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Medicine and Science in Sports and... May 2023South Asians (SAs) have an elevated risk of cardiovascular disease (CVD) compared with White Europeans (WEs). Postprandial endothelial function (flow-mediated dilatation...
INTRODUCTION
South Asians (SAs) have an elevated risk of cardiovascular disease (CVD) compared with White Europeans (WEs). Postprandial endothelial function (flow-mediated dilatation (FMD%)) in SA women and SA men with central obesity has not been investigated. Research in other populations has highlighted that a 1% higher FMD% is associated with a ~13% lower risk of future CVD events. We investigated whether FMD% and lipemia, two markers for CVD risk, were higher in SAs versus WEs, whether walking improved FMD% and lipemia, and if there were ethnic differences in the response.
METHODS
Lean premenopausal women (study 1; 12 SA, 12 WE) and men with central obesity (study 2; 15 SA, 15 WE) completed two 2-d trials. On day 1, participants walked for 60 min at 60% of their peak oxygen uptake or rested. On day 2, participants rested and consumed two high-fat meals over 8 h. Repeated ultrasound assessments of endothelial function and venous blood samples for CVD risk markers were taken.
RESULTS
Compared with WEs, SAs had lower postprandial FMD% (study 1, -1.32%; study 2, -0.54%) and higher postprandial triacylglycerol concentrations (study 1, 0.31 mmol·L -1 ·h -1 ; study 2, 0.55 mmol·L -1 ·h -1 ). Walking improved postprandial FMD% (study 1, 1.12%; study 2, 0.94%) and resulted in no significant change or small reductions in postprandial triacylglycerol concentrations (study 1, -0.01 mmol·L -1 ·h -1 ; study 2, -0.25 mmol·L -1 ·h -1 ). Exercise-induced changes in FMD% and triacylglycerol were consistent between ethnic groups.
CONCLUSIONS
Walking mitigated the adverse postprandial effect of a high-fat diet on FMD% to a similar extent in SA and WE women and men, even with no/small improvements in triacylglycerol. This study highlights the importance of exercise to clinically improve FMD% in SAs and WEs.
Topics: Male; Humans; Female; European People; Obesity, Abdominal; South Asian People; Triglycerides; Walking; Hyperlipidemias; Cardiovascular Diseases; Postprandial Period; Cross-Over Studies; Dietary Fats; White People
PubMed: 36729923
DOI: 10.1249/MSS.0000000000003098 -
International Journal of Environmental... Jan 2023Extreme carbohydrate deficits during a ketogenic diet (KD) may result in metabolic adaptations reflective of low energy availability; however, the manifestation of these... (Randomized Controlled Trial)
Randomized Controlled Trial
Chronic and Postprandial Metabolic Responses to a Ketogenic Diet Compared to High-Carbohydrate and Habitual Diets in Trained Competitive Cyclists and Triathletes: A Randomized Crossover Trial.
Extreme carbohydrate deficits during a ketogenic diet (KD) may result in metabolic adaptations reflective of low energy availability; however, the manifestation of these adaptations outside of exercise have yet to be elucidated in cyclists and triathletes. The purpose of this study is to investigate the chronic and postprandial metabolic responses to a KD compared to a high-carbohydrate diet (HCD) and habitual diet (HD) in trained competitive cyclists and triathletes. For this randomized crossover trial, six trained competitive cyclist and triathletes (F: 4, M: 2) followed an ad libitum KD and HCD for 14 d each after their HD. Fasting energy expenditure (EE), respiratory exchange ratio (RER), and fat and carbohydrate oxidation (FatOx and CarbOx, respectively) were collected during their HD and after 14 d on each randomly assigned KD and HCD. Postprandial measurements were collected on day 14 of each diet following the ingestion of a corresponding test meal. There were no significant differences in fasting EE, RER, FatOx, or CarbOx among diet conditions (all p > 0.050). Although postprandial RER and CarbOx were consistently lower following the KD meal, there were no differences in peak postprandial RER (p = 0.452), RER incremental area under the curve (iAUC; p = 0.416) postprandial FatOx (p = 0.122), peak FatOx (p = 0.381), or FatOx iAUC (p = 0.164) between the KD and HD meals. An ad libitum KD does not significantly alter chronic EE or substrate utilization compared to a HCD or HD; postprandial FatOx appears similar between a KD and HD; this is potentially due to the high metabolic flexibility of cyclists and triathletes and the metabolic adaptations made to habitual high-fat Western diets in practice. Cyclists and triathletes should consider these metabolic similarities prior to a KD given the potential health and performance impairments from severe carbohydrate restriction.
Topics: Diet, Ketogenic; Cross-Over Studies; Energy Metabolism; Diet, High-Fat; Blood Glucose; Postprandial Period
PubMed: 36673864
DOI: 10.3390/ijerph20021110 -
PloS One 2020"Quantile-dependent expressivity" describes an effect of the genotype that depends upon the level of the phenotype (e.g., whether a subject's triglycerides are high or...
PURPOSE
"Quantile-dependent expressivity" describes an effect of the genotype that depends upon the level of the phenotype (e.g., whether a subject's triglycerides are high or low relative to its population distribution). Prior analyses suggest that the effect of a genetic risk score (GRS) on fasting plasma triglyceride levels increases with the percentile of the triglyceride distribution. Postprandial lipemia is well suited for testing quantile-dependent expressivity because it exposes each individual's genotype to substantial increases in their plasma triglyceride concentrations. Ninety-seven published papers were identified that plotted mean triglyceride response vs. time and genotype, which were converted into quantitative data. Separately, for each published graph, standard least-squares regression analysis was used to compare the genotype differences at time t (dependent variable) to average triglyceride concentrations at time t (independent variable) to assess whether the genetic effect size increased in association with higher triglyceride concentrations and whether the phenomenon could explain purported genetic interactions with sex, diet, disease, BMI, and drugs.
RESULTS
Consistent with the phenomenon, genetic effect sizes increased (P≤0.05) with increasing triglyceride concentrations for polymorphisms associated with ABCA1, ANGPTL4, APOA1, APOA2, APOA4, APOA5, APOB, APOC3, APOE, CETP, FABP2, FATP6, GALNT2, GCKR, HL, IL1b, LEPR, LOX-1, LPL, MC4R, MTTP, NPY, SORT1, SULF2, TNFA, TCF7L2, and TM6SF2. The effect size for these polymorphisms showed a progressively increasing dose-response, with intermediate effect sizes at intermediate triglyceride concentrations. Quantile-dependent expressivity provided an alternative interpretation to their interactions with sex, drugs, disease, diet, and age, which have been traditionally ascribed to gene-environment interactions and genetic predictors of drug efficacy (i.e., personalized medicine).
CONCLUSION
Quantile-dependent expressivity applies to the majority of genetic variants affecting postprandial triglycerides, which may arise because the impaired functionalities of these variants increase at higher triglyceride concentrations. Purported gene-drug interactions may be the manifestations of quantile-dependent expressivity, rather than genetic predictors of drug efficacy.
Topics: Adult; Apolipoprotein C-III; Apolipoproteins A; Cholesterol, HDL; Female; Genotype; Humans; Hyperlipidemias; Male; Membrane Proteins; Middle Aged; Phenotype; Polymorphism, Single Nucleotide; Postprandial Period; Regression Analysis; Triglycerides
PubMed: 32101585
DOI: 10.1371/journal.pone.0229495 -
The Journal of Nutrition Nov 2021Metabolic abnormalities substantially increase the risk of noncommunicable diseases, which are among the leading causes of mortality globally. Mitigating and preventing...
Metabolic abnormalities substantially increase the risk of noncommunicable diseases, which are among the leading causes of mortality globally. Mitigating and preventing these adverse consequences remains challenging due to a limited understanding of metabolic health. Metabolic flexibility, a key tenet of metabolic health, encompasses the responsiveness of interrelated pathways to maintain energy homeostasis throughout daily physiologic challenges, such as the response to meal challenges. One critical underlying research gap concerns the measurement of postprandial metabolic flexibility, which remains incompletely understood. We concisely review the methodology for assessment of postprandial metabolic flexibility in recent human studies. We identify 3 commonalities of study design, specifically the nature of the challenge, nature of the response measured, and approach to data analysis. Primary interventions were acute short-term nutrition challenges, including single- and multiple-macronutrient tolerance tests. Postmeal challenge responses were measured via laboratory assays and instrumentation, based on a diverse set of metabolic flexibility indicators [e.g., energy expenditure (whole-body indirect calorimetry), glucose and insulin kinetics, metabolomics, transcriptomics]. Common standard approaches have been diabetes-centric with single-macronutrient challenges (oral-glucose-tolerance test) to characterize the postprandial response based on glucose and insulin metabolism; or broad measurements of energy expenditure with calculated macronutrient oxidation via indirect calorimetry. Recent methodological advances have included the use of multiple-macronutrient meal challenges that are more representative of physiologic meals consumed by free-living humans, combinatorial approaches for assays and instruments, evaluation of other metabolic flexibility indicators via precision health, systems biology, and temporal perspectives. Omics studies have identified potential novel indicators of metabolic flexibility, which provide greater granularity to prior evidence from canonical approaches. In summary, recent findings indicate the potential for an expanded understanding of postprandial metabolic flexibility, based on nonclassical measurements and methodology, which could represent novel dynamic indicators of metabolic diseases.
Topics: Blood Glucose; Calorimetry, Indirect; Cross-Over Studies; Energy Metabolism; Humans; Insulin; Meals; Postprandial Period
PubMed: 34293154
DOI: 10.1093/jn/nxab263 -
Nutrients Jan 2022This review focuses on the added value provided by a research strategy applying metabolomics analyses to assess phenotypic flexibility in response to different... (Review)
Review
This review focuses on the added value provided by a research strategy applying metabolomics analyses to assess phenotypic flexibility in response to different nutritional challenge tests in the framework of metabolic clinical studies. We discuss findings related to the Oral Glucose Tolerance Test (OGTT) and to mixed meals with varying fat contents and food matrix complexities. Overall, the use of challenge tests combined with metabolomics revealed subtle metabolic dysregulations exacerbated during the postprandial period when comparing healthy and at cardiometabolic risk subjects. In healthy subjects, consistent postprandial metabolic shifts driven by insulin action were reported (e.g., a switch from lipid to glucose oxidation for energy fueling) with similarities between OGTT and mixed meals, especially during the first hours following meal ingestion while differences appeared in a wider timeframe. In populations with expected reduced phenotypic flexibility, often associated with increased cardiometabolic risk, a blunted response on most key postprandial pathways was reported. We also discuss the most suitable statistical tools to analyze the dynamic alterations of the postprandial metabolome while accounting for complexity in study designs and data structure. Overall, the in-depth characterization of the postprandial metabolism and associated phenotypic flexibility appears highly promising for a better understanding of the onset of cardiometabolic diseases.
Topics: Cardiovascular Diseases; Glucose Tolerance Test; Humans; Meals; Metabolome; Postprandial Period
PubMed: 35276829
DOI: 10.3390/nu14030472 -
Journal of Gastrointestinal and Liver... Dec 2023Functional dyspepsia (FD) is a common upper gastrointestinal disorder, characterized by bothersome epigastric pain or burning, fullness after meals or early satiety. The... (Review)
Review
Functional dyspepsia (FD) is a common upper gastrointestinal disorder, characterized by bothersome epigastric pain or burning, fullness after meals or early satiety. The precise pathophysiology remains incompletely understood but may include the role of disordered gut-brain communication leading to disturbances in gastro-duodenal physiological functioning. Even if there are several pharmacological treatment options, it is a chronic and relapsing disorder with persistent symptoms that makes its management difficult. Yoga is a fast-spreading complementary and alternative medicine (CAM) specialty, that has gained attention in the medical field for its ability to address the physical, emotional, mental and social aspects of health and disease. Various other CAM therapies are being used for FD with varying efficacy. However, apart from one research study that used yoga therapy on abdominal pain related functional gastrointestinal disorders in children which included a few FD cases as well (11.6%), no other study using yoga therapy has been done in FD as per our best knowledge. Therefore, in the present review, we have summarized the current scientific understanding of the probable effects of yoga on the pathophysiological mechanisms involved in FD (gastric motility, fundic accommodation, hypersensitivity, duodenal inflammation, psychological distress and gut-brain dysfunction). The literature suggests yoga can have a beneficial role in the management of FD. However, rigorous research and clinical trials are required to confirm the same.
Topics: Child; Humans; Dyspepsia; Yoga; Abdominal Pain; Gastrointestinal Diseases; Postprandial Period
PubMed: 38147600
DOI: 10.15403/jgld-4867 -
The American Journal of Clinical... Aug 2023Serving whey protein before a meal in order to lower postprandial blood glucose concentrations is known as a premeal. The underlying mechanisms are only partly... (Meta-Analysis)
Meta-Analysis
Whey Protein Premeal Lowers Postprandial Glucose Concentrations in Adults Compared with Water-The Effect of Timing, Dose, and Metabolic Status: a Systematic Review and Meta-analysis.
BACKGROUND
Serving whey protein before a meal in order to lower postprandial blood glucose concentrations is known as a premeal. The underlying mechanisms are only partly understood but may involve stimulation of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and insulin secretion together with a slower gastric emptying rate.
OBJECTIVES
The objective of this systematic review and meta-analysis was to review all randomized clinical trials investigating premeals with whey protein in comparison with a nonactive comparator (control) that evaluated plasma glucose, GLP-1, GIP, insulin, and/or gastric emptying rate. Secondary aims included subgroup analyses on the timing and dose of the premeal together with the metabolic state of the participants [lean, obese, and type 2 diabetes mellitus (T2DM)].
METHODS
We searched EMBASE, CENTRAL, PUBMED, and clinicaltrials.gov and found 16 randomized crossover trials with a total of 244 individuals. The last search was performed on 9 August, 2022.
RESULTS
Whey protein premeals lowered peak glucose concentration by -1.4 mmol/L [-1.9 mmol/L; -0.9 mmol/L], and the area under the curve for glucose was -0.9 standard deviation (SD) [-1.2 SD; -0.6 SD] compared with controls (high certainty). In association with these findings, whey protein premeals elevated GLP-1 (low certainty) and peak insulin (high certainty) concentrations and slowed gastric emptying rate (high certainty) compared with controls. Subgroup analyses showed a more pronounced and prolonged glucose-lowering effect in individuals with T2DM compared with participants without T2DM. The available evidence did not elucidate the role of GIP. The protein dose used varied between 4 and 55 g, and meta-regression analysis showed that the protein dose correlated with the glucose-lowering effects.
CONCLUSIONS
In conclusion, whey protein premeals lower postprandial blood glucose, reduce gastric emptying rate, and increase peak insulin. In addition, whey protein premeals may elevate plasma concentrations of GLP-1. Whey protein premeals may possess clinical potential, but the long-term effects await future clinical trials.
Topics: Humans; Adult; Whey Proteins; Glucagon; Blood Glucose; Diabetes Mellitus, Type 2; Water; Insulin; Glucagon-Like Peptide 1; Gastric Inhibitory Polypeptide; Glucose; Gastric Emptying; Postprandial Period
PubMed: 37536867
DOI: 10.1016/j.ajcnut.2023.05.012 -
Annals of Internal Medicine Jun 2020
Review
Topics: Acupuncture Therapy; Dyspepsia; Humans; Postprandial Period; Recovery of Function; Syndrome
PubMed: 32422080
DOI: 10.7326/P20-0006 -
The American Journal of Clinical... Oct 2022There has been growing interest in studying postprandial glucose responses using continuous glucose monitoring (CGM) in nondiabetic individuals. Accurate measurement of... (Clinical Trial)
Clinical Trial
BACKGROUND
There has been growing interest in studying postprandial glucose responses using continuous glucose monitoring (CGM) in nondiabetic individuals. Accurate measurement of glucose responses to meals can facilitate applications such as precision nutrition and early detection of diabetes.
OBJECTIVES
We aimed to quantify the discordance between simultaneous postprandial glucose measurements made using plasma and CGM.
METHODS
We studied 10 nondiabetic older adults who randomly consumed 9 predefined meals of varying macronutrient compositions. Glucose was measured for 8 h after the meal by the CGM, blood samples for plasma collection were taken regularly, and plasma glucose was quantified using gold-standard laboratory measurement and a fingerstick blood glucose meter. The primary outcome measured was the mean absolute relative difference (MARD) of CGM and fingerstick measurements relative to the gold standard. Secondary outcomes were Bland-Altman statistics, Clarke Error Grid, and time in range metrics. Additional subgroup analyses were performed by stratifying the postprandial glucose measurements based on the macronutrient composition of the meals.
RESULTS
When compared against the gold-standard postprandial glucose measurements, the fingerstick meter was more accurate (MARD: 8.0%; 95% CI: 7.6%, 8.6%) than the CGM (MARD: 13.7%; 95% CI: 13.1%, 14.3%; P < 0.0001). After the meals, Bland-Altman analysis demonstrated that the CGM underestimated the 8-h gold-standard glucose rise by 12.8 mg/dL on average (P < 0.0001), whereas the fingerstick meter did so by 5.5 mg/dL on average (P < 0.0001). The CGM underestimated the time spent in the 70-180 mg/dL range (P = 0.002) and overestimated the time spent <70 mg/dL (P < 0.0001) compared with the other 2 methods.
CONCLUSIONS
We discovered discordance between gold standard, fingerstick, and CGM in measuring plasma glucose concentrations after a meal. Consequently, emerging applications of CGM in healthy individuals, such as precision nutrition and diabetes onset prediction, may need to account for these discordances.This trial was registered at clinicaltrials.gov as NCT04928872.
Topics: Aged; Blood Glucose; Blood Glucose Self-Monitoring; Diabetes Mellitus, Type 1; Glucose; Humans; Postprandial Period
PubMed: 35776949
DOI: 10.1093/ajcn/nqac181 -
Therapeutic Advances in Cardiovascular... Aug 2015Postprandial hypotension, defined as a fall in systolic blood pressure (SBP) of 20 mmHg or greater within 2 hours after a meal, is a risk factor for stroke, coronary... (Review)
Review
Postprandial hypotension, defined as a fall in systolic blood pressure (SBP) of 20 mmHg or greater within 2 hours after a meal, is a risk factor for stroke, coronary events and mortality. The clinical suspicion is typically raised by episodes of postprandial syncope or falls, whereas asymptomatic postprandial hypotension is mostly neglected. The magnitude of the postprandial fall in SBP, as detected by 24-hour recording in apparently healthy middle-aged to elderly subjects, was proportional to the severity of the silent cerebrovascular damage. Postprandial hypotension can also be detected by self-measured blood pressure before and within 2 hours after meals using automatic devices. The review highlights the value of home blood pressure monitoring (HBPM) as a screening test for asymptomatic postprandial hypotension in hypertensive patients. Using a HBPM protocol that included duplicated blood pressure measurements before and after three consecutive lunches, we detected unsuspected postprandial hypotension in 27.4% of the 230 hypertensive patients screened. The prevalence of postprandial hypotension was 13.2% in controlled and 42.2% in uncontrolled hypertensive patients (p < 0.001), raising the dilemma of further lowering blood pressure in the setting of postprandial hypotension. The inclusion of preprandial and postprandial measurements in the protocol of HBPM is useful to identify hypertensive patients with postprandial hypotension and may guide adjustments in antihypertensive treatment according to postprandial blood pressure.
Topics: Aged; Antihypertensive Agents; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Humans; Hypertension; Hypotension; Middle Aged; Postprandial Period; Risk Factors
PubMed: 26187907
DOI: 10.1177/1753944715593444