted) (FiO2 = 0.12) or normoxia in the fasting state. In the third study (CH-Fed), 9 healthy men (24 ± 4.5 years) were exposed to 6 h of normoxia or CH in a constant prandial state. ßOHB, NEFA and insulin levels were measured during all sessions. Results: In the IH-Fed study, ßOHB and NEFA levels tended to be greater over 6 h of IH (condition × time interaction, ßOHB p = 0.108 and NEFA p = 0.062) compared to normoxia. In the CH-Fasted study, ßOHB and NEFA levels increased over time in both experimental conditions, this effect being greater under CH (condition × time interaction, ßOHB p = 0.070; NEFA p = 0.046). In the CH-Fed study, ßOHB levels slightly increased up to 180 min before falling back to initial concentrations by the end of the protocol in both normoxia and CH (main effect of time, p = 0.062), while NEFA were significantly higher under CH (p = 0.006). Conclusion: Acute normobaric hypoxia exposure tends to increase plasma ßOHB concentrations over time in healthy men. The stimulating effect of hypoxia on plasma ßOHB levels is however attenuated during postprandial and prandial states.

Oral fat tolerance testing identifies abnormal pancreatic β-cell function and insulin resistance in individuals with normal glucose tolerance.

Insulin sensitivity and β-cell function are affected by lipid metabolism disorders, even before the onset of type 2 diabetes. People are in the postprandial state most of the time. Therefore, identifying postprandial hyperlipemia is important. This study aimed to assess patients with abnormalities in lipid metabolism, but with normal glucose tolerance, using oral fat tolerance testing (OFTT) to identify defects in insulin sensitivity and β-cell function. We included 248 volunteers with normal glucose tolerance who underwent OFTT. They were divided into three groups in accordance with their fasting and 4-h postprandial triglyceride (TG) concentrations. Their lipid concentrations during OFTT were compared. The disposition index (DI) was applied to estimate β-cell function, and the Matsuda insulin sensitivity index (ISIM ) was used to assess insulin sensitivity. We used multiple linear regression analysis to estimate the relationships of fasting and postprandial TG concentrations with β-cell function and insulin sensitivity . The changes in TG concentrations during OFTT were more marked than those in low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol or total cholesterol concentrations. As lipid metabolism deteriorated, the ISIM and the DI gradually decreased. Multiple linear regression analysis showed that fasting and 4-h postprandial TG concentrations affected LnISIM and LnDI. In individuals with normal glucose tolerance, β-cell function and insulin sensitivity gradually decrease with a deterioration in the lipid profile. Not only fasting TG, but also postprandial TG concentrations are independent risk factors for impaired β-cell function and insulin resistance.

A Gene Variation at the ZPR1 Locus (rs964184) Interacts With the Type of Diet to Modulate Postprandial Triglycerides in Patients With Coronary Artery Disease: From the Coronary Diet Intervention With Olive Oil and Cardiovascular Prevention Study.

Background and Aimsrs964184 variant in the ZPR1 gene has been associated with blood lipids levels both in fasting and postprandial state and with the risk of myocardial infarction in high-risk cardiovascular patients. However, whether this association is modulated by diet has not been studied.ObjectiveTo investigate whether the type of diet (low-fat or Mediterranean diets) interacts with genetic variability at this loci to modulate fasting and postprandial lipids in coronary patients.Materials and MethodsThe genotype of the rs964184 polymorphism was determined in the Cordioprev Study population (NCT00924937). Fasting and Postprandial triglycerides were assessed before and after 3 years of dietary intervention with either a Mediterranean or a low-fat diet. Postprandial lipid assessment was done by a 4-h oral fat tolerance test (OFTT). Differences in triglycerides levels were identified using repeated-measures ANCOVA.ResultsFrom 523 patients (85% males, mean age 59 years) that completed the OFTT at baseline and after 3 years of intervention and had complete genotype information, 125 of them were carriers of the risk allele G. At the start of the study, these patients showed a higher fasting and postprandial triglycerides (TG) plasma levels. After 3 years of dietary intervention, G-carriers following a Mediterranean Diet maintained higher fasting and postprandial triglycerides, while those on the low-fat diet reduced their postprandial triglycerides to similar values to the population without the G-allele.ConclusionAfter 3 years of dietary intervention, the altered postprandial triglyceride response induced by genetic variability in the rs964184 polymorphism of the ZPR1 gene can be modulated by a low-fat diet, better than by a Mediterranean diet, in patients with coronary artery disease.

Maternal Chronic Perceived Stress, but Not Acute Stress Exposure, Is Associated With Ghrelin Levels Among Hispanic Pregnant Women With Overweight or Obesity

ObjectivesThe aim of this study is to test the effects of maternal chronic and acute psychological stress on plasma ghrelin levels among pregnant women with overweight or obesity.MethodsN = 33 Hispanic women without diabetes and a pre-pregnancy BMI of 25.0–34.9 Kg/m2 participated in a crossover study at 28–32 weeks’ gestation. Perceived stress levels over the past month were assessed by the Perceived Stress Scale. Women attended the lab in the fasted state on two separate days and consumed a breakfast shake immediately after a fasting blood and saliva sample collection on each visit, followed by a 15 minute task: friendly conversation (control) on visit 1 or the standardized Trier Social Stress Test on visit 2 to elicit acute stress. Six postprandial blood and saliva samples were collected at intervals up to 2 hours post-prandial and assayed for ghrelin and cortisol, respectively. The area-under-the-curve (AUC) for ghrelin and cortisol were computed. Differences in ghrelin AUC between visits were compared by paired t-tests and repeated measures ANOVA adjusting for gestational age at visit 2. Associations between perceived stress scores with fasting and ghrelin AUC, and between cortisol AUC and ghrelin AUC following acute stress exposure were analyzed by linear regression, adjusting for gestational age.ResultsPerceived stress score was positively associated with ghrelin levels both in the fasted (beta = 0.06, p = 0.02, 95% CI = 0.01, 0.12) and postprandial state (beta = 0.05, p = 0.02, 95% CI = 0.01, 0.09), which remained significant after adjusting for gestational age. Mean ghrelin AUC following a meal was lower after acute stress compared to the control condition (10.19 ± 0.37 vs 10.24 ± 0.40, p = 0.03), but this difference was not significant after adjusting for gestational age (p = 0.59). Salivary cortisol reactivity to acute stress was also not associated with ghrelin AUC (beta = −0.02, p = 0.92, 95% CI = −0.38, 0.35).ConclusionsChronic perceived stress in pregnant women with overweight and obesity may contribute to higher ghrelin levels both in the fasted state and after consuming a meal. Postprandial ghrelin is not affected by acute stress exposure in this population of women in the third trimester of pregnancy.Funding SourcesNational Institute of Child Health and Human Development.

Effects of the Type and Emulsification of Oil on Postprandial Appetite Responses in Healthy Young Adults

ObjectivesPrevious studies revealed that consuming different types of oil or the same type of oil but whether being emulsified could result in a different subsequent food intake. While these results suggest that different types of oils or emulsification could affect appetite control, very limited data exist. Therefore, this study aimed to investigate the impact of type and emulsification of oil on postprandial appetite responses.MethodsThis is a randomized, controlled, double-blinded crossover study and 16 healthy males and females aged between 21 and 29 participated in the study. All participants consumed a high-fat isocaloric breakfast meal containing 29 g of one of the following four oil: i) olive oil-water non-emulsified; ii) olive oil-water emulsified; (iv) coconut oil-water non-emulsified, v) coconut oil-water emulsified. Five hours after the test breakfast meal, subjects received a standard low-fat lunch. Six appetites components including hunger, desire to eat, prospective consumption, fullness, nausea and bloating were evaluated over a 10-hour postprandial duration by using visual analogue scales (VAS). The net incremental area under the curve (iAUC) of appetite VAS was calculated by the trapezoidal method.ResultsThe iAUC value (mean ± SE) of hunger VAS was higher with the oil emulsified group (-512.2 ± 137.4) than the oil non-emulsified group (-785.4 ± 132.9) over a 5-hour postprandial period (P < 0.05), but the difference became insignificant over a 10-hour postprandial period. On the other hand, the coconut oil group resulted in higher fullness VAS than the olive oil group (P < 0.05), for both iAUC0-5 hour (coconut oil: 813.3 ± 146.0; olive oil: 575.4 ± 139.8) and iAUC0-10 hour values (coconut oil: 1,785.9 ± 311.3; olive oil: 1,368.5 ± 306.3). There is no interaction effect of the emulsification and the type of oil on all the six subjective appetites VAS during the postprandial state.ConclusionsThe type and emulsification of oil in a high-fat meal could cause differential appetite responses over a certain postprandial duration. Physiological measures, such as appetite-regulating hormones, energy expenditure and substrate oxidation rates, are necessary to elucidate the differences in subjective appetite responses in future studies.Funding SourcesNational University of Singapore and Agency for Science, Technology and Research, Industry Alignment.

A Meal Rich in Palm Oil or Butter Modifies the Sphingolipid Profile of Postprandial Triglyceride-Rich Lipoproteins From Type 2 Diabetic Patients

ObjectivesElevated concentrations of triglyceride-rich lipoproteins (TGRL) in the fasting and postprandial states are a risk factor for cardiovascular events in type 2 diabetes (T2D). Dyslipidemia in T2D is associated with modifications in the lipidome of plasma lipoproteins and some plasma sphingolipids (SP) have been validated as potent predictive biomarkers of cardiovascular disease occurrence. The objective of our clinical study was to determine whether sphingolipids (SP) are modified in postprandial triglyceride-rich lipoproteins (TGRL) from type 2 diabetic (T2D) patients as compared to fasting TGRL, following a saturated fatty meal. MethodsIn a randomized parallel-group study, 30 T2D women ingested a breakfast including 20 g lipids from either hazelnut cocoa palm oil-rich spread (Palm Nut) or butter. TGRL were isolated by ultracentrifugation at fasting and 4 hours after the ingested meal. SP classes and SP molecular species were analyzed by tandem mass spectrometry. ResultsCompared with plasma from healthy subjects, plasma from fasting T2D patients had higher ceramide (Cer, +34%) and ganglioside (GM3, +28%) concentrations, and lower concentrations of sphingosylphosphorylcholine (-66%). In postprandial TGRL compared to fasting TGRL from T2D patients, total Cer concentrations and especially C16:0, C24:1 and C24:0 molecular species, increased after the Palm Nut (+45%) or Butter (+40%) breakfast. A positive correlation was observed in the Palm Nut group between changes (D 4 h postprandial-fasting) of summed C16:0 + C22:0 + C24:1 + C24:0 Cer concentrations in TGRL, and changes in plasma TG, TGRL TG as well as TGRL C16:0 concentrations. ConclusionsThe ingestion of a single fat-rich meal from a vegetable or dairy source by T2D patients led to increased concentrations of Cer in postprandial TGRL and could contribute to the increased atherogenicity of TGRL in T2D. Funding SourcesThis work was supported by Inserm.