RESUMO
Wild-type (WT) mice maintain viable levels of blood glucose even when adipose stores are depleted by 6 d of 60% calorie restriction followed by a 23-h fast (hereafter designated as "starved" mice). Survival depends on ghrelin, an octanoylated peptide hormone. Mice that lack ghrelin suffer lethal hypoglycemia when subjected to the same starvation regimen. Ghrelin is known to stimulate secretion of growth hormone (GH), which in turn stimulates secretion of IGF-1 (insulin-like growth factor-1). In the current study, we found that starved ghrelin-deficient mice had a 90% reduction in plasma IGF-1 when compared with starved WT mice. Injection of IGF-1 in starved ghrelin-deficient mice caused a twofold increase in glucose production and raised blood glucose to levels seen in starved WT mice. Increased glucose production was accompanied by increases in plasma glycerol, fatty acids and ketone bodies, and hepatic triglycerides. All of these increases were abolished when the mice were treated with atglistatin, an inhibitor of adipose tissue triglyceride lipase. We conclude that IGF-1 stimulates adipose tissue lipolysis in starved mice and that this lipolysis supplies energy and substrates that restore hepatic gluconeogenesis. This action of IGF-1 in starved mice is in contrast to its known action in inhibiting adipose tissue lipase in fed mice. Surprisingly, the ghrelin-dependent maintenance of plasma IGF-1 in starved mice was not mediated by GH. Direct injection of GH into starved ghrelin-deficient mice failed to increase plasma IGF-1. These data call attention to an unsuspected role of IGF-1 in the adaptation to starvation.
Assuntos
Glicemia , Fator de Crescimento Insulin-Like I , Inanição , Adaptação Fisiológica , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/enzimologia , Tecido Adiposo/metabolismo , Animais , Glicemia/metabolismo , Ácidos Graxos/sangue , Grelina/metabolismo , Gluconeogênese , Glicerol/sangue , Hormônio do Crescimento/metabolismo , Fator de Crescimento Insulin-Like I/análise , Fator de Crescimento Insulin-Like I/metabolismo , Corpos Cetônicos/sangue , Lipase/antagonistas & inibidores , Lipase/metabolismo , Lipólise , Fígado/metabolismo , Camundongos , Compostos de Fenilureia/farmacologia , Inanição/sangue , Inanição/metabolismo , Triglicerídeos/metabolismoRESUMO
AIM: To examine the effects of the thiazolidinedione (TZD) pioglitazone on reducing ketone bodies in non-obese patients with T2DM treated with the sodium-glucose cotransporter-2 (SGLT2) inhibitor canagliflozin. METHODS: Crossover trials with two periods, each treatment period lasting 4 weeks, with a 4-week washout period, were conducted. Participants were randomly assigned in a 1:1 ratio to receive pioglitazone combined with canagliflozin (PIOG + CANA group) versus canagliflozin monotherapy (CANA group). The primary outcome was change (Δ) in ß-hydroxybutyric acid (ß-HBA) before and after the CANA or PIOG + CANA treatments. The secondary outcomes were Δchanges in serum acetoacetate and acetone, the rate of conversion into urinary ketones, and Δchanges in factors related to SGLT2 inhibitor-induced ketone body production including non-esterified fatty acids (NEFAs), glucagon, glucagon to insulin ratio, and noradrenaline (NA). Analyses were performed in accordance with the intention-to-treat principle. RESULTS: Twenty-five patients with a mean age of 49 ± 7.97 years and a body mass index of 25.35 ± 2.22 kg/m2 were included. One patient discontinued the study during the washout period. Analyses revealed a significant increase in the levels of serum ketone bodies and an elevation in the rate of conversion into urinary ketones after both interventions. However, differernces in levels of ketone bodies (except for acetoacetate) in the PIOG + CANA group were significantly smaller than in the CANA group (219.84 ± 80.21 µmol/L vs. 317.69 ± 83.07 µmol/L, p < 0.001 in ß-HBA; 8.98 ± 4.17 µmol/L vs. 12.29 ± 5.27 µmol/L, p = 0.018 in acetone). NEFA, glucagon, glucagon to insulin ratio, and NA were also significantly increased after both CANA and PIOG + CANA treatments; while only NEFAs demonstrated a significant difference between the two groups. Correlation analyses revealed a significant association between the difference in Δchanges in serum NEFA levels with the differences in Δchanges in ketones of ß-HBA and acetoacetate. CONCLUSION: Supplementation of pioglitazone could alleviate canagliflozin-induced ketone bodies. This benefit may be closely associated with decreased substrate NEFAs rather than other factors including glucagon, fasting insulin and NA.
Assuntos
Canagliflozina , Estudos Cross-Over , Diabetes Mellitus Tipo 2 , Quimioterapia Combinada , Hipoglicemiantes , Corpos Cetônicos , Pioglitazona , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Masculino , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/sangue , Pessoa de Meia-Idade , Corpos Cetônicos/sangue , Feminino , Pioglitazona/uso terapêutico , Canagliflozina/uso terapêutico , Hipoglicemiantes/uso terapêutico , Ácido 3-Hidroxibutírico/sangue , Acetoacetatos/sangue , Insulina/sangue , Adulto , Glucagon/sangue , Tiazolidinedionas/uso terapêutico , Ácidos Graxos não Esterificados/sangue , Glicemia/efeitos dos fármacos , Glicemia/metabolismoRESUMO
Available evidence indicates that elevated blood ketones are associated with improved hypoxic tolerance in rodents. From this perspective, we hypothesized that exogenous ketosis by oral intake of the ketone ester (R)-3-hydroxybutyl (R)-3-hydroxybutyrate (KE) may induce beneficial physiological effects during prolonged exercise in acute hypoxia. As we recently demonstrated KE to deplete blood bicarbonate, which per se may alter the physiological response to hypoxia, we evaluated the effect of KE both in the presence and absence of bicarbonate intake (BIC). Fourteen highly trained male cyclists performed a simulated cycling race (RACE) consisting of 3-h intermittent cycling (IMT180') followed by a 15-min time-trial (TT15') and an all-out sprint at 175% of lactate threshold (SPRINT). During RACE, fraction of inspired oxygen ([Formula: see text]) was gradually decreased from 18.6% to 14.5%. Before and during RACE, participants received either 1) 75 g of ketone ester (KE), 2) 300 mg/kg body mass bicarbonate (BIC), 3) KE + BIC, or 4) a control drink in addition to 60 g of carbohydrates/h in a randomized, crossover design. KE counteracted the hypoxia-induced drop in blood ([Formula: see text]) and muscle oxygenation by â¼3%. In contrast, BIC decreased [Formula: see text] by â¼2% without impacting muscle oxygenation. Performance during TT15' and SPRINT were similar between all conditions. In conclusion, KE slightly elevated the degree of blood and muscle oxygenation during prolonged exercise in moderate hypoxia without impacting exercise performance. Our data warrant to further investigate the potential of exogenous ketosis to improve muscular and cerebral oxygenation status, and exercise tolerance in extreme hypoxia.
Assuntos
Bicarbonatos/administração & dosagem , Hidroxibutiratos/administração & dosagem , Hipóxia , Corpos Cetônicos/sangue , Cetose/sangue , Contração Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Administração Oral , Adulto , Bicarbonatos/metabolismo , Ciclismo , Estudos Cross-Over , Método Duplo-Cego , Tolerância ao Exercício/efeitos dos fármacos , Humanos , Hidroxibutiratos/metabolismo , Masculino , Músculo Esquelético/metabolismo , Fatores de Tempo , Adulto JovemRESUMO
BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent, paralleling the obesity epidemic. Ketone bodies are produced in the liver, but it is currently uncertain whether circulating ketone bodies are increased in the context of NAFLD. We investigated the association between NAFLD and circulating ketone bodies and determined the extent to which NAFLD and circulating ketone bodies are associated with all-cause mortality. METHODS: Plasma ketone bodies were measured by nuclear magnetic resonance spectroscopy in participants of the general population-based PREVEND study. A fatty liver index (FLI) ≥60 was regarded as a proxy of NAFLD. Associations of an elevated FLI and ketone bodies with all-cause mortality were investigated using Cox regression analyses. RESULTS: The study included 6,297 participants aged 54 ± 12 years, of whom 1,970 (31%) had elevated FLI. Participants with elevated FLI had higher total ketone bodies (194 [153-259] vs 170 [133-243] µmol/L; P < .001) than participants without elevated FLI. During 7.9 [7.8-8.9] years of follow-up, 387 (6%) participants died. An elevated FLI was independently associated with an increased risk of mortality (HR: 1.34 [1.06-1.70]; P = .02). Higher total ketone bodies were also associated with an increased mortality risk (HR per doubling: 1.29 [1.12-1.49]; P < .001). Mediation analysis suggested that the association of elevated FLI with all-cause mortality was in part mediated by ketone bodies (proportion mediated: 10%, P < .001). CONCLUSION: Circulating ketone bodies were increased in participants with suspected NAFLD. Both suspected NAFLD and higher circulating ketone bodies are associated with an increased risk of all-cause mortality.
Assuntos
Corpos Cetônicos/sangue , Mortalidade , Hepatopatia Gordurosa não Alcoólica/sangue , Adulto , Idoso , Índice de Massa Corporal , Causas de Morte , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ressonância Magnética Nuclear Biomolecular , Modelos de Riscos Proporcionais , Triglicerídeos/sangue , Circunferência da Cintura , gama-Glutamiltransferase/sangueRESUMO
PURPOSE: The purpose of this study was to determine the effects of 3 consecutive days of endurance training in hypoxia on hepcidin responses. METHOD: Nine active healthy males completed two trials, consisting of 3 consecutive days of endurance training in either hypoxia [fraction of inspired oxygen (FiO2): 14.5%) or normoxia (FiO2: 20.9%). On days 1-3, participants performed one 90 min session of endurance training per day, consisting of high-intensity endurance interval exercise [10 × 4 min of pedaling at 80% of maximal oxygen uptake ([Formula: see text]O2max) with 2 min of active rest at 30% of [Formula: see text]O2max] followed by 30 min of continuous exercise at 60% of [Formula: see text]O2max. Venous blood samples were collected prior to exercise each day during the experimental period (days 1-4) to determine serum hepcidin, iron, ferritin, haptoglobin, and ketone body concentrations. RESULT: Serum iron (p < 0.0001), ferritin (p = 0.005) and ketone body (p < 0.0001) concentrations increased significantly in both trials on days 2-4 compared with day 1, with no significant differences between trials. No significant changes in serum haptoglobin concentrations were observed throughout the experimental period in either trial. Serum hepcidin concentrations also increased significantly on days 2-4 compared with day 1 in both trials (p = 0.004), with no significant differences observed between trials. CONCLUSION: 3 consecutive days of endurance training in hypoxia did not affect hepcidin concentrations compared with endurance training in normoxia.
Assuntos
Treino Aeróbico/métodos , Hepcidinas/sangue , Treinamento Intervalado de Alta Intensidade/métodos , Hipóxia/fisiopatologia , Treino Aeróbico/efeitos adversos , Ferritinas/sangue , Haptoglobinas/análise , Treinamento Intervalado de Alta Intensidade/efeitos adversos , Humanos , Hipóxia/sangue , Ferro/sangue , Corpos Cetônicos/sangue , Masculino , Consumo de Oxigênio , Adulto JovemRESUMO
PURPOSE: Fibroblast growth factor (FGF) 21 is a circulating hormone with metabolic regulatory importance. In mice, FGF21 increases in response to a ketogenic diet and fasting. In humans, a similar increase is only observed after prolonged starvation. We aim to study the acute effects of ketone bodies on circulating FGF21 levels in humans. METHODS: Participants from three randomized, placebo-controlled crossover studies, with increased endogenous or exogenous ketone bodies, were included. Study 1: patients with type 1 diabetes (T1D) (n = 9) were investigated after a) insulin deprivation and lipopolysaccharide (LPS) injection and b) insulin-controlled euglycemia. Study 2: patients with T1D (n = 9) were investigated after a) total insulin deprivation for 9 hours and b) insulin-controlled euglycemia. Study 3: Healthy adults (n = 9) were examined during a) 3-hydroxybutyrate (OHB) infusion and b) saline infusion. Plasma FGF21 was measured with immunoassay in serial samples. RESULTS: Circulating OHB levels were significantly increased to 1.3, 1.5, and 5.5 mmol/l in the three studies, but no correlations with FGF21 levels were found. Also, no correlations between FGF21, insulin, or glucagon were found. Insulin deprivation and LPS injection resulted in increased plasma FGF21 levels at t = 120 min (p = .005) which normalized at t = 240 min. CONCLUSION: We found no correlation between circulating FGF21 levels and levels of ketone bodies. This suggests that it is not ketosis per se which controls FGF21 production, but instead a rather more complex regulatory mechanism. TRIAL REGISTRATION: clinicaltrials.gov ID number: Study 1: NCT02157155 (5/6-2014), study 2: NCT02077348 (4/3-2014), and study 3: NCT02357550 (6/2-2015).
Assuntos
Diabetes Mellitus Tipo 1/sangue , Fatores de Crescimento de Fibroblastos/sangue , Insulina/metabolismo , Corpos Cetônicos/sangue , Ácido 3-Hidroxibutírico/administração & dosagem , Ácido 3-Hidroxibutírico/sangue , Adulto , Estudos Cross-Over , Feminino , Humanos , Corpos Cetônicos/administração & dosagem , Lipopolissacarídeos/administração & dosagem , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
BACKGROUND: Recent evidence indicates that insulin resistance (IR) in obesity may develop independently in different organs, representing different etiologies toward type 2 diabetes and other cardiometabolic diseases. The aim of this study was to investigate whether IR in the liver and IR in skeletal muscle are associated with distinct metabolic profiles. METHODS: This study includes baseline data from 634 adults with overweight or obesity (BMI ≥ 27 kg/m2) (≤65 years; 63% women) without diabetes of the European Diogenes Study. Hepatic insulin resistance index (HIRI) and muscle insulin sensitivity index (MISI), were derived from a five-point OGTT. At baseline 17 serum metabolites were identified and quantified by nuclear-magnetic-resonance spectroscopy. Linear mixed model analyses (adjusting for center, sex, body mass index (BMI), waist-to-hip ratio) were used to associate HIRI and MISI with these metabolites. In an independent sample of 540 participants without diabetes (BMI ≥ 27 kg/m2; 40-65 years; 46% women) of the Maastricht Study, an observational prospective population-based cohort study, 11 plasma metabolites and a seven-point OGTT were available for validation. RESULTS: Both HIRI and MISI were associated with higher levels of valine, isoleucine, oxo-isovaleric acid, alanine, lactate, and triglycerides, and lower levels of glycine (all p < 0.05). HIRI was also associated with higher levels of leucine, hydroxyisobutyrate, tyrosine, proline, creatine, and n-acetyl and lower levels of acetoacetate and 3-OH-butyrate (all p < 0.05). Except for valine, these results were replicated for all available metabolites in the Maastricht Study. CONCLUSIONS: In persons with obesity without diabetes, both liver and muscle IR show a circulating metabolic profile of elevated (branched-chain) amino acids, lactate, and triglycerides, and lower glycine levels, but only liver IR associates with lower ketone body levels and elevated ketogenic amino acids in circulation, suggestive of decreased ketogenesis. This knowledge might enhance developments of more targeted tissue-specific interventions to prevent progression to more severe disease stages.
Assuntos
Resistência à Insulina , Obesidade/metabolismo , Sobrepeso/metabolismo , Adulto , Feminino , Humanos , Corpos Cetônicos/sangue , Fígado/metabolismo , Masculino , Metabolômica , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Músculo Esquelético/metabolismo , Estudos Observacionais como Assunto , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Objective- Loss-of-function (LOF) variants in the ANGPTL3 (angiopoietin-like protein 3) have been associated with low levels of plasma lipoproteins and decreased coronary artery disease risk. We aimed to determine detailed metabolic effects of genetically induced ANGPTL3 deficiency in fasting and postprandial state. Approach and Results- We studied individuals carrying S17X LOF mutation in ANGPTL3 (6 homozygous and 32 heterozygous carriers) and 38 noncarriers. Nuclear magnetic resonance metabolomics was used to quantify 225 circulating metabolic measures. We compared metabolic differences between LOF carriers and noncarriers in fasting state and after a high-fat meal. In fasting, ANGPTL3 deficiency was characterized by similar extent of reductions in LDL (low-density lipoprotein) cholesterol (0.74 SD units lower concentration per LOF allele [95% CI, 0.42-1.06]) as observed for many TRL (triglyceride-rich lipoprotein) measures, including VLDL (very-low-density lipoprotein) cholesterol (0.75 [95% CI, 0.45-1.05]). Within most lipoprotein subclasses, absolute levels of cholesterol were decreased more than triglycerides, resulting in the relative proportion of cholesterol being reduced within TRLs and their remnants. Further, ß-hydroxybutyrate was elevated (0.55 [95% CI, 0.21-0.89]). Homozygous ANGPTL3 LOF carriers showed essentially no postprandial increase in TRLs and fatty acids, without evidence for adverse compensatory metabolic effects. Conclusions- In addition to overall triglyceride- and LDL cholesterol-lowering effects, ANGPTL3 deficiency results in reduction of cholesterol proportion within TRLs and their remnants. Further, ANGPTL3 LOF carriers had elevated ketone body production, suggesting enhanced hepatic fatty acid ß-oxidation. The detailed metabolic profile in human knockouts of ANGPTL3 reinforces inactivation of ANGPTL3 as a promising therapeutic target for decreasing cardiovascular risk.
Assuntos
Proteínas Semelhantes a Angiopoietina/deficiência , Jejum/sangue , Lipoproteínas/sangue , Metaboloma , Período Pós-Prandial , Adulto , Alelos , Proteína 3 Semelhante a Angiopoietina , Proteínas Semelhantes a Angiopoietina/genética , Doenças Cardiovasculares/prevenção & controle , LDL-Colesterol/sangue , Gorduras na Dieta , Feminino , Genótipo , Humanos , Corpos Cetônicos/sangue , Fígado/metabolismo , Mutação com Perda de Função , Masculino , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Triglicerídeos/sangueRESUMO
BACKGROUND: Ketosis is a metabolic disorder often triggered by anorexia in animals fed on high energy diets. Although mostly described in pregnant female guinea pigs, under the name of pregnancy toxicosis; there is limited information on ketosis in males and non-pregnant females, often presented to clinics with anorexia or inappetence. The objective of this study was to observe progression of ketosis in guinea pigs, document the changes and evaluate diagnostic methods and a therapeutic approach. RESULTS: Twenty eight adult guinea pigs (Cavia porcellus), castrated males and intact females of obese and slim body condition were fasted for 3 days and refed afterwards. The slim animals served as control group for body condition. Either slim and fat animals were divided into two treatment groups: half of them received fluid replacements with glucose subcutaneously, the other half did not receive any injection and served as treatment control. Serum beta-hydroxybutyrate, and urine acetoacetate and acetone were measured during and after fasting. Serum ALT, bile acids and liver histology were also analyzed after 7 days of refeeding (and therapy). Females and obese guinea pigs showed a significantly higher increase in ketone bodies in serum and urine. Obese, female, or animals not receiving therapy needed more time to regulate ketone bodies to normal levels than slim animals, males or animals receiving therapy. Liver histology revealed increased hepatocyte degeneration and higher glycogen content in obese animals and animals receiving therapy, and additionally more glycogen content in males. Only minor hepatic fat accumulation was documented. Bile acids showed good correlation to histological liver changes whereas ALT did not. CONCLUSIONS: Female and obese animals react more intensively to fasting. As preventive management, animals should be kept in adequate body condition, fasting should be avoided, and anorexia should be treated immediately. In such a case, urinary dip sticks to detect ketone bodies are a useful diagnostic tool. Glucose therapy leads to faster cessation of ketogenesis and should be recommended in cases of ketosis. However, it needs to be adjusted to avoid hepatocyte glycogen overload and degeneration. Measuring bile acids presents a valuable indicator of liver damage.
Assuntos
Privação de Alimentos , Cetose/veterinária , Doenças dos Roedores/diagnóstico , Ácido 3-Hidroxibutírico/sangue , Acetoacetatos/urina , Acetona/urina , Fenômenos Fisiológicos da Nutrição Animal , Animais , Ácidos e Sais Biliares , Feminino , Glucose/administração & dosagem , Cobaias , Corpos Cetônicos/sangue , Corpos Cetônicos/urina , Cetose/diagnóstico , Cetose/terapia , Fígado/metabolismo , Fígado/patologia , Masculino , Obesidade/complicações , Obesidade/veterinária , Doenças dos Roedores/terapiaRESUMO
The aim of this study was to examine the effects of α-lipoic acid (α-LA) on liver mitochondrial bioenergetics and oxidative status for 8 weeks in normal-healthy animals. A pair-fed group was included to differentiate between α-LA direct effects and those changes due to reduced food intake. α-LA decreased body weight gain, liver weight and insulin levels with no differences compared to its pair-fed group. α-LA significantly reduced energy efficiency, the activity of the electron transport chain complexes and induced a lower efficiency of oxidative phosphorylation with reduced ATP production. α-LA supplementation directly decreased plasma triglycerides (TGs), free fatty acids and ketone bodies levels. A significant reduction in hepatic TG content was also observed. A significant up-regulation of Cpt1a, Acadl and Sirt3, all ß-oxidation genes, along with a significant deacetylation of the forkhead transcription factor 3a (FOXO3A) was found in α-LA-treated animals. Thus, α-LA along with a standard chow diet has direct actions on lipid metabolism and liver by modulating mitochondrial function in normal-weight rats. These results should be taken into account when α-LA is administered or recommended to a healthy population.
Assuntos
Carnitina O-Palmitoiltransferase/metabolismo , Metabolismo Energético , Proteína Forkhead Box O3/metabolismo , Fígado/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Sirtuínas/metabolismo , Ácido Tióctico/farmacologia , Animais , Glicemia , Carnitina O-Palmitoiltransferase/genética , Ácidos Graxos não Esterificados/sangue , Proteína Forkhead Box O3/genética , Corpos Cetônicos/sangue , Metabolismo dos Lipídeos , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Masculino , Mitocôndrias/metabolismo , Fosforilação , Ratos , Ratos Wistar , Sirtuínas/genética , Triglicerídeos/sangue , Regulação para CimaRESUMO
ß-Klotho (encoded by Klb) is an obligate coreceptor, mediating both fibroblast growth factor (FGF)15 and FGF21 signaling. Klb-/- mice are refractory to metabolic FGF15 and FGF21 action and exhibit derepressed (increased) bile acid (BA) synthesis. Here, we deeply phenotyped male Klb-/- mice on a pure C57BL/6J genetic background, fed a chow diet focusing on metabolic aspects. This aims to better understand the physiological consequences of concomitant FGF15 and FGF21 signaling deficiency, in particular on the gut-liver axis. Klb-/- mice present permanent growth restriction independent of adiposity and energy balance. Klb-/- mice also exhibit few changes in carbohydrate metabolism, combining normal gluco-tolerance, insulin sensitivity, and fasting response with increased gluconeogenic capacity and decreased glycogen mobilization. Livers of Klb-/- mice reveal pathologic features, including a proinflammatory status and initiation of fibrosis. These defects are associated to a massive shift in BA composition in the enterohepatic system and blood circulation featured by a large excess of microbiota-derived deoxycholic acid, classically known for its genotoxicity in the gastrointestinal tract. In conclusion, ß-Klotho is a gatekeeper of hepatic integrity through direct action (mediating FGF21 anti-inflammatory signaling) and indirect mechanisms (mediating FGF15 signaling that maintains BA level and composition).
Assuntos
Ácidos e Sais Biliares/metabolismo , Peso Corporal/fisiologia , Trato Gastrointestinal/metabolismo , Cirrose Hepática/metabolismo , Fígado/metabolismo , Proteínas de Membrana/metabolismo , Adiposidade/genética , Animais , Metabolismo Energético/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Gluconeogênese/fisiologia , Corpos Cetônicos/sangue , Proteínas Klotho , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Transdução de Sinais/fisiologiaRESUMO
BACKGROUND/AIMS: Systemic hyperlipidemia and intracellular lipid accumulation induced by chronic high fat diet (HFD) leads to enhanced fatty acid oxidation (FAO) and ketogenesis. The present study was aimed to determine whether activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) by surplus free fatty acids (FA) in hyperlipidemic condition, has a positive feedback regulation over FAO and ketogenic enzymes controlling lipotoxicity and cardiac apoptosis. METHODS: 8 weeks old C57BL/6 wild type (WT) or PPAR-γ-/- mice were challenged with 16 weeks 60% HFD to induce obesity mediated type 2 diabetes mellitus (T2DM) and diabetic cardiomyopathy. Treatment course was followed by echocardiographic measurements, glycemic and lipid profiling, immunoblot, qPCR and immunohistochemistry (IHC) analysis of PPAR-γ and following mitochondrial metabolic enzymes 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS2), mitochondrial ß- hydroxy butyrate dehydrogenase (BDH1) and pyruvate dehydrogenase kinase isoform 4 (PDK4). In vivo model was translated in vitro, with neonatal rat cardiomyocytes (NRCM) treated with PPAR-γ agonist/antagonist and PPAR-γ overexpression adenovirus in presence of palmitic acid (PA). Apoptosis was determined in vivo from left ventricular heart by TUNEL assay and immunoblot analysis. RESULTS: We found exaggerated circulating ketone bodies production and expressions of the related mitochondrial enzymes HMGCS2, BDH1 and PDK4 in HFD-induced diabetic hearts and in PA-treated NRCM. As a mechanistic approach we found HFD mediated activation of PPAR-γ is associated with the above-mentioned mitochondrial enzymes. HFD-fed PPAR-γ-/-mice display decreased hyperglycemia, hyperlipidemia associated with increased insulin responsiveness as compared to HFD-fed WT mice PPAR-γ-/-HFD mice demonstrated a more robust functional recovery after diabetes induction, as well as significantly reduced myocyte apoptosis and improved cardiac function. CONCLUSIONS: PPAR-γ has been described previously to regulate lipid metabolism and adipogenesis. The present study suggests for the first time that increased PPAR-γ expression by HFD is responsible for cardiac dysfunction via upregulation of mitochondrial enzymes HMGCS2, BDH1 and PDK4. Targeting PPAR-γ and its downstream mitochondrial enzymes will provide novel strategies in preventing metabolic and myocardial dysfunction in diabetes mellitus.
Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Cardiomiopatias Diabéticas/metabolismo , Dieta Hiperlipídica/efeitos adversos , Ácidos Graxos/metabolismo , Corpos Cetônicos/metabolismo , PPAR gama/metabolismo , Disfunção Ventricular Esquerda/metabolismo , Animais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/patologia , Cardiomiopatias Diabéticas/sangue , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/patologia , Ácidos Graxos/sangue , Hipertrofia Ventricular Esquerda/sangue , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/metabolismo , Hipertrofia Ventricular Esquerda/patologia , Corpos Cetônicos/sangue , Masculino , Camundongos Endogâmicos C57BL , Oxirredução , Disfunção Ventricular Esquerda/sangue , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/patologiaRESUMO
Recent clinical trials have demonstrated a strong cardiovascular (CV) protective effect of sodium/glucose cotransporter (SGLT) 2 inhibitors, a recently introduced class of hypoglycaemic agents. The improvement in glycated haemoglobin and other conventional risk factors explains only a portion of the observed reduction in CV risk. A relevant feature of SGLT2-inhibitor-treated diabetic patients is the increase in circulating levels of ketone bodies, which has been proposed to mediate part of the beneficial effects of this class of drugs, mainly through their bioenergetic properties. However, ketone bodies are emerging as potent anti-inflammatory molecules, and inflammation is a recognized risk factor for the development of CV events. In this framework, we hypothesize that, through their unique mechanism of action and by increasing circulating ketone bodies, SGLT2 inhibitors indirectly target the IL-1ß pathway and thus produce a consistent amelioration of low-grade inflammation, a clinically relevant phenomenon in diabetic patients with high CV risk. This attenuation could slow the progression of CV disease and especially the atherosclerotic process, which is sensitive to environmental changes, even over a short time period. To test this conceptual structure, it would be necessary to measure circulating pro-inflammatory molecules in patients treated with SGLT inhibitors. The addition of inflammatory markers to the list of clinical data measured in FDA-requested, large CV outcome trials could provide supplementary information regarding potential secondary effects of new anti-hyperglycaemic drugs, considering that the inflammatory process is an often neglected cornerstone of CV diseases.
Assuntos
Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Inflamação/sangue , Inflamação/complicações , Corpos Cetônicos/sangue , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Doenças Cardiovasculares/sangue , Sistema Cardiovascular/efeitos dos fármacos , Humanos , Inflamação/patologia , Corpos Cetônicos/fisiologia , Fatores de RiscoRESUMO
Sodium glucose co-transporter 2 (SGLT2) inhibitors have been associated with increased serum ketone body levels in patients with type 2 diabetes mellitus (T2DM). In the present analysis we evaluated serum ketone body levels and variability in 1278 Japanese patients with T2DM treated with canagliflozin 100 or 200 mg. Similar mean increases in ketone body concentrations of ~2-fold were seen with both canagliflozin doses. The median (interquartile range) percent change from baseline was 62% (0;180) for acetoacetate and 78% (2;236) for ß-hydroxybutyrate. Approximately two-thirds of the variability in each ketone measure was attributed to intra-subject variability. Intra-subject variability was higher for serum ketones than other metabolites. Patients in the lowest response tertile exhibited no increase in ketones. Those in the highest response tertile tended to be male and have higher fasting plasma glucose levels, lower insulin levels, and longer T2DM duration at baseline. Moreover, changes in serum ketones were not fully explained by changes in plasma fatty acids, suggesting downstream effects of SGLT2 inhibition on hepatic metabolism that favour ketogenesis. In summary, increases in serum ketone bodies with canagliflozin were greater and more variable than changes in other metabolic measures in Japanese patients with T2DM.
Assuntos
Variação Biológica da População/efeitos dos fármacos , Canagliflozina/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Corpos Cetônicos/sangue , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Regulação para Cima/efeitos dos fármacos , Ácido 3-Hidroxibutírico/sangue , Acetoacetatos/sangue , Glicemia/análise , Canagliflozina/administração & dosagem , Canagliflozina/efeitos adversos , Diabetes Mellitus Tipo 2/sangue , Cetoacidose Diabética/induzido quimicamente , Cetoacidose Diabética/fisiopatologia , Cetoacidose Diabética/prevenção & controle , Relação Dose-Resposta a Droga , Ácidos Graxos não Esterificados/sangue , Feminino , Seguimentos , Humanos , Hiperglicemia/prevenção & controle , Hipoglicemia/induzido quimicamente , Hipoglicemia/prevenção & controle , Japão , Masculino , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Caracteres Sexuais , Inibidores do Transportador 2 de Sódio-Glicose/administração & dosagem , Inibidores do Transportador 2 de Sódio-Glicose/efeitos adversosRESUMO
AIMS: When treated with basal insulin peglispro (BIL), patients with type 1 diabetes mellitus (T1DM) exhibit weight loss and lower prandial insulin requirements versus insulin glargine (GL), while total insulin requirements remain similar. One possible explanation is enhanced lipid oxidation and improved ability to switch between glucose and lipid metabolism with BIL. This study compared the effects of BIL and GL on glucose and lipid metabolism in subjects with T1DM. MATERIALS AND METHODS: Fifteen subjects with T1DM were enrolled into this open-label, randomised, crossover study, and received once-daily stable, individualised, subcutaneous doses of BIL and GL for 4 weeks each. Respiratory quotient (RQ) was measured using whole-room calorimetry, and energy expenditure (EE) and concentrations of ketone bodies (3-hydroxybutyrate) and acylcarnitines were assessed. RESULTS: Mean sleep RQ was lower during the BIL (0.822) than the GL (0.846) treatment period, indicating greater lipid metabolism during the post-absorptive period with BIL. Increases in carbohydrate oxidation following breakfast were greater during BIL than GL treatment (mean change in RQ following breakfast 0.111 for BIL, 0.063 for GL). Furthermore, BIL treatment increased total daily EE versus GL (2215.9 kcal/d for BIL, 2135.5 kcal/d for GL). Concentrations of ketone bodies and acylcarnitines appeared to be higher following BIL than GL treatment. CONCLUSIONS: BIL increased sleeping fat oxidation, EE, ketone bodies, acylcarnitines and post-prandial glucose metabolism when switching from conventional insulin, thus, restoring metabolic flexibility and increasing thermogenesis. These changes may explain the previously observed weight loss with BIL versus GL.
Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Glicólise/efeitos dos fármacos , Hipoglicemiantes/efeitos adversos , Insulina Glargina/efeitos adversos , Insulina Lispro/análogos & derivados , Lipólise/efeitos dos fármacos , Polietilenoglicóis/efeitos adversos , Termogênese/efeitos dos fármacos , Adulto , Metabolismo Basal/efeitos dos fármacos , Biomarcadores/sangue , Desjejum , Carnitina/análogos & derivados , Carnitina/sangue , Estudos Cross-Over , Diabetes Mellitus Tipo 1/sangue , Esquema de Medicação , Monitoramento de Medicamentos , Feminino , Seguimentos , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Insulina Glargina/administração & dosagem , Insulina Glargina/uso terapêutico , Insulina Lispro/administração & dosagem , Insulina Lispro/efeitos adversos , Insulina Lispro/uso terapêutico , Corpos Cetônicos/agonistas , Corpos Cetônicos/sangue , Masculino , Pessoa de Meia-Idade , Oxirredução , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/uso terapêutico , Adulto JovemRESUMO
Diabetes mellitus (DM) could cause pilot incapacitation and result in aviation fatalities. The mechanisms could be directly as a consequence of acute hypoglycemia/subacute diabetic ketoacidosis (DKA) or indirectly as an acute cardiovascular event by contributing to the development of atherosclerosis in coronary or carotid and cerebral arteries. In this study, DM-related fatal flight accidents in the US National Transport Bureau's database between years 2011-2016 were analyzed with special emphasis on postmortem (PM) glucose levels and correlation of toxicological reports with anamnestic information on DM. Additionally, autopsy results on coronary arteries were reviewed. In 43 out of 1491 (~ 3%) fatal accidents pilots had DM. Postmortem glucose or glycated hemoglobin percentage (Hb1Ac) was measured in 12 of the 43 cases; while antidiabetic medication was found in 14 of the cases (only two of the cases had both glucose measurements and medication). With the increasing prevalence of DM, a possibility of pilot incapacitation due to DM or complications of DM should be actively studied, even if no anamnestic information of DM was available. While PM hypoglycemia is difficult to assess, we propose a systematic investigation based on measurement of glucose, Hb1Ac%, and ketone bodies, and documentation of atherosclerotic lesions in major arteries to identify or rule out DM as a cause of pilot incapacitation.
Assuntos
Acidentes Aeronáuticos/estatística & dados numéricos , Diabetes Mellitus/epidemiologia , Pilotos , Adulto , Idoso , Glicemia/análise , Doença da Artéria Coronariana/patologia , Diabetes Mellitus/metabolismo , Glucose/metabolismo , Hemoglobinas Glicadas/análise , Humanos , Hipoglicemiantes/sangue , Corpos Cetônicos/sangue , Pessoa de Meia-Idade , Estados Unidos/epidemiologia , Corpo Vítreo/metabolismoRESUMO
Hypothermia is defined as a core body temperature below 35°C and can be caused by environmental exposure, drug intoxication, metabolic or nervous system dysfunction. This lethal pathology with medico-legal implications is complex to diagnose because macroscopic and microscopic lesions observed at the autopsy and the histological analysis are suggestive but not pathognomonic. Postmortem biochemical explorations have been progressively developed through the study of several biomarkers to improve the diagnosis decision cluster. Here, we present an updated review with novel biomarkers (such as catecholamines O-methylated metabolites, thrombomodulin and the cardiac oxyhemoglobin ratio) as well as some propositional interpretative postmortem thresholds and, to the best of our knowledge, for the first time, we present the most adapted strategy of sampling and analyses to identify biomarkers of hypothermia. For our consideration, the most relevant identified biomarkers are urinary catecholamines and their O-methylated metabolites, urinary free cortisol, blood cortisol, as well as blood, vitreous humor and pericardial fluid for ketone bodies and blood free fatty acids. These biomarkers are increased in response either to cold-mediated stress or to bioenergetics ketogenesis crisis and significantly contribute to the diagnosis by exclusion of death by hypothermia.
Assuntos
Biomarcadores/metabolismo , Hipotermia/diagnóstico , Biomarcadores/sangue , Catecolaminas/sangue , Catecolaminas/metabolismo , Ácidos Graxos não Esterificados/sangue , Ciências Forenses , Humanos , Hidrocortisona/sangue , Hipotermia/patologia , Corpos Cetônicos/sangue , Trombomodulina/sangueRESUMO
This study aimed to investigate the effect of branched chain amino acids (BCCAs) on perioperative temperature, glucose and fat metabolism in patients with gastrointestinal tumors. Fifty-six patients undergoing gastrointestinal tumor surgery were included in the study and randomly divided into two groups of 28 patients each: an experimental and a control group. During surgery, the experimental group received 5.64mL·Kg-1·h-1(4KJ·Kg-1·h-1) of BCCAs intravenously, through an infusion pump, and the control group received an equal volume of NaCl 0.9%. Vital signs were continuously monitored during the operation. Nasopharynx temperature levels of glucose, insulin, free fatty acid and ketone bodies in the blood were determined 30 min before anesthesia (t 0), after anesthesia and before surgery (t 1), 30 min after the start of surgery (t 2), 2 h after start of surgery (t 3) and 1 h after the end of surgery (T4). Patients shivering intensity (Wrench grading) and pain degree [Visual analogue scale (VAS)]) were estimated 1 h after the endotracheal tube was removed. Nasopharynx temperature was decreased (p less than 0.05) in both groups after anesthesia induction, while 1 h after the tube was removed it was higher in the experimental group than the control group (p less than 0.05); compared with pre-surgery values, blood glucose levels were increased during surgery in both groups, but the experimental group had a lower increasing trend compared to the control group, though without statistical significance (p>0.05). Insulin levels were significantly different between the two groups at all time-points during surgery (p less than 0.05). However, the rising trend of the experimental group was more dramatic during the period from t 0 to t 3. One hour after surgery (t 4), the insulin levels varied, but still at higher levels than pre-surgery, with a significant difference (p less than 0.05); levels of free fatty acids had a downward trend in both groups, and levels in the experimental group continued to decline until 1 h after surgery. Patients who received branched chain amino acids had less temperature decrease during surgery. Moreover, blood glucose levels were not increased, which limits fat mobilization and leads to production of ketone bodies, reduces the shivering and its intensity after surgery.
Assuntos
Aminoácidos de Cadeia Ramificada/uso terapêutico , Glicemia/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Adulto , Idoso , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Ácidos Graxos não Esterificados/sangue , Feminino , Neoplasias Gastrointestinais/cirurgia , Humanos , Insulina/sangue , Corpos Cetônicos/sangue , Masculino , Pessoa de Meia-Idade , Período PerioperatórioRESUMO
The aim of this study was to evaluate whether the use of subcutaneous mineral supplementation would affect metabolic parameters, immunological response, milk quality and composition of dairy cows in the postpartum period. Twelve pregnant primiparous Holstein cows, were divided into two groups: six animals supplemented with the mineral complex (magnesium, phosphorus, potassium, selenium and copper), and six animals used as controls. Milk samples were collected every two other weeks postpartum up to sixty days of lactation to analyze composition and quality. Blood samples were collected, and the levels of ketone bodies, total proteins, glucose, albumin, and globulin were measured. The catalase and superoxide enzymes, reactive oxygen species, tumor necrosis factor, and interleukins were determined. Animals supplemented with minerals showed lower levels of ketone bodies and somatic cell counts on days 30, 45 and 60 of the experiment, without changes in milk composition compared to the control group. Supplemented cows had lower levels reactive oxygen species and increased superoxide enzymes activity. Total protein, globulin and cytokine levels were higher in cows supplemented with mineral complexes. Therefore, we can conclude that subcutaneous mineral supplementation improved the immune response and minimized the oxidative stress in dairy cows during lactation.
Assuntos
Antioxidantes/metabolismo , Suplementos Nutricionais , Sistema Imunitário/efeitos dos fármacos , Leite/citologia , Minerais/farmacologia , Animais , Glicemia/análise , Bovinos , Contagem de Células/veterinária , Citocinas/sangue , Feminino , Injeções Subcutâneas/veterinária , Corpos Cetônicos/sangue , Leite/química , Período Pós-Parto , Espécies Reativas de Oxigênio/metabolismo , Soroalbumina Bovina/análise , Soroglobulinas/análiseRESUMO
OBJECTIVES: We designed a study to compare rapid intravenous rehydration based on 0.9% normal saline (NS) or on NS + glucose 2.5% serum (SGS 2.5%) in patients with dehydration secondary to acute gastroenteritis. Our hypothesis is that the addition of glucose 2.5% serum (SGS 2.5%) to 0.9% saline solution could reduce the proportion of hospital admissions and return emergency visits in these patients. The secondary objective was to identify differences in the evolution of blood glucose and ketonemia between the groups. METHODS: We designed a prospective randomized open-label clinical trial that was conducted in 2 tertiary hospitals over 9 months. Patients were randomized to receive SGS 2.5% or NS. Baseline clinical, analytical, and disease-related data were collected. Data were analyzed using SPSS. RESULTS: The frequency of hospitalization in the SGS 2.5% group was 30.3% (n = 23) compared with 34.8% (n = 24) in the NS group, although the difference was not statistically significant (P = 0.59). The frequency of return visits to the emergency department was 17.8% (n = 8) in the NS group and 5.6% (n = 3) in the SGS 2.5% group (P = 0.091). Changes in glucose and ketone levels were more favorable in the SGS 2.5% group. CONCLUSIONS: Our results enabled us to conclude that there were no significant differences in hospital admission or return visits to the emergency department between children with dehydration secondary to acute gastroenteritis.