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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 -
Giornale Italiano Di Nefrologia :... 2016Vitamin K-dependent matrix Gla protein (MGP) is a key inhibitor of vascular calcification (VC). MGP is synthesized by chondrocytes and vascular smooth muscle cells... (Review)
Review
Vitamin K-dependent matrix Gla protein (MGP) is a key inhibitor of vascular calcification (VC). MGP is synthesized by chondrocytes and vascular smooth muscle cells (VSMC) and the absence or inactivity of MGP results in excessive calcification of both growth plate and vasculature. Apart from its vitamin K dependency little is known about other factors that influence MGP metabolism. Phosphate, calcium and magnesium are involved in bone mineralization and play an important role in VC. In this review we provide a summary of the effect of phosphate, calcium, and magnesium on MGP metabolism. Elevated phosphate and calcium levels promote VC, in part by increasing the release of matrix vesicles (MV) that under the influence of calcium and phosphate become calcification competent. Phosphate and calcium simultaneously induce an upregulation of MGP protein and gene expression, which possibly inhibits calcification. Elevated phosphate levels did not change MGP protein levels in MV. On the contrary, elevated calcium concentrations caused a decrease of MGPloading in MV, which might in part explainthe calcifying effects of MV. Magnesium is a known inhibitor of VC. However, magnesium has been shown to have an inhibitory effect on MGP synthesis induced through downregulation of the calcium-sensing receptor and hereby causing a decrease in calcium induced MGP upregulation. There might also be stimulatory effect of magnesium on MGP in which the TRPM7 channel is involved. In conclusion there is a clear interaction between MGP and phosphate, calcium and magnesium. The upregulation of MGP by phosphate and calcium might be a cellular response that possibly results in the mitigation of VC.
Topics: Calcium; Calcium-Binding Proteins; Extracellular Matrix Proteins; Humans; Magnesium; Phosphates; Vascular Calcification; Matrix Gla Protein
PubMed: 28134400
DOI: No ID Found -
Journal of Nippon Medical School =... 2018Epigenetic inactivation of tumor suppressor genes is an important molecular mechanism in the formation and development of human tumors. The purpose of our study was to... (Review)
Review
BACKGROUND/AIM
Epigenetic inactivation of tumor suppressor genes is an important molecular mechanism in the formation and development of human tumors. The purpose of our study was to evaluate the correlation between the methylation level of the secreted frizzled-related protein 1 (SFRP1) gene and the risk of renal cell carcinoma (RCC).
METHODS
The relevant literature was searched in detail in several electronic databases. The methodological heterogeneity was analyzed by meta-regression and subgroup analyses. The odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated to summarize the dichotomous outcomes of our meta-analysis.
RESULTS
The ten included articles contained 535 RCC samples and 475 normal controls. The results demonstrated that the methylation level of the SFRP1 promoter region was significantly correlated with an increased incidence of RCC (OR=13.72; 95% CI: 6.01-31.28; P=0.000). Furthermore, the eligible studies that had sufficient clinical data about the RCC cases were included in the analysis, and the results indicated that the frequency of SFRP1 promoter methylation was associated with a higher histological grade (P=0.000), tumor stage (P=0.033), tumor size (≥5 cm; P=0.029), and distant metastasis (P=0.047).
CONCLUSION
Our results indicate that the methylation level of the SFRP1 promoter region is increased in patients with RCC compared to normal controls and might be involved in the occurrence and development of RCC. Additional well-designed studies are needed to further verify our conclusions.
Topics: Carcinoma, Renal Cell; Confidence Intervals; Humans; Incidence; Intercellular Signaling Peptides and Proteins; Kidney Neoplasms; Membrane Proteins; Meta-Analysis as Topic; Methylation; Neoplasm Metastasis; Neoplasm Staging; Odds Ratio; Promoter Regions, Genetic; Risk
PubMed: 29731501
DOI: 10.1272/jnms.2018_85-13 -
Current Osteoporosis Reports Oct 2019Bone turnover is a regulated process. Osteoglycin is suggested to have an important impact on bone function but may also affect cardiovascular and metabolic functions....
PURPOSE OF REVIEW
Bone turnover is a regulated process. Osteoglycin is suggested to have an important impact on bone function but may also affect cardiovascular and metabolic functions. This review investigates the action of osteoglycin in bone as well as its potential endocrine effects.
RECENT FINDINGS
Osteoglycin is expressed by several tissues including bone and muscle. Some studies suggest that osteoglycin increases osteoblast differentiation whereas others suggest that osteoglycin decreases osteoblast differentiation. Thus, findings on the influence of osteoglycin in bone are conflicting. A recent study found increased bone mass in osteoglycin deficient mice. Another study reported that osteoglycin is a marker of low bone mineral density and vertebral fractures in women with type 2 diabetes. Furthermore, clinical studies link osteoglycin to insulin resistance and cardiovascular disease. Osteoglycin may be a novel marker of a muscle, pancreatic, and bone axis. However, current evidence is limited and further research investigating osteoglycin in both a pre-clinical and a clinical setting is needed.
Topics: Animals; Biomarkers; Bone Density; Bone Remodeling; Cardiovascular Diseases; Cell Differentiation; Humans; Insulin Resistance; Intercellular Signaling Peptides and Proteins
PubMed: 31396918
DOI: 10.1007/s11914-019-00523-z -
Future Medicinal Chemistry Oct 2019Proteolysis-targeting chimeras (PROTACs) have received much attention for their promising therapeutic intervention in recent years. These molecules, with the mechanism...
Proteolysis-targeting chimeras (PROTACs) have received much attention for their promising therapeutic intervention in recent years. These molecules, with the mechanism of simultaneous recruitment of target protein and an E3 ligase, can trigger the cellular ubiquitin-proteasome system to degrade the target proteins. This article systematically introduces the mechanism of small-molecule PROTACs, and summarized the research progress of small-molecule PROTACs. The prospect for further application and the problems to be solved are also discussed.
Topics: Cell Line, Tumor; Humans; Proteasome Endopeptidase Complex; Proteolysis; Recombinant Fusion Proteins; Ubiquitin
PubMed: 31571504
DOI: 10.4155/fmc-2019-0161 -
Acta Anaesthesiologica Scandinavica May 2021The number of studies measuring breakdown products of the glycocalyx in plasma has increased rapidly during the past decade. The purpose of the present systematic review... (Review)
Review
BACKGROUND
The number of studies measuring breakdown products of the glycocalyx in plasma has increased rapidly during the past decade. The purpose of the present systematic review was to assess the current knowledge concerning the association between plasma concentrations of glycocalyx components and structural assessment of the endothelium.
METHODS
We performed a literature review of Pubmed to determine which glycocalyx components change in a wide variety of human diseases and conditions. We also searched for evidence of a relationship between plasma concentrations and the thickness of the endothelial glycocalyx layer as obtained by imaging methods.
RESULTS
Out of 3,454 publications, we identified 228 that met our inclusion criteria. The vast majority demonstrate an increase in plasma glycocalyx products. Sepsis and trauma are most frequently studied, and comprise approximately 40 publications. They usually report 3-4-foldt increased levels of glycocalyx degradation products, most commonly of syndecan-1. Surgery shows a variable picture. Cardiac surgery and transplantations are most likely to involve elevations of glycocalyx degradation products. Structural assessment using imaging methods show thinning of the endothelial glycocalyx layer in cardiovascular conditions and during major surgery, but thinning does not always correlate with the plasma concentrations of glycocalyx products. The few structural assessments performed do not currently support that capillary permeability is increased when the plasma levels of glycocalyx fragments in plasma are increased.
CONCLUSIONS
Shedding of glycocalyx components is a ubiquitous process that occurs during both acute and chronic inflammation with no sensitivity or specificity for a specific disease or condition.
Topics: Capillary Permeability; Endothelium, Vascular; Glycocalyx; Humans; Plasma; Sepsis; Syndecan-1
PubMed: 33595101
DOI: 10.1111/aas.13797 -
PloS One 2016Hemodialysis patients experience an elevated risk of malnutrition associated with increased morbidity and mortality. Nocturnal hemodialysis (NHD) results in more... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Hemodialysis patients experience an elevated risk of malnutrition associated with increased morbidity and mortality. Nocturnal hemodialysis (NHD) results in more effective removal of waste products and fluids. Therefore, diet and fluid restrictions are less restricted in NHD patients. However, it is ambiguous whether transition from conventional hemodialysis (CHD) to NHD leads to improved intake and nutritional status. We studied the effect of NHD on protein intake, laboratory indices of nutritional status, and body composition.
STUDY DESIGN
Systematic review with meta-analysis.
POPULATION
NHD patients.
SEARCH STRATEGY
Systematic literature search from databases, Medline, Cinahl, EMBASE and The Cochrane Library, to identify studies reporting on nutritional status post-transition from CHD to NHD.
INTERVENTION
Transition from CHD to NHD.
OUTCOMES
Albumin, normalized protein catabolic rate (nPCR), dry body weight (DBW), body mass index (BMI), phase angle, protein intake, and energy intake.
RESULTS
Systematic literature search revealed 13 studies comprising 282 patients that made the transition from CHD to NHD. Meta-analysis included nine studies in 229 patients. In control group controlled studies (n = 4), serum albumin increased significantly from baseline to 4-6 months in NHD patients compared with patients that remained on CHD (mean difference 1.3 g/l, 95% CI 0.02; 2.58, p = 0.05). In baseline controlled studies, from baseline to 4-6 months of NHD treatment, significant increases were ascertained in serum albumin (mean difference (MD) 1.63 g/l, 95% CI 0.73-2.53, p<0.001); nPCR (MD 0.16 g/kg/day; 95% CI 0.04-0.29, p = 0.01); protein intake (MD 18.9 g, 95% CI 9.7-28.2, p<0.001); and energy intake (MD 183.2 kcal, 95% CI 16.8-349.7, p = 0.03). Homogeneity was rejected only for nPCR (baseline versus 4-6 months). DBW, BMI, and phase angle did not significantly change. Similar results were obtained for comparison between baseline and 8-12 months of NHD treatment.
LIMITATIONS
Most studies had moderate sample sizes; some had incomplete dietary records and relatively brief follow-up period. Studies markedly differed with regard to study design.
CONCLUSIONS
NHD is associated with significantly higher protein and energy intake as well as increases in serum albumin and nPCR. However, the data on body composition are inconclusive.
Topics: Adult; Albumins; Body Composition; Body Mass Index; Body Weight; Case-Control Studies; Circadian Rhythm; Energy Intake; Female; Food; Humans; Male; Middle Aged; Nutritional Status; Renal Dialysis
PubMed: 27322616
DOI: 10.1371/journal.pone.0157621 -
International Journal of Sport... May 2018Coffee is one of the most consumed beverages in the world, and it can improve insulin sensitivity, stimulating glucose uptake in skeletal muscle when adequate... (Review)
Review
Coffee is one of the most consumed beverages in the world, and it can improve insulin sensitivity, stimulating glucose uptake in skeletal muscle when adequate carbohydrate intake is observed. The aim of this review is to analyze the effects of coffee and coffee components on muscle glycogen metabolism. A literature search was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis, and seven studies were included, that explored the effects of coffee components on various substances and signaling proteins. In one of the studies with humans, caffeine was shown to increase glucose levels, Ca/calmodulin-dependent protein kinase phosphorylation, glycogen resynthesis rates, and glycogen accumulation after exercise. After intravenous injection of caffeine in rats, caffeine increased adenosine monophosphate-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) phosphorylation, and glucose transport. In in vitro studies, caffeine raised AMPK and ACC phosphorylation, increasing glucose transport activity and reducing energy status in rat muscle cells. Cafestol and caffeic acid increased insulin secretion in rat beta cells and glucose uptake into human muscle cells. Caffeic acid also increased AMPK and ACC phosphorylation, reducing the energy status and increasing glucose uptake in rat muscle cells. Chlorogenic acid did not show any positive or negative effect. The findings from this review must be taken with caution due to the limited number of studies on the subject. In conclusion, various coffee components had a neutral or positive role in the metabolism of glucose and muscle glycogen, whereas no detrimental effect was described. Coffee beverages should be tested as an option for athletes' glycogen recovery.
Topics: AMP-Activated Protein Kinases; Acetyl-CoA Carboxylase; Animals; Coffee; Exercise; Glycogen; Humans; Insulin Resistance; Insulin-Secreting Cells; Muscle Cells; Muscle, Skeletal; Phosphorylation; Rats
PubMed: 29345166
DOI: 10.1123/ijsnem.2017-0342 -
Diabetes & Metabolic Syndrome 2021Systemic review (SR) and meta-analysis (MA) of interventional studies are considered as the highest level of evidence for clinical decision making. Therefore, we...
BACKGROUND AND AIMS
Systemic review (SR) and meta-analysis (MA) of interventional studies are considered as the highest level of evidence for clinical decision making. Therefore, we systematically summarized all high-quality evidence on the usage of coconut oil for health-related benefits from SRs and MA.
METHODS
PubMed®, Web of science®, SciVerse Scopus®, and EMBASE® databases were systematically searched to select SRs and SRs with MA of interventional studies reporting health-related clinical outcomes of coconut oil. Similar studies were grouped based on their respective clinical areas. A methodological quality appraisal was conducted for all included SRs and SRs with MA using the Critical Appraisal Checklist for Systematic Reviews.
RESULTS
A total of seven papers were selected for inclusion in this review, consisting of three MA and one SR on cardio-metabolic health, one SR on oral health, and one SR and one MA each on skin health. Coconut oil significantly increases serum total cholesterol, low-density- and high-density- lipoprotein cholesterol levels compared to poly- and mono-unsaturated oils. Limited studies showed that topical use of coconut oil helps in the prevention and treatment of atopic dermatitis and oil pulling for the prevention of dental caries. All four studies on cardiometabolic health and the SR on oral health had a high score in the quality assessment, SR with MA on skin health fulfilled high-quality scoring whereas the SR on the same topic had a low-quality scoring.
CONCLUSIONS
In summary, consistent and strong evidence shows that coconut oil has an adverse effect on the lipids parameters associated with cardio-metabolic health, with limited studies to conclude the effects of atopic dermatitis and oil pulling.
Topics: Cholesterol, HDL; Cholesterol, LDL; Coconut Oil; Dental Caries; Humans; Lipid Metabolism; Meta-Analysis as Topic; Randomized Controlled Trials as Topic; Skin Physiological Phenomena; Systematic Reviews as Topic
PubMed: 33689936
DOI: 10.1016/j.dsx.2021.02.032 -
Nutrition Journal Oct 2023It is suggested that supplementation with milk protein (MP) has the potential to ameliorate the glycemic profile; however, the exact impact and certainty of the findings... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
It is suggested that supplementation with milk protein (MP) has the potential to ameliorate the glycemic profile; however, the exact impact and certainty of the findings have yet to be evaluated. This systematic review and dose-response meta-analysis of randomized controlled trials (RCTs) assessed the impact of MP supplementation on the glycemic parameters in adults.
METHODS
A systematic search was carried out among online databases to determine eligible RCTs published up to November 2022. A random-effects model was performed for the meta-analysis.
RESULTS
A total of 36 RCTs with 1851 participants were included in the pooled analysis. It was displayed that supplementation with MP effectively reduced levels of fasting blood glucose (FBG) (weighted mean difference (WMD): -1.83 mg/dL, 95% CI: -3.28, -0.38; P = 0.013), fasting insulin (WMD: -1.06 uU/mL, 95% CI: -1.76, -0.36; P = 0.003), and homeostasis model assessment of insulin resistance (HOMA-IR) (WMD: -0.27, 95% CI: -0.40, -0.14; P < 0.001) while making no remarkable changes in serum hemoglobin A1c (HbA1c) values (WMD: 0.01%, 95% CI: -0.14, 0.16; P = 0.891). However, there was a significant decline in serum levels of HbA1c among participants with normal baseline body mass index (BMI) based on sub-group analyses. In addition, HOMA-IR values were significantly lower in the MP supplement-treated group than their untreated counterparts in short- and long-term supplementation (≤ 8 and > 8 weeks) with high or moderate doses (≥ 60 or 30-60 g/d) of MP or whey protein (WP). Serum FBG levels were considerably reduced upon short-term administration of a low daily dose of WP (< 30 g). Furthermore, the levels of serum fasting insulin were remarkably decreased during long-term supplementation with high or moderate daily doses of WP.
CONCLUSION
The findings of this study suggest that supplementation with MP may improve glycemic control in adults by reducing the values of fasting insulin, FBG, and HOMA-IR. Additional trials with longer durations are required to confirm these findings.
Topics: Adult; Humans; Glycated Hemoglobin; Blood Glucose; Milk Proteins; Diabetes Mellitus, Type 2; Dietary Supplements; Insulin; Insulin Resistance; Whey Proteins
PubMed: 37798798
DOI: 10.1186/s12937-023-00878-1