Postprandial Changes Research Articles

Postprandial hepatic stiffness changes on magnetic resonance elastography in healthy volunteers

Magnetic resonance elastography (MRE) is a reliable noninvasive method for assessment of hepatic stiffness. Liver stiffness is known to be affected by elevated postprandial portal blood flow in patients with chronic liver disease. The goal of this study was to determine whether food intake affects liver stiffness in the absence of known liver disease. We evaluated 100 volunteers (35 men and 65 women) who met inclusion criteria. The subjects had two MRE examinations, first while fasting and then 30 min after a test meal. Fourteen subjects also had two additional MRE exams 1 h 30 min and 2 h 30 min after the meal. Liver stiffness was measured by placing the largest possible polygon ROIs on the four widest liver slices and calculated as a mean of stiffness values from each slice. The correlation of liver stiffness values before and after the meal was assessed using a paired t-test. To evaluate the relationship between the change in postprandial liver stiffness and fasting liver stiffness values, linear regression was performed. The liver stiffness values in the fasting state ranged from 1.84 to 2.82 kPa, with a mean of 2.30 ± 0.23 kPa (95% CI 2.25–2.34). At 30 min after the meal, liver stiffness values ranged from 2.12 to 3.50 kPa, with a mean of 2.70 ± 0.28 kPa (95% CI 2.64–2.75), demonstrating a systematic postprandial increase by 0.40 ± 0.23 kPa (17.7 ± 3.5%). Meal intake significantly increases liver stiffness in healthy individuals, which persists for at least 2 h 30 min. Patients should fast for 3–4 h before MRE examinations to avoid fibrosis overstaging due to postprandial liver stiffness augmentation.

Acute Toxicity Study and Antidiabetic Activity of Marine Alga-Halimeda Gracilis Chooranam (HGC) In Freshwater Zebrafish Model

Purpose: The study aimed to assess the acute toxicity and anti-diabetic activity of Halimedagracilis (green marine alga). Methods: The Halimedagraciliswere collected from the coastal area of the Gulf of Mannar biosphere reserve and shade dried. Methanolic extract of Halimedagracilis (MEHG) was prepared and it was screened for acute toxicity and anti-diabetic activity in the Zebrafish model. In the Acute toxicity study, the Zebrafishes were grouped into 6 groups and dosed with 6.25, 12.5, 25, 50, and 100mg/L of MEHG and observed at 0, 24, 48, 72, and 96 hours’ intervals. Foranti-diabetic activity analysis diabetes was induced using streptozotocin (STZ). The Zebrafish were divided into six groups- control group, positive control, diabetic Zebrafish with three doses of MEHG, and standard control (treated with metformin). Results: Acute toxicity studyshowed no significant behavioral changes and LC50 was determined as 100mg/L. In the diabetic study, test groups when compared to the control group showed: a significant reduction in both fasting and postprandial blood glucose levels and significant changes in the regeneration of pancreatic β-cells, and reduced vacuolization in the islets of Langerhans. Images of the regenerating caudal fins taken at 24, 48 and 72-hours post-amputation displayed significant limb regeneration in MEHG treated fish compared to the control group. Conclusion: These results prove that MEHG in STZ- induced diabetic Zebrafish possess potent anti-diabetic action by ameliorating blood glucose regulation, promoting pancreatic cell regeneration,minimizing long-term diabetic complications bypreventing the emergence of metabolic memory but no behavioral changes.

Fortifying a meal with oyster mushroom powder beneficially affects postprandial glucagon-like peptide-1, non-esterified free fatty acids and hunger sensation in adults with impaired glucose tolerance: a double-blind randomized controlled crossover trial

PurposeImpaired glucose tolerance (IGT) is a pathophysiological condition characterized by insulin resistance with known metabolic consequences such as postprandial hyperglycemia and hypertriglyceridemia. We hypothesized that fortifying a meal with mushrooms rich in β-glucans may diminish glucose and triglyceride responses by improving postprandial gastrointestinal hormone release.MethodsIn a randomized controlled crossover study, 22 subjects with IGT ingested a meal either enriched with 20 g powder (8.1 g β-glucans) of oven-dried Pleurotus ostreatus (enriched meal, EN) or without enrichment (control meal, CON). Blood was collected before and repeatedly within 4 h after the meal to determine AUC of glucose (primary outcome), insulin, triglycerides, non-esterified free fatty acids (NEFAs), glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP) and ghrelin. Appetite sensations (hunger, satiety, fullness, and desire to eat) were assessed before and after meal consumption by visual analog scales.ResultsPostprandial glucose, insulin, triglycerides, GIP and ghrelin concentrations as well as the corresponding AUCs did not differ between EN and CON. NEFAs-AUC was 14% lower (P = 0.026) and GLP-1-AUC 17% higher (P = 0.001) after EN compared to CON. Appetite ratings did not differ between treatments, except for hunger (AUC 22% lower after EN vs. CON; P = 0.031).ConclusionThe observed immediate postprandial metabolic changes indicate that an easily manageable fortification of a single meal with powder from dried oyster mushrooms as β-glucan source may improve postprandial metabolism. If the effect is preserved long term, this measure can diminish the risk for further development of overweight/obesity and type 2 diabetes in subjects with IGT.Clinical trial registrationGerman Clinical Trial Register on 09/08/2018; trial-ID: DRKS00015244.

Meal-induced inflammation: postprandial insights from the Personalised REsponses to DIetary Composition Trial (PREDICT) study in 1000 participants

ABSTRACTBackgroundMeal-induced metabolic changes trigger an acute inflammatory response, contributing to chronic inflammation and associated diseases.ObjectivesWe aimed to characterize variability in postprandial inflammatory responses using traditional (IL-6) and novel [glycoprotein acetylation (GlycA)] biomarkers of inflammation and dissect their biological determinants with a focus on postprandial glycemia and lipemia.MethodsPostprandial (0–6 h) glucose, triglyceride (TG), IL-6, and GlycA responses were measured at multiple intervals after sequential mixed-nutrient meals (0 h and 4 h) in 1002 healthy adults aged 18–65 y from the PREDICT (Personalised REsponses to DIetary Composition Trial) 1 study, a single-arm dietary intervention study. Measures of habitual diet, blood biochemistry, gut microbiome composition, and visceral fat mass (VFM) were also collected.ResultsThe postprandial changes in GlycA and IL-6 concentrations were highly variable between individuals. Participants eliciting an increase in GlycA and IL-6 (60% and 94% of the total participants, respectively) had mean 6-h increases of 11% and 190%, respectively. Peak postprandial TG and glucose concentrations were significantly associated with 6-h GlycA (r = 0.83 and r = 0.24, respectively; both P < 0.001) but not with 6-h IL-6 (both P > 0.26). A random forest model revealed the maximum TG concentration was the strongest postprandial TG predictor of postprandial GlycA and structural equation modeling revealed that VFM and fasting TG were most strongly associated with fasting and postprandial GlycA. Network Mendelian randomization demonstrated a causal link between VFM and fasting GlycA, mediated (28%) by fasting TG. Individuals eliciting enhanced GlycA responses had higher predicted cardiovascular disease risk (using the atherosclerotic disease risk score) than the rest of the cohort.ConclusionsThe variable postprandial increases in GlycA and their associations with TG metabolism highlight the importance of modulating TG in concert with obesity to reduce GlycA and associated low-grade inflammation–related diseases.This trial was registered at clinicaltrials.gov as NCT03479866.

Metabolomic Profiling Demonstrates Postprandial Changes in Fatty Acids and Glycerophospholipids Are Associated with Fasting Inflammation in Guatemalan Adults

BackgroundMetabolic flexibility is the responsiveness to heterogeneous physiological conditions, such as food ingestion. A key unresolved question is how inflammation affects metabolic flexibility. ObjectivesOur study objective was to compare metabolic flexibility, specifically the metabolomic response to a standardized meal, by fasting inflammation status. MethodsParticipants in Guatemala (n = 302, median age 44 y, 43.7% men) received a standardized, mixed-macronutrient liquid meal. Plasma samples (fasting, 2 h postmeal) were assayed by dual-column LC [reverse phase (C18) and hydrophilic interaction LC (HILIC)] with ultra-high-resolution MS, for concentrations of 6 inflammation biomarkers: high-sensitivity C-reactive protein (hsCRP), leptin, resistin, IL-10, adiponectin, and soluble TNF receptor II (TNFsR). We summed the individual inflammation biomarker z-scores, after reverse-coding of anti-inflammation biomarkers. We identified features with peak areas that differed between fasting and postmeal (false discovery rate–adjusted q <0.05) and compared median log2 postprandial/fasting peak area ratios by inflammation indicators. ResultsWe found 1397 C18 and 974 HILIC features with significant postprandial/fasting feature ratios (q <0.05). Overall inflammation z-score was directly associated with the postprandial/fasting feature ratios of arachidic acid, and inversely associated with the feature ratio of lysophosphatidic acid (LPA), adjusting for age and sex (all P < 0.05). The postprandial/fasting ratio of arachidic acid was negatively correlated with resistin, IL-10, adiponectin, and TNFsR concentrations (all P < 0.05). Feature ratios of several fatty acids—myristic acid [m/z 227.2018, retention time (RT) 229], heptadecanoic acid (m/z 269.2491, RT 276), linoleic acid (m/z 280.2358, RT 236)—were negatively correlated with fasting plasma concentrations of leptin (nanograms per milliliter) and adiponectin (micrograms per milliliter), respectively (all P < 0.05). The postprandial/fasting ratio of LPA was positively correlated with IL-10 and adiponectin (both P < 0.05); and the ratio of phosphatidylinositol was positively correlated with hsCRP (P < 0.05). ConclusionsPostprandial responses of fatty acids and glycerophospholipids are associated with fasting inflammation status in adults in Guatemala.

Altered Adiponectin Response in Older Women Following Dextrose and High-Fat Dietary Challenges.

Despite its beneficialproperties,higheradiponectinconcentrations are paradoxically associated with mortality in advanced age. Several mechanisms are being discussed. However, little is known about postprandial regulation of adiponectin in older adults. We assessed age-specific differences of the adiponectin response to different test meals considering potential determinants. Older(n=20)andyounger(n=22)womenare randomizedtoadextrose(DEX)orhigh-fat(HF)dietarychallenge. Postprandial adiponectin and fibroblast growth factor 21 (FGF21) concentrations are measured before and 60, 120, 240 min after ingestion. We assessed postprandial changes and group differences using linear mixed models controlled for possible determinants. In younger women, postprandial adiponectin remains stable after both test meals. In contrast, adiponectin increases following DEX and decreases after HF in older women, irrespective of control variables. Postprandial adiponectin is positively associated with malondialdehyde and inversely associated with interleukin-6 following DEX and also negatively associated with metabolic parameters after both test meals. In older women, elevated postprandial FGF21 concentrations are associated with a higher adiponectin response (β = 30.7, 95% CI 10.6-50.8, p= 0.007). Adiponectin response is associated with type of dietary challenge, age, and FGF21 response. Age-group differences are partly attributable to metabolic parameters and oxidative stress.

Interstitial postprandial hyperlipidemia and remnant lipoproteins in type 2 diabetes mellitus

Background and Aims: Diabetic dyslipidemia is characterized by elevated fasting serum TG and VLDL and low HDL-c. Postprandial hypertriglyceridemia and changes in remnant-like lipoprotein particles are well recognized in T2D, but the metabolism and /or clearance of these triglyceride-rich lipoproteins (TGRL) is less clear. The interstitial fluid (IF) represents the immediate environment of most cells in the body and studying postprandial changes in this compartment should provide novel insights into the increased cardiovascular risk observed in T2D.

Insulin Directly Regulates the Circadian Clock in Adipose Tissue.

Adipose tissue (AT) is a key metabolic organ which functions are rhythmically regulated by an endogenous circadian clock. Feeding is a "zeitgeber" aligning the clock in AT with the external time, but mechanisms of this regulation remain largely unclear. We tested the hypothesis that postprandial changes of the hormone insulin directly entrain circadian clocks in AT and investigated a transcriptional-dependent mechanism of this regulation. We analyzed gene expression in subcutaneous AT (SAT) of obese subjects collected before and after the hyperinsulinemic-euglycemic clamp or control saline infusion (SC). The expressions of core clock genes PER2, PER3, and NR1D1 in SAT were differentially changed upon insulin and saline infusion, suggesting insulin-dependent clock regulation. In human stem cell-derived adipocytes, mouse 3T3-L1 cells, and AT explants from mPer2Luc knockin mice, insulin induced a transient increase of the Per2 mRNA and protein expression, leading to the phase shift of circadian oscillations, with similar effects for Per1 Insulin effects were dependent on the region between -64 and -43 in the Per2 promoter but not on CRE and E-box elements. Our results demonstrate that insulin directly regulates circadian clocks in AT and isolated adipocytes, thus representing a primary mechanism of feeding-induced AT clock entrainment.

A Preliminary Study Showing the Impact of Genetic and Dietary Factors on GC-MS-Based Plasma Metabolome of Patients with and without PROX1-Genetic Predisposition to T2DM up to 5 Years Prior to Prediabetes Appearance.

Risk factors for type 2 diabetes mellitus (T2DM) consist of a combination of an unhealthy, imbalanced diet and genetic factors that may interact with each other. Single nucleotide polymorphism (SNP) in the prospero homeobox 1 (PROX1) gene is a strong genetic susceptibility factor for this metabolic disorder and impaired β-cell function. As the role of this gene in T2DM development remains unclear, novel approaches are needed to advance the understanding of the mechanisms of T2DM development. Therefore, in this study, for the first time, postprandial changes in plasma metabolites were analysed by GC–MS in nondiabetic men with different PROX1 genotypes up to 5 years prior to prediabetes appearance. Eighteen contestants (12 with high risk (HR) and 6 with low risk (LR) genotype) participated in high-carbohydrate (HC) and normo-carbohydrate (NC) meal-challenge tests. Our study concluded that both meal-challenge tests provoked changes in 15 plasma metabolites (amino acids, carbohydrates, fatty acids and others) in HR, but not LR genotype carriers. Postprandial changes in the levels of some of the detected metabolites may be a source of potential specific early disturbances possibly associated with the future development of T2DM. Thus, accurate determination of these metabolites can be important for the early diagnosis of this metabolic disease.

The Effects of Gold Kiwifruit Intake Timing with or without Pericarp on Postprandial Blood Glucose Level.

The purpose of this study was to examine how gold kiwifruit pericarp (pericarp is defined as the skin of the fruit) consumption and the timing thereof affect the postprandial blood glucose profile. The study was conducted on twelve healthy volunteers (six men and six women). According to our results, the simultaneous intake of gold kiwifruit with bread and the prior intake of gold kiwifruit evidently suppressed the postprandial blood glucose elevation compared with exclusive bread intake. There was no significant difference in postprandial blood glucose changes between the ingestion of gold kiwifruit pericarp and pulp and that of gold kiwifruit pulp only. The highest postprandial blood glucose elevation was suppressed by 27.6% and the area under the blood glucose elevation curve by 29.3%, even with the exclusive ingestion of gold kiwifruit pulp. We predicted that the ingestion of both the pericarp and pulp of gold kiwifruit would reduce the postprandial blood glucose elevation to a greater extent than that of gold kiwifruit pulp only; however, there was no significant difference between the two. These results indicate that gold kiwifruit consumption significantly suppresses the postprandial blood glucose elevation regardless of pericarp presence or absence and the timing of ingestion.

Change in Postprandial Level of Remnant Cholesterol After a Daily Breakfast in Chinese Patients With Hypertension.

Background: Hypertension (HBP) is usually accompanied by hypertriglyceridemia that represents the increased triglyceride-rich lipoproteins and cholesterol content in remnant lipoproteins [i.e., remnant cholesterol (RC)]. According to the European Atherosclerosis Society (EAS), high RC (HRC) is defined as fasting RC ≥0.8 mmol/L and/or postprandial RC ≥0.9 mmol/L. However, little is known about postprandial change in RC level after a daily meal in Chinese patients with HBP.Methods: One hundred thirty-five subjects, including 90 hypertensive patients (HBP group) and 45 non-HBP controls (CON group), were recruited in this study. Serum levels of blood lipids, including calculated RC, were explored at 0, 2, and 4 h after a daily breakfast. Receiver operating characteristic (ROC) curve analysis was used to determine the cutoff point of postprandial HRC.Results: Fasting TG and RC levels were significantly higher in the HBP group (P < 0.05), both of which increased significantly after a daily meal in the two groups (P < 0.05). Moreover, postprandial RC level was significantly higher in the HBP group (P < 0.05). ROC curve analysis showed that the optimal cutoff point for RC after a daily meal to predict HRC corresponding to fasting RC of 0.8 mmol/L was 0.91 mmol/L, which was very close to that recommended by the EAS, i.e., 0.9 mmol/L. Fasting HRC was found in 31.1% of hypertensive patients but not in the controls. According to the postprandial cutoff point, postprandial HRC was found in approximately half of hypertensive patients and ~1-third of the controls.Conclusion: Postprandial RC level increased significantly after a daily meal, and hypertensive patients had higher percentage of HRC at both fasting and postprandial states. More importantly, the detection of postprandial lipids could be helpful to find HRC.

Metabolomic Profiling Demonstrates Postprandial Changes in Saturated Fatty Acids and Glycerophospholipids Are Associated With Fasting Inflammation

ObjectivesMetabolic flexibility is the responsiveness to heterogeneous physiologic conditions, such as food ingestion. A key unresolved question is how inflammation affects metabolic flexibility. Our study objective was to compare metabolic flexibility, specifically the metabolomic response to a standardized meal, by fasting inflammation status, among Guatemalan adults. MethodsParticipants (n = 302, median age 44 years, 43.7% men) received a standardized, mixed-macronutrient liquid meal. Plasma samples (fasting, 2 hr post-meal) were assayed by dual column liquid chromatography (reverse phase [C18] and hydrophilic interaction liquid chromatography [HILIC]) with ultra-high resolution mass spectrometry, and for concentrations of 6 inflammation biomarkers (hsCRP, leptin, resistin, IL-10, adiponectin, TNFsR). We summed the 6 fasting inflammation biomarker Z-scores, after reverse-coding of anti-inflammation biomarkers. For feature selection, we identified features with peak areas differing between fasting and post-meal (FDR-adjusted q < 0.05) and compared median log2 postprandial/fasting peak area ratios by inflammation indicators. Results1,397 C18 and 967 HILIC features had significant log2 postprandial/fasting peak area ratios (q < 0.05). These log2 feature peak area ratios clustered differentially between people in the lowest tertile vs higher 2 tertiles of the inflammation index. The inflammation index was directly associated with log2 ratios of arachidic acid, and inversely associated with log2 ratios of caproic acid and lysophosphatidic acid, adjusting for age and sex (all P < 0.05). The log2 ratio of arachidic acid was negatively correlated with resistin, IL-10, adiponectin, and TNFsR concentrations (all P < 0.05). The log2 ratio of caproic acid was positively correlated with adiponectin and IL-10 concentrations, and negatively correlated with hsCRP concentration (all P < 0.05). The log2 ratio of lysophosphatidic acid was positively correlated with IL-10 and adiponectin, and log2 ratio of phosphatidylinositol was positively correlated with hsCRP (all P < 0.05). ConclusionsOur findings showed that postprandial responses of saturated fatty acids and glycerophospholipids were associated with fasting inflammation. Funding SourcesNational Institutes of Health (HD075784, HL007745).

Relationship Between Oxytocin Levels and Brain Volume in Anorexia Nervosa Compared to Healthy Controls

Background: A disruption in food motivation pathways has been described in females with anorexia nervosa (AN), a psychiatric disorder characterized by food restriction despite low weight. We have shown that in AN and healthy controls (HC), levels of oxytocin (OXT), a hormone involved in lactation, social behavior and weight regulation, decrease after a meal. In HC, we identified a relationship between postprandial change in OXT and subjective appetite, yet this association was absent in females with AN, suggesting a disconnect between OXT and appetite regulation in AN. Prior studies have shown that gray matter volume of the amygdala and hippocampus, areas rich in OXT receptors, correlate with OXT levels in HC. Furthermore, these regions play a central role in food reward and decreased volume has been reported in AN. We hypothesized that the relationship between postprandial change in OXT and amygdala and hippocampal gray matter volume would differ between AN and HC. Methods: We performed a cross-sectional study of 51 females (23 restrictive AN; 28 HC). We drew blood for OXT levels fasting and 60 min after a standard meal and performed T1-weighted MRI scans of the brain in the fasted state. MRI data was quality controlled and processed with FreeSurfer. Average gray matter brain volumes were extracted from the bilateral amygdala and hippocampus for each subject. Linear regression models were used to determine differences between AN and HC of postprandial percent change in OXT on amygdala and hippocampus gray matter volume. Results: Median [IQR] age was higher in females with AN (20.6 years [19.3, 21.5]) than HC (18.8 years [IQR 17.6, 20.3], p=0.02), and percentage of ideal body weight was lower in AN (75.5%) than HC (97.4%, p<0.01). Right hippocampus volume, adjusted for age and total intracranial volume, was significantly lower in AN (estimated difference -188 dm3 [95%-CI -360, -17], p=0.04). Percent change in OXT was not different (p=0.5) but there was a trend for a positive interaction effect (p=0.08) for AN and percent change in OXT on right hippocampus volume. Posthoc exploratory analysis indicated a positive correlation in AN (R2=0.41, p=0.02) and no correlation in HC (R2=0.17,p=0.4) between percent change in OXT and right hippocampus volume. There was no significant between group difference in volume nor postprandial change in OXT for the bilateral amygdala or left hippocampus between groups. Discussion: Our results indicate smaller right hippocampus volume and a trend towards a positive association with postprandial change in OXT in AN compared to HC. Future studies will be important to better define the relationships between OXT secretion and food motivation brain regions and the impact on eating behavior in AN.

Neurobiology of Avoidant/Restrictive Food Intake Disorder in Youth With Overweight/Obesity Versus Healthy Weight

Objective: Avoidant/restrictive food intake disorder (ARFID) occurs across the weight spectrum, however research addressing the coexistence of ARFID with overweight/obesity (OV/OB) is lacking. We aimed to establish co-occurrence of OV/OB and ARFID and to characterize divergent neurobiological features of ARFID by weight. Method: Youth with full/subthreshold ARFID (11 with healthy weight [HW], 12 with OV/OB) underwent fasting brain fMRI scan while viewing food/non-food images (M age = 16.92 years, 65% female, 87% white). We compared groups on BOLD response to high-calorie foods (HCF) (vs. objects) in food cue processing regions of interest. Following fMRI scanning, we evaluated subjective hunger pre- vs. post-meal. We used a mediation model to explore the association between BMI, brain activation and hunger. Results: Participants with ARFID and OV/OB demonstrated significant hyperactivation in response to HCF (vs. objects) in the orbitofrontal cortex (OFC) and anterior insula compared with HW subjects with ARFID. Mediation analysis yielded a significant indirect effect of group (HW vs. OV/OB) on hunger via OFC activation (effect=18.39, SE=11.27, 95% CI [-45.09, -3.00]), suggesting that OFC activation mediates differences in hunger between ARFID participants with HW and OV/OB. Conclusions: Compared to youth with ARFID and HW, those with OV/OB demonstrate hyperactivation of brain areas critical for reward value of food cues. Postprandial changes in subjective hunger depend on BMI and are mediated by OFC activation to food cues. Whether these neurobiological differences contribute to selective hyperphagia in ARFID presenting with OV/OB and represent potential treatment targets is an important area for future investigation.

Effect of withholding food on serum concentrations of cobalamin, folate, trypsin-like immunoreactivity, and pancreatic lipase immunoreactivity in healthy dogs.

To evaluate the effects of withholding food on the results for measurements of serum concentrations of cobalamin, folate, canine pancreatic lipase immunoreactivity (cPLI), and canine trypsin-like immunoreactivity (cTLI) in healthy dogs. 11 healthy employee- or student-owned dogs. Food was withheld from the dogs for 12 hours, baseline blood samples were collected, then dogs were fed. Postprandial blood samples collected 1, 2, 4, and 8 hours later were assessed. A mixed-effects ANOVA model with fasting duration (time) as a fixed factor and dog as a random effect was fit for each analyte variable. Additionally, a mixed-effects ANOVA model controlling for the variable of time was fit to assess whether lipemia affected serum concentrations of the analytes. The median serum cobalamin concentration was lower at 4 hours (428 ng/L) and 8 hours (429 ng/L) postprandially, compared with baseline (479 ng/L), but this difference was not clinically meaningful. Although there were no substantial differences in serum concentrations of folate, cPLI, or cTLI, postprandial changes in serum concentrations of cTLI or folate could potentially affect diagnoses in some dogs. Although results indicated that feedings rarely resulted in clinically important differences in the median serum concentrations of cobalamin, folate, cPLI, or cTLI in healthy dogs, given the further processing required for lipemic samples, withholding food for at least 8 hours is an appropriate recommendation when measuring these analytes. Similar research is needed in dogs with gastrointestinal disease to determine whether the withholding of food is necessary when measuring these analytes in affected dogs.

Fasting and postprandial ghrelin changes in older and younger volunteers.

Little evidence is available on how both forms of ghrelin change during the aging process. Most of the earlier studies measured only total ghrelin levels and mainly in the fasting state. This study aimed to assess periprandial changes of acylated and deacylated ghrelin (AG, DAG) in volunteers aged ≥65 and <65 years and to establish an association between both forms of ghrelin and nutritional status in older volunteers. Venous blood for serum AG and DAG assays were collected in sixty volunteers after an overnight fast and two hours after the consumption of a standard 300 kcal-mixed meal. In those aged 65 years or more nutritional status was assessed. Levels of DAG and AG were lower in older compared to younger volunteers in the fasting state as well as postprandial. DAG levels after a meal decreased in older, but not in younger subjects. However, significantly higher levels of postprandial AG were found in subjects with a risk of malnutrition and those with reduced appetite in comparison to well-nourished ones. Interestingly, elderly subjects with the lowest insulin and BMI had the lowest fasting AG levels and subjects with too high BMI and hyperinsulinemia presented also the highest fasting AG levels. In older subjects, levels of both forms of ghrelin were lower and differential postprandial AG and DAG responses were observed when compared to younger subjects.

Neurobiology of Avoidant/Restrictive Food Intake Disorder in Youth with Overweight/Obesity Versus Healthy Weight

ABSTRACT Objective: Avoidant/restrictive food intake disorder (ARFID) occurs across the weight spectrum, however research addressing the coexistesnce of ARFID with overweight/obesity (OV/OB) is lacking. We aimed to establish co-occurrence of OV/OB and ARFID and to characterize divergent neurobiological features of ARFID by weight. Method: Youth with full/subthreshold ARFID (12 with healthy weight [HW], 11 with OV/OB) underwent fasting brain fMRI scan while viewing food/non-food images (M age = 16.92 years, 65% female, 87% white). We compared groups on BOLD response to high-calorie foods (HCF) (vs. objects) in food cue processing regions of interest. Following fMRI scanning, we evaluated subjective hunger pre- vs. post-meal. We used a mediation model to explore the association between BMI, brain activation, and hunger. Results: Participants with ARFID and OV/OB demonstrated significant hyperactivation in response to HCF (vs. objects) in the orbitofrontal cortex (OFC) and anterior insula compared with HW participants with ARFID. Mediation analysis yielded a significant indirect effect of group (HW vs. OV/OB) on hunger via OFC activation (effect = 18.39, SE = 11.27, 95% CI [−45.09, −3.00]), suggesting that OFC activation mediates differences in hunger between ARFID participants with HW and OV/OB. Conclusions: Compared to youth with ARFID and HW, those with OV/OB demonstrate hyperactivation of brain areas critical for the reward value of food cues. Postprandial changes in subjective hunger depend on BMI and are mediated by OFC activation to food cues. Whether these neurobiological differences contribute to selective hyperphagia in ARFID presenting with OV/OB and represent potential treatment targets is an important area for future investigation.

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

PurposePalmitic and stearic acids have different effects on fasting serum lipoproteins. However, the effects on postprandial lipemia and glycemia are less clear. Also, the effects of a second meal may differ from those of the first meal. Therefore, we studied the effects of two consecutive mixed meals high in palmitic acid- or stearic acid-rich fat blends on postprandial lipemia and glycemia.MethodsIn a randomized, crossover study, 32 participants followed 4-week diets rich in palmitic or stearic acids, At the end of each dietary period, participants consumed two consecutive meals each containing ± 50 g of the corresponding fat blend.ResultsPostprandial concentrations of triacylglycerol (diet-effect: − 0.18 mmol/L; p = 0.001) and apolipoprotein B48 (diet-effect: − 0.68 mg/L; p = 0.002) were lower after stearic-acid than after palmitic-acid intake. Consequently, total (iAUC0–8 h) and first meal (iAUC0–4 h) responses were lower after stearic-acid intake (p ≤ 0.01). Second meal responses (iAUC4–8 h) were not different. Postprandial changes between the diets in non-esterified fatty acids (NEFA) and C-peptide differed significantly over time (p < 0.001 and p = 0.020 for diet*time effects, respectively), while those for glucose and insulin did not. The dAUC0–8 h, dAUC0–4 h, and dAUC4–8 h for NEFA were larger after stearic-acid intake (p ≤ 0.05). No differences were observed in the iAUCs of C-peptide, glucose, and insulin. However, second meal responses for glucose and insulin (iAUC4–8 h) tended to be lower after stearic-acid intake (p < 0.10).ConclusionConsumption of the stearic acid-rich meals lowered postprandial lipemia as compared with palmitic acid. After the second stearic acid-rich meal, concentrations of C-peptide peaked earlier and those of NEFA decreased more.Clinical trial registry This trial was registered at clinicaltrials.gov as NCT02835651 on July 18, 2016.

A pilot study investigating the use of 4D flow MRI for the assessment of splanchnic flow in patients suspected of mesenteric ischaemia

The most common cause of chronic mesenteric ischaemia is atherosclerosis which results in limitation of blood flow to the gastrointestinal tract. This pilot study aimed to evaluate 4D flow MRI as a potential tool for the analysis of blood flow changes post-prandial within the mesenteric vessels. The mesenteric vessels of twelve people were scanned; patients and healthy volunteers. A baseline MRI scan was performed after 6 h of fasting followed by a post-meal scan. Two 4D flow datasets were acquired, over the superior mesenteric artery (SMA) and the main portal venous vessels. Standard 2D time-resolved PC-MRI slices were also obtained across the aorta above the coeliac trunk, superior mesenteric vein, splenic vein and portal vein (PV). In the volunteer cohort there was a marked increase in blood flow post-meal within the PV (p = 0.028), not seen in the patient cohort (p = 0.116). Similarly, there were significant flow changes within the SMA of volunteers (p = 0.028) but not for the patient group (p = 0.116). Our pilot data has shown that there is a significant haemodynamic response to meal challenge in the PV and SMA in normal subjects compared to clinically apparent CMI patients. Therefore, the interrogation of mesenteric venous vessels exclusively is a feasible method to measure post-prandial flow changes in CMI patients.

Effect of maternal supplementation with essential fatty acids and conjugated linoleic acid on metabolic and endocrine development in neonatal calves

We tested the hypothesis that the maternal supply of essential fatty acids (EFA), especially α-linolenic acid, and conjugated linoleic acid (CLA), affects glucose metabolism, the endocrine regulation of energy metabolism and growth, and the intestinal development of neonatal calves. We studied calves from dams that received an abomasal infusion of 76 g/d coconut oil (CTRL; n = 9), 78 g/d linseed oil and 4 g/d safflower oil (EFA; n = 9), 38 g/d Lutalin (BASF SE) containing 27% cis-9,trans-11 and trans-10,cis-12 CLA (CLA; n = 9), or a combination of EFA and CLA (EFA+CLA; n = 11) during the last 63 d of gestation and early lactation. Calves received colostrum and transition milk from their own dam for the first 5 d of life. Insulin-like growth factor (IGF)-I, leptin, and adiponectin concentrations were measured in milk. Blood samples were taken before first colostrum intake, 24 h after birth, and from d 3 to 5 of life before morning feeding to measure metabolic and endocrine traits in plasma. On d 3 of life, energy expenditure was evaluated by a bolus injection of NaH13CO3 and determination of CO2 appearance rate. On d 4, additional blood samples were taken to evaluate glucose first-pass uptake and 13CO2 enrichment after [13C6]-glucose feeding and intravenous [6,6-2H2]-glucose bolus injection, as well as postprandial changes in glucose, nonesterified fatty acids (NEFA), insulin, and glucagon. On d 5, calves were killed 2 h after feeding and samples of small intestinal mucosa were taken for histomorphometric measurements. The concentrations of IGF-I, adiponectin, and leptin in milk decreased during early lactation in all groups, and the concentrations of leptin in first colostrum was higher in EFA than in CTRL cows. Plasma glucose concentration before first colostrum intake was higher in EFA calves than in non-EFA calves and was lower in CLA calves than in non-CLA calves. Plasma IGF-I concentration was higher on d 1 before colostrum intake in EFA calves than in EFA+CLA calves and indicated an overall CLA effect, with lower plasma IGF-I in CLA than in non-CLA calves. Postprandial NEFA concentration was lowest in EFA and CLA calves. The postprandial rise in plasma insulin was higher in EFA than in non-EFA calves. Plasma adiponectin concentration increased from d 1 to d 2 in all groups and was higher on d 3 in CLA than in non-CLA calves. Plasma leptin concentration was higher on d 4 and 5 in EFA than in non-EFA calves. Maternal fatty acid treatment did not affect energy expenditure and first-pass glucose uptake, but glucose uptake on d 4 was faster in EFA than in non-EFA calves. Crypt depth was lower, and the ratio of villus height to crypt depth was higher in the ilea of CLA than non-CLA calves. Elevated plasma glucose and IGF-I in EFA calves immediately after birth may indicate an improved energetic status in calves when dams are supplemented with EFA. Maternal EFA and CLA supplementation influenced postprandial metabolic changes and affected factors related to the neonatal insulin response.