RESUMO
A diet rich in fruits and vegetables has been associated with several health benefits. However, the effects on body weight (BW) and metabolic markers are not fully known. The present study investigated the effects of increased intake of fruits and vegetables in overweight and obese men and women on dietary habits, anthropometry and metabolic control. In a 16-week controlled intervention, thirty-four men and thirty-four women aged 35-65 years (BMI>27 kg/m2) were randomised to an intervention (IN) or a reference (RG) group. All participants received general dietary advice, and subjects in the IN group received fruits and vegetables for free, of which ≥500 g had to be eaten daily. BW, waist circumference (WC), sagittal abdominal diameter (SAD), plasma insulin, blood glucose, glycated Hb (HbA1c), serum lipids, blood pressure, plasminogen activator inhibitor-1 activity, urinary isoprostane (iso-8-PGF 2α) and serum carotenoids were measured. Diet was assessed using 3-d weighed food records. In all, thirty subjects in the IN group and thirty-two in the RG group completed the intervention. Intake of fruits and vegetables doubled in the IN group, whereas intake of fruits increased in the RG group. Serum α- and ß-carotene concentrations and intakes of folate and vitamin C increased significantly in the IN group. Energy intake, BW, WC and SAD decreased significantly in both groups. Supine systolic blood pressure decreased significantly in the IN group, with no between-group differences. No significant changes were observed for other metabolic markers. Provision of fruits and vegetables led to substantially increased intakes, with subsequent favourable changes in anthropometry and insulin levels, which tended to be more pronounced in the IN group. The observed improvements may, in combination with improved nutritional markers, have health benefits in the long term.
Assuntos
Composição Corporal , Peso Corporal , Dieta , Frutas , Sobrepeso/dietoterapia , Verduras , Adulto , Idoso , Ácido Ascórbico/sangue , Pressão Sanguínea , Índice de Massa Corporal , Carotenoides/sangue , Ingestão de Energia , Feminino , Ácido Fólico/sangue , Humanos , Isoprostanos/urina , Masculino , Pessoa de Meia-Idade , Inibidor 1 de Ativador de Plasminogênio/sangue , Fatores de Risco , Circunferência da CinturaRESUMO
OBJECTIVE: Little is known about the transfer of essential fatty acids (FAs) across the human blood-brain barrier (BBB) in adulthood. In this study, we investigated whether oral supplementation with omega-3 (n-3) FAs would change the FA profile of the cerebrospinal fluid (CSF). METHODS: A total of 33 patients (18 receiving the n-3 FA supplement and 15 receiving placebo) were included in the study. These patients were participants in the double-blind, placebo-controlled randomized OmegAD study in which 204 patients with mild Alzheimer's disease (AD) received 2.3 g n-3 FA [high in docosahexaenoic acid (DHA)] or placebo daily for 6 months. CSF FA levels were related to changes in plasma FA and to CSF biomarkers of AD and inflammation. RESULTS: At 6 months, the n-3 FA supplement group displayed significant increases in CSF (and plasma) eicosapentaenoic acid (EPA), DHA and total n-3 FA levels (P < 0.01), whereas no changes were observed in the placebo group. Changes in CSF and plasma levels of EPA and n-3 docosapentaenoic acid were strongly correlated, in contrast to those of DHA. Changes in DHA levels in CSF were inversely correlated with CSF levels of total and phosphorylated tau, and directly correlated with soluble interleukin-1 receptor type II. Thus, the more DHA increased in CSF, the greater the change in CSF AD/inflammatory biomarkers. CONCLUSIONS: Oral supplementation with n-3 FAs conferred changes in the n-3 FA profile in CSF, suggesting transfer of these FAs across the BBB in adults.
Assuntos
Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Barreira Hematoencefálica , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/uso terapêutico , Ácido Eicosapentaenoico/administração & dosagem , Ácido Eicosapentaenoico/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/metabolismo , Administração Oral , Adulto , Doença de Alzheimer/tratamento farmacológico , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Progressão da Doença , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Docosa-Hexaenoicos/farmacocinética , Método Duplo-Cego , Ácido Eicosapentaenoico/sangue , Ácido Eicosapentaenoico/líquido cefalorraquidiano , Ácidos Graxos Ômega-3/sangue , Ácidos Graxos Ômega-3/líquido cefalorraquidiano , Seguimentos , Humanos , Fosforilação , Proteínas tau/sangue , Proteínas tau/líquido cefalorraquidianoRESUMO
BACKGROUND AND AIMS: Two Amerindian populations--Shuar women living in the Amazonian rain forest under traditional conditions and urbanized women in a suburb of Lima were studied. The fatty acid composition in plasma lipids and the relationships between fatty acid composition and metabolic variables were studied, as well as in a reference group of Swedish women. METHODS AND RESULTS: Fasting plasma was used for analyses of glucose, insulin, leptin and fatty acid composition. Women in Lima had more body fat, higher fasting insulin and leptin and lower insulin sensitivity than the Shuar women, who had insulin sensitivity similar to Swedish women. Shuar women had very high proportions (mean; SD) of palmitoleic (13.2; 3.9%) and oleic (33.9; 3.7%) acids in the plasma cholesteryl esters with very low levels of linoleic acid (29.1; 6.1 3%), as expected on a low fat, high carbohydrate diet. The estimated activity of delta 9 (SCD-1) desaturase was about twice as high in the Shuar compared with Lima women, suggesting neo lipogenesis, while the delta 5 desaturase activity did not differ. The Lima women, as well as the Swedish, showed strong positive correlations between SCD-1 activity on the one hand and fasting insulin and HOMA index on the other. These associations were absent in the Shuar women. CONCLUSIONS: The high SCD-1 activity in the Shuar women may reflect increased lipogenesis in adipose tissue. It also illustrates how a low fat diet rich in non-refined carbohydrates can be linked to a good metabolic situation.
Assuntos
Ácidos Graxos Dessaturases/sangue , Ácidos Graxos/sangue , Indígenas Sul-Americanos , Resistência à Insulina/etnologia , População Branca , Adiposidade/etnologia , Adulto , Glicemia/análise , Índice de Massa Corporal , Dessaturase de Ácido Graxo Delta-5 , Dieta com Restrição de Gorduras , Carboidratos da Dieta/metabolismo , Equador/epidemiologia , Feminino , Humanos , Insulina/sangue , Leptina/sangue , Pessoa de Meia-Idade , Peru/epidemiologia , Características de Residência , População Rural , Estearoil-CoA Dessaturase/sangue , População Suburbana , Suécia/epidemiologia , Adulto JovemRESUMO
OBJECTIVE: the aim of this study was to investigate the effects of a healthy Nordic diet (ND) on cardiovascular risk factors. DESIGN AND SUBJECTS: in a randomized controlled trial (NORDIET) conducted in Sweden, 88 mildly hypercholesterolaemic subjects were randomly assigned to an ad libitum ND or control diet (subjects' usual Western diet) for 6 weeks. Participants in the ND group were provided with all meals and foods. Primary outcome measurements were low-density lipoprotein (LDL) cholesterol, and secondary outcomes were blood pressure (BP) and insulin sensitivity (fasting insulin and homeostatic model assessment-insulin resistance). The ND was rich in high-fibre plant foods, fruits, berries, vegetables, whole grains, rapeseed oil, nuts, fish and low-fat milk products, but low in salt, added sugars and saturated fats. RESULTS: the ND contained 27%, 52%, 19% and 2% of energy from fat, carbohydrate, protein and alcohol, respectively. In total, 86 of 88 subjects randomly assigned to diet completed the study. Compared with controls, there was a decrease in plasma cholesterol (-16%, P < 0.001), LDL cholesterol (-21%, P < 0.001), high-density lipoprotein (HDL) cholesterol (-5%, P < 0.01), LDL/HDL (-14%, P < 0.01) and apolipoprotein (apo)B/apoA1 (-1%, P < 0.05) in the ND group. The ND reduced insulin (-9%, P = 0.01) and systolic BP by -6.6 ± 13.2 mmHg (-5%, P < 0.05) compared with the control diet. Despite the ad libitum nature of the ND, body weight decreased after 6 weeks in the ND compared with the control group (-4%, P < 0.001). After adjustment for weight change, the significant differences between groups remained for blood lipids, but not for insulin sensitivity or BP. There were no significant differences in diastolic BP or triglyceride or glucose concentrations. CONCLUSIONS: a healthy ND improves blood lipid profile and insulin sensitivity and lowers blood pressure at clinically relevant levels in hypercholesterolaemic subjects.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Hipercolesterolemia/dietoterapia , Adulto , Idoso , Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/etiologia , LDL-Colesterol/sangue , Feminino , Humanos , Hipercolesterolemia/sangue , Hipercolesterolemia/complicações , Resistência à Insulina/fisiologia , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Suécia , Resultado do TratamentoRESUMO
BACKGROUND: Rapeseed oil (RO), also known as canola oil, principally contains the unsaturated fatty acids 18:1n-9, 18:2n-6 and 18:3n-3 and may promote cardiometabolic health. OBJECTIVE: To investigate the effects on lipoprotein profile, factors of coagulation and insulin sensitivity of replacing a diet rich in saturated fat from dairy foods (DF diet) with a diet including RO-based fat (RO diet). DESIGN: During a 2×3-week randomized, controlled, cross-over trial, 20 free-living hyperlipidaemic subjects were provided with isocaloric test diets that differed in fat composition alone. Blood lipoprotein profile, coagulation and fibrinolytic factors and insulin sensitivity (euglycaemic clamp) were determined before and after the dietary intervention. RESULTS: All subjects completed the study, and compliance was high according to changes in serum fatty acids. The RO diet, but not the DF diet, reduced the levels of serum cholesterol (-17%), triglycerides (-20%) and low-density lipoprotein cholesterol (-17%), cholesterol/high-density lipoprotein (HDL) cholesterol ratio (-21%), apolipoprotein (apo) B/apo A-I ratio (-4%) and factor VII coagulant activity (FVIIc) (-5%) from baseline. These changes were significantly different between the diets (P=0.05 to P<0.0001), except for FVIIc (P=0.1). The RO diet, but not the DF diet, modestly increased serum lipoprotein(a) (+6%) and tended to increase the glucose disappearance rate (K-value, +33%). HDL cholesterol, insulin sensitivity, fibrinogen and tissue plasminogen activator inhibitor-1 levels did not change from baseline or differ between the two diets. CONCLUSIONS: In a diet moderately high in total fat, replacing dairy fat with RO causes a rapid and clinically relevant improvement in serum lipoprotein profile including lowering of triglycerides in hyperlipidaemic individuals.
Assuntos
Laticínios , Gorduras Insaturadas na Dieta/administração & dosagem , Ácidos Graxos/sangue , Hiperlipidemias/dietoterapia , Óleos de Plantas/administração & dosagem , Análise de Variância , Colesterol/sangue , Estudos Cross-Over , Método Duplo-Cego , Ácidos Graxos Monoinsaturados , Feminino , Humanos , Lipoproteínas/sangue , Masculino , Óleo de Brassica napus , SuéciaRESUMO
BACKGROUND: Excessive energy intake and obesity lead to the metabolic syndrome (MetS). Dietary saturated fatty acids (SFAs) may be particularly detrimental on insulin sensitivity (SI) and on other components of the MetS. OBJECTIVE: This study determined the relative efficacy of reducing dietary SFA, by isoenergetic alteration of the quality and quantity of dietary fat, on risk factors associated with MetS. DESIGN: A free-living, single-blinded dietary intervention study. SUBJECTS AND METHODS: MetS subjects (n = 417) from eight European countries completed the randomized dietary intervention study with four isoenergetic diets distinct in fat quantity and quality: high-SFA; high-monounsaturated fatty acids and two low-fat, high-complex carbohydrate (LFHCC) diets, supplemented with long chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) (1.2 g per day) or placebo for 12 weeks. SI estimated from an intravenous glucose tolerance test (IVGTT) was the primary outcome measure. Lipid and inflammatory markers associated with MetS were also determined. RESULTS: In weight-stable subjects, reducing dietary SFA intake had no effect on SI, total and low-density lipoprotein cholesterol concentration, inflammation or blood pressure in the entire cohort. The LFHCC n-3 PUFA diet reduced plasma triacylglycerol (TAG) and non-esterified fatty acid concentrations (P < 0.01), particularly in men. CONCLUSION: There was no effect of reducing SFA on SI in weight-stable obese MetS subjects. LC n-3 PUFA supplementation, in association with a low-fat diet, improved TAG-related MetS risk profiles.
Assuntos
Gorduras na Dieta/administração & dosagem , Comportamento Alimentar/fisiologia , Resistência à Insulina/fisiologia , Síndrome Metabólica/prevenção & controle , Obesidade/dietoterapia , Dieta com Restrição de Gorduras/métodos , Gorduras na Dieta/metabolismo , Ingestão de Energia/fisiologia , Europa (Continente) , Ácidos Graxos/administração & dosagem , Ácidos Graxos/efeitos adversos , Ácidos Graxos Insaturados/administração & dosagem , Feminino , Glicerol/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/metabolismo , Fatores de RiscoRESUMO
AIM: To explore the relationship between essential fatty acids (FA) and weight changes in adolescent girls with eating disorders (ED). METHODS: Blood samples were obtained from 220 girls with ED and 39 healthy controls. The girls with ED were 15.3 ± 1.5 years of age and weighed 49.8 ± 8.7 kg (BMI 18.3 ± 2.8 kg/m(2)) after a weight loss of 6.8 ± 6.4 kg. FA were analysed in plasma phospholipids (PPL) and erythrocyte membranes (ERY). RESULTS: The proportions of saturated and monounsaturated FA were increased during weight loss, while linoleic acid (18:2ω6) was decreased. The proportions of eicosapentanoic acid (EPA) (20:5ω3) and docosahexanoic acid (DHA) (22:6ω3) in PPL and ERY did not differ from controls. The activity of stearoyl-CoA-desaturase was increased as evidenced by an increased product/precursor ratio and correlated with the rate of weight loss. The activities of delta-6-desaturase and delta-5-desaturase did not differ from controls. The rate of weight loss was inversely correlated with delta-6-desaturase and directly correlated with delta-5-desaturase. CONCLUSION: The FA profile indicates low-fat intake, fat mobilization from stores and an increased conversion of essential FA at the delta-5-desaturase step during weight loss in adolescent girls with ED. Normal levels of EPA and DHA were maintained.
Assuntos
Ácidos Graxos Essenciais/sangue , Transtornos da Alimentação e da Ingestão de Alimentos/sangue , Redução de Peso , Adolescente , Peso Corporal , Estudos de Casos e Controles , Dessaturase de Ácido Graxo Delta-5 , Ácidos Docosa-Hexaenoicos/sangue , Ácidos Eicosanoicos/sangue , Membrana Eritrocítica/química , Ácidos Graxos Dessaturases/sangue , Feminino , Humanos , Estado Nutricional , Fosfolipídeos/químicaRESUMO
AIMS/HYPOTHESIS: Dietary fatty acids may affect insulin sensitivity. Adipose tissue fatty acid composition partly reflects long-term dietary intake, but data from large studies regarding relationships with insulin sensitivity are lacking. We aimed to determine the association between adipose tissue fatty acids and insulin sensitivity in elderly Swedish men. METHODS: In a cross-sectional analysis of the community-based Uppsala Longitudinal Study of Adult Men (n = 795, mean age 71 years), adipose tissue biopsies were obtained and fatty acid composition was determined by gas-liquid chromatography. Insulin sensitivity was measured directly by a euglycaemic clamp. RESULTS: Palmitic acid (16:0), the major saturated fatty acid (SFA) in the diet and in adipose tissue, was negatively correlated with insulin sensitivity (r = -0.14), as were 16:1 n-7 (r = -0.15), 20:3 n-6 (r = -0.31), 20:4 n-6 (r = -0.38), 22:4 n-6 (r = -0.37) and 22:5 n-3 (r = -0.24; p < 0.001 for all). Some minor SFAs were positively correlated; 12:0 (r = 0.46), 14:0 (r = 0.32), 17:0 (r = 0.21) and 18:0 (r = 0.41; p < 0.001 for all), as were essential polyunsaturated fatty acids (PUFAs) 18:2 n-6 (r = 0.10, p < 0.01) and 18:3 n-3 (r = 0.16, p < 0.001). Docosahexaenoic acid (22:6 n-3) was negatively correlated (r = -0.11, p < 0.01), whereas eicosapentaenoic acid (20:5 n-3) was not (r = -0.02, NS). Most associations diminished or disappeared in lean individuals, indicating an effect of obesity. CONCLUSIONS/INTERPRETATION: Adipose tissue enriched with palmitic acid and depleted of essential PUFAs is associated with insulin resistance. The positive association between minor SFAs and insulin sensitivity merits further investigation.
Assuntos
Tecido Adiposo/química , Diabetes Mellitus Tipo 2/etiologia , Gorduras na Dieta/efeitos adversos , Resistência à Insulina , Ácido Palmítico/análise , Idoso , Cromatografia Gasosa , Estudos Transversais , Ácidos Docosa-Hexaenoicos/análise , Ácido Eicosapentaenoico/análise , Ácidos Graxos Insaturados/análise , Técnica Clamp de Glucose , Inquéritos Epidemiológicos , Humanos , Estudos Longitudinais , Masculino , Análise de Regressão , Inquéritos e Questionários , SuéciaRESUMO
AIMS/HYPOTHESIS: To investigate the association of serum concentrations and dietary intake of beta-carotene and alpha-tocopherol with type 2 diabetes incidence. METHODS: Serum beta-carotene, alpha-tocopherol, lifestyle factors (BMI, physical activity and smoking) and metabolic factors (insulin sensitivity [homeostasis model assessment], acute insulin response and impaired fasting glucose) were analysed in 846 50-year-old non-diabetic Swedish men (participants in the Uppsala Longitudinal Study of Adult Men). Diabetes was identified in 245 participants at reinvestigations after 10, 20 and 27 years. At the 20 year reinvestigation, dietary intake of beta-carotene and alpha-tocopherol, insulin sensitivity (euglycaemic-hyperinsulinaemic clamp) and insulin secretion (early insulin response in OGTT) were determined. RESULTS: The highest tertile of serum beta-carotene at age 50 (>0.335 mumol/l) was associated with 59% lower risk of diabetes during follow-up compared with the lowest tertile (<0.210 mumol/l) after adjustment for lifestyle and metabolic factors (p < 0.01). The highest tertile of lipid-corrected serum alpha-tocopherol at age 50 (>3.67 mumol/mmol) was associated with 46% lower risk of diabetes compared with the lowest tertile (<3.25 mumol/mmol) independently of metabolic factors (p < 0.05). Moreover, lower serum beta-carotene and alpha-tocopherol concentrations were independently associated with impaired insulin sensitivity (p < 0.001), but not with early insulin response, in a subsample of non-diabetic individuals 20 years later. Dietary intake of beta-carotene and alpha-tocopherol independently predicted type 2 diabetes during 7 years of follow-up. CONCLUSIONS/INTERPRETATION: Serum concentrations and dietary intakes of beta-carotene and alpha-tocopherol independently predicted insulin resistance and type 2 diabetes incidence during 27 years of follow-up in a community-based study of men. This result supports the importance of impaired antioxidant status for the development of insulin resistance and type 2 diabetes.
Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , alfa-Tocoferol/sangue , beta Caroteno/sangue , Adulto , Idoso , Glicemia/análise , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/prevenção & controle , Dieta , Exercício Físico , Seguimentos , Intolerância à Glucose/sangue , Intolerância à Glucose/epidemiologia , Humanos , Estilo de Vida , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fumar/epidemiologia , SuéciaRESUMO
AIM/HYPOTHESIS: The objective of this study was to describe the relation of serum fatty acids and desaturase activity (DA) to overweight, insulin sensitivity and cardiovascular disease (CVD) risk factors in adolescents. METHODS: The relations of % serum phospholipid (PL) and cholesteryl ester (CE) fatty acids and estimated DA with CVD risk factors were examined in 264 adolescents (average age 15 years). Fatty acids were determined by gas liquid chromotography. Surrogate measures of DA were expressed as ratios of serum fatty acids: Delta9 DA=16:0/16:1; Delta6 DA=20:3,n6/18:2,n6 (PL) or 18:3,n6/18:2,n6 (CE); and Delta5 DA=20:4,n6/20:3,n6. Spearman partial correlations of fatty acids (%) and DA ratios with CVD risk factors were reported, adjusting for age, sex, race, Tanner stage, energy intake and physical activity. RESULTS: Overweight adolescents compared to normal weight had more adverse levels of CVD risk factors, composition of PL and CE fatty acids in serum, and Delta6 DA and Delta5 DA ratios. Linoleic acid was inversely related to body mass index (BMI), waist circumference and triglycerides (PAssuntos
Doenças Cardiovasculares/etiologia
, Ésteres do Colesterol/sangue
, Ácidos Graxos/sangue
, Sobrepeso/sangue
, Fosfolipídeos/sangue
, Adolescente
, Índice de Massa Corporal
, Ácidos Graxos Dessaturases/sangue
, Feminino
, Humanos
, Resistência à Insulina
, Masculino
, Sobrepeso/fisiopatologia
, Fatores de Risco
, Circunferência da Cintura
RESUMO
OBJECTIVE: To evaluate the metabolic effect of three different kinds of dietary proteins as part of composite meals with similar macronutrient composition in healthy subjects. DESIGN: A randomised meal study. SETTING: Metabolic ward. SUBJECTS AND METHODS: In total, 17 healthy women, 30-65 years old, consumed three meals in randomised order. The meals consisted of foodstuffs with similar nutrient composition but different types of protein (cod, cottage cheese, or soy protein isolate). The distribution of energy from protein, fat and carbohydrates was 33, 26, and 41 energy percent, respectively. Total amount of energy was 2300 kJ. Blood samples were drawn for assay of B-glucose, S-insulin, S-free fatty acids, S-triglycerides, and C-peptide in the fasting state and at seven times (20, 40, 60, 90, 120, 180, and 240 min) after starting to eat the test meal. RESULTS: The blood glucose response after the cod protein meal differed from that of the soy protein meal, with a larger area under the curve (AUC) calculated up to 120 min. The serum insulin response after the milk protein meal differed from that of the cod protein meal with a larger AUC calculated up to 240 min. The insulin/C-peptide and the insulin/glucose ratios differed between the meals; the insulin/C-peptide ratio was higher after the milk protein meal compared to the cod, and soy protein meal at 120 min. The insulin/glucose ratio was lower after the cod protein meal compared to the milk, and soy protein meals at 120 min. The results showed that the metabolic responses differed after meals with similar macronutrient composition containing cod-, milk-, or soy protein.
Assuntos
Glicemia/metabolismo , Proteínas Alimentares/administração & dosagem , Proteínas Alimentares/metabolismo , Insulina/metabolismo , Adulto , Idoso , Área Sob a Curva , Peptídeo C/sangue , Estudos Cross-Over , Carboidratos da Dieta/administração & dosagem , Carboidratos da Dieta/metabolismo , Gorduras na Dieta/administração & dosagem , Gorduras na Dieta/metabolismo , Relação Dose-Resposta a Droga , Ácidos Graxos não Esterificados/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Proteínas do Leite/administração & dosagem , Período Pós-Prandial , Proteínas de Soja/administração & dosagem , Triglicerídeos/sangueRESUMO
OBJECTIVE: Proteins involved in cellular fatty acid (FA) uptake and metabolism may be of relevance in the context of disturbed FA metabolism associated with insulin resistance. Therefore this study investigated relationships between FA handling protein mRNA expression in adipose tissue, FA composition of adipose tissue and serum, and markers of insulin resistance. SUBJECTS: 75 subjects with a range of insulin sensitivities recruited from a cohort of 294 healthy 63-year-old Swedish men. MEASUREMENTS: Anthropometric and biochemical variables (e.g. waist-hip-ratio (WHR) and homeostasis model assessment (HOMA) index of insulin sensitivity), FA composition of the subcutaneous (s.c.) gluteal adipose tissue, serum nonesterified FA (NEFA) and serum phospholipid compartments (by gas-liquid chromatography; n = 294), and mRNA levels of FA handling proteins (adipocyte and keratinocyte lipid binding proteins, fatty acid transport protein (FATP) -1 and -4, CD36/fatty acid translocase, plasma membrane fatty acid binding protein, and acyl-CoA synthase-1 (ACS1)) in s.c. gluteal adipose tissue (by quantitative real-time polymerase chain reaction; n = 75). RESULTS: ACS1 expression was negatively correlated with measures of insulin resistance and central obesity (ACS1 versus HOMA: r = -0.28, P<0.05; ACS1 versus WHR: r = -0.23, P<0.05), with an opposite trend for FATP4. Further analysis of ACS1 expression levels revealed correlations with adipose tissue 16:0 (r = -0.27, P<0.05) and NEFA 16:1 (r = 0.29, P<0.05), FA composition variables which in turn correlated with HOMA index (r = 0.39, P<0.001 and r = -0.23, P<0.05, respectively, n = 75). Moreover, NEFA 16:1 predicted ACS1 expression independently of HOMA, WHR and adipose tissue 16:0 in multiple regression analysis (standardized coefficient = 0.27, P<0.05). CONCLUSION: Significant associations were found between measures of insulin sensitivity, adipose tissue FA handling protein expression, and specific FA composition variables. Although causal relationships could not be identified these findings suggest a role of FA handling proteins in relation to insulin sensitivity, via their involvement in FA trafficking and metabolism. In particular they indicate links between ACS1 activity, the distribution of 16:0 and 16:1, and insulin sensitivity, which may be of physiological relevance.
Assuntos
Tecido Adiposo/metabolismo , Coenzima A Ligases/metabolismo , Ácidos Graxos/metabolismo , Resistência à Insulina/fisiologia , Insulina/metabolismo , Tecido Adiposo/anatomia & histologia , Tecido Adiposo/enzimologia , Biomarcadores/sangue , Estudos de Coortes , Proteínas de Transporte de Ácido Graxo/metabolismo , Proteínas de Ligação a Ácido Graxo/metabolismo , Ácidos Graxos/análise , Humanos , Masculino , Pessoa de Meia-Idade , Relação Cintura-QuadrilRESUMO
In an attempt to characterise the apolipoprotein-E-binding proteins of rat liver endothelial cells, we prepared membranes from monolayer cultures of liver endothelial cells as an enriched source of membrane receptors. The membranes could specifically bind iodinated very-low-density lipoproteins (VLDL) and the binding could be inhibited effectively by unlabelled VLDL and high-density lipoproteins, but only moderately by low-density lipoproteins. To identify the binding proteins, we performed immunoprecipitation studies of solubilised iodinated liver endothelial cells and cell membranes, respectively, using purified apolipoprotein E and monospecific polyclonal IgG directed towards this apolipoprotein. The antibodies together with the bound apolipoprotein E and iodinated liver endothelial cell proteins were harvested with staphylococcal protein A-Sepharose. The immunoprecipitates were subjected to sodium dodecyl sulphate-polyacrylamide gel electrophoresis, and after autoradiography of the dried gel, the Mr of the liver endothelial cell proteins bound to apolipoprotein E could be determined. Two protein bands with molecular masses of 55-60 and 110, and a weak band of 170 kDa could be detected from intact cells. These proteins were specifically precipitated only in the presence of divalent cations, and might represent cell-surface receptors for apolipoprotein-E-containing lipoproteins. Additional bands were seen when cell membranes were used, the most prominent ones having molecular masses of 32 and 35 kDa. These proteins could be of intracellular origin, or they may be degradation products of the other apolipoprotein-E-binding proteins.
Assuntos
Apolipoproteínas E/metabolismo , Proteínas de Transporte/metabolismo , Endotélio/metabolismo , Fígado/metabolismo , Citoesqueleto de Actina/metabolismo , Animais , Proteínas de Transporte/isolamento & purificação , Membrana Celular/metabolismo , Endotélio/citologia , Fígado/citologia , Masculino , Proteínas de Membrana/isolamento & purificação , Proteínas de Membrana/metabolismo , Peso Molecular , Testes de Precipitina , Ratos , Ratos EndogâmicosRESUMO
Rat liver endothelial cells in primary cultures take up and degrade 125I-labelled human very-low-density lipoproteins (VLDL) in a saturable fashion at physiological triacylglycerol concentrations. The iodinated VLDL are readily taken up by the freshly isolated endothelial cells and degradation products appear in the medium about 30 min after the addition of VLDL to the cultures. Uptake and degradation at 37 degrees C are effectively inhibited by unlabelled human VLDL, low-density lipoproteins (LDL), high-density lipoproteins and lymph chylomicrons, but only modestly by acetylated LDL. Purified apolipoproteins E and C-III:1 also compete with the uptake of iodinated VLDL, but when degradation was studied for longer periods of time, such a competition could not be demonstrated. This may be due to the fact that the added apolipoproteins become associated with the lipoproteins. In binding experiments at 7 degrees C, iodinated apolipoprotein C III:1 bound to the liver endothelial cells in a manner characteristic of receptor binding with a dissociation constant of 0.5 microM. This binding could not only be inhibited by unlabelled apolipoprotein C-III:1 but also by unlabelled apolipoprotein E. The results indicate that rat liver endothelial cells carry receptors for VLDL and that these recognize the apolipoproteins E, C-III and B on the lipoprotein surface. Considering the large endothelial surface and high blood flow through the liver, significant quantities of lipoproteins can be taken up and degraded, thus influencing the levels of circulating lipoproteins in the in vivo situation.
Assuntos
Lipoproteínas VLDL/metabolismo , Fígado/metabolismo , Animais , Apolipoproteínas C/metabolismo , Apolipoproteínas E/metabolismo , Transporte Biológico , Células Cultivadas , Quilomícrons/metabolismo , Endotélio/metabolismo , Lipoproteínas HDL/metabolismo , RatosRESUMO
BACKGROUND: -Left ventricular hypertrophy (LVH) is a common risk factor for cardiovascular mortality. Causes other than hypertension have not previously been investigated longitudinally. The aim of the present study was to determine hemodynamic, metabolic, and psychosocial predictors at 50 years of age for the prevalence of echocardiographic LVH and geometric subtypes at age 70 by use of a large sample of men from the general population followed up for 20 years. Methods and Results-In 1970 to 1973, all men born from 1920 to 1924 and residing in Uppsala County, Sweden, were invited to participate in a health survey aimed at identifying risk factors for cardiovascular disease. At a reinvestigation 20 years later, echocardiographic left ventricular mass index was determined in 475 subjects. A 1-SD increase in body mass index, systolic or diastolic blood pressure, fasting LDL/HDL cholesterol, serum triglycerides, or the serum cholesterol ester proportion of several saturated fatty acids or oleic acid at age 50 significantly increased the odds of having LVH at age 70 by 27% to 41%, whereas an increase in linoleic acid proportion was protective. Almost all metabolic predictors were independent of ischemic heart disease, valvular disease, and use of antihypertensive medication at age 70. CONCLUSIONS: -Dyslipidemia and indices of a low dietary intake of linoleic acid and high intake of saturated and monounsaturated fats, as well as hypertension and obesity, at age 50 predicted the prevalence of LVH 20 years later in this prospective longitudinal cohort study, thereby suggesting that lipids may be important in the origin of LVH.
Assuntos
Ésteres do Colesterol/sangue , Ácidos Graxos/sangue , Hiperlipidemias/complicações , Hipertrofia Ventricular Esquerda/etiologia , Fatores Etários , Idoso , Análise de Variância , Pressão Sanguínea , Índice de Massa Corporal , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Gorduras na Dieta , Ecocardiografia Doppler , Inquéritos Epidemiológicos , Ventrículos do Coração/diagnóstico por imagem , Hemodinâmica , Humanos , Hiperlipidemias/sangue , Hipertrofia Ventricular Esquerda/sangue , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/epidemiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade/complicações , Razão de Chances , Estudos Prospectivos , Psicologia , Fatores de Risco , Suécia/epidemiologia , Fatores de Tempo , Triglicerídeos/sangueRESUMO
This investigation was undertaken to study whether the risk to develop non-insulin-dependent diabetes mellitus (NIDDM) among 50-year-old men during a 10-year follow-up period was related to the fatty acid composition of their serum cholesterol esters. There were highly significant differences in the initial health survey between the fatty acid composition in serum in subjects who remained normoglycemic (n = 1,753) and in those who later developed NIDDM (n = 75). The main differences were that the latter had higher proportions of saturated fatty acids and palmitoleic acid (16:1 omega-7), a low proportion of linoleic acid (18:2 omega-6), and a relatively high content of gamma-linolenic (18:3 omega-6) and dihomo-gamma-linolenic (20:3 omega-6) acids in the serum cholesterol esters. The picture was similar also after adjusting for differences in body mass index. In a logistic model, a high proportion of dihomo-gamma-linolenic acid remained a significant contributor to the development of diabetes, along with the height of the insulin index, the blood glucose concentration at 60 min, and the fasting insulin concentration. The increased risk to develop NIDDM related to the serum cholesterol ester fatty acid composition may be mediated by diet and/or genetic factors.
Assuntos
Ésteres do Colesterol/sangue , Diabetes Mellitus Tipo 2/sangue , Ácidos Graxos/sangue , Ácido 8,11,14-Eicosatrienoico/sangue , Glicemia/análise , Estudos de Coortes , Seguimentos , Humanos , Insulina/sangue , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
Tissue samples were taken from the gastrocnemius muscle of 26 randomly selected, glucose-tolerant, 48-yr-old men. Hexokinase, phosphorylase, lactate dehydrogenase (LDH), succinate dehydrogenase, and lipoprotein lipase activity (LPLA), as well as the area per fiber type and capillary density, were determined. Mean fiber area correlated positively with relative body weight (r equals 0.53, P less than 0.01), but capillary density did not. The result is that, in cases of high body weight, each capillary supplies a larger muscle fiber area. Serum insulin concentration in the fasting state correlated positively with body weight (r equals 0.77, P less than 0.001) and with mean fiber area per capillary (r equals 0.87; P less than 0.001). Only during the latter part of an oral glucose tolerance test (OGTT) did blood glucose concentrations correlate with relative body weight and mean fiber area per capillary (r equals 0.42, r equals 0.51, P less than 0.05). A stepwise multiple regression analysis showed that the different muscle morphology measurements could account for 3/4 of the variation in the fasting serum insulin concentration, the fasting insulin/glucose ratio, and the blood glucose concentration at 120 min in the OGTT. Of the intracellular enzymes, only LDH (r equals -0.71, P less than 0.001) correlated with the mean fiber area per capillary. LPLA correlated with capillary density (r equals 0.66, P less than 0.001), and, long with the muscle morphology measurements, could account for 3/4 of the variation in serum triglyceride concentrations. The results show that a large mean muscle fiber area/capillary ratio indicates a morphologic imbalance, which is related to both glucose tolerance and various degrees of insulin sensitivity.
Assuntos
Glicemia/metabolismo , Insulina/sangue , Músculos/fisiologia , Peso Corporal , Jejum , Teste de Tolerância a Glucose , Hexoquinase/metabolismo , Humanos , L-Lactato Desidrogenase/metabolismo , Lipase Lipoproteica/metabolismo , Masculino , Pessoa de Meia-Idade , Músculos/enzimologia , Fosforilases/metabolismo , Succinato Desidrogenase/metabolismoRESUMO
The underlying mechanisms by which smoking induces cardiovascular diseases are largely unknown. The effect of smoking status on the cyclooxygenase (COX)-mediated inflammatory indicator prostaglandin F(2alpha) (PGF(2alpha)) has never been studied. Associations of cytokines and antioxidants and smoking status, have shown conflicting results. Urinary 15-keto-dihydro-PGF(2alpha) (a major metabolite of PGF(2alpha)), serum interleukin-6 (IL-6) and high sensitivity C-reactive protein (hsCRP), serum amyloid protein A (SAA), urinary 8-iso-PGF(2alpha) (an F(2)-isoprostane, indicator of oxidative stress), and serum alpha-tocopherol were quantified in a population-based sample (n = 642) of 77-year old men without diabetes. Fifty-five men were current smokers and 391 former smokers. Inflammatory indicators were increased in current smokers (15-keto-dihydro-PGF(2alpha), P < 0.001; IL-6, P = 0.01) than non-smokers. 8-iso-PGF(2alpha) was increased (P < 0.01) and alpha-tocopherol reduced (P < 0.001) in current smokers. Further, former smokers had increased formation of 15-keto-dihydro-PGF(2alpha), IL-6 and 8-iso-PGF(2alpha) compared non-smokers. This is the first study to show that smokers have increased PGF(2alpha) formation, thus enhanced COX-mediated inflammation, in addition to elevated levels of cytokines and isoprostanes. Subclinical COX- and cytokine-mediated inflammation and oxidative stress are ongoing processes not only in active smokers but also in former smokers which may contribute to the accelerated atherosclerosis associated with smoking.
Assuntos
Envelhecimento/metabolismo , Dinoprosta/biossíntese , F2-Isoprostanos/biossíntese , Interleucina-6/biossíntese , Fumar/efeitos adversos , Idoso , Antioxidantes/metabolismo , Biomarcadores/sangue , Biomarcadores/urina , Proteína C-Reativa/metabolismo , Estudos de Coortes , Citocinas/metabolismo , Dinoprosta/análogos & derivados , Dinoprosta/urina , Humanos , Inflamação/etiologia , Interleucina-6/sangue , Estudos Longitudinais , Masculino , Estresse Oxidativo , Prostaglandina-Endoperóxido Sintases/metabolismo , Abandono do Hábito de Fumar , Fatores de Tempo , Tocoferóis/sangueRESUMO
Low-dose aspirin (acetylsalicylic acid) is used as prophylaxis against cardiovascular diseases. The effect of aspirin on inflammation and oxidative stress, processes known to be involved in cardiovascular diseases, are not fully known. The cyclooxygenase(COX)-mediated inflammatory indicator prostaglandin F2alpha (PGF2alpha) (15-keto-dihydro-PGF2alpha), cytokine-mediated inflammatory indicators (interleukin-6, high-sensitivity C-reactive protein, serum amyloid A protein), and oxidative stress indicators (8-iso-PGF2alpha, tocopherols) were quantified in men with daily 75 mg of aspirin (n=175) and control men (n=464), all of age 77, in a cross-sectional study. Men treated with aspirin had decreased levels of urinary 15-keto-dihydro-PGF2alpha than controls (P<0.01), independent of possible cardiovascular risk factors. Aspirin-treated men had increased levels of alpha-tocopherol than controls (P<0.05). This is the first study to indicate that low-dose aspirin treatment is associated with decreased levels of PGF2alpha. This observation suggests a possible COX-mediated anti-inflammatory effect of low-dose aspirin, which should be further confirmed by intervention studies.
Assuntos
Aspirina/farmacologia , Dinoprosta/metabolismo , Dinoprosta/urina , Prostaglandina-Endoperóxido Sintases/metabolismo , Idoso , Antioxidantes/análise , Aspirina/administração & dosagem , Proteína C-Reativa/metabolismo , Humanos , Inflamação/sangue , Inflamação/enzimologia , Inflamação/metabolismo , Interleucina-6/sangue , Masculino , Estresse Oxidativo/efeitos dos fármacos , Proteína Amiloide A Sérica/metabolismo , alfa-Tocoferol/sangue , gama-Tocoferol/sangueRESUMO
High plasminogen activator inhibitor (PAI)-1 levels and poor dietary fat quality are potential risk factors for cardiovascular disease. The aim was to investigate the cross-sectional associations between PAI-1 activity and dietary nutrient intake, focusing on fat quality, in a population-based study of 871 men aged 70 years. The relationship between PAI-1 and the fatty acid composition in serum cholesterol esters (n=381 men) was also studied. The estimated total fat intake was positively associated with PAI-1 activity. The intake of both monounsaturated and polyunsaturated fatty acids was positively associated with PAI-1 activity, whereas the intake of saturated fatty acids was not. In serum cholesterol esters, higher proportions of palmitoleic and dihomo-gamma-linolenic acid, a lower proportion of linoleic acid, and reduced estimated Delta5-desaturase activity were associated with higher PAI-1 levels. These associations were confounded by factors representing the insulin resistance syndrome. PAI-1 activity was positively associated with gamma-linolenic and arachidonic acid, independent of potential confounders. In conclusion, this study demonstrates that dietary intake of unsaturated fatty acids is positively associated with PAI-1 activity, whereas intake of saturated fatty acids is not. The associations present between PAI-1 activity and the fatty acid proportions in serum cholesterol esters are partly influenced by metabolic syndrome-related factors.