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The main objective of the study was to investigate the effects of prenatal exercise interventions on maternal body composition at 28 weeks gestation and 7-14 days after delivery. We also explored associations between physical activity (PA) per se and body composition. This study presents secondary outcomes of the FitMum randomized controlled trial, which included healthy inactive pregnant women at gestational age ≤ 15+0 weeks. They were randomized to structured supervised exercise training, motivational counselling on PA, or standard care. Maternal body composition was measured by doubly labeled water at 28 weeks gestation (n = 134) and by dual-energy X-ray absorptiometry scan 7-14 days after delivery (n = 117). PA, including moderate-to-vigorous-intensity PA (MVPA), active kilocalories, and steps, were measured continuously from inclusion to delivery by a wrist-worn activity tracker. One hundred fifty pregnant women were included with a median pre-pregnancy body mass index (BMI) of 24.1 (21.6-27.9) kg/m2. We found no differences between groups in fat mass, fat percentage or fat-free mass at 28 weeks gestation or 7-14 days after delivery. Visceral adipose tissue mass and bone mineral density measured 7-14 days after delivery did not differ between groups either. Linear regression analyses adjusted for pre-pregnancy BMI showed that a higher number of daily steps was associated with lower fat mass, fat percentage, and visceral adipose tissue mass at 28 weeks gestation and 7-14 days after delivery. Active kilocalories during pregnancy was positively associated with fat-free mass 7-14 days after delivery. Neither structured supervised exercise training nor motivational counselling on PA during pregnancy affected maternal body composition at 28 weeks gestation or 7-14 days after delivery compared to standard care. Interestingly, when adjusted for pre-pregnancy BMI, higher number of daily steps was associated with lower fat content during pregnancy and after delivery, whereas MVPA and active kilocalories were not. Trial registration: ClinicalTrials.gov; NCT03679130; 20/09/2018.
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Composição Corporal , Exercício Físico , Humanos , Feminino , Gravidez , Composição Corporal/fisiologia , Adulto , Exercício Físico/fisiologia , Índice de Massa Corporal , Cuidado Pré-Natal/métodos , Absorciometria de Fóton , Terapia por Exercício/métodos , Densidade Óssea/fisiologiaRESUMO
It is not completely clear which organs are responsible for glucagon elimination in humans, and disturbances in the elimination of glucagon could contribute to the hyperglucagonemia observed in chronic liver disease and chronic kidney disease (CKD). Here, we evaluated kinetics and metabolic effects of exogenous glucagon in individuals with stage 4 CKD (n =16), individuals with Child-Pugh A-C cirrhosis (n = 16) and matched control individuals (n = 16), before, during and after a 60-minute glucagon infusion (4 ng/kg/min). Individuals with CKD exhibited a significantly lower mean metabolic clearance rate of glucagon (14.0 [95% CI 12.2;15.7] mL/kg/min) both compared to individuals with cirrhosis (19.7 [18.1;21.3] mL/kg/min, P < 0.001) and to control individuals (20.4 [18.1;22.7] mL/kg/min, P < 0.001). Glucagon half-life was significantly prolonged in the CKD group (7.5 [6.9;8.2] minutes) compared to individuals with cirrhosis (5.7 [5.2;6.3] minutes, P = 0.002) and control individuals (5.7 [5.2;6.3] minutes, P < 0.001). No difference in the effects of exogenous glucagon on plasma glucose, amino acids, or triglycerides was observed between groups. In conclusion, chronic kidney disease, but not liver cirrhosis leads to a significant reduction in glucagon clearance, supporting the kidneys as a primary site for human glucagon elimination.
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BACKGROUND: Intrahepatic triacylglycerol (liver TG) content is associated with hepatic insulin resistance and dyslipidemia. Liver TG content can be modulated within days under hypocaloric conditions. OBJECTIVES: We hypothesized that 4 d of eucaloric low-carbohydrate/high-fat (LC) intake would decrease liver TG content, whereas a high-carbohydrate/low-fat (HC) intake would increase liver TG content, and further that alterations in liver TG would be linked to dynamic changes in hepatic glucose and lipid metabolism. METHODS: A randomized crossover trial in males with 4 d + 4 d of LC and HC, respectively, with ≥2 wk of washout. 1H-magnetic resonance spectroscopy (1H-MRS) was used to measure liver TG content, with metabolic testing before and after intake of an LC diet (11E% carbohydrate corresponding to 102 ± 12 {mean ± standard deviation [SD]) g/d, 70E% fat} and an HC diet (65E% carbohydrate corresponding to 537 ± 56 g/d, 16E% fat). Stable [6,6-2H2]-glucose and [1,1,2,3,3-D5]-glycerol tracer infusions combined with hyperinsulinemic-euglycemic clamps and indirect calorimetry were used to measure rates of hepatic glucose production and lipolysis, whole-body insulin sensitivity and substrate oxidation. RESULTS: Eleven normoglycemic males with overweight or obesity (BMI 31.6 ± 3.7 kg/m2) completed both diets. The LC diet reduced liver TG content by 35.3% (95% confidence interval: -46.6, -24.1) from 4.9% [2.4-11.0] (median interquartile range) to 2.9% [1.4-6.9], whereas there was no change after the HC diet. After the LC diet, fasting whole-body fat oxidation and plasma beta-hydroxybutyrate concentration increased, whereas markers of de novo lipogenesis (DNL) diminished. Fasting plasma TG and insulin concentrations were lowered and the hepatic insulin sensitivity index increased after LC. Peripheral glucose disposal was unchanged. CONCLUSIONS: Reduced carbohydrate and increased fat intake for 4 d induced a marked reduction in liver TG content and increased hepatic insulin sensitivity. Increased rates of fat oxidation and ketogenesis combined with lower rates of DNL are suggested to be responsible for lowering liver TG. This trial was registered at clinicaltrials.gov as NCT04581421.
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Estudos Cross-Over , Fígado , Obesidade , Sobrepeso , Triglicerídeos , Humanos , Masculino , Triglicerídeos/metabolismo , Fígado/metabolismo , Adulto , Sobrepeso/metabolismo , Sobrepeso/dietoterapia , Obesidade/metabolismo , Obesidade/dietoterapia , Dieta com Restrição de Carboidratos , Carboidratos da Dieta/administração & dosagem , Carboidratos da Dieta/metabolismo , Adulto Jovem , Pessoa de Meia-Idade , Resistência à InsulinaRESUMO
OBJECTIVE: The metabolic phenotype of totally pancreatectomised patients includes hyperaminoacidaemia and predisposition to hypoglycaemia and hepatic lipid accumulation. We aimed to investigate whether the loss of pancreatic glucagon may be responsible for these changes. METHODS: Nine middle-aged, normal-weight totally pancreatectomised patients, nine patients with type 1 diabetes (C-peptide negative), and nine matched controls underwent two separate experimental days, each involving a 150-min intravenous infusion of glucagon (4â ng/kg/min) or placebo (saline) under fasting conditions while any basal insulin treatment was continued. RESULTS: Glucagon infusion increased plasma glucagon to similar high physiological levels in all groups. The infusion increased hepatic glucose production and decreased plasma concentration of most amino acids in all groups, with more pronounced effects in the totally pancreatectomised patients compared with the other groups. Glucagon infusion diminished fatty acid re-esterification and tended to decrease plasma concentrations of fatty acids in the totally pancreatectomised patients but not in the type 1 diabetes patients. CONCLUSION: Totally pancreatectomised patients were characterised by increased sensitivity to exogenous glucagon at the level of hepatic glucose, amino acid, and lipid metabolism, suggesting that the metabolic disturbances characterising these patients may be rooted in perturbed hepatic processes normally controlled by pancreatic glucagon.
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Diabetes Mellitus Tipo 1 , Glucagon , Fígado , Pancreatectomia , Humanos , Glucagon/sangue , Glucagon/metabolismo , Masculino , Pessoa de Meia-Idade , Feminino , Fígado/metabolismo , Fígado/efeitos dos fármacos , Adulto , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/sangue , Metabolismo dos Lipídeos/efeitos dos fármacos , Glicemia/metabolismo , Glicemia/efeitos dos fármacos , Aminoácidos/metabolismo , Aminoácidos/administração & dosagem , Aminoácidos/sangue , Glucose/metabolismoRESUMO
BACKGROUND & AIMS: Cirrhosis is associated with insulin resistance and impaired glucose tolerance, which may be caused by impairments at different tissue levels (liver, skeletal muscle, and/or beta cell). METHODS: Here, glucose kinetics at whole-body and skeletal muscle level in patients with cirrhosis (Child-Pugh A and B) were studied during parenteral nutrition using the isotope dilution technique and arteriovenous balance approach across the leg. As opposed to the euglycemic hyperinsulinemic clamp or glucose tolerance tests applied in previous studies, this approach provides a nutrient composition more similar to a normal meal while circumventing any possible portal-systemic shunting, impaired hepatic uptake and incretin effect. RESULTS: We confirmed the presence of hepatic and peripheral insulin resistance in our patient population. Endogenous glucose production was less suppressed in response to parenteral nutrition. However, glucose uptake in skeletal muscle was increased. CONCLUSION: Our results suggests that in our study participants with cirrhosis, the hepatic and peripheral insulin resistance is compensated for by increased insulin secretion and thus, increased glucose uptake in muscle. Hereby, glucose homeostasis is maintained.
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Glucose , Resistência à Insulina , Humanos , Masculino , Cirrose Hepática Alcoólica , Músculo Esquelético , Insulina , Cirrose Hepática , Nutrição ParenteralRESUMO
BACKGROUND: Breast cancer survivors are a growing population due to improved treatment. It is known that postmenopausal women treated for breast cancer may experience weight gain and increased insulin resistance, but detailed knowledge on how chemotherapy impact metabolic and endocrine mechanisms remain unknown. OBJECTIVES: We performed a thorough, preliminary study to elucidate the differing mechanisms of postprandial absorption and metabolism in postmenopausal early breast cancer (EBC) patients treated with adjuvant chemotherapy compared to healthy controls. We hypothesize that chemotherapy has a negative impact on metabolism in EBC patients. METHODS: We examined four postmenopausal women shortly after treatment with chemotherapy for EBC and four age-matched healthy women who served as controls using isotopic tracers during a mixed meal-test. Blood was sampled during the 240 min meal-test to examine postprandial absorption and endogenous synthesis of lipid and carbohydrate metabolites. RESULTS: We found that insulin concentrations were numerically higher before the meal-test in the EBC patients compared to controls (76.3 pmol/L vs 37.0 pmol/L; P = 0.06). Glucose kinetics was increased postprandial (most pronounced at 30 min, 9.46 mmol/L vs 7.33 mmol/L; P = 0.51), with no difference between the groups regarding liver glucose output. Fatty acid kinetics showed a numeric increase in oleic acid rate of appearance in BC patients, but only during the first hour after the mixed meal. There was no significant difference in VLDL-TAG synthesis between the two groups. CONCLUSIONS: This preliminary study is unique in using advanced tracer methods to investigate in vivo metabolism of EBC patients after chemotherapy although no statistical differences in glucose and fatty acid kinetics was seen compared to controls. However, during the first two postprandial hours, oral glucose and oleic acid appearance in the systematic circulation was elevated in the EBC patients. This could be due to changes in gastrointestinal uptake and further studies with altered set-up could provide valuable insights.
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Neoplasias da Mama , Glucose , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Ácido Oleico , Pós-Menopausa , Dados Preliminares , Glicemia/metabolismo , Insulina , Ácidos Graxos , Período Pós-Prandial , TriglicerídeosRESUMO
Objective: In obesity and type 2 diabetes, hyperglucagonaemia may be caused by elevated levels of glucagonotropic amino acids due to hepatic glucagon resistance at the level of amino acid turnover. Here, we investigated the effect of exogenous glucagon on circulating amino acids in obese and non-obese individuals with and without type 2 diabetes. Design: This was a post hoc analysis in a glucagon infusion study performed in individuals with type 2 diabetes (n = 16) and in age, sex, and body mass index-matched control individuals without diabetes (n = 16). Each group comprised two subgroups of eight individuals with and without obesity, respectively. Methods: All participants received a 1-h glucagon infusion (4 ng/kg/min) in the overnight fasted state. Plasma amino acid concentrations were measured with frequent intervals. Results: Compared to the control subgroup without obesity, baseline total amino acid levels were elevated in the control subgroup with obesity and in the type 2 diabetes subgroup without obesity. In all subgroups, amino acid levels decreased by up to 20% in response to glucagon infusion, which resulted in high physiological steady-state glucagon levels (mean concentration: 74 pmol/L, 95% CI [68;79] pmol/L). Following correction for multiple testing, no intergroup differences in changes in amino acid levels reached significance. Conclusion: Obesity and type 2 diabetes status was associated with elevated fasting levels of total amino acids. The glucagon infusion decreased circulating amino acid levels similarly in all subgroups, without significant differences in the response to exogenous glucagon between individuals with and without obesity and type 2 diabetes. Significance statement: The hormone glucagon stimulates glucose production from the liver, which may promote hyperglycaemia if glucagon levels are abnormally elevated, as is often seen in type 2 diabetes and obesity. Glucagon levels are closely linked to, and influenced by, the levels of circulating amino acids. To further investigate this link, we measured amino acid levels in individuals with and without obesity and type 2 diabetes before and during an infusion of glucagon. We found that circulating amino acid levels were higher in type 2 diabetes and obesity, and that glucagon infusion decreased amino acid levels in both individuals with and without type 2 diabetes and obesity. The study adds novel information to the link between circulating levels of glucagon and amino acids.
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BACKGROUND: Metabolic effects of empagliflozin treatment include lowered glucose and insulin concentrations, elevated free fatty acids and ketone bodies and have been suggested to contribute to the cardiovascular benefits of empagliflozin treatment, possibly through an improved cardiac function. We aimed to evaluate the influence of these metabolic changes on cardiac function in patients with T2D. METHODS: In a randomized cross-over design, the SGLT2 inhibitor empagliflozin (E) was compared with insulin (I) treatment titrated to the same level of glycemic control in 17 patients with type 2 diabetes, BMI of > 28 kg/m2, C-peptide > 500 pM. Treatments lasted 5 weeks and were preceded by 3-week washouts (WO). At the end of treatments and washouts, cardiac diastolic function was determined with magnetic resonance imaging from left ventricle early peak-filling rate and left atrial passive emptying fraction (primary and key secondary endpoints); systolic function from left ventricle ejection fraction (secondary endpoint). Coupling between cardiac function and fatty acid concentrations, was studied on a separate day with a second scan after reduction of plasma fatty acids with acipimox. Data are Mean ± standard error. Between treatment difference (ΔT: E-I) and treatments effects (ΔE: E-WO or ΔI: I -WO) were evaluated using Students' t-test or Wilcoxon signed rank test as appropriate. RESULTS: Glucose concentrations were similar, fatty acids, ketone bodies and lipid oxidation increased while insulin concentrations decreased on empagliflozin compared with insulin treatment. Cardiac diastolic and systolic function were unchanged by either treatment. Acipimox decreased fatty acids with 35% at all visits, and this led to reduced cardiac diastolic (ΔT: -51 ± 22 ml/s (p < 0.05); ΔE: -33 ± 26 ml/s (ns); ΔI: 37 ± 26 (ns, p < 0.05 vs ΔE)) and systolic function (ΔT: -3 ± 1% (p < 0.05); ΔE: -3 ± 1% (p < 0.05): ΔI: 1 ± 2 (ns, ns vs ΔE)) under chronotropic stress during empagliflozin compared to insulin treatment. CONCLUSIONS: Despite significant metabolic differences, cardiac function did not differ on empagliflozin compared with insulin treatment. Impaired cardiac function during acipimox treatment, could suggest greater cardiac reliance on lipid metabolism for proper function during empagliflozin treatment in patients with type 2 diabetes. TRIAL REGISTRATION: EudraCT 2017-002101-35, August 2017.
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Apêndice Atrial , Diabetes Mellitus Tipo 2 , Humanos , Insulina , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Estudos Cross-Over , Glucose , Ácidos Graxos , Corpos CetônicosRESUMO
OBJECTIVE: Insulin remains the only glucose-lowering treatment modality recommended for totally pancreatectomized patients. We investigated the effects of the sodium-glucose cotransporter 2 inhibitor empagliflozin on fasting and postprandial glucose concentrations in pancreatectomized patients and matched healthy control participants. RESEARCH DESIGN AND METHODS: In a randomized, double-blind, placebo-controlled crossover study, 10 pancreatectomized patients and 10 matched control participants underwent two 3-h liquid mixed meal tests preceded by two doses of 25 mg empagliflozin (administered the night before and in the morning of the meal test) or placebo, respectively. Basal insulin was administered as usual, but bolus insulin was omitted before the meal test during experimental days. RESULTS: Compared with placebo, empagliflozin lowered fasting plasma glucose (5.0 ± 0.4 vs. 7.9 ± 0.9 mmol/L [mean ± SEM], P = 0.007) and postprandial plasma glucose excursions as assessed by baseline-subtracted area under the curve (1,080 [733; 1,231] vs. 1,169 [1,036; 1,417] pmol/L × min [median (25th and 75th percentiles)], P = 0.014) in the pancreatectomized patients. In the control participants, empagliflozin lowered fasting plasma glucose compared with placebo (5.1 ± 0.1 vs. 5.5 ± 0.1 mmol/L, P = 0.008) without affecting postprandial glucose excursions significantly. The pancreatomy group exhibited greater postprandial glucagon excursions compared with the control group on both experimental days (P ≤ 0.015); no within-group differences between days were observed. CONCLUSIONS: Empagliflozin administered the day before and immediately before a standardized liquid mixed meal test normalized fasting hyperglycemia and improved postprandial glucose tolerance in pancreatectomized patients.
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Diabetes Mellitus Tipo 2 , Hiperglicemia , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Estudos Cross-Over , Glicemia , Hiperglicemia/tratamento farmacológico , Hiperglicemia/prevenção & controle , Insulina/uso terapêutico , Jejum , Glucose/uso terapêutico , Método Duplo-Cego , Período Pós-PrandialRESUMO
CONTEXT: Hyperglucagonemia is observed in individuals with obesity and contributes to the hyperglycemia of patients with type 2 diabetes. Hyperglucagonemia may develop due to steatosis-induced hepatic glucagon resistance resulting in impaired hepatic amino acid turnover and ensuing elevations of circulating glucagonotropic amino acids. OBJECTIVE: We evaluated whether glucagon resistance could be induced in healthy individuals by a hypercaloric diet intervention designed to increase hepatic fat content. METHODS: We recruited 20 healthy male individuals to follow a hypercaloric diet and a sedentary lifestyle for 2 weeks. Amino acid concentrations in response to infusion of glucagon were assessed during a pancreatic clamp with somatostatin and basal insulin. The reversibility of any metabolic changes was assessed 8 weeks after the intervention. Hepatic steatosis was assessed by magnetic resonance spectroscopy. RESULTS: The intervention led to increased hepatic fat content (382% [206%; 705%], P < .01). Glucagon infusion led to a decrease in the concentration of total amino acids on all experimental days, but the percentage change in total amino acids was reduced (-2.5% ± 0.5% vs -0.2% ± 0.7%, P = .015) and the average slope of the decline in the total amino acid concentration was less steep (-2.0 ± 1.2 vs -1.2 ± 0.3â µM/min, P = .016) after the intervention compared to baseline. The changes were normalized at follow-up. CONCLUSION: Our results indicate that short-term unhealthy behavior, which increases hepatic fat content, causes a reversible resistance to the effect of glucagon on amino acid concentrations in healthy individuals, which may explain the hyperglucagonemia associated with obesity and diabetes.
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Diabetes Mellitus Tipo 2 , Fígado Gorduroso , Humanos , Masculino , Glucagon/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Fígado/metabolismo , Fígado Gorduroso/metabolismo , Aminoácidos/metabolismo , Obesidade/complicações , Obesidade/metabolismo , Dieta , Insulina/metabolismoRESUMO
Aims: Hyperglucagonaemia contributes to the pathophysiology in type 2 diabetes (T2D), but the mechanisms behind the inappropriate glucagon secretion are not fully understood. Glucagon and amino acids are regulated in a feedback loop referred to as the liver-α cell axis. Individuals with non-alcoholic fatty liver disease (NAFLD) appear to be glucagon resistant, disrupting the liver-α cell axis resulting in hyperglucagonaemia and hyperaminoacidaemia. We investigated the associations between circulating glucagon, amino acids, and liver fat content in a cohort of individuals with T2D. Methods: We included 110 individuals with T2D in this cross-sectional study. Liver fat content was quantified using 1H magnetic resonance spectroscopy (MRS). Associations between liver fat content and plasma glucagon and amino acids, respectively, were estimated in multivariate linear regression analyses. Results: Individuals with NAFLD (n = 52) had higher plasma glucagon concentrations than individuals without NAFLD (n = 58). The positive association between plasma glucagon concentrations and liver fat content was confirmed in the multivariable regression analyses. Plasma concentrations of isoleucine and glutamate were increased, and glycine and serine concentrations were decreased in individuals with NAFLD. Concentrations of other amino acids were similar between individuals with and without NAFLD, and no clear association was seen between liver fat content and amino acids in the regression analyses. Conclusion: MRS-diagnosed NAFLD in T2D is associated with hyperglucagonaemia and elevated plasma concentrations of isoleucine and glutamate and low plasma concentrations of glycine and serine. Whether NAFLD and glucagon resistance per se induce these changes remains to be elucidated.
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An important area within clinical research is in vivo metabolism of ketone bodies (ß-hydroxybutyrate and acetoacetate) and in connection metabolites that may affect their production and/or cellular transport such as the keto-acids from the branched-chain amino acids, lactate and pyruvate. To determine in vivo metabolite turnover, availability of accurate and sensitive methods for analyzing the plasma concentrations of these metabolites and their stable isotopically labeled enrichments is mandatory. Therefore, the present study describes a high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous analysis of ketone bodies, α-keto acids, lactate, pyruvate, and their tracer enrichments in humans using 2 different derivatization techniques with 4-bromo-N-methylbenzylamine and O-benzylhydroxylamine as derivatization reagents, and 1-ethyl-3-dimethylaminopropyl carbodiimide as coupling compound followed by a single LC-MS/MS run. The method was validated for matrix effects, linearity, accuracy, precision, recovery, stability, and enrichment (ratio) analysis of a stable isotopically labelled analytes (tracers) continuously infused in humans divided by the unlabeled endogenous analyte (tracee) that makes it possible to quantify the analyte in vivo synthesis and degradation rates. The applied parallel derivatization procedure yielded good sensitivity for all analytes of interest and their tracers. Despite the double derivatization method, mixing the ethyl acetate portions at the final stage made it possible to simultaneously analyze all compounds in a single LC-MS/MS run. Moreover, the liquid chromatography method was optimized to robustly quantify the keto acids derived from leucine (α-keto-isocaproic acid) and isoleucine (α-keto-ß-methylvaleric acid), the compounds with similar chemical structure and identical molecular weights. The presented method is designed and validated for human plasma. However, care should be taken in blood sampling and processing procedures as well as quick freezing and storage at -80 °C due to the instability of especially acetoacetate.
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Ácido Láctico , Ácido Pirúvico , Humanos , Acetoacetatos , Corpos Cetônicos , Cromatografia Líquida , Espectrometria de Massas em Tandem , CetoácidosRESUMO
BACKGROUND: McArdle disease is caused by myophosphorylase deficiency leading to blocked glycogenolysis in skeletal muscle. Consequently, individuals with McArdle disease have intolerance to physical activity, muscle fatigue, and pain. These symptoms vary according to the availability of alternative fuels for muscle contraction. In theory, a modified ketogenic diet (mKD) can provide alternative fuels in the form of ketone bodies and potentially boost fat oxidation. METHODS: This randomized, single-blind, placebo-controlled, cross-over study aimed to investigate if a mKD improves exercise capacity in individuals with McArdle disease. Participants were randomized to follow a mKD (75-80% fat, 15% protein, 5-10% carbohydrates) or placebo diet (PD) first for three weeks, followed by a wash-out period, and then the opposite diet. The primary outcome was change in heart rate during constant-load cycling. Secondary outcomes included change in plasma metabolites, perceived exertion, indirect calorimetry measures, maximal exercise capacity, and patient-reported outcomes. RESULTS: Fifteen out of 20 patients with genetically verified McArdle disease completed all study visits, and 14 were included in the data analyses. We found that the mKD induced a metabolic shift towards increased fat oxidation (â¼60% increase), and a 19-fold increase in plasma ß-hydroxybutyrate (p < 0.05). The mKD did not improve heart rate responses during constant-load cycling but did improve patient-reported outcomes and maximal exercise capacity (â¼20% increase) compared to the PD. CONCLUSION: The mKD did not alleviate all McArdle disease-related symptoms but did induce some positive changes. To date, no satisfactory treatment options exist other than exercise training. To that end, a mKD can be a possible nutritional strategy for some individuals with McArdle disease who are motivated to undertake a restrictive diet. CLINICAL TRIAL REGISTRATION: clinical trials.gov: NCT04044508.
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Dieta Cetogênica , Doença de Depósito de Glicogênio Tipo V , Humanos , Doença de Depósito de Glicogênio Tipo V/metabolismo , Estudos Cross-Over , Método Simples-Cego , Músculo Esquelético , Corpos Cetônicos/metabolismoRESUMO
BACKGROUND: An Achilles tendon rupture (ATR) is a frequent injury and results in the activation of tendon cells and collagen expression, but it is unknown to what extent turnover of the tendon matrix is altered before or after a rupture. PURPOSE/HYPOTHESIS: The purpose of this study was to characterize tendon tissue turnover before and immediately after an acute rupture in patients. It was hypothesized that a rupture would result in pronounced collagen synthesis in the early phase (first 2 weeks) after the injury. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: The study included patients (N = 18) eligible for surgery after an ATR. At the time of inclusion, the patients ingested deuterium oxide (2H2O) orally, and on the day of surgery (within 14 days of the injury), they received a 3-hour flood-primed infusion of an 15N-proline tracer. During surgery, the patients had 1 biopsy specimen taken from the ruptured part of the Achilles tendon and 1 that was 3 to 5 cm proximal to the rupture as a control. The biopsy specimens were analyzed for carbon-14 (14C) levels in the tissue to calculate long-term turnover (years), incorporation of 2H-alanine (from 2H2O) into the tissue to calculate the fractional synthesis rate (FSR) of proteins in the short term (days), and incorporation of 15N-proline into the tissue to calculate the acute FSR (hours). RESULTS: Both the rupture and the control samples showed consistently lower levels of 14C compared with the predicted level of 14C in a healthy tendon, which indicated increased tendon turnover in a fraction (48% newly synthesized) of the Achilles tendon already for a prolonged period before the rupture. Over the first days after the rupture, the synthesis rate for collagen was relatively constant, and the average synthesis rate on the day of surgery (2-14 days after the rupture) was 0.025% per hour, irrespective of the length of time after a rupture and the site of sampling (rupture vs control). No differences were found in the FSR between the rupture and control samples in the days after the rupture. CONCLUSION: Higher than normal tissue turnover in the Achilles tendon before a rupture indicated that changes in the tendon tissue preceded the injury. In addition, we observed no increase in tendon collagen tissue turnover in the first 2 weeks after an ATR. This favors the view that an increase in the formation of new tendon collagen is not an immediate phenomenon during the regeneration of ruptured tendons in patients. REGISTRATION: NCT03931486 (ClinicalTrials.gov identifier).
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Tendão do Calcâneo , Traumatismos dos Tendões , Humanos , Tendão do Calcâneo/lesões , Radioisótopos de Carbono/metabolismo , Estudos Transversais , Colágeno/metabolismo , Ruptura/cirurgia , Ruptura/patologia , Traumatismos dos Tendões/patologiaRESUMO
Alcoholic liver cirrhosis (ALC) is accompanied by sarcopenia. The aim of this study was to investigate the acute effects of balanced parenteral nutrition (PN) on skeletal muscle protein turnover in ALC. Eight male patients with ALC and seven age- and sex-matched healthy controls were studied for 3 h of fasting followed by 3 h of intravenous PN (SmofKabiven 1,206 mL: amino acid = 38 g, carbohydrates = 85 g, and fat = 34 g) 4 mL/kg/h. We measured leg blood flow and sampled paired femoral arteriovenous concentrations and quadriceps muscle biopsies while providing a primed continuous infusion of [ring-2d5]-phenylalanine to quantify muscle protein synthesis and breakdown. Patients with ALC exhibited shorter 6-min walking distance (ALC: 487 ± 38 vs. controls: 722 ± 14 m, P < 0.05), lower hand-grip strength (ALC: 34 ± 2 vs. controls: 52 ± 2 kg, P < 0.05), and computed tomography (CT)-verified leg muscle loss (ALC: 5,922 ± 246 vs. controls: 8,110 ± 345 mm2, P < 0.05). Net leg muscle phenylalanine uptake changed from negative (muscle loss) during fasting to positive (muscle gain) in response to PN (ALC: -0.18 ± +0.01 vs. 0.24 ± 0.03 µmol/kg muscle·min-1; P < 0.001 and controls: -0.15 ± 0.01 vs. 0.09 ± 0.01 µmol/kg muscle·min-1; P < 0.001) but with higher net muscle phenylalanine uptake in ALC than controls (P < 0.001). Insulin concentrations were substantially higher in patients with ALC during PN. Our results suggest a higher net muscle phenylalanine uptake during a single infusion of PN in stable patients with ALC with sarcopenia compared with healthy controls.NEW & NOTEWORTHY Muscle protein turnover responses to parenteral nutritional (PN) supplementation have not previously been studied in stable alcoholic liver cirrhosis (ALC). We applied stable isotope tracers of amino acids to directly quantify net muscle protein turnover responses to PN in sarcopenic males with ALC and healthy controls. We found a higher net muscle protein gain in ALC during PN, thereby providing the physiological rationale for future clinical trials of PN as a potential countermeasure to sarcopenia.
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Músculo Esquelético , Nutrição Parenteral , Sarcopenia , Humanos , Masculino , Aminoácidos/metabolismo , Cirrose Hepática/metabolismo , Cirrose Hepática Alcoólica/terapia , Cirrose Hepática Alcoólica/metabolismo , Proteínas Musculares/metabolismo , Proteínas Musculares/farmacologia , Músculo Esquelético/metabolismo , Fenilalanina , Sarcopenia/complicações , Estudos de Casos e ControlesRESUMO
BACKGROUND: The skeletal muscle mass decreases with age and the responsiveness of aging muscles' protein synthesis rate (MPS) to protein intake seems to deteriorate. OBJECTIVE: This study investigated the impact of 12 months of protein supplementation with or without physical exercise training on the basal and postprandial MPS and the skeletal muscle metabolome of healthy older Danes (> 65 years, 29 females/37 males). METHODS: Subjects were randomized to follow one of five intervention groups: (1) carbohydrate, (2) collagen protein, (3) whey protein, (4) home-based light resistance training with whey protein, and (5) center-based heavy-load resistance training with whey protein. Before and after the intervention, a tracer infusion trial was conducted to measure basal and postprandial MPS in response to intake of a cocktail consisting of 20 g whey hydrolysate + 10 g glucose. In addition, the skeletal muscle metabolome was measured using gas chromatography-mass spectrometry (GC-MS) at basal state and 4 h after the intake of the cocktail. RESULTS: One year of daily protein or carbohydrate supplementation did not alter the basal and protein-stimulated postprandial muscle protein synthesis rate or the muscle metabolome of healthy older Danes. Basal MPS (%/h) at baseline for all subjects were 0.0034 ± 0,011 (mean ± SD). In contrast to previous studies, no difference was observed in basal MPS between males and females (p = 0.75). With the developed untargeted GC-MS methodology, it was possible to detect and tentatively annotate > 70 metabolites from the human skeletal muscle samples. CONCLUSION: One year of protein supplementation in comparison to an isocaloric-control supplement seems to affect neither the MPS at basal or postprandial state nor the skeletal muscle metabolome. CLINICAL TRIAL REGISTRY: Number: NCT02115698, clinicaltrials.gov/ct2/show/NCT02115698.
Assuntos
Proteínas Musculares , Treinamento Resistido , Feminino , Humanos , Masculino , Carboidratos/farmacologia , Suplementos Nutricionais/análise , Método Duplo-Cego , Exercício Físico , Metaboloma , Músculo Esquelético/metabolismo , Proteínas do Soro do Leite/farmacologia , IdosoRESUMO
Diet-induced weight loss is associated with improved beta-cell function in people with type 2 diabetes (T2D) with remaining secretory capacity. It is unknown if adding exercise to diet-induced weight loss improves beta-cell function and if exercise volume is important for improving beta-cell function in this context. Here, we carried out a four-armed randomized trial with a total of 82 persons (35% females, mean age (s.d.) of 58.2 years (9.8)) with newly diagnosed T2D (<7 years). Participants were randomly allocated to standard care (n = 20), calorie restriction (25% energy reduction; n = 21), calorie restriction and exercise three times per week (n = 20), or calorie restriction and exercise six times per week (n = 21) for 16 weeks. The primary outcome was beta-cell function as indicated by the late-phase disposition index (insulin secretion multiplied by insulin sensitivity) at steady-state hyperglycemia during a hyperglycemic clamp. Secondary outcomes included glucose-stimulated insulin secretion and sensitivity as well as the disposition, insulin sensitivity, and secretion indices derived from a liquid mixed meal tolerance test. We show that the late-phase disposition index during the clamp increases more in all three intervention groups than in standard care (diet control group, 58%; 95% confidence interval (CI), 16 to 116; moderate exercise dose group, 105%; 95% CI, 49 to 182; high exercise dose group, 137%; 95% CI, 73 to 225) and follows a linear dose-response relationship (P > 0.001 for trend). We report three serious adverse events (two in the control group and one in the diet control group), as well as adverse events in two participants in the diet control group, and five participants each in the moderate and high exercise dose groups. Overall, adding an exercise intervention to diet-induced weight loss improves glucose-stimulated beta-cell function in people with newly diagnosed T2D in an exercise dose-dependent manner (NCT03769883).
Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Feminino , Humanos , Pessoa de Meia-Idade , Masculino , Diabetes Mellitus Tipo 2/terapia , Exercício Físico/fisiologia , Glucose , Redução de PesoRESUMO
The extent to which increased liver fat content influences differences in circulating metabolites and/or lipids between low-birth-weight (LBW) individuals, at increased risk of type 2 diabetes (T2D), and normal-birth-weight (NBW) controls is unknown. The objective of the study was to perform untargeted serum metabolomics and lipidomics analyses in 26 healthy, non-obese early-middle-aged LBW men, including five men with screen-detected and previously unrecognized non-alcoholic fatty liver disease (NAFLD), compared with 22 age- and BMI-matched NBW men (controls). While four metabolites (out of 65) and fifteen lipids (out of 279) differentiated the 26 LBW men from the 22 NBW controls (p ≤ 0.05), subgroup analyses of the LBW men with and without NAFLD revealed more pronounced differences, with 11 metabolites and 56 lipids differentiating (p ≤ 0.05) the groups. The differences in the LBW men with NAFLD included increased levels of ornithine and tyrosine (PFDR ≤ 0.1), as well as of triglycerides and phosphatidylcholines with shorter carbon-chain lengths and fewer double bonds. Pathway and network analyses demonstrated downregulation of transfer RNA (tRNA) charging, altered urea cycling, insulin resistance, and an increased risk of T2D in the LBW men with NAFLD. Our findings highlight the importance of increased liver fat in the pathogenesis of T2D in LBW individuals.
Assuntos
Diabetes Mellitus Tipo 2 , Hepatopatia Gordurosa não Alcoólica , Recém-Nascido , Masculino , Humanos , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/etiologia , Diabetes Mellitus Tipo 2/complicações , Lipidômica , Recém-Nascido de Baixo Peso , LipídeosRESUMO
BACKGROUND: Human milk for very preterm infants need fortification for optimal growth and development but the optimal fortification product remains to be identified. AIMS: To investigate feasibility, safety and preliminary efficacy on growth and blood biochemistry when using intact bovine colostrum (BC) as a fortifier to human milk in very preterm infants. METHODS: In an open-label, multicenter, randomized controlled pilot trial (infants 26-31 weeks' gestation), mother's own milk or donor human milk was fortified with powdered BC (n = 115) or a conventional fortifier (CF, bovine-milk-based, n = 117) until 35 weeks' postmenstrual age. Fortifiers and additional micronutrients were added to human milk according to local guidelines to achieve optimal growth (additional protein up to +1.4 g protein/100 mL human milk). Anthropometry was recorded weekly. Clinical morbidities including necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) were recorded. Clinical biochemistry included plasma amino acid (AA) levels to assess protein metabolic responses to the new fortifier. RESULTS: A total of 232 infants, gestational age (GA) 28.5 ± 1.4 (weeks + days), fulfilled inclusion criteria. Birthweight, GA and delta Z scores from birth to end of intervention on weight, length or head circumference did not differ between groups, nor between the subgroups of small for gestational age infants. Likewise, incidence of NEC (BC: 3/115 vs. CF: 5/117, p = 0.72, unadjusted values), LOS (BC: 23/113 vs. CF: 14/116, p = 0.08) and other morbidities did not differ. BC infants received more protein than CF infants (+10%, p < 0.05) and showed several elevated AA levels (+10-40%, p < 0.05). CONCLUSION: Infants fortified with BC showed similar growth but received more protein and showed a moderate increase in plasma AA-levels, compared with CF. Adjustments in protein composition and micronutrients in BC-based fortifiers may be required to fully suit the needs for very preterm infants.
Assuntos
Enterocolite Necrosante , Doenças do Prematuro , Sepse , Lactente , Gravidez , Feminino , Recém-Nascido , Animais , Bovinos , Humanos , Leite Humano/química , Recém-Nascido Prematuro , Colostro , Recém-Nascido de muito Baixo Peso , Sepse/epidemiologia , Doenças do Prematuro/prevenção & controle , Micronutrientes/análise , Alimentos Fortificados , Enterocolite Necrosante/epidemiologia , Enterocolite Necrosante/prevenção & controleRESUMO
BACKGROUND & AIM: For older adults, the dietary protein intake has shown to be skewed towards the evening meal. Resultingly, the vital source of essential amino acids could be insufficient after some meals, while after the evening meal the dietary protein could be suboptimally utilized for protein synthesis. The present study explored if an even distribution of the protein intake could improve the dietary amino acid absorption and whole-body protein net-balance. METHODS: Twenty-four healthy elderly males and females were included in a randomized controlled trial. Ten days of habituation to either an EVEN (n = 12) or SKEWED (n = 12) protein intake, was followed by a trial day. The total protein intake was controlled at 1.5 g/kg LBM, divided into 30% at each main meal in EVEN, and into 15% at breakfast and lunch and 60% at dinner in SKEWED. Snacks with 5% of the protein intake were served between meals. Energy intake in the meals and snacks were equal in both groups. Intrinsically labelled 2H5-phenylalanine minced meat was served as the dietary protein to assess the amino acid absorption. On the trial day, infusion of 2H8-phenylalanine and 2H2-tyrosine, and blood samples taken over 11 h were used to measure whole-body protein turnover. Vastus lateralis muscle biopsies were taken to measure 9 h muscle protein FSR. RESULTS: Amino acid absorption rates and concentrations were greater in EVEN compared to SKEWED protein intake. Whole-body protein breakdown rates were lower with similar protein synthesis rates, and consequently the net-balance was greater in EVEN after breakfast and lunch compared to SKEWED and were the same in both groups after dinner. Muscle protein FSR were not different between EVEN and SKEWED. CONCLUSIONS: The whole-body protein net-balance was more positive in EVEN compared to SKEWED for an extended time of the measured period, driven by a lower whole-body protein breakdown in EVEN. CLINICAL TRIALS REGISTRATION: NCT03870425, https://clinicaltrials.gov/ct2/show/NCT03870425.