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1.
Obesity (Silver Spring) ; 21(1): 170-7, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23505183

RESUMO

OBJECTIVE: We aimed to analyze the retinol binding protein-4 (RBP4) messenger RNA (mRNA) expression profiles in adipose tissues and liver of morbidly obese (MO) women with or without nonalcoholic fatty liver disease (NAFLD), and to study the relationships with other pro- and anti-inflammatory adipokines in vivo and in vitro. DESIGN AND METHODS: We performed a cross-sectional analysis of subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT) and liver samples from four lean and 45 MO women with or without NAFLD by enzyme-linked immunosorbent assay and real-time reverse transcription-PCR. We also studied RBP4 expression in HepG2 hepatocytes under various inflammatory stimuli. RESULTS: Circulating RBP4 levels were higher in MO women, and specifically, in MO subjects with NAFLD compared with normal liver controls (lean and MO). RBP4 liver expression was higher in nonalcoholic steatohepatitis (NASH)-moderate/severe than in NASHmild. Overall RBP4 gene expression was higher in liver than in adipose tissues. Among them, the higher expression corresponded to SAT. VAT expression was lower in the MO cohort. In HepG2, RBP4 mRNA expression was reduced by tumor necrosis factor (TNF)-α and increased by adiponectin treatment. CONCLUSIONS: The results obtained in MO women with NAFLD, brings up the use of RBP4 and other adipokines as a panel of noninvasive molecular biomarkers when NAFLD is suspected. Further studies are needed with other obesity groups.


Assuntos
Fígado Gorduroso/sangue , Gordura Intra-Abdominal/metabolismo , Fígado/metabolismo , Obesidade Mórbida/sangue , Proteínas Plasmáticas de Ligação ao Retinol/metabolismo , Gordura Subcutânea/metabolismo , Adiponectina/farmacologia , Adulto , Estudos Transversais , Fígado Gorduroso/complicações , Feminino , Células Hep G2 , Humanos , Fígado/patologia , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica , Obesidade Mórbida/complicações , Obesidade Mórbida/patologia , RNA Mensageiro , Valores de Referência , Proteínas Plasmáticas de Ligação ao Retinol/genética , Fator de Necrose Tumoral alfa/metabolismo
2.
AIDS Res Hum Retroviruses ; 27(2): 143-52, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20854131

RESUMO

Tumor necrosis factor alpha (TNF-α) is thought to be involved in the pathogenic and metabolic events associated with HIV-1 infection. We assessed whether carriage of the TNF-α gene promoter single nucleotide polymorphism (SNP) is associated with lipodystrophy and metabolic derangements in HIV-1-infected patients treated with cART. We also assessed variations in TNF-α receptor plasma levels. The study group comprised 286 HIV-1-infected patients (133 with and 153 without lipodystrophy) and 203 uninfected controls (UC). TNF-α -238G > A, -308G > A, and -863 C > A SNP were assessed using PCR-RFLPs on white cell DNA. Plasma sTNF-α R1 and R2 levels were measured by ELISA. Student's t test, the χ(2) test, Pearson correlations, and the logistic regression test were performed for statistical analysis. The TNF-α -308G > A SNP was significantly associated with lipodystrophy in the univariate analysis (p = 0.04). This association, however, was no longer significant in the multivariate analysis. A meta-analysis of the published literature and our own data, which included 284 patients with lipodystrophy and 338 without lipodystrophy, showed that there was no relationship between the TNF-α -238G > A and -308G > A SNP and lipodystrophy (p > 0.05 for all comparisons). HIV-1-infected patients had greater sTNF-α R2 plasma levels than UC (p = 0.001) whereas sTNF-α R1 and R2 levels were not significantly different in both the HIV-1-infected cohorts, lipodystrophy vs. nonlipodystrophy (p = NS). In our cohort of white Spaniards the TNF-α -238G > A, -308G > A, and -863C > A SNP were not associated with lipodystrophy in HIV-1-infected patients treated with cART. This finding was replicated in a meta-analysis of the published data, which showed no associations between the TNF-α -238G > A and -308G > A SNP and lipodystrophy. In HIV-1-infected patients under cART there is a systemic overproduction of sTNF-α R2, which is unrelated to the presence of lipodystrophy.


Assuntos
Fármacos Anti-HIV/efeitos adversos , Variação Genética , Infecções por HIV/tratamento farmacológico , Lipodistrofia/induzido quimicamente , Fator de Necrose Tumoral alfa/genética , Adulto , Estudos de Casos e Controles , Quimioterapia Combinada , Feminino , Infecções por HIV/complicações , Humanos , Masculino , Pessoa de Meia-Idade
3.
Obes Surg ; 20(9): 1258-64, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20544399

RESUMO

BACKGROUND: Although the adipokine retinol-binding protein-4 (RBP4) has been implicated in the development of obesity-related insulin resistance, its role in human obesity is still unclear. Our objectives were to find out the effect on RBP4 systemic levels of a weight loss induced by gastric bypass surgery and to analyze RBP4 relationships with insulin resistance, parameters of body composition, lipid metabolism, and inflammation. METHODS: Sixty-three obese women were analyzed before and 12 months after surgery of systemic concentrations of RBP4, fasting glucose, insulin, lipid profile molecules, and inflammation-related proteins (C-reactive protein, tumor necrosis factor-alpha receptors 1 and 2, interleukin-18, and adiponectin), and waist and hip circumference measurements, body mass index calculation, and insulin resistance index by homeostasis model assessment were also made. RESULTS: We found that RBP4 levels were lower after weight reduction by gastric bypass surgery (p < 0.0001). We found RBP4 associated with triglycerides before (beta = 0.37, p = 0.02) and after surgery (beta = 0.59, p < 0.0001) and negatively with weight loss after surgery (beta = -0.37, p = 0.003). When expressed as a percentage of change, the decrease of RBP4 was related to the reduction in the levels of triglycerides and with the increase in HDL-cholesterol (beta = 0.73, p = 0.02 and beta = 0.62, p = 0.04, respectively). Others parameters analyzed, including inflammatory markers, were not related to RBP4. CONCLUSIONS: This study shows that, in obese women and after a substantial weight loss due to bariatric surgery, RBP4 was related to weight status and lipid parameters rather than to insulin sensitivity or inflammatory markers.


Assuntos
Derivação Gástrica , Lipídeos/sangue , Obesidade/sangue , Proteínas Plasmáticas de Ligação ao Retinol/análise , Redução de Peso , Adipocinas/análise , Adiponectina/análise , HDL-Colesterol/sangue , Feminino , Humanos , Mediadores da Inflamação/sangue , Resistência à Insulina , Pessoa de Meia-Idade , Obesidade/cirurgia , Triglicerídeos/sangue
4.
BMC Med Genet ; 11: 63, 2010 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-20420684

RESUMO

BACKGROUND: Tumor necrosis factor alpha (TNF-alpha) is thought to be involved in the various immunogenetic events that influence HIV-1 infection. METHODS: We aimed to determine whether carriage of the TNF-alpha-238G>A, -308G>A and -863 C>A gene promoter single nucleotide polymorphisms (SNP) and the CCR5 Delta 32 variant allele influence the risk of HIV-1 infection and disease progression in Caucasian Spaniards. The study group consisted of 423 individuals. Of these, 239 were uninfected (36 heavily exposed but uninfected [EU] and 203 healthy controls [HC]) and 184 were HIV-1-infected (109 typical progressors [TP] and 75 long-term nonprogressors [LTNP] of over 16 years' duration). TNF-alpha SNP and the CCR5 Delta 32 allele were assessed using PCR-RFLP and automatic sequencing analysis methods on white blood cell DNA. Genotype and allele frequencies were compared using the chi 2 test and the Fisher exact test. Haplotypes were compared by logistic regression analysis. RESULTS: The distribution of TNF-alpha-238G>A, -308G>A and -863 C>A genetic variants was non-significantly different in HIV-1-infected patients compared with uninfected individuals: -238G>A, p = 0.7 and p = 0.3; -308G>A, p = 0.05 and p = 0.07; -863 C>A, p = 0.7 and p = 0.4, for genotype and allele comparisons, respectively. Haplotype analyses, however, indicated that carriers of the haplotype H3 were significantly more common among uninfected subjects (p = 0.04). Among the infected patients, the distribution of the three TNF-alpha genetic variants assessed was non-significantly different between TP and LTNP: -238G>A, p = 0.35 and p = 0.7; -308G>A, p = 0.7 and p = 0.6: -863 C>A, p = 0.2 and p = 0.2, for genotype and allele comparisons, respectively. Haplotype analyses also indicated non-significant associations. Subanalyses in the LTNP subset indicated that the TNF-alpha-238A variant allele was significantly overrepresented in patients who spontaneously controlled plasma viremia compared with those who had a detectable plasma viral load (genotype comparisons, p = 0.02; allele comparisons, p = 0.03). The CCR5 Delta 32 distribution was non-significantly different in HIV-1-infected patients with respect to the uninfected population (p = 0.15 and p = 0.2 for genotype and allele comparisons, respectively) and in LTNP vs TP (p = 0.4 and p = 0.5 for genotype and allele comparisons, respectively). CONCLUSIONS: In our cohort of Caucasian Spaniards, TNF-alpha genetic variants could be involved in the vulnerability to HIV-1 infection. TNF-alpha genetic variants were unrelated to disease progression in infected subjects. The -238G>A SNP may modulate the control of viremia in LTNP. Carriage of the CCR5 Delta 32 variant allele had no effect on the risk of infection and disease progression.


Assuntos
Infecções por HIV/genética , HIV-1 , Receptores CCR5/genética , Fator de Necrose Tumoral alfa/genética , Adulto , Progressão da Doença , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Populações Vulneráveis , População Branca
5.
AIDS ; 22(7): 893-6, 2008 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-18427208

RESUMO

We determined the IL-6 -174 G>C single nucleotide polymorphism, IL-6 mRNA expression in subcutaneous adipose tissue (SAT) and IL-6 plasma levels in HIV-1-infected patients with and without lipodystrophy and uninfected controls. HIV-1-infected patients had a greater prevalence of the IL-6 -174 C/C genotype and the C allele, higher SAT IL-6 mRNA expression and plasma IL-6 levels than controls. The IL-6 -174 G>C genotype distribution and allele frequencies, SAT IL-6 mRNA expression and IL-6 plasma levels were non-significantly different between HIV-1-infected patients with and without lipodystrophy.


Assuntos
Infecções por HIV/imunologia , HIV-1 , Síndrome de Lipodistrofia Associada ao HIV/imunologia , Interleucina-6/genética , Polimorfismo de Nucleotídeo Único , Adulto , Alelos , Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Estudos de Casos e Controles , Estudos Transversais , Feminino , Frequência do Gene , Genótipo , Infecções por HIV/tratamento farmacológico , Síndrome de Lipodistrofia Associada ao HIV/tratamento farmacológico , Humanos , Interleucina-6/sangue , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/análise , Gordura Subcutânea/imunologia
6.
Drug Alcohol Depend ; 92(1-3): 91-9, 2008 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17728075

RESUMO

BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) is thought to be a critical driving force of inflammatory damage in alcoholic liver disease (ALD). We aimed to establish whether there is a correlation between plasma levels of the soluble TNF-alpha receptors 1 and 2 (sTNFR1 and sTNFR2) and the severity of liver damage in patients with ALD. We also aimed to elucidate whether functionally active polymorphisms in the promoter region of the TNF-alpha gene modulate the development of ALD. DESIGN: We studied 614 Spaniards. Of these, 278 were alcoholics (103 without liver histologic abnormalities, 89 with non-cirrhotic liver disease and 86 with cirrhosis) and 336 were non-alcoholics (115 healthy controls, 114 with non-alcoholic non-cirrhotic liver disease and 107 with cirrhosis unrelated to alcohol). Plasma levels of sTNFR1 and sTNFR2 were determined by ELISA and results were expressed in ng/mL and subsequently converted in log(10). TNF-alpha gene promoter region polymorphisms at the positions -238, -308 and -863 were assessed by restriction fragment length polymorphisms (RFLPs) on white cell DNA. Differences in plasma sTNFR1 and sTNFR2 levels between groups were compared with the one-way and two-factor analysis of variance test, and Student's t-test. Genotype distribution and allele frequencies in the different groups were compared using the chi(2) test or Fisher's exact test. RESULTS: sTNFR1 and sTNFR2 plasma levels were significantly higher in patients with cirrhosis than in those with non-cirrhotic liver disease (p<0.001) and individuals without liver disease (p<0.001), both in the alcoholic and the non-alcoholic group. Among cirrhotics, sTNFR1 and sTNFR2 levels had a significant positive correlation with the severity of the liver disease, graded with the Child-Pugh's score (p=0.003 and p<0.001, respectively). TNF-alpha genotype distribution and allele frequencies of the three loci assessed were similar in the groups studied, hence no particular genotype or haplotype could be linked to ALD. CONCLUSIONS: The TNF-alpha system is activated in patients with cirrhosis of the liver irrespective of aetiology. TNF-alpha polymorphisms at positions -238, -308 and -863 are not linked to ALD.


Assuntos
Hepatopatias Alcoólicas/genética , Fator de Necrose Tumoral alfa/genética , Idoso , Consumo de Bebidas Alcoólicas/psicologia , DNA/genética , Feminino , Genótipo , Humanos , Hepatopatias Alcoólicas/epidemiologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Fragmento de Restrição/genética , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas/genética , Estudos Prospectivos , Receptores Tipo I de Fatores de Necrose Tumoral/sangue , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo II do Fator de Necrose Tumoral/sangue , Receptores Tipo II do Fator de Necrose Tumoral/genética , Espanha/epidemiologia , População Branca
7.
Endocrinol Nutr ; 55(9): 383-8, 2008 Oct.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-22974450

RESUMO

AIMS: Research into new risk markers for diabetic kidney disease is required. We aimed to study 24-hour urinary interleukin- 6 excretion (uIL-6) in type 2 diabetic patients in relation to organ damage induced by increased blood pressure. METHODS: 24-hour uIL-6 and albumin excretion and 24-hour blood pressure recording were evaluated in 49 patients with type 2 diabetes and normal renal function. Patients with optimized mean 24-hour systolic blood pressure (SBP), defined as SBP ≤ 130 mmHg, and those with uncontrolled SBP (SBP > 130 mmHg) were compared. Multiple linear regression analysis was performed to study significant contributors to variance in the 24-hour uIL-6 excretion rate. RESULTS: Albumin excretion rate (AER) and uIL-6 were significantly correlated (r=0.63; p<0.0001). Patients with mean 24-hour SBP above 130 mmHg (n=27) had significantly higher mean uIL-6 excretion than those with a mean 24-hour SBP equal to or below 130 mmHg (n=22) (p=0.009). The strength of the association of uIL-6 with diurnal and mean diastolic blood pressure (DBP) was significantly greater than that with AER. Mean SBP (p<0.0001) contributed to 25% of AER variance after body mass index, age, sex, mean SBP, mean DBP, HbA1c and smoking status were accounted for. Mean 24-hour SBP (p=0.005) and smoking (p=0.03) contributed to 15% and 9%, respectively, of uIL-6 variance. CONCLUSIONS: Increased uIL-6, perhaps by reflecting significant tissue damage and remodelling, could be a marker for increased mean SBP in type 2 diabetes.

8.
Endocrinology ; 146(5): 2210-20, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15677760

RESUMO

The gene encoding the human TNF alpha receptor (TNFR) 2 contains polymorphisms in the 3' untranslated region (UTR). Previous studies have shown that some variant alleles in this region are associated with obesity and insulin resistance. However, the effect of these polymorphisms on the expression of TNFR2 has not been studied to date. To examine the role played by different haplotypes in the control of TNFR2 expression (haplotypes A1-A5, referring to nucleotides 1663 G/A, 1668 T/G, and 1690 T/C), we introduced these sequences into the 3'-UTR of a heterologous reporter gene and expressed the corresponding constructs in a human T-cell line. We demonstrate that a 485-nt fragment of the TNFR2 3'-UTR that contains a U-rich region decreases reporter expression and that haplotypes A1-A4 exert a stronger effect than A5. Furthermore, time-course assays of mRNA stability using actinomycin D revealed that haplotypes A1-A4 destabilize the mRNA. The proximal TNFR2 3'-UTR, independently of haplotype differences, responded to T-cell activation by increasing mRNA decay. Electromobility shift analysis demonstrated that protein(s) found in T-cell extracts bind to the 485-nt fragment. We suggest that an increased rate of TNFR2 mRNA decay protects cells from unrestrained TNF alpha effects and that this protection is weakened in A5 subjects. These findings may explain the association of this haplotype with obesity and increased leptin levels.


Assuntos
Regiões 3' não Traduzidas/genética , Regulação da Expressão Gênica , Genes Reporter/genética , Polimorfismo Genético/genética , Receptores Tipo II do Fator de Necrose Tumoral/genética , Regiões 3' não Traduzidas/química , Regiões 3' não Traduzidas/metabolismo , Sequência de Bases , Citomegalovirus/genética , Dactinomicina/farmacologia , Estabilidade de Medicamentos , Citometria de Fluxo , Expressão Gênica/genética , Proteínas de Fluorescência Verde/genética , Haplótipos , Humanos , Células Jurkat , Cinética , Leptina/sangue , Ativação Linfocitária , Dados de Sequência Molecular , Obesidade/genética , Regiões Promotoras Genéticas/genética , Estrutura Secundária de Proteína , RNA Mensageiro/análise , Receptores Tipo II do Fator de Necrose Tumoral/química , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , Linfócitos T , Transfecção
9.
Obes Res ; 12(6): 962-71, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15229336

RESUMO

OBJECTIVE: To evaluate interactions among leptin, adiponectin, resistin, ghrelin, and proinflammatory cytokines [tumor necrosis factor receptors (TNFRs), interleukin-6 (IL-6)] in nonmorbid and morbid obesity. RESEARCH METHODS AND PROCEDURES: We measured these hormones by immunoenzyme or radiometric assays in 117 nonmorbid and 57 morbidly obese patients, and in a subgroup of 34 morbidly obese patients before and 6 months after gastric bypass surgery. Insulin resistance by homeostasis model assessment, lipid profile, and anthropometrical measurements were also performed in all patients. RESULTS: Average plasma lipids in morbidly obese patients were elevated. IL-6, leptin, adiponectin, and resistin were increased and ghrelin was decreased in morbidly obese compared with nonmorbidly obese subjects. After adjusting for age, gender, and BMI in nonmorbidly obese, adiponectin was positively associated with HDLc and gender and negatively with weight (beta = -0.38, p < 0.001). Leptin and resistin correlated positively with soluble tumor necrosis factor receptor (sTNFR) 1 (beta = 0.24, p = 0.01 and beta = 0.28, p = 0.007). In the morbidly obese patients, resistin and ghrelin were positively associated with sTNFR2 (beta = 0.39, p = 0.008 and beta = 0.39, p = 0.01). In the surgically treated morbidly obese group, body weight decreased significantly and was best predicted by resistin concentrations before surgery (beta = 0.45, p = 0.024). Plasma lipids, insulin resistance, leptin, sTNFR1, and IL-6 decreased and adiponectin and ghrelin increased significantly. Insulin resistance improved after weight loss and correlated with high adiponectin levels. DISCUSSION: TNFalpha receptors were involved in the regulatory endocrine system of body adiposity independently of leptin and resistin axis in nonmorbidly obese patients. Our results suggest coordinated roles of adiponectin, resistin, and ghrelin in the modulation of the obesity proinflammatory environment and that resistin levels before surgery treatment are predictive of the extent of weight loss after bypass surgery.


Assuntos
Citocinas/sangue , Derivação Gástrica , Hormônios Ectópicos/sangue , Peptídeos e Proteínas de Sinalização Intercelular , Obesidade Mórbida/sangue , Hormônios Peptídicos/sangue , Proteínas/metabolismo , Redução de Peso/fisiologia , Adiponectina , Adulto , Glicemia/metabolismo , Colesterol/sangue , Feminino , Grelina , Humanos , Insulina/sangue , Resistência à Insulina , Interleucina-6/sangue , Leptina/sangue , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/cirurgia , Resistina , Fator de Necrose Tumoral alfa/metabolismo
10.
Diabetes Care ; 26(5): 1362-8, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12716789

RESUMO

OBJECTIVE: Fatty acids (FAs) have been involved in the development of chronic inflammatory conditions such as insulin resistance and obesity. However, the relation among insulin resistance, obesity, inflammatory activity (circulating interleukin [IL]-6) and dietary FAs has been scarcely studied in otherwise healthy subjects. RESEARCH DESIGN AND METHODS: We aimed to study these interactions in 123 overweight (BMI 26.9 +/- 2.4 kg/m(2) [means +/- SD]) subjects and 109 lean (BMI 21.7 +/- 1.7 kg/m(2), P < 0.000001) subjects. IL-6 was measured by immunoassay and FA by gas liquid cromatography. RESULTS: The percentage of saturated FAs (r = 0.30, P = 0.01) and omega-6 FAs (r = -0.32, P = 0.001) were significantly associated with circulating IL-6, whereas the percentage of omega-3 FAs correlated negatively with C-reactive protein in overweight subjects (P = 0.04). Saturated-to-omega-3 and saturated-to-omega-6 FA ratios were significantly and positively associated with C-reactive protein (P < 0.0001) and IL-6 (P < 0.001), respectively. In contrast, none of these associations reached statistical significance in lean subjects. Those subjects in the most insulin-sensitive quintile (homeostasis model assessment value) showed a significantly higher percentage of linoleic acid (C18:2 varpi6) (P = 0.03) and a significantly lower level of araquidic (C20:0) (P = 0.04), behenic (C22:0) (P = 0.009), lignoceric (C24:0) (P = 0.02), and nervonic (C24:1 varpi9) (P = 0.001) FAs than the remaining subjects. In parallel, the most insulin-sensitive subjects showed significantly decreased C-reactive protein (P = 0.03). Serum C-reactive protein was significantly associated with percent linoleic acid and eicosapentaenoic acid in nonsmoking men (P = 0.03 and P = 0.04, respectively) and with docosahexaenoic acid in nonsmoking women (r = -0.46, P < 0.0001). We constructed a multivariant regression analysis to predict circulating IL-6. Age, BMI, waist-to-hip ratio (WHR), smoking status, and the relation of saturated to omega-6 or saturated to omega-3 FAs were considered as independent variables separately in men and women. In overweight men, the ratio of saturated to omega-3 FAs (P = 0.01), but not age, sex, BMI, WHR, or smoking status, independently contributed to 17% of IL-6 variance. In lean men, smoking status (P = 0.02), but not the remaining variables, contributed to 8% of IL-6 variance. CONCLUSIONS: Dietary FAs (as inferred from plasma FA concentration) seem to be linked to inflammatory activity in overweight subjects and in subjects with insulin resistance. Being overweight modulates the relation of FAs to inflammatory markers.


Assuntos
Gorduras na Dieta , Ácidos Graxos não Esterificados/sangue , Ácidos Graxos/sangue , Inflamação/fisiopatologia , Resistência à Insulina , Obesidade/fisiopatologia , Adulto , Glicemia/metabolismo , Pressão Sanguínea , Constituição Corporal , Índice de Massa Corporal , Doenças Cardiovasculares/epidemiologia , Feminino , Humanos , Inflamação/sangue , Interleucina-6/sangue , Masculino , Obesidade/sangue , Análise de Regressão , Fatores de Risco , Fumar , Magreza
11.
J Clin Endocrinol Metab ; 88(4): 1780-4, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12679473

RESUMO

Soluble CD14 (sCD14), detectable at high concentrations constitutively present in the circulation, plays a key role in the neutralization of lipopolysaccharide, one of the most potent biologic response modifiers currently recognized and involved in the regulation of the inflammatory cascade. We tested whether circulating sCD14 was linked to inflammatory parameters and to insulin resistance in apparently healthy subjects. Serum sCD14 concentration did not significantly correlate with body mass index (BMI), waist to hip ratio, systolic or diastolic blood pressure, serum glucose, fasting insulin, fasting insulin resistance index [homeostasis model assessment (HOMA)], or serum uric acid among 123 subjects. The association between sCD14 and fasting insulin (r = -0.19, P = 0.08) and between sCD14 and HOMA (r = -0.21, P = 0.06) tended toward statistical significance among men. Unexpectedly, sCD14 correlated positively with fasting triglycerides (TG) in all the subjects (r = 0.22, P = 0.014), and this association was most significant in men (r = 0.34, P = 0.002). After controlling for TG, the relationships between sCD14 levels and fasting insulin (r = -0.25, P = 0.029), HOMA (r = -0.28, P = 0.014), and uric acid (r = -0.30, P = 0.006) were significant in men. Among nonsmoking men (n = 44), sCD14 significantly correlated with waist diameter (r = -0.30, P = 0.03), diastolic blood pressure (r = -0.34, P = 0.022), and HOMA (r = -0.30, P = 0.03). In a multiple linear regression analysis, BMI (P < 0.00001), TG (P = 0.003), and sCD14 (P = 0.04) (but not age, sex, waist, or smoking status) independently contributed to 26% of HOMA variance. A polymorphism of the CD14 gene, a C-to-T transition at bp -159 from the major transcription start site, seems to play a significant role in regulating serum sCD14 levels. In a subsample of 33 healthy subjects, carriers of the T allele were similar (in age, sex, BMI, fat mass, waist to hip ratio, blood pressure, and fasting glucose and insulin levels) to C/C homozygotes. In the former, integrated area under the curve for serum glucose concentrations after an oral glucose tolerance test was significantly lower (P = 0.02), and insulin sensitivity (SI) index (minimal model analysis) significantly higher (P = 0.036), than in C/C homozygotes. Among 32 type 2 diabetic subjects, carriers of the T allele also showed a significantly higher SI index (P = 0.03) and had significantly lower C-reactive protein (P = 0.03) and lower circulating soluble intercellular adhesion molecule-1 concentrations (P = 0.01) than did C/C homozygotes. To our knowledge, this is the first study to suggest an effect of a genetic polymorphism on both SI (healthy subjects and type 2 diabetic patients) and endothelial dysfunction (sICAM-1 levels) in type 2 diabetes mellitus.


Assuntos
Inflamação/fisiopatologia , Resistência à Insulina , Receptores de Lipopolissacarídeos/fisiologia , Adulto , Glicemia/análise , Pressão Sanguínea , Constituição Corporal , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Endotélio Vascular/fisiopatologia , Jejum , Feminino , Genótipo , Teste de Tolerância a Glucose , Homeostase , Humanos , Insulina/sangue , Molécula 1 de Adesão Intercelular/sangue , Receptores de Lipopolissacarídeos/sangue , Receptores de Lipopolissacarídeos/genética , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Regiões Promotoras Genéticas , Caracteres Sexuais , Fumar
12.
J Clin Endocrinol Metab ; 87(10): 4686-90, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12364459

RESUMO

It has been suggested that a low grade inflammatory state could predispose for developing insulin resistance and contribute to the development of obesity and type 2 diabetes. Corticosteroid-binding globulin (CBG), the main plasma protein transport for cortisol, has been shown to be negatively regulated by insulin and IL-6, at least in vitro, suggesting that insulin resistance and inflammation may both contribute to decreasing CBG levels. In the present study we measured CBG concentrations in a human healthy population and investigated the relationships of CBG with anthropometric and biochemical markers for inflammation and/or insulin resistance. The data showed that the mean serum CBG level was significantly lower in males (n = 151) than in females (n = 113; 32.5 +/- 9.1 vs. 39.2 +/- 13.9 mg/liter; P < 0.0001). In both sexes serum CBG levels were correlated negatively with age (r = -0.12; P = 0.04), body mass index (r = -0.31; P < 0.0001), waist to hip ratio (WHR; r = -0.39; P < 0.0001), systolic (r = -0.15; P < 0.01) and diastolic (r = -0.15; P = 0.01) blood pressures, and HOMA, an index of insulin resistance (r = -0.12; P = 0.04). In addition, the CBG concentration was negatively associated with serum IL-6 concentrations (r = -0.23; P = 0.017) and with the soluble fraction of TNFalpha receptors, soluble TNF receptor 1 (sTNFR1; r = -0.35; P < 0.0001), and sTNFR2 (r = -0.56; P < 0.0001) in women. A stepwise regression analysis using CBG as an independent variable showed that sex (P < 0.00001), body mass index (P = 0.0002), and HOMA (P = 0.0005), but not systolic blood pressure, diastolic blood pressure, IL-6, sTNFR1, or sTNFR2, constituted significant independent factors that explained 21% of the CBG variance (14%, 2%, and 5%, respectively). In a subsample of 120 men and 68 women, fasting serum free cortisol (calculated as the ratio fasting cortisol/CBG) was significantly associated with WHR (r = 0.24; P = 0.001), systolic (r = 0.18; P = 0.01) and diastolic (r = 0.19; P = 0.007) blood pressures, and HOMA value (r = 0.20; P = 0.005), but not with BMI or age. BMI (P < 0.0001), free cortisol (P = 0.003), and CBG (P = 0.009), but not WHR and age, contributed to 20%, 6%, and 8%, respectively, of HOMA variance in women in a multiple regression analysis. In this model only BMI (P < 0.0001) independently contributed to HOMA variance in men. These findings support the hypothesis that the CBG level is an interesting indicator for both insulin resistance and low grade inflammation. Whether the decrease in CBG levels is genetic by nature or directly associated to increased insulin and/or IL-6 merits further investigation. Nevertheless, because CBG has been shown to be expressed by the adipose tissue, decreased CBG could create locally increased cortisol disposal, with no change in circulating cortisol, and facilitate fat accumulation, insulin resistance, and type 2 diabetes.


Assuntos
Resistência à Insulina , Transcortina/análise , Adulto , Antígenos CD/sangue , Pressão Sanguínea , Composição Corporal , Constituição Corporal , Índice de Massa Corporal , Jejum , Feminino , Homeostase , Humanos , Hidrocortisona/sangue , Inflamação/sangue , Insulina/sangue , Interleucina-6/sangue , Masculino , Pessoa de Meia-Idade , Receptores do Fator de Necrose Tumoral/sangue , Receptores Tipo I de Fatores de Necrose Tumoral , Receptores Tipo II do Fator de Necrose Tumoral , Análise de Regressão , Caracteres Sexuais
13.
Am J Physiol Endocrinol Metab ; 282(4): E952-9, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11882518

RESUMO

Tumor necrosis factor-alpha (TNF-alpha) is increasingly recognized as a key component in the development of insulin resistance and increased blood pressure. In a sample of 368 individuals, the ratio of soluble TNF-alpha receptors (sTNFR2/sTNFR1) correlated positively with systolic and diastolic blood pressure (P < 0.01). This ratio was significantly greater in type 2 diabetic subjects (DM-2) than in type 1 diabetic patients and was greater than in control nondiabetic subjects (P < 0.00001). The TNF-alpha receptor 1 (TNFR1) density in peripheral blood monocytes was similar in DM-2 patients and in nondiabetic subjects. After phorbol 12-myristate 13-acetate, TNFR1 shedding was significantly decreased in DM-2 compared with control subjects, and it was directly associated with insulin sensitivity (r = 0.54, P = 0.03). Serum sTNFR1 concentration was also linked to the vasodilatory response to glyceryltrinitrate (P = 0.01). Conversely, TNF-alpha receptor 2 shedding was negatively associated with insulin sensitivity (r = -0.54, P = 0.03), whereas shedding of L-selectin showed no significant association. After exercise-induced lowering of blood pressure, a parallel decrease in sTNFR2/sTNFR1 was observed in DM-2 patients. Our findings suggest that insulin resistance and blood pressure are linked to altered shedding of TNF-alpha receptors in DM-2. The latter seems reversible and is not genetically determined.


Assuntos
Antígenos CD/sangue , Pressão Sanguínea , Diabetes Mellitus Tipo 2/fisiopatologia , Insulina/farmacologia , Receptores do Fator de Necrose Tumoral/sangue , Adulto , Idoso , Índice de Massa Corporal , Diabetes Mellitus Tipo 1/fisiopatologia , Feminino , Citometria de Fluxo , Humanos , Resistência à Insulina , Masculino , Pessoa de Meia-Idade , Monócitos/química , Nitroglicerina/farmacologia , Receptores Tipo I de Fatores de Necrose Tumoral , Receptores Tipo II do Fator de Necrose Tumoral , Solubilidade , Acetato de Tetradecanoilforbol/farmacologia , Vasodilatação/efeitos dos fármacos
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