RESUMEN
PURPOSE: This study aimed to determine whether L-arginine supplementation lasting for 18 months maintained long-lasting effects on diabetes incidence, insulin secretion and sensitivity, oxidative stress, and endothelial function during 108 months among subjects at high risk of developing type 2 diabetes. METHODS: One hundred and forty-four middle-aged subjects with impaired glucose tolerance and metabolic syndrome were randomized in 2006 to an L-arginine supplementation (6.4 g orally/day) or placebo therapy lasting 18 months. This period was followed by a 90-month follow-up. The primary outcome was a diagnosis of diabetes during the 108 month study period. Secondary outcomes included changes in insulin secretion (proinsulin/c-peptide ratio), insulin sensitivity (IGI/HOMA-IR), oxidative stress (AOPPs), and vascular function. After the 18 month participation, subjects that were still free of diabetes and willing to continue their participation (104 subjects) were further followed until diabetes diagnosis, with a time span of about 9 years from baseline. RESULTS: Although results derived from the 18 month of the intervention study demonstrated no differences in the probability of becoming diabetics, at the end of the study, the cumulative incidence of diabetes was of 40.6% in the L-arginine group and of 57.4% in the placebo group. The adjusted HR for diabetes (L-arginine vs. placebo) was 0.66; 95% CI 0.48, 0.91; p < 0.02). Proinsulin/c-peptide ratio (p < 0.001), IGI/HOMA-IR (p < 0.01), and AOPP (p < 0.05) levels were ameliorated in L-arginine compared to placebo. CONCLUSIONS: These results may suggest that the administration of L-arginine could delay the development of T2DM for a long period. This effect could be mediated, in some extent, by L-arginine-induced reduction in oxidative stress.
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Arginina/administración & dosificación , Intolerancia a la Glucosa/tratamiento farmacológico , Síndrome Metabólico/tratamiento farmacológico , Administración Oral , Glucemia/metabolismo , Péptido C/sangre , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Dieta , Células Endoteliales , Ejercicio Físico , Estudios de Seguimiento , Humanos , Insulina/sangre , Resistencia a la Insulina , Persona de Mediana Edad , Estrés Oxidativo/efectos de los fármacos , Tamaño de la Muestra , Encuestas y Cuestionarios , Resultado del TratamientoRESUMEN
AIM/HYPOTHESIS: Hepatic insulin resistance (HIR) is considered to be an independent predictor of metabolic disorders and plays an important role in systemic inflammation, which contributes to abnormalities in cardiovascular disease (CVD) risk factors. The aim of this study was to investigate the relationship between HIR and new markers of cardiovascular risks, including leptin/adiponectin ratio (L/A), lipoprotein(a) [Lp(a)], and tumor necrosis factor alpha (TNF-α), at comparable whole body insulin sensitivity in non-diabetic individuals with or without CVD and at high risk of developing type 2 diabetes. METHODS: The HIR index, L/A, Lp(a), and TNF-α were measured in 50 participants with CVD and in 200 without CVD (1:4 ratio). These were also matched for the homeostatic model assessment for insulin resistance (HOMA-IR) and Matsuda-insulin sensitivity index (ISI) in an observational study design. RESULTS: The HIR index (1.52 ± 0.14 vs. 1.45 ± 0.17, p < 0.02), L/A (3.22 ± 3.10 vs. 2.09 ± 2.27, p < 0.004), and levels of Lp(a) (66.6 ± 49.5 vs. 37.9 ± 3 6.8 mg/dL, p < 0.0001) and TNF-α (18.9 ± 21.8 vs. 5.4 ± 7.1 pg/mL, p < 0.0001) were higher in those with CVD than those without CVD. HOMA-IR and ISI were not significantly different (p = 0.88 and p = 0.35, respectively). The HIR index was directly correlated with L/A (r = 0.41, p < 0.0001), Lp(a) (r = 0.20, p < 0.002), TNF- α (r = 0.14, p < 0.03), and diastolic blood pressure (DBP) (r = 0.13, p < 0.03). The stepwise model analysis showed that L/A, Lp(a), and TNF-α explained about 20% of the variation in the HIR indices of all the participants (p < 0.02). CONCLUSIONS/INTERPRETATIONS: Our results suggest a positive association between HIR and new markers of cardiovascular risk [L/A, Lp(a), and TNF- α] at comparable whole body insulin sensitivity in those with or without CVD and at high risk of developing type 2 diabetes.
Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Adiponectina , Enfermedades Cardiovasculares/epidemiología , Diabetes Mellitus Tipo 2/complicaciones , Factores de Riesgo de Enfermedad Cardiaca , Humanos , Leptina , Lipoproteína(a) , Factor de Necrosis Tumoral alfaRESUMEN
BACKGROUND & AIMS: Excess nutrient supply, such as high fat and high glucose intake, promotes oxidative stress and advanced glycation end products accumulation. Oxidative stress and AGE accumulation cause pathological elevation of arginase activity and pro-inflammatory signaling implicated in endothelial dysfunction. Several studies showed positive effects of l-arginine supplementation in endothelial function but little is currently known about the role of l-arginine as prevention of endothelial dysfunction caused by excessive nutrient supply (overfeeding). Our aim was to evaluate a possible protective effect of l-arginine on endothelial dysfunction caused by excessive nutrient supply (overfeeding), using human endothelial cells line in an in vitro study. METHODS: Endothelial EA.hy926 cells were pre-treated with 1.72 mM of l-arginine for 24 h and afterwards subjected to nutritional stress (high lipid, high insulin and high glucose concentrations) for further 24 h. After treatment discontinuation, the cells were kept in culture for 48 h, in physiological condition, to evaluate the effects of treatments after normalization. RESULTS: Excess nutrient supply in EA.hy926 cell line showed an increase of oxidative and nitrosative stress, a rise of AGEs production, high arginase activity, leading the cells to acidosis and to cell death. l-arginine pretreatment protects the cells by reducing apoptosis, acidosis, oxidative and nitrosative stress, arginase activity and AGE accumulation. l-arginine pretreatment reduces AGEs generation and accumulation by regulating STAB1 and RAGE gene expression levels. STAB1, acting as receptor scavenger of AGEs, interferes with AGE-RAGE binding and thus prevents activation of intracellular signaling pathways leading to cell damage. Moreover the reduction of oxidative stress promotes a decrease of excessive activation of arginase involved in endothelial dysfunction. The effects of pretreatment with l-arginine last even in the absence of stimuli and despite after treatment discontinuation. CONCLUSIONS: An early l-arginine treatment is able to prevent oxidative stress and AGEs accumulation caused by overfeeding in human endothelial cell line by regulating STAB1/RAGE gene expression and by reducing excess arginase activity. The positive effects of l-arginine pretreatment continue even after treatment discontinuation in normal conditions.
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Arginina/farmacología , Endotelio Vascular/efectos de los fármacos , Fenómenos Fisiológicos de la Nutrición/efectos de los fármacos , Hipernutrición/prevención & control , Sustancias Protectoras/farmacología , Línea Celular , Células Endoteliales/efectos de los fármacos , Productos Finales de Glicación Avanzada/metabolismo , Humanos , Hipernutrición/metabolismo , Estrés Oxidativo/efectos de los fármacos , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: To evaluate the influence of gender on the relationship between inflammation and hyperinsulinemia in first-degree relatives of type 2 diabetic patients independently of metabolic syndrome. METHODS: Study group consisted in 217 first-degree relatives with normal glucose tolerance after an oral glucose tolerance test. A logistic analysis, adjusted for age, sex and all the components of the metabolic syndrome, was used to determine the relationship between interleukin-6 (IL-6) and leptin and tertiles of fasting insulin, and to take into account the influence of gender. RESULTS: In the whole cohort, IL-6 and leptin were significantly higher and adiponectin significantly lower in the III tertile when corrected for age, body mass index (BMI) and metabolic syndrome components. In women, but not in men, IL-6 and leptin remained significantly higher when corrected for metabolic syndrome. In the whole cohort and in women, univariate correlations between IL-6 concentrations and the parameters under evaluation showed that IL-6 and leptin were positively correlated with age, BMI, waist, systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting glucose, fasting insulin, Delta AUC insulin area, triglyceride (TG), free fatty acids (FFA) and monocyte chemoattractant protein-1 (MCP-1) and inversely correlated with HDL cholesterol (HDL-C) and adiponectin. In women a forward stepwise linear regression analysis in a model including age, BMI, features of metabolic syndrome, fasting insulin, Delta AUC insulin and insulin sensitivity index (ISI) index revealed that only IL-6 and leptin were independently associated with fasting insulin levels. CONCLUSIONS: In first-degree relatives normal glucose tolerant women, fasting hyperinsulinemia, independently of the presence of metabolic syndrome, is associated with elevated IL-6 and leptin levels, suggesting an increased cardiovascular risk.
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Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad , Hiperinsulinismo/complicaciones , Inflamación/complicaciones , Síndrome Metabólico/complicaciones , Adiponectina/sangre , Adulto , Índice de Masa Corporal , Enfermedades Cardiovasculares/fisiopatología , Diabetes Mellitus Tipo 2/sangre , Familia , Femenino , Humanos , Hiperinsulinismo/sangre , Hiperinsulinismo/genética , Inflamación/sangre , Inflamación/genética , Insulina/sangre , Interleucina-6/sangre , Masculino , Síndrome Metabólico/sangre , Persona de Mediana Edad , Análisis de Regresión , Factores de Riesgo , Caracteres SexualesRESUMEN
Although several observations suggest that insulin resistance/compensatory hyperinsulinemia (IR/CH) has a direct effect on endothelial function, independently of the metabolic abnormalities associated with the defect in insulin action, this relation has not been evaluated in apparently healthy individuals. To address this issue, we measured endothelial-dependent vasodilation in response to forearm ischemia (flow-mediated dilation [FMD]) in 47 nonsmoking, healthy volunteers without known risk factors for atherosclerosis. Measurements were also made of multiple anthropometric, metabolic, and hemodynamic variables related to IR/CH. Decreases in FMD were significantly correlated (analysis of variance for linear trend) with (1) male gender (p = 0.003), (2) waist circumference (p = 0.038), (3) higher fasting plasma insulin (p = 0.015) and triglyceride concentrations (p = 0.023), and (4) lower concentrations of high-density lipoprotein cholesterol (p = 0.001). Multivariate linear regression analysis indicated that only plasma insulin (beta -0.424) was independently associated (p <0.001) with changes in FMD, and individual differences in insulin concentrations, along with gender and brachial artery diameter at baseline, accounted for approximately 39% of the variability in FMD. In conclusion, IR/CH is an independent predictor of decreases in endothelial-dependent vasodilation in apparently healthy individuals, in the absence of traditional risk factors for atherosclerosis.
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Antebrazo/irrigación sanguínea , Insulina/sangre , Isquemia/fisiopatología , Vasodilatación/fisiología , Anciano , Arteria Braquial/diagnóstico por imagen , Arteria Braquial/fisiología , HDL-Colesterol/sangre , Endotelio Vascular/fisiología , Ayuno , Femenino , Humanos , Masculino , Persona de Mediana Edad , Flujo Sanguíneo Regional/fisiología , Factores Sexuales , Triglicéridos/sangre , Ultrasonografía , Relación Cintura-CaderaRESUMEN
Impaired insulin sensitivity and endothelial dysfunction are important markers in the development of restenosis after coronary stenting. In addition, new markers of inflammation and endothelium activation, such as increased leptin levels, also have to considered. Many studies have shown that hyperinsulinemia and insulin resistance increase neointimal index measured six months after coronary stenting, and that insulin-sensitizers have beneficial effects by decreasing the rate of restenosis. The role of endothelial dysfunction in the process of restenosis is a fascinating problem. The pathobiology of restenosis in stented arteries is largely related to neointimal hyperplasia, which is dependent upon several factors, such as a reduction in nitric oxide activity that determines endothelial dysfunction and oxidative stress. Abnormal endothelium-dependent vasodilation (related to decreased nitric oxide production in the insulin-resistant state) might be explained by alterations in intracellular signaling and increased endothelin-1 production. Leptin is a hormone related to both fat metabolism and insulin resistance that has been recognized as an independent predictor of coronary restenosis. Chronic hyperleptinemia can reduce the synthesis of nitric oxide owing to the increased oxidative stress in endothelial cells. As a result, the goal in prevention of in-stent restenosis is to develop drugs that are able to act both as insulin- and endothelium-sensitizers.
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Reestenosis Coronaria/sangre , Reestenosis Coronaria/fisiopatología , Endotelio Vascular/patología , Resistencia a la Insulina/fisiología , Leptina/sangre , Animales , Reestenosis Coronaria/patología , Endotelio Vascular/metabolismo , HumanosRESUMEN
BACKGROUND: We tested the hypothesis that asymmetric dimethylarginine (ADMA) levels could be elevated and influence endothelin-1 and nitric oxide release and action in patients with cardiac syndrome X (CSX). In addition, we evaluated whether an intravenous infusion of L-arginine would improve endothelial function in these subjects. METHODS AND RESULTS: Nine patients with CSX and 14 control subjects underwent a continuous infusion of L-arginine (0.125 g/min) or saline for 120 minutes. Sixty minutes after L-arginine or saline infusions, an intravenous insulin bolus (0.1 U/kg) combined with a euglycemic clamp was performed. Basal ADMA and endothelin-1 levels were higher in patients with CSX than in controls. At the end of the first hour of infusion, compared with saline, L-arginine infusion increased basal forearm blood flow, nitrite and nitrate (NOx), and forearm cGMP release and decreased endothelin-1. After insulin bolus, during saline, insulin-induced NOx, endothelin-1, and forearm cGMP release was almost abolished. Conversely, L-arginine restored a physiological profile of all endothelial variables compared with control subjects. In control subjects, compared with saline infusion, L-arginine infusion did not modify any parameter. ADMA levels were positively correlated with basal endothelin-1 levels and negatively correlated with insulin-induced incremental levels of NOx and forearm cGMP release. CONCLUSIONS: Plasma ADMA levels are increased in patients with CSX, and they are correlated with increases in endothelin-1 and reductions in insulin-induced increments in plasma NOx and cGMP, effects that are reversed by intravenous L-arginine. These data suggest that increased ADMA levels play a role in the abnormal vascular reactivity that is observed in patients with CSX.
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Angina de Pecho/sangre , Angina de Pecho/fisiopatología , Arginina/análogos & derivados , Arginina/sangre , Arginina/farmacología , Endotelina-1/sangre , Endotelio Vascular/efectos de los fármacos , Angina de Pecho/diagnóstico por imagen , Arginina/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Angiografía Coronaria , GMP Cíclico/metabolismo , Endotelio Vascular/fisiología , Femenino , Antebrazo/irrigación sanguínea , Humanos , Infusiones Intravenosas , Insulina/farmacología , Masculino , Persona de Mediana Edad , Óxido Nítrico/sangre , Flujo Sanguíneo Regional/efectos de los fármacos , SíndromeRESUMEN
BACKGROUND: Previously undiagnosed diabetes, impaired glucose tolerance, and insulin resistance are common in patients with acute myocardial infarction and coronary heart disease (CHD) and might be involved in early restenosis after stent implantation. To evaluate whether markers of insulin resistance syndrome, including leptin, and endothelial dysfunction are related to increased rate of early restenosis, we studied nondiabetic patients with CHD after successful coronary stenting. METHODS AND RESULTS: Both patients with CHD undergoing coronary stenting (120 patients) and control subjects (58 patients) were submitted to an oral glucose tolerance test (OGTT). Fasting leptin levels and fasting and postglucose load insulin sensitivity were assessed. Endothelial function was measured by nitrite and nitrate release (NOx) during OGTT. More than 50% of patients treated with stent implantation presented impaired glucose tolerance or type 2 diabetes, which was previously undiagnosed. These patients also had higher glucose, insulin, and leptin levels than control subjects. Among the stented patients, insulin and leptin levels were higher in patients with restenosis than in patients without restenosis. A significant increase in NOx levels was found during OGTT both in patients without restenosis and in control subjects. On the contrary, NOx profiles were blunted in patients with restenosis. At multiple regression analysis, only DeltaAUC-NOx areas and insulin sensitivity index showed an independent correlation with the minimal lumen diameter at follow-up. CONCLUSIONS: We demonstrated that insulin resistance and endothelial dysfunction are independent predictors of early restenosis after coronary stenting.
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Reestenosis Coronaria/fisiopatología , Resistencia a la Insulina , Leptina/sangre , Óxido Nítrico/sangre , Stents , Área Bajo la Curva , Glucemia , Implantación de Prótesis Vascular/efectos adversos , Angiografía Coronaria , Enfermedad Coronaria/cirugía , Reestenosis Coronaria/sangre , Reestenosis Coronaria/diagnóstico por imagen , Reestenosis Coronaria/cirugía , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/diagnóstico , Endotelio Vascular/fisiopatología , Estudios de Seguimiento , Prueba de Tolerancia a la Glucosa , Humanos , Insulina/sangre , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Análisis de Regresión , Stents/efectos adversos , Grado de Desobstrucción VascularRESUMEN
Endothelial nitric oxide synthase (eNOS) variants were previously demonstrated in cardiovascular disease. To evaluate whether eNOS gene variants are associated with insulin resistance and type 2 diabetes, we evaluated polymorphisms in Exon7 (E298D), intron 18 (IVS18 + 27A-->C), and intron 23 (IVS23 + 10G-->T) in 159 type 2 diabetic patients without macrovascular complications and in 207 healthy control subjects. Samples for all hormonal and metabolic variables were obtained after an overnight fast. The D298 and IVS18 + 27C alleles, but not the IVS23 + 10G-->T variant, were significantly more frequent in type 2 diabetic patients than in control subjects. The two- and three-loci haplotype analysis showed that there is a statistically significant association between the eNOS variants and type 2 diabetes. No significant differences were observed in the clinical characteristics of type 2 diabetic patients according to genotypes (except for visceral obesity [waist-to-hip ratio], which was significantly more present in D298 homozygotes). Healthy control subjects homozygous for both D298 and IVS18 + 27C presented higher insulin, C-peptide, and nitric oxide levels, as well as higher HOMA (homeostasis model assessment) values than the double wild-type homozygotes, with values superimposable on those found in type 2 diabetic patients. In conclusion, we described a significant association between eNOS gene polymorphisms and type 2 diabetes, suggesting a new genetic susceptibility factor for hyperinsulinemia, insulin resistance, and type 2 diabetes.
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Diabetes Mellitus Tipo 2/genética , Resistencia a la Insulina/genética , Óxido Nítrico Sintasa/genética , Polimorfismo Genético , Enfermedades Cardiovasculares/enzimología , Enfermedades Cardiovasculares/genética , Diabetes Mellitus Tipo 2/enzimología , Angiopatías Diabéticas/enzimología , Angiopatías Diabéticas/genética , Exones , Variación Genética , Humanos , Intrones , Óxido Nítrico Sintasa de Tipo III , Valores de ReferenciaRESUMEN
OBJECTIVE: To evaluate whether variants of the eNOS gene are associated with endothelial and metabolic responses to L-arginine (L-arg) supplementation. MATERIAL AND METHODS: We examined a single nucleotide polymorphism of the eNOS gene (rs753482-A>C) to investigate the effects of this variant on endothelial function (EF), colony-forming unit-endothelial cell (CFU-EC) number, asymmetric-dimethylarginine (ADMA) level, insulin sensitivity index (ISI), and insulin secretion (IS) in a post hoc analysis of the L-arg trial. The L-arg trial (6.4 g/day for 18 months) was a single-center, randomized, double-blind, parallel-group, placebo-controlled, phase III trial in individuals with impaired glucose tolerance and metabolic syndrome. followed by a 12-month extended follow-up period after termination of the study drug (NCT 00917449). RESULTS: At baseline, EF, CFU-EC numbers, ADMA levels, and ISI were impaired in subjects carrying minor allele C (both heterozygotes, AC and homozygotes, CC) as compared to subjects carrying major allele A (homozygotes, AA) (p<0.01). Compared to placebo, L-arg increased EF, CFU-EC numbers, and ISI, and improved ADMA levels and IS (p<0.01). The greatest improvements were found in AA subjects treated with L-arg, while the worst results were found in AC+CC subjects treated with placebo. In the placebo-treated subjects, EF, CFU-EC, ISI, and IS were significantly lower and ADMA was significantly higher in AC+CC subjects than in AA subjects. CONCLUSIONS: Treatment with L-arg induced similar improvements in EF, CFU-EC numbers, ADMA levels, ISI, and IS in both AA subjects and AC+CC subjects. The presence of minor allele resulted in the worst prognosis in terms of EF, CFU-EC numbers, ADMA levels, ISI, and IS during the 30-month observation period.
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Arginina/administración & dosificación , Glucosa/metabolismo , Óxido Nítrico Sintasa de Tipo III/genética , Farmacogenética , Método Doble Ciego , Prueba de Tolerancia a la Glucosa , Humanos , Placebos , Polimorfismo de Nucleótido SimpleRESUMEN
BACKGROUND: HIV-infected adults with lipodystrophy, characterized by excess accumulation of intra-abdominal adipose tissue (IAT), showed impaired growth hormone (GH) secretion. Data are lacking in paediatric lipodystrophy with the same features. METHODS: Twenty-five pubertal HIV-infected children were assessed for GH response (GH-AUC(0-120 min)) to arginine + GHRH testing, insulin-like growth factor-1 (IGF-1), IGF binding protein 3 (IGFBP-3), insulin, glucose, cholesterol, triglycerides, free fatty acids and nitric oxide levels. Body composition and IAT content were evaluated by dual-energy x-ray-absorptiometry and magnetic resonance imaging. An excess accumulation of IAT was defined as a value > 41 cm2. Differences between children with (V+) and without (V-) excess IAT were assessed by non-parametric tests and multivariate analysis. RESULTS Ten V+ (mean IAT, 82.5 cm2) and 15 V- (mean IAT, 26.8 cm2) were identified; they were similar for age (13.8 versus 14.8 years), body mass index (20.2 versus 19.5 kg/m2), male : female ratio (3/7 versus 8/7), months on highly active antiretroviral therapy (54.5 versus 55 months). V+ showed lower GH-AUC(0-120 min) (16.4 versus 31.6 microg x h/l; P = 0.002), lower IGF-1 concentrations (384 versus 515 ng/ml; P = 0.03) and higher insulin levels (17.8 versus 10.5 microIU/ml; P = 0.01) than V-. V+, as compared to V-, showed lower lean mass (total, P = 0.025; arms, P = 0.024; legs, P = 0.008) and higher fat mass (total, P = 0.0038; arms, P = 0.028; trunk, P < 0.0001). Lipid profile and glucose, IGFBP-3, nitric oxide and free fatty acids levels were similar in the two groups. GH-AUC(0-120 min) correlated negatively with IAT content and insulin levels. CONCLUSION: Impaired GH secretion is detectable in pubertal children with increased visceral adiposity and hyperinsulinemia. GH therapy should be considered in lipodystrophic HIV-infected children with excess IAT.
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Terapia Antirretroviral Altamente Activa/efectos adversos , Hormona del Crecimiento/metabolismo , VIH-1 , Síndrome de Lipodistrofia Asociada a VIH/fisiopatología , Adolescente , Arginina , Glucemia/análisis , Estudios de Casos y Controles , Colesterol/sangre , Femenino , Hormona Liberadora de Hormona del Crecimiento , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/fisiopatología , Síndrome de Lipodistrofia Asociada a VIH/tratamiento farmacológico , Humanos , Insulina/sangre , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/análisis , Masculino , Análisis Multivariante , Estadísticas no Paramétricas , Triglicéridos/sangreRESUMEN
Thirteen hypertensive patients with microvascular angina were studied before and after receiving oral L-arginine (4 weeks, 2 g, 3 times daily). L-arginine significantly improved angina class, systolic blood pressure at rest, and quality of life. Maximal forearm blood flow, plasma L-arginine, L-arginine:asymmetric dimethyl arginine ratio, and cyclic guanylate monophosphate increased significantly after treatment. In medically treated hypertensive patients with micro-vascular angina, oral L-arginine may represent a useful therapeutic option.
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Arginina/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Endotelio Vascular/efectos de los fármacos , Hipertensión/fisiopatología , Angina Microvascular/fisiopatología , Administración Oral , Anciano , Presión Sanguínea/fisiología , Endotelio Vascular/fisiopatología , Femenino , Humanos , Hipertensión/complicaciones , Hipertensión/tratamiento farmacológico , Masculino , Angina Microvascular/complicaciones , Angina Microvascular/tratamiento farmacológico , Persona de Mediana EdadRESUMEN
Hypoglycaemia associated with lactic acidosis is a rare complication of lymphomas; only four cases have been previously reported. Recent studies provide evidence of direct consumption of glucose by the tumour cells, leading to lactic acidosis. We report the case of a 64-year-old patient with a gastric diffuse large B cell non-Hodgkin's lymphoma transformed from an indolent mucosa associated lymphoid tissue (MALT) lymphoma, admitted to our department for acute renal failure due to a tumour lysis syndrome. After recovery from renal failure, she developed severe hypoglycaemia and lactic acidosis refractory to therapy. She died after the onset of shock and coma.
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Acidosis Láctica/etiología , Hipoglucemia/etiología , Linfoma de Células B de la Zona Marginal/complicaciones , Neoplasias Gástricas/complicaciones , Lesión Renal Aguda/etiología , Resultado Fatal , Femenino , Humanos , Linfoma de Células B de la Zona Marginal/metabolismo , Persona de Mediana Edad , Neoplasias Gástricas/metabolismo , Síndrome de Lisis Tumoral/complicacionesRESUMEN
The aim of this study was to investigate glucose tolerance, insulin secretion and insulin resistance according to smoking habits in first-degree relatives of type 2 diabetes patients, a population at high risk for developing diabetes. One thousand three hundred (646 females and 654 males) subjects underwent an oral glucose tolerance test (OGTT) to investigate their glucose metabolism and answered questionnaires about their lifestyle habits. Smoker subjects showed significant impairment compared with non-smoker subjects in 2-h post-oral glucose tolerance test (2hOGTT, 129.3 ± 40.2 vs. 117.7 ± 37.6 mg/dl, p < 0.001), the OGTT insulin sensitivity (386.3 ± 54.9 vs. 400.5 ± 53.4 ml min(-1) m(2), p < 0.01) method and the insulin sensitivity and secretion index-2 (ISSI-2, 1.7 ± 0.8 vs. 2.0 ± 1.0, p < 0.005). Metabolic syndrome (MS) was higher in the smoker than in the non-smoker group (46.5 vs. 29.7 %, p < 0001), and smokers were more sedentary than non-smokers (3.94 ± 3.77 vs. 4.86 ± 4.41 h/week, p < 0.001). Smokers showed an increased risk of impaired glucose regulation (IGR: impaired glucose tolerance or diabetes mellitus) with a hazard ratio (HR) adjusted by gender, metabolic syndrome and physical activity of 1.78, 95 % CI 1.27-2.47 (p < 0.001). The association between smoking and MS conferred a risk of IGR that was five times higher (HR 5.495, 95 % CI 4.07-7.41, p < 0.001). Smoking habit was a significant explanatory variable in a multiple forward stepwise regression analysis performed using 2hOGTT and ISSI-2 as dependent variables (p < 0.0001, R = 0.313 and p < 0.0001, R = 0.347, respectively). In conclusions, our results show that tobacco smoking is tightly associated with impairments in glucose metabolism and insulin sensitivity and insulin secretion.
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Diabetes Mellitus Tipo 2/metabolismo , Glucosa/metabolismo , Resistencia a la Insulina , Insulina/metabolismo , Síndrome Metabólico/etiología , Fumar/efectos adversos , Adulto , Diabetes Mellitus Tipo 2/etiología , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Masculino , Síndrome Metabólico/metabolismo , Persona de Mediana Edad , LinajeRESUMEN
AIMS: Nitric oxide (NO) plays a key role in vascular homeostasis and is produced by endothelial NO synthase (eNOS), encoded by NOS3 gene. We previously reported the genetic association between NOS3 rs753482-A>C polymorphism on intron 19 and coronary artery disease (CAD). In the attempt of conferring functional implication to the rs753482-A>C polymorphism, we investigated its influence on transcript maturation. METHODS AND RESULTS: A transcript variant skipping exons 20-21 is prevalent in carriers of the rs753482-C allele and is translated in a novel truncated form of eNOS. The truncated eNOS displays increased basal NO production, is insensitive to calcium stimulation, and, upon heterodimerization with the full-length eNOS protein, exerts a dominant-negative effect on NO production. CAD patients and healthy subjects' carriers of the rs753482-C genotype are characterized by increased NO basal levels in peripheral blood and platelets, and negatively respond to oral glucose load by failing to increase NO synthesis following insulin wave. Furthermore, forearm vasodilation after reactive hyperaemia is dramatically impaired in rs753482-C carriers. CONCLUSIONS: We demonstrated that subjects carrying the rs753482-C genotype express a novel stable truncated form of eNOS with altered enzymatic activity that influences NO production and endothelial function. These findings open to new intriguing perspectives to several diseases involving vascular response to NO.
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Enfermedad de la Arteria Coronaria/genética , Endotelio Vascular/enzimología , Frecuencia de los Genes/genética , Óxido Nítrico Sintasa de Tipo III/genética , Polimorfismo Genético/genética , Adulto , Anciano , Enfermedad de la Arteria Coronaria/enzimología , Frecuencia de los Genes/fisiología , Predisposición Genética a la Enfermedad , Pruebas Genéticas/métodos , Genotipo , Humanos , Persona de Mediana Edad , Vasodilatación/fisiologíaRESUMEN
OBJECTIVE: The aim of this study was to evaluate the effects of a new L-arginine-enriched biscuit on endothelial function, insulin sensitivity/secretion and body composition. MATERIALS/METHODS: The project was composed of two studies. The first study was an acute pilot postprandial study in 7 healthy subjects that evaluated bio-availability and vascular effects of L-arginine-enriched biscuits that contained 6.6 gL-arginine, 21.9 g carbohydrates, 3.6 g protein, 7.5 g fat and 4.3 g dietary fiber compared with placebo biscuits and 6.6 g powdered L-arginine. Subjects underwent the tests in random order, in at least 14-day intervals. The second study was a double-blind crossover study in 15 obese subjects with IGT and MS. These subjects consumed 6.6 g of L-arginine-enriched biscuits or placebo biscuits in a 1600 kcal diet. Each study period lasted 2 weeks with a 2-week washout in between. Endothelial function, glucose tolerance, insulin sensitivity and insulin secretion were evaluated at the end of each intervention period. RESULTS: In the first study, the groups that received the L-arginine-enriched biscuits and the powdered L-arginine had similarly increased L-arginine, NOx and cGMP levels and post-ischemic blood flow (PI-BF). In both cases, these levels were significantly higher than those in the placebo biscuit recipient group. In the second study, the L-arginine-enriched biscuit recipient group displayed increased L-arginine, NOx, cGMP, PI-BF, and Matsuda index levels, whereas their circulating glucose, proinsulin/insulin ratio and fat mass were decreased compared with the placebo biscuit recipient group. CONCLUSIONS: L-Arginine-enriched biscuits with low sugar and protein content enhance endothelial function and improve glucose metabolism, insulin sensitivity and insulin secretion in subjects with IGT and MS.
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Arginina/administración & dosificación , Endotelio Vascular/efectos de los fármacos , Intolerancia a la Glucosa/tratamiento farmacológico , Síndrome Metabólico/tratamiento farmacológico , Obesidad/tratamiento farmacológico , Composición Corporal/fisiología , Peso Corporal/fisiología , Colesterol/sangre , Estudios Cruzados , GMP Cíclico/sangre , Método Doble Ciego , Endotelio Vascular/metabolismo , Femenino , Intolerancia a la Glucosa/metabolismo , Humanos , Insulina/metabolismo , Secreción de Insulina , Masculino , Síndrome Metabólico/sangre , Síndrome Metabólico/metabolismo , Persona de Mediana Edad , Óxido Nítrico Sintasa de Tipo II/sangre , Obesidad/sangre , Obesidad/metabolismo , Proyectos Piloto , Bocadillos , Triglicéridos/sangreRESUMEN
Primary objective was to evaluate whether an intensified insulin therapy (IIT) incorporating the target of normal fasting glucose and HbA1c levels could halve the incidence of restenosis/amputation/SCA/death at 6 months after peripheral angioplasty compared with standard care (SC) in patients with type 2 diabetes (DMT2) affected by critical limb ischemia (CLI). Forty-six consecutive patients with DMT2 and CLI were randomly assigned to a parallel, open-label study with IIT (basal-bolus glulisine + glargine administrations) or SC (glargine administration + oral antidiabetic drugs). A SNP of eNOS (rs753482-A>C) and circulating CD34(+) and CD34(+)KDR(+) progenitor cells were determined. At the end of the study, although HbA1c levels were lower in IIT than in SC (6.9 ± 1.3 % vs. 7.6 ± 1.2 %, p < 0.05), IIT did not reduce the cumulative incidence of restenosis/amputation/SCA/death (52 and 65 %, respectively, odd ratio 0.59; CI 95 %: 0.21-1.62, p = 0.59). rs753482AC+CC as compared with rs753482AA increased the cumulative incidence of restenosis/amputation/SCA/death (79 and 42 %; odd ratio 5.3; CI 95 %: 1.41-19.5, p < 0.02). Baseline CD34(+)KDR(+) were higher in rs753482AA (166.2 ± 154.0 × 10(6) events) than in rs753482AC+CC (63.1 ± 26.9 × 10(6) events, p < 0.01). At the end of the study, the highest circulating CD34(+)KDR(+) were found in IIT rs753482AA (246.9 ± 194.0 × 10(6) events) while the lowest levels were found in SC rs753482AC+CC (70.9 ± 45.0 × 10(6) events). IIT did not decrease the cumulative incidence of restenosis/amputation/SCA/death in DMT2 and CLI patients. These patients correspond to a class of fragile subjects at high risk of cardiovascular events, and new predictors of restenosis should be contemplated, such as of eNOS polymorphism, (rs753482-A>C SNP) and circulating endothelial progenitor cells.
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Glucemia/efectos de los fármacos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Insulina/administración & dosificación , Óxido Nítrico Sintasa de Tipo III/genética , Enfermedad Arterial Periférica/metabolismo , Anciano , Anciano de 80 o más Años , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Extremidades/irrigación sanguínea , Ayuno , Femenino , Humanos , Hipoglucemiantes/administración & dosificación , Incidencia , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/epidemiología , Enfermedad Arterial Periférica/genética , Polimorfismo Genético/fisiología , Resultado del TratamientoRESUMEN
AIMS: The study was designed to compare a combined aerobic and resistance training (ART) with an aerobic training (AT) over hemodynamic, glucose metabolism and endothelial factors, adipokines and pro-inflammatory marker release in a population of obese type 2 diabetic patients. METHODS: Forty-seven patients were randomly assigned to aerobic (27 patients) or aerobic plus resistance (20 patients) exercise trainings, on the top of a diet regime. Anthropometric, metabolic, hormonal and inflammatory variables were measured at hospitalization and discharge. RESULTS: Both exercise programs equally improved body weight and fructosamine levels however ART only partially decreased HOMA index compared with AT (ART: -25% vs AT: -54%, p<0.01). Mean blood pressure (AT: -3.6 mmHg vs ART: +0.6 mmHg, p<0.05) and endothelin-1 (ET-1) incremental areas during walking test (AT: -11% vs ART: +30%, p<0.001) decreased after AT while increased after ART. Adiponectin levels increased by 54% after AT while decreased by 13% after ART (p<0.0001) and matrix metalloproteinase-2 (MMP-2), tumor necrosis factor-alpha (TNF-alpha) and monocyte chemoattractan protein-1 (MCP-1) levels significantly decreased in AT while increased in ART group. CONCLUSIONS: Compared with AT, ART similarly enhanced body weight loss but exerted less positive effects on insulin sensitivity and endothelial factors, adipokines and pro-inflammatory marker release.
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Biomarcadores/metabolismo , Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/fisiopatología , Dieta , Ejercicio Físico/fisiología , Obesidad/complicaciones , Entrenamiento de Fuerza , Glucemia/metabolismo , Peso Corporal , Diabetes Mellitus Tipo 2/etiología , Femenino , Humanos , Inflamación/etiología , Masculino , Persona de Mediana Edad , PronósticoRESUMEN
OBJECTIVE: Recent studies suggested that the blockade of the renin-angiotensin system (RAS) may be associated with metabolic benefits. However, data about the potential influence of the ACE insertion/deletion (I/D) genotype on insulin resistance have been contradictory with studies of limited sample sizes. The purpose of this study was to investigate the relationship between the ACE gene I/D polymorphism and both insulin sensitivity and glucose intolerance in a large cohort of healthy subjects. RESEARCH DESIGN AND METHODS: A total of 1,286 participants in the Relationship Between Insulin Sensitivity and Cardiovascular Disease Risk Study had a 75-g oral glucose tolerance test and a hyperinsulinemic-euglycemic clamp to assess whole-body insulin sensitivity. RESULTS: Age, BMI, waist, fat-free mass (ffm), and physical activity did not differ by ACE genotype. Fasting glucose and insulin were similar among genotypes, but 2-h glucose levels were higher in DD than in ID and II subjects (DD: 5.9 +/- 1.7; ID: 5.7 +/- 1.5; II: 5.6 +/- 1.5 mmol/l) (P = 0.004). Participants with the DD genotype were more likely to have impaired glucose tolerance than those with the ID and II genotypes (13.1 vs. 8.7%; P = 0.02). Insulin sensitivity was lower in participants with the DD genotype than in those with the II genotype (136 +/- 63 vs. 147 +/- 65 micromol x min(-1)x kg ffm(-1) x mmol(-1) x l(-1); P = 0.02). The presence of the D allele was associated with a trend, albeit not significant, for reduced insulin secretion during the oral glucose tolerance test (P = 0.07). CONCLUSIONS: The ACE I/D polymorphism is associated with whole-body insulin sensitivity and with impaired glucose tolerance in our healthy population. These findings confirm potential interactions between the RAS and glucose metabolism.
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Glucemia/metabolismo , Elementos Transponibles de ADN , Resistencia a la Insulina/genética , Insulina/fisiología , Peptidil-Dipeptidasa A/genética , Polimorfismo Genético , Adulto , Índice de Masa Corporal , Femenino , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , Valores de Referencia , Eliminación de SecuenciaRESUMEN
Little is known about the association of endothelial nitric oxide synthase (NOS3) gene polymorphisms and the presence of insulin resistance and the early evolution of atherosclerosis in nondiabetic subjects with cardiovascular disease (CAD) and stent implantation. The present study was performed in an attempt to better understand whether metabolic, endothelial, and angiographic findings characteristic of subjects with cardiovascular disease and in-stent restenosis are related to NOS3 variants. This is a case-control study performed from 2002 to 2006. All subjects admitted to the study were recruited in the Nord-Centre of Italy, most from Milan and its surrounding towns. Measures of glucose tolerance, insulin sensitivity, markers of endothelial dysfunction, forearm vasodilation, and adipokine levels were determined and associated to the frequency of two single-nucleotide polymorphisms of NOS3, i.e., Glu298Asp (rs1799983, G/T) and rs753482 (intron 18 A/C). A total of 747 subjects, not known to have diabetes, were evaluated: 333 subjects had asymptomatic CAD, 106 subjects had unstable angina and were evaluated for in-stent restenosis 6 mo after stent placement, and 308 were control subjects. The presence of TT and CC minor alleles was significantly greater in case groups compared with control subjects. At phenotypic level, subjects with the polymorphisms were characterized by hyperinsulinemia and reduced reactive hyperemia, whereas increased leptin and decreased adiponectin levels were present in subjects with restenosis in the presence of reduced minimal lumen diameter and length of stenosis almost doubled. Hyperinsulinemia, endothelial dysfunction, and a more atherogenic profile seem to be peculiar features of subjects with asymptomatic CAD and restenosis carrying NOS3 gene variants.