Total Branched-chain Amino Acids Research Articles

1275-P: Higher Branched-Chain Amino Acids in Youth with Type 2 Diabetes Paradoxically Increased by Short-Term Metformin

Branched chain amino acids (BCAA) are important signaling molecules that are strongly related to type 2 diabetes (T2D), but the data linking BCAAs to reduced insulin sensitivity (IS) in youth is conflicting. This complex relationship of BCAAs with IS and glycemia may be further confounded by metformin that potentially alters BCAA synthesis and transport via gut mechanisms. Therefore, we compared: (1) BCAAs in 20 youth with T2D pre-metformin to 10 normal glucose tolerant (NGT) age/BMI-matched controls and (2) the change in BCAAs after 3 months of metformin in 8 youth with T2D. Fasting BCAAs were measured with nuclear magnetic resonance spectroscopy and IS and oral disposition index (oDI) calculated during a multi-sample 75g OGTT. Compared to NGT, youth with T2D had higher BCAAs and hemoglobin A1c (HbA1c) but lower IS and oDI (Table). Higher total BCAAs pre-metformin correlated with HbA1c (r=0.6, P<0.001,), inversely correlated with oDI (r= -0.5, P=0.02,), but not with IS or BMI (r=0.2, P>0.2). Metformin decreased HbA1c and increased leucine and isoleucine (Table), but there was no change in BMI, IS or valine (all P>0.05). In youth, higher BCAAs were related to lower β-cell function relative to IS and worse glycemia. Although metformin improved glycemia, BCAAs were paradoxically increased suggesting that BCAAs may not be a useful treatment biomarker or indicator of changes in metabolic status. Disclosure A. Meyers: None. C.K. Cravalho: None. A. Villalobos-Perez: None. S. Matta: None. L. Mabundo: None. A.B. Courville: None. M.L. Sampson: None. J.D. Otvos: Employee; Self; LabCorp. S.T. Chung: None. Funding National Institutes of Health (to S.T.C., L.M., A.B.C.)

Probiotic Administration Increases Amino Acid Absorption from Plant Protein: a Placebo-Controlled, Randomized, Double-Blind, Multicenter, Crossover Study

The fate of dietary protein in the gut is determined by microbial and host digestion and utilization. Fermentation of proteins generates bioactive molecules that have wide-ranging health effects on the host. The type of protein can affect amino acid absorption, with animal proteins generally being more efficiently absorbed compared with plant proteins. In contrast to animal proteins, most plant proteins, such as pea protein, are incomplete proteins. Pea protein is low in methionine and contains lower amounts of branched-chain amino acids (BCAAs), which play a crucial role in muscle health. We hypothesized that probiotic supplementation results in favorable changes in the gut microbiota, aiding the absorption of amino acids from plant proteins by the host. Fifteen physically active men (24.2 ± 5.0 years; 85.3 ± 12.9 kg; 178.0 ± 7.6 cm; 16.7 ± 5.8% body fat) co-ingested 20 g of pea protein with either AminoAlta™, a multi-strain probiotic (5 billion CFU L. paracasei LP-DG® (CNCM I-1572) plus 5 billion CFU L. paracasei LPC-S01 (DSM 26760), SOFAR S.p.A., Italy) or a placebo for 2 weeks in a randomized, double-blind, crossover design, separated by a 4-week washout period. Blood samples were taken at baseline and at 30-, 60-, 120-, and 180-min post-ingestion and analyzed for amino acid content. Probiotic administration significantly increased methionine, histidine, valine, leucine, isoleucine, tyrosine, total BCAA, and total EAA maximum concentrations (Cmax) and AUC without significantly changing the time to reach maximum concentrations. Probiotic supplementation can be an important nutritional strategy to improve post-prandial changes in blood amino acids and to overcome compositional shortcomings of plant proteins. ClinicalTrials.gov Identifier: ISRCTN38903788

Lipoprotein insulin resistance score and branched-chain amino acids increase after adrenalectomy for unilateral aldosterone-producing adenoma: a preliminary study

Background and aimsPrimary aldosteronism (PA) due to unilateral aldosterone-producing adenoma (APA) is preferentially treated by unilateral adrenalectomy (ADX), but little is known about the changes in lipid and glucose metabolism that may occur after ADX.MethodsWe studied 19 non-diabetic patients who did not use lipid-lowering drugs with PA due to APA before and 6 months after unilateral ADX. Fasting plasma lipids, lipoprotein subfractions, branched-chain amino acids (BCAA), and GlycA, a pro-inflammatory glycoprotein biomarker, were measured by nuclear magnetic resonance (NMR) spectroscopy. The Lipoprotein Insulin Resistance (LP-IR) score, which is based on six lipoprotein variables, was calculated.ResultsIn all patients, hyperaldosteronism was resolved after ADX. Body mass index and fasting plasma glucose were unchanged, but HbA1c increased (p = 0.002). Plasma triglycerides, large triglyceride-rich lipoprotein (TRL) cholesterol, and large TRL particles were increased (p < 0.01), resulting in an increase in TRL size (p = 0.027). High-density lipoprotein size was decreased (p = 0.015). LP-IR scores (p = 0.001) and total BCAA (p = 0.017) were increased, but GlycA remained unaltered.ConclusionsBased on increases in LP-IR scores and BCAA, which each have been shown to predict new onset type 2 diabetes mellitus independent of conventional risk factors in the general population, this preliminary study suggests that diabetes risk is not improved but may even be increased after ADX for APA despite remission of PA.

Branched-chain amino acids: Abundance of their transporters and metabolizing enzymes in adipose tissue, skeletal muscle, and liver of dairy cows at high or normal body condition

Branched-chain amino acids (BCAA) are major components of milk protein and important precursors for nonessential AA. Thus, the BCAA transport and break-down play a key role in the metabolic adaptation to the high nutrient demands in lactation. However, in monogastrics, increased BCAA levels have been linked with obesity and certain metabolic disorders such as impaired insulin sensitivity. Our objective was to study the effect of over-conditioning at calving on plasma BCAA levels as well as the tissue abundance of the most relevant BCAA transporters and degrading enzymes in dairy cows during late pregnancy and early lactation. Thirty-eight Holstein cows were allocated 15 wk antepartum to either a normal- (NBCS) or over-conditioned (HBCS) group, receiving 6.8 or 7.2 MJ of NEL/kg of DM, respectively, during late lactation to reach the targeted differences in body condition score (BCS) and back fat thickness (BFT; NBCS: BCS <3.5, BFT <1.2 cm; HBCS: BCS >3.75, BFT >1.4 cm) until dry-off. During the dry period and next lactation, cows were fed the same diets, whereby differences in BCS and BFT were maintained: prepartum means were 3.16 ± 0.06 and 1.03 ± 0.07 cm (NBCS) vs. 3.77 ± 0.08 and 1.89 ± 0.11 cm (HBCS), postpartum means were 2.89 ± 0.06 and 0.81 ± 0.05 cm (NBCS) vs. 3.30 ± 0.06 and 1.38 ± 0.08 cm (HBCS). Blood and biopsies from liver, semitendinosus muscle, and subcutaneous adipose tissue (scAT) were sampled at d 49 antepartum, 3, 21, and 84 postpartum. Free BCAA were analyzed and the mRNA abundance of solute carrier family 1 member 5 (SLC1A5), SLC7A5, and SLC38A2 as well as branched-chain aminotransferase 2 (BCAT2), branched-chain α-keto acid dehydrogenase E1α (BCKDHA), and branched-chain α-keto acid dehydrogenase E1β (BCKDHB) as well as the protein abundance of BCKDHA were assessed. Concentrations of all BCAA changed with time, most markedly in HBCS cows, with a nadir around calving. Apart from Ile, neither individual nor total BCAA differed between groups. The HBCS group had greater BCKDHA mRNA as well as higher prepartum BCKDHA protein abundance in scAT than NBCS cows, pointing to a greater oxidative capacity for the irreversible degradation of BCAA transamination products in scAT of over-conditioned cows. Prepartum hepatic BCKDHA protein abundance was lower in HBCS than in NBCS cows. In both groups, SLC1A5, SLC7A5, and BCAT2 mRNA were most abundant in scAT, whereas SLC38A2 was higher in scAT and muscle compared with liver, and BCKDHA and BCKDHB mRNA were greatest in liver and muscle, respectively. Our results indicate that scAT may be a major site of BCAA uptake and initial catabolism, with the former, however, being independent of BCS and time relative to calving in dairy cows.

Nutritional, phytoconstituents, and free radical scavenging potentials of Cola lepidota K. Schum. and Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill. leaves

This study was carried out to determine the essential oil components, protein qualities, fatty acid composition, and free radical scavenging potentials of leaves of Cola lepidota K. Schum. (Malvaceae) and Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill. (Irvingiaceae) using chromatographic and spectrophotometric methods. Thirty five bioactive components were isolated from C. lepidota leaves with myrcene, phytol, ephedrine, hexadecanoic acid, and 1,14-tetradecanediol as the main compounds while phytol, 2-furancarboxaldehyde, 5-(hydroxymethyl)-, 1-hexadecyne, carotene, and humulene were the predominant components of the I. gabonensis leaves. Leucine and arginine were the predominant essential amino acids, whereas glutamic acid and serine were the main non-essential amino acids in both leaves. The total amino acid (TAA) (70.92 g/100g), total non-essential amino acid (TNEAA) (45.87 g/100 g), and total acidic amino acid (TAAA) (23.01 g/100 g) of C. lepidota were high whereas I. gabonensis recorded higher Total essential amino acid (TEAA) (28.98 g/100 g), total aromatic amino acid (TArAA) (7.21 g/100 g), total branched chain amino acid (TBCAA) (14.28 g/100g), predicted protein efficiency ratios (P-PERs), and essential amino acid index (EAAI). C. lepidota contained 55.72% of unsaturated fatty acids, with predominance of linolenic and linoleic acids, while I. gabonensis produced 74.46% of saturated fatty acids, having myristic, lauric, and palmitic acid as the main compounds. All the radical scavenging potentials of both leaves were concentration dependent and produced higher DPPH, hydrogen peroxide, and ABTS radical scavenging potentials than the standards. This study has thus provided the scientific backing for the inclusion of both leaves for dietary and therapeutic purposes.

Proteins and Amino Acids Treated with Atmospheric Plasma Show Significantly Increased Bioavailability in Humans.

Background:Muscle mass is an important determinant of metabolic health and physical function. It has previously been demonstrated that the postprandial rise in circulating essential amino acids acts as the main stimulus for muscle protein synthesis (MPS). The current study investigated the postprandial plasma essential amino acid (EAA) and branched-chain amino acid (BCAA) responses of (1) Hydrolyzed whey protein isolate (HWPI) compared to plasma treated non-hydrolyzed whey protein isolate (PT-NHWPI), (2) standard branch-chain amino acids (S-BCAA) compared to plasma treated branch-chained amino acids (PT-BCAA), (3) standard pea protein (S-PP), compared to plasma treated pea protein (PT-PP), and (4) HWPI compared to PT-PP.Methods:Ten subjects (24.6 ± 5.3 years; 178.8 ± 8.1 cm; 78.6 ± 10.1 kg) participated in a double-blind, randomized, crossover trial comparing four separate protein conditions (HWPI, PT-NHWPI, S-PP, PT-PP). A separate cohort of ten subjects (26.4 ± 7.4 years; 178.8 ± 5.9 cm; 85 ± 12.3 kg) participated in a double-blind randomized, crossover trial comparing two branch-chain amino acid conditions: S-BCAA and PT-BCAA. All conditions were administered following a 7-day washout. Plasma EAA and BCAA concentrations were assessed from blood donated by subjects at pre-consumption, 30-, 60-, 90-, 120-, and 180 minutes post-consumption.Results:Blood plasma levels of total EAA and BCAA concentration were significantly greater in all treated conditions at 30-, 60-, 90-, and 120 minutes post consumption (P < .05). There were no differences between PT-PP and HWPI.Discussion:All proteins significantly elevated EAAs, and BCAAs from basal levels. However, we conclude that the consumption of the treated proteins significantly raises blood levels of EAAs, and BCAAs to a greater extent across multiple dairy, vegan, and isolated BCAA conditions. Moreover, atmospheric plasma treatment of a vegan protein source makes its amino acid response similar to whey. Thus, protein supplementation with that has undergone Ingredient Optimized® atmospheric plasma treatment technology may be highly beneficial for improving the blood plasma amino acid response.

The impact of persistent milk consumption in the pathogenesis of type 2 diabetes mellitus

Background: Milk and sugar are excessively consumed in a Western diet. There is increasing epidemiological evidence that the intake of unfermented pasteurized cow´s milk is associated with an increased risk of type 2 diabetes mellitus (T2D). It is the intention of this review to provide translational biochemical evidence for milk´s diabetogenic mode of action. Milk proteins provide the highest amounts of branched-chain amino acids (BCAAs) and thus contribute to total BCAA intake, which enhances BCAA plasma levels associated with increased risk of T2D. The consumption of pasteurized milk raises plasma levels of miRNA-29b, which is a diabetogenic miRNA promoting insulin resistance (IR). miRNA29b inhibits the activity of branched-chain-keta acid dehydrogenase, the rate limiting enzyme of BCAA catabolism, which is impaired in patients with IR and T2D. Milk consumption stimulates mTORC1 activity and increases insulin synthesis. -cell mTORC1 is overactivated in T2D patients resulting in impaired autophagy which enhances endoplasmic reticulum (ER) stress associated with a greater risk of early -cell apoptosis, the pathogenic hallmark of T2D. Chronic insulinotropic action of milk-derived BCAAs, IR-promoting mTORC1 overactivity, and miRNA-29b signaling combined with excessive glucose-mediated insulin secretion overburden -cell insulin homeostasis. Epidemiological and translational evidence identifies continued milk intake as a promoter of T2D, the most common metabolic disease of Western civilization. Keywords: Branched-chain amino acids, branched-chain-keto acid dehydrogenase, diabetes mellitus type 2, insulin resistance, milk, miRNA-29b, mechanistic target of rapamycin complex 1.

Association between dyslipidemia and plasma levels of branched-chain amino acids in the Japanese population without diabetes mellitus

Branched-chain amino acids (BCAAs) play a key role in energy homeostasis. We aimed to investigate the association between plasma BCAA levels and dyslipidemia in the Japanese population without diabetes mellitus. This cross-sectional study included 4952 participants without diabetes mellitus, enrolled in the Tsuruoka Metabolomic Cohort Study. Plasma BCAA levels were measured by capillary electrophoresis-mass spectrometry. Correlations between lipid and BCAA profiles were evaluated by sex-stratified multiple linear regression analyses, after adjusting for confounders. Logistic regression was used to identify associations between BCAAs and metabolic dyslipidemia (MD) defined as triglyceride levels ≥150mg/dL, high-density lipoprotein cholesterol levels ≤40mg/dL for men and ≤50mg/dL for women, or low-density lipoprotein cholesterol (LDL-C) levels ≥140mg/dL. In both sexes, the levels of individual BCAAs and the total BCAA levels correlated positively with triglyceride levels and negatively with high-density lipoprotein cholesterol levels. Valine, leucine, and total BCAA levels were weakly and positively correlated with LDL-C levels. Increased BCAA levels showed positive associations with MD. However, associations between BCAAs and elevated LDL-C levels were unclear. Furthermore, the associations between BCAA levels and MD regardless of fasting blood sugar (FBS) levels (high or low). Although valine, leucine, and total BCAA levels were weakly associated with elevated LDL-C levels in the high-FBS group, no such association was observed in the low-FBS group. BCAAs might be associated with MD independently of the FBS level and might play an important role in lipid metabolism and dyslipidemia.

1702-P: Fine-Scale Haplotype Mapping of PPM1K Gene Reveals New Genetic Markers for the Study of Insulin Resistance at Clinical Scale

Branched chain amino acids (BCAA) plasma levels represent potential biomarkers for development of type 2 diabetes (T2D). Mendelian randomization and prospective studies indicated causal relationship between SNPs in PPM1K (protein phosphatase Mg2+/Mn2+ dependent 1K) gene (Chr 4q22.1) and increased risk of incident T2D while other studies, including ours suggested the contribution of MUT (metylmalonyl-CoA mutase) gene (Chr 6p12.3) in insulin resistance (IR). To define genetic markers we performed fine-scale haplotype mapping of PPM1K in two populations (French and Romanians) with metabolic syndrome (n = 465). SNPs were genotyped with Affymetrix and enriched by imputation at 1000 genome density (BEAGLE 4.1). Haplotype association was performed by sliding window (4 SNPs windowing) and analyzed in HAPLOVIEW and PHASE 2.1. Previous leader SNPs in PPM1K (rs7678928 and rs1440581) were not associated with IR in our population but haplotype mapping revealed two major signals downstream (GGGC) and upstream (ACAG), centered by rs71609524 and rs4423843 with P &amp;lt; 3.76 x 10-3 (OR 1.59, 95% CI [1.13 - 2.23]) and &amp;lt; 4.72x10-3 (OR 1.50, 95% CI [1.12 - 2.01]), respectively. Values were weaker that those from MUT gene (P-value of the most significant haplotype, centered by rs2167284 was &amp;lt; 10-5). Total BCAA plasma levels were associated with PPM1K by several SNPs, including rs7656367 and rs4693955 with P &amp;lt; 5 x 10-3, OR of 0.41 and 3.22, respectively. Interestingly, correlation trend test with leucine, isoleucine and valine were better correlated with SNPs in the MUT gene: rs10948396 was associated with P &amp;lt; 7.91 x 10-5 (Bonferroni 6 x 10-2) and confirmed by correlation with total BCAA levels (P &amp;lt; 1.60 x 10-6, Bonferroni 1.22 x 10-3). These data suggest synergistic effects and indicate that new valuable genetic markers can be defined for clinical trials using fine-scale haplotype mapping, thus revealing complex relationship between genes in the determinism of IR and BCAA metabolism. Disclosure S. Haydar: None. C. Lautier: None. F. Grigorescu: None. Funding MEDIGENE (FP7-279171)

Association between plasma essential amino acids and atherogenic lipid profile in a Chinese population: A cross-sectional study

Background and aimsThe association between amino acids and small dense low-density lipoprotein cholesterol (sdLDL-C) and remnant-like particle cholesterol (RLP-C) remains poorly understood. This study aims to investigate the association between plasma essential amino acids (EAAs) and atherogenic lipid profiles. MethodsPlasma amino acid levels of 475 individuals were measured using liquid chromatography-mass spectrometry. SdLDL-C, RLP-C, and other lipid components were evaluated. Associations between EAAs and lipid components or dyslipidemia were determined using correlation analysis and multivariate logistic regression. ResultsConcentrations of plasma branched-chain amino acid (BCAA) were positively correlated with sdLDL-C, RLP-C, and triglycerides (TG) levels, but inversely correlated with high-density lipoprotein cholesterol (HDL-C). In contrast, threonine concentration was inversely correlated with sdLDL-C, RLP-C, and TG. Compared with the lowest tertile, individuals in the highest tertile of plasma total BCAAs level had an odds ratio (OR) of 2.33 (95% confidence interval [CI]: 1.35, 4.03) for the risk of high sdLDL-C, 3.63 (95%CI: 1.69, 7.80) for the risk of high RLP-C, 3.10 (95%CI: 1.66, 5.80) for the risk of high TG, and 3.67 (95%CI: 2.00, 6.73) for atherogenic lipid triad (all p < 0.01). In contrast, compared with the lowest tertile, individuals in the highest plasma threonine tertile had a 43% lower OR for high sdLDL-C, 56% lower OR for high TG, and 55% lower OR for lipid triad risk (all p < 0.05). ConclusionsAmong the EAAs evaluated, elevated plasma BCAAs were significantly associated with increased risk of atherogenic lipid profile. In contrast, elevated threonine was associated with reduced risk of atherogenic lipid profile.

Abstract MP59: The Differential Effects of Amount and Intensity of Aerobic Exercise Training on MVX, a Novel Mortality Risk Multimarker

Introduction: Metabolic Vulnerability Index (MVX) is a novel spectroscopic multimarker of mortality risk. MVX reflects components of nutrition and systemic inflammation status and is hypothesized to enhance disease and mortality risk stratification. As Studies Targeting Risk Reduction Interventions through Defined Exercise (STRRIDE) has previously demonstrated the ability of aerobic exercise training to improve traditional markers of cardiometabolic health, we hypothesized that aerobic exercise intervention also would result in beneficial changes in the components of MVX. Methods: Participants (n=222, previously sedentary, overweight men and women with mild to moderate dyslipidemia from STRRIDE) were randomized to either a 6-month control group or to one of three supervised aerobic exercise groups for 8-months: 1) low amount moderate intensity (LM): 14 kcal/kg/wk at 40-55% VO 2peak ; 2) low amount vigorous intensity (LV): 14 kcal/kg/wk at 65-80% VO 2peak ; 3) high amount vigorous intensity (HV): 21 kcal/kg/wk at 65-80% VO 2peak . Blood samples were obtained after an overnight fast at both baseline and study completion (16-24 hr after the final training bout for exercisers). Nuclear magnetic resonance spectroscopy was performed on the Vantera ® clinical analyzer at LabCorp to determine MVX score. MVX has two components: inflammation index [INFX; combined concentrations of GlycA and small HDL particle subspecies (diameters &lt; 9 nm)] and metabolic malnutrition index (MALNX; combined concentrations of total branched chain amino acids and ketone bodies). MVX, INFX, and MALNX are all scaled from 1 (lowest risk) to 100 (highest risk). Paired t-tests determined whether the post- minus pre- intervention change scores within each group were significant (p&lt;0.05). We used analysis of covariance accounting for baseline values to determine difference between groups. Results: The inactive control group did not exhibit significant changes in any of the multimarkers. After 8-months of exercise training, the LM group experienced significant decreases in all three scores: INFX (-2.1 ± 5.2), MALNX (-3.1 ± 11.3), and MVX (-3.9 ± 9.1). The LV group significantly decreased their INFX score (-1.5 ± 3.8), yet significantly increased MALNX (2.2 ± 6.8). The HV group significantly decreased their INFX (-1.6 ± 4.8) and MVX scores (-1.9 ± 5.6). For the LM group, the beneficial changes in MALNX and MVX were significantly greater than the LV group. Conclusion: Aerobic exercise improved components of the novel risk-prediction multimarker MVX, with the LM group displaying the best responses across all three scores. As ongoing research investigates the clinical utility of these mulitmarkers, this study provides evidence for the ability of exercise intervention to beneficially change MVX score.

The Profile of Plasma Free Amino Acids in Type 2 Diabetes Mellitus with Insulin Resistance: Association with Microalbuminuria and Macroalbuminuria.

Altered plasma levels of branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) may predict the development of insulin resistance and other type 2 diabetes mellitus (T2DM) associated comorbidities. To elucidate the role of plasma free amino acids (PFAAs) profile as a biomarker for early detection of diabetic kidney disease, quantitative measurement of PFAAs profile was determined for 90 T2DM subjects, 30 were free of nephropathy, 30 with microalbuminuria, 30 with macroalbuminuria, and in addition to 30 healthy controls. The plasma levels of valine, leucine, isoleucine, phenylalanine, citrulline, and total BCAAs were significantly increased in diabetic normoalbuminuria group when compared to controls. However, the total BCAAs level was significantly decreased in diabetic patients with micro and macroalbuminuria. Other amino acid plasma levels as tyrosine, arginine, ornithine, glycine, and the total AAAs level were significantly decreased in all diabetic subgroups compared to controls. Significant positive correlations between total BCAAs, valine, leucine, isoleucine, serum insulin, glucose, and HOMA-IR values in the diabetic normoalbuminuria group were found. The use of altered PFAAs profile as a prognostic factor in T2DM patients at risk for microalbuminuria or macroalbuminuria might reduce or prevent the incidence of end-stage diabetic renal disease.

Changes in tissue abundance and activity of enzymes related to branched-chain amino acid catabolism in dairy cows during early lactation

Branched-chain α-keto acid dehydrogenase (BCKDH) complex catalyzes the irreversible oxidative decarboxylation of branched-chain α-keto acids. This reaction is considered as the rate-limiting step in the overall branched-chain amino acid (BCAA) catabolic pathway in mammals. For characterizing the potential enzymatic involvement of liver, skeletal muscle, adipose tissue (AT), and mammary gland (MG) in BCAA metabolism during early lactation, tissue and blood samples were examined on d 1, 42, and 105 after parturition from 25 primiparous Holstein cows. Serum BCAA profiles were analyzed and the mRNA and protein abundance as well as the activity in the different tissues were assessed for the BCAA catabolic enzymes, partly for the branched-chain aminotransferase and completely for BCKDH. Total BCAA concentration in serum was lowest on d 1 after parturition and increased thereafter to a steady level for the duration of the experiment. Pronounced differences between the tissues were observed at all molecular levels. The mRNA abundance of the mitochondrial isoform of branched-chain aminotransferase (BCATm) was greatest in AT as compared with the other tissues studied, indicating that AT might be an important contributor in the initiation of BCAA catabolism in dairy cows. From the different subunits of the BCKDH E1 component, only the mRNA for the β polypeptide (BCKDHB), not for the α polypeptide (BCKDHA), was elevated in liver. The BCKDHA mRNA abundance was similar across all tissues except muscle, which tended to lower values. Highest BCKDHA protein abundance was observed in both liver and MG, whereas BCKDHB protein was detectable in these tissues but could not be quantified. Adipose tissue and muscle only displayed abundance of the α subunit, with muscle having the lowest BCKDHA protein of all tissues. We found similarities in protein abundance for both BCKDH E1 subunits in liver and MG; however, the corresponding overall BCKDH enzyme activity was 7-fold greater in liver compared with MG, allowing for hepatic oxidation of BCAA transamination products. Reduced BCKDH activity in MG associated with no measurable activity in AT and muscle may favor sparing of BCAA for the synthesis of the different milk components, including nonessential AA. Deviating from previously published data on BCAA net fluxes and isotopic tracer studies in ruminants, our observed results might in part be due to complex counter-regulatory mechanisms during early lactation.

Primary aldosteronism is associated with decreased low-density and high-density lipoprotein particle concentrations and increased GlycA, a pro-inflammatory glycoprotein biomarker.

Primary aldosteronism (PA) may confer increased cardiovascular risk beyond effects on systemic blood pressure, but contributing mechanisms remain incompletely understood. We compared plasma (apo)lipoproteins and lipoprotein particle characteristics, GlycA, a pro-inflammatory glycoprotein biomarker of enhanced chronic inflammation, and plasma total branched-chain amino acids (BCAA), measured using nuclear magnetic resonance (NMR) spectroscopy, between patients with PA, control subjects without hypertension, subjects with untreated hypertension and subjects with treated hypertension. Twenty PA patients were individually matched with 2819 control subjects without hypertension, 501 subjects with untreated hypertension and 878 subjects with treated hypertension participating in the PREVEND (Prevention of Renal and Vascular End-Stage Disease) cohort study with respect to age, sex, body mass index, smoking and statin use. The Vantera® Clinical Analyzer was used to determine NMR-based laboratory parameters. Total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (apo) B, apolipoprotein A-I (apoA-I), LDL particle and HDL particle concentrations were all decreased in PA subjects vs control subjects and subjects with untreated hypertension (P<0.016). Triglycerides (TG) and triglyceride-rich lipoprotein (TRL) concentrations were lower in PA subjects vs subjects with (untreated) hypertension. GlycA was increased in PA vs the three comparator groups (P<0.016). Total BCAA concentrations were unaltered in PA. Primary aldosteronism is associated with lower concentrations of LDL and HDL particles and to some extent also with lower TG and TRL particle concentrations. PA is also characterized by increased GlycA levels, indicating enhanced low-grade chronic inflammation. Low HDL particle concentrations and increased GlycA could contribute to accelerated cardiovascular disease development in PA.

Dietary branched-chain amino acids intake exhibited a different relationship with type 2 diabetes and obesity risk: a meta-analysis.

To assess whether oral branched-chain amino acids (BCAA) supplementation exerts influence on circulating BCAA and the significance of dietary BCAA in type 2 diabetes and obesity risk. We searched PUBMED, EMBASE and Cochrane library through June 2018 to retrieve and screen published reports for inclusion in the meta-analysis after methodological assessment. Heterogeneity of studies was evaluated using I2 statistics, while sensitivity analysis and funnel plot were used to evaluate the potential effect of individual studies on the overall estimates and publication bias, respectively, using RevMan 5.3. Eight articles on randomized clinical trial of oral BCAA supplementation, and seven articles on dietary BCAA intake and type 2 diabetes/obesity risks were eligible for inclusion in our meta-analyses. Mean difference and 95% confidence interval (CI) of circulating leucine was 39.65 (3.54, 75.76) µmol/L, P = 0.03 post-BCAA supplementation. Also, OR and 95% CI for higher total BCAA intake and metabolic disorder risks were, 1.32 (1.14, 1.53), P = 0.0003-type 2 diabetes and 0.62 (0.47, 0.82), P = 0.0008-obesity. Oral BCAA supplementation exerts modest influence on circulating leucine profile and higher total BCAA intake is positively and contra-positively associated with type 2 diabetes and obesity risk, respectively.

Low Levels of Branched Chain Amino Acids, Eicosapentaenoic Acid and Micronutrients Are Associated with Low Muscle Mass, Strength and Function in Community-Dwelling Older Adults.

Sarcopenia, the age-related decrease in muscle mass and function can result in adverse health outcomes and subsequent loss of independence. Inadequate nutrition is an important contributor to the aetiology of sarcopenia, and dietary strategies are studied to prevent or delay this geriatric syndrome. The present study investigated whether there is an association between biochemical nutrient status markers, muscle parameters and sarcopenia in community-dwelling older adults. Data from the cross-sectional Maastricht Sarcopenia study (MaSS) were used, in which skeletal muscle index (SMI), 4 meter gait speed, 5 times chair stand and handgrip strength were assessed among older adults (n=227). Sarcopenia was defined following the algorithm of the European Working Group on Sarcopenia in Older People. Fasted blood samples were analyses on amino acids levels, RBC phospholipid profile, 25-hydroxyvitamin D (25(OH)D), α-tocopherol, magnesium and homocysteine were determined in fasted blood levels. Generalized linear modelling and logistic regression were used for data analysis. Lower blood levels of essential amino acids (EAA), total branched-chain amino acids (BCAA) and leucine were associated with lower SMI (P<0.001), strength (P<0.001) and longer time to complete the chair stand (P<0.05), whereas no association was found for total amino acids (TAA). Lower levels of eicosapentaenoic acid (EPA), 25(OH)D and homocysteine were associated with lower muscle parameter values (P<0.05). No significant associations were found for SFA, MUFA, PUFA, n-3 and n-6 fatty acids, docosahexaenoic acid (DHA), α-tocopherol-cholesterol ratio and magnesium. Sarcopenia was more frequent among those with lower levels of leucine, BCAA, EAA, EPA, 25(OH)D and higher levels of homocysteine (P<0.05). Age and BMI were identified as relevant covariates. A robust association was only found for lower gait speed and lower 25(OH)D levels. Compromised muscle parameters are associated with low blood values of specific amino acids, fatty acids, vitamin D and high homocysteine.

High Serum Branched-Chain Amino Acids Level Independently Predicts Incident Heart Failure—The Hong Kong Diabetes Register

Background: Obesity predicts cardiovascular(CV)-renal disease. Contrary to claims that branched-chain amino acids (BCAA)-rich diet/supplements may improve weight and insulin resistance, recent data suggest impaired oxidation of BCAA (leucine, isoleucine and valine) may contribute to CV-renal disease. We examined the associations of serum BCAA, obesity and CV-renal events in a prospective Chinese T2D cohort (1994-2007). Method: We measured serum total BCAA in 579 and 566 patients (top and lowest BMI quintiles respectively) using the colorimetric ELISA kit. Patients were monitored for clinical outcomes with data censored on May 2015. We analysed the effect of serum BCAA on incident CV-renal events using multivariate Cox regression. Results: At baseline, obese group had shorter T2D duration, worse clinical profile and higher serum BCAA than lean group. After 11 years of follow-up, obese group had higher incidence of heart failure (HF), chronic kidney and any CV disease than the lean group. In all patients, every unit increase in Ln (BCAA) elevated the risk of incident HF by 64% (hazard ratio [HR] 1.64, 95% CI 1.01-2.66). Conclusions: Serum BCAA independently predicted incident HF in T2D population even after adjustment for obesity. The associations of this biomarker with dietary patterns and clinical outcomes will provide new insights regarding the health impacts of nutrition. Model 1Model 2EventHR (95% CI)P-valueEventHR (95% CI)P-valueAny CV disease181 (21.5%)1.37 (1.01-1.85)0.044167 (21.0%)1.26 (0.88-1.79)0.206Heart failure91 (9.4%)1.59 (1.06-2.39)0.02585 (9.3%)1.64 (1.01-2.66)0.045Coronary heart disease103 (11.4%)1.19 (0.78-1.81)0.42897 (11.4%)1.05 (0.65-1.71)0.836Stroke100 (10.2%)1.42 (0.96-2.10)0.08390 (9.8%)1.35 (0.86-2.10)0.191Chronic kidney disease401 (52.0%)1.15 (0.89-1.49)0.271379 (51.6%)0.89 (0.65-1.22)0.463Model 1: adjusted for age, sex, T2D duration Model 2: Model 1 + A1c, systolic BP, LDL-cholesterol, log(triglyceride), BMI top and lowest quintiles (0,1), log(ACR), baseline eGFR, use of insulin, RAS inhibitors, oral blood glucose/lipid lowering agents, smoking status Disclosure L. Lim: Research Support; Self; AstraZeneca. Speaker's Bureau; Self; Sanofi-Aventis. E.S.H. Lau: None. A. Luk: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc.. Research Support; Self; Sanofi. E. Chow: Research Support; Self; Sanofi. H. Lee: None. R.C. Ma: Research Support; Self; AstraZeneca, Bayer AG, Merck Sharp &amp; Dohme Corp., Pfizer Inc.. Advisory Panel; Self; Boehringer Ingelheim GmbH, Nippon Boehringer Ingelheim Co. Ltd. J.C. Chan: Consultant; Self; Bayer AG. Other Relationship; Self; Bayer AG. Consultant; Self; Sanofi. Other Relationship; Self; Sanofi, Eli Lilly and Company, Amgen Inc.. Consultant; Self; AstraZeneca, Merck &amp; Co., Inc., Pfizer Inc.. Other Relationship; Self; Pfizer Inc.. Board Member; Self; Asia Diabetes Foundation. Stock/Shareholder; Self; GemVCare. Other Relationship; Self; Merck Sharp &amp; Dohme Corp.. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Novartis AG, Eli Lilly and Company. A.P. Kong: Research Support; Self; AstraZeneca.

Exercise Training in Standardbred Horses Alters the Skeletal Muscle Metabolome and Plasma Amino Acid Profile: Implications for the “Athlete's Paradox”

To date equine skeletal muscle metabolism has centered on a limited number of candidate metabolites. As such, there is a dearth of information regarding global changes in skeletal muscle metabolism following exercise training. Thus, the purpose of this study was to determine the effects of exercise training on skeletal muscle metabolism through changes in the skeletal muscle metabolome in healthy, untrained Standardbred horses. In addition, we aimed to determine the extent to which protein metabolism is also altered through changes in the concentrations of plasma amino acids (AA). We hypothesized that training would significantly alter the skeletal muscle metabolome, as well as protein metabolism, as reflected in changes in the plasma AA profile. Eight untrained, Standardbred horses (n=4 mares, n=4 geldings; 3–9 yrs; 485 ± 13 kg, mean ± S.E.) underwent a 12‐week training program that significantly increased VO2 and exercise capacity (p&lt;0.05). Percutaneous needle biopsies were obtained from the M. gluteus medius in the untrained state (UT) and again following training (TR). Frozen muscle samples were submitted to Metabolon, Inc. for global metabolite profiling via UHPLC‐MS/MS. Blood obtained via jugular venipuncture was placed into EDTA tubes for the measurement of plasma AA concentrations via HPLC. For metabolomics analysis, differences between UT and TR samples were evaluated by two way‐ANOVA and Welch's t‐test for paired comparisons and considered significant at p&lt;0.05. For plasma AAs, differences were analyzed via Student's t‐test and considered significant at p&lt;0.05. Training resulted in significant alterations in lipid, branched‐chain amino acid (BCAA), and nucleotide metabolite classes in skeletal muscle. Of note, analysis revealed significant increases in the relative abundance of almost every identified FFA and complex lipid species in TR compared to UT muscle (p&lt;0.05), particularly the long‐chain (LC)‐acylcarnitines and diacylglycerides (DAGs) (1.5 to 2.3‐fold increases). Further, TR muscle exhibited increased fold‐changes (1.2 to 4.2‐fold) of C4 and several C5 BCAA‐derived acylcarnitines compared to UT (p&lt;0.05). In plasma, training caused a significant 36% increase in the concentration of total essential AAs (p&lt;0.05), of which and interestingly there was a significant increase in total BCAAs (42%, p&lt;0.05) and phenylalanine (27%, p&lt;0.05). In conclusion, exercise training significantly increased blood concentrations of total EAAs and BCAAs alongside significant increases in the relative abundances of certain skeletal muscle metabolites (i.e. LC‐acylcarnitines, BCAA‐derived acylcarnitines, and DAGs) that have been shown to be elevated during obesity and are proposed to play a role in the development of insulin resistance. These data underscore the complex nature of static metabolic signatures and the role that certain metabolites play in mediating health and disease. Future research should aim to utilize other sophisticated techniques that can address issues of metabolite flux and tissue utilization.Support or Funding InformationThis research was supported by: the New Jersey Institute for Food, Nutrition and Health (IFNH), USDA NIFA (NC 1184), the Rutgers University Equine Science Center (ESC), and the New Jersey Agriculture Experiment Station (NJAES).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

A novel NMR-based assay to measure circulating concentrations of branched-chain amino acids: Elevation in subjects with type 2 diabetes mellitus and association with carotid intima media thickness

ObjectivesPlasma branched-chain amino acid (BCAA) levels, measured on nuclear magnetic resonance (NMR) metabolomics research platforms or by mass spectrometry, have been shown to be associated with type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). We developed a new test for quantification of BCAA on a clinical NMR analyzer and used this test to determine the clinical correlates of BCAA in 2 independent cohorts. Design and methodsThe performance of the NMR-based BCAA assay was evaluated. A method comparison study was performed with mass spectrometry (LC-MS/MS). Plasma BCAA were measured in the Insulin Resistance Atherosclerosis Study (IRAS, n = 1209; 376 T2DM subjects) and in a Groningen cohort (n = 123; 67 T2DM subjects). In addition, carotid intima media thickness (cIMT) was measured successfully in 119 subjects from the Groningen cohort. ResultsNMR-based BCAA assay results were linear over a range of concentrations. Coefficients of variation for inter- and intra-assay precision ranged from 1.8–6.0, 1.7–5.4, 4.4–9.1, and 8.8–21.3%, for total BCAA, valine, leucine, and isoleucine, respectively. BCAA quantified from the same samples using NMR and LC-MS/MS were highly correlated (R2 = 0.97, 0.95 and 0.90 for valine, leucine and isoleucine). In both cohorts total and individual BCAA were elevated in T2DM (P = 0.01 to ≤0.001). Moreover, cIMT was associated with BCAA independent of age, sex, T2DM and metabolic syndrome (MetS) categorization or alternatively of individual MetS components. ConclusionsBCAA levels, measured by NMR in the clinical laboratory, are elevated in T2DM and may be associated with cIMT, a proxy of subclinical atherosclerosis.

Association between plasma concentrations of branched-chain amino acids and adipokines in Japanese adults without diabetes

Previous studies have consistently reported an association between circulating levels of branched-chain amino acids (BCAAs) or adipokines and insulin resistance; however, the association between BCAA and adipokine levels remains to be clarified. In this cross-sectional study involving 678 participants (435 men) without diabetes, plasma BCAA (valine, leucine, and isoleucine), adipokine (total and high molecular weight [HMW] adiponectin, leptin, and tumor necrosis factor-α [TNF-α]) concentrations, and an updated homeostasis model assessment of insulin resistance (HOMA2-IR) were measured. The association between the concentrations of total BCAAs and adipokines was adjusted for confounding factors, including body mass index. For the lowest and highest BCAA quartiles, the adjusted geometric mean levels of HMW adiponectin were, respectively, 1.51 and 0.91 μg/mL, in men (P for trend < 0.0001); 3.61 and 2.29 μg/mL, in women (P = 0.0005). The corresponding geometric mean levels for leptin were 1681 and 2620 pg/mL, in men (P = 0.003), and 4270 and 6510 pg/mL, in women (P = 0.003). Those for HOMA2-IR were 0.89 and 1.11, in men (P < 0.0001), and 0.79 and 0.96, in women (P < 0.0001); no significant association was found with TNF-α. These results suggest significant associations between BCAA concentrations and those for adiponectin, leptin and HOMA2-IR in individuals without diabetes.