IS HOMEOSTASIS MODEL ASSESSMENT FOR INSULIN RESISTANCE >2.5 A DISTINGUISHED CRITERIA FOR METABOLIC DYSFUNCTION-ASSOCIATED FATTY LIVER DISEASE IDENTIFICATION?

BACKGROUND: Insulin resistance (IR), assessed by different criteria, is an important factor in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). More recently with the characterization of this metabolic dysfunction-associated fatty liver disease (MAFLD), one of the proposed criteria for this diagnosis has been the determination of the homeostasis model assessment-insulin resistance (HOMA-IR). OBJECTIVE: The purpose of this study was to evaluate the relationship of HOMA-IR>2.5 with clinical, metabolic, biochemical and histological data obtained in non-diabetic patients diagnosed with NAFLD by liver biopsy. METHODS: Cross-sectional, retrospective study was carried out with data from 174 adult individuals of both genders with non-diabetics NAFLD, without obvious signs of portal hypertension. The body mass index (BMI) was classified according to the World Health Organization (1998), and the metabolic syndrome by the criteria of NCEP-ATP-III. Biochemical tests were evaluated using an automated method and insulinemia through immunofluorometric assay. Histological findings were classified according to Kleiner et al. (2005). RESULTS: The mean age of the studied population was 53.6±11.2 years, with 60.3% being female. The average BMI was 30.3 kg/m2 and 75.9% of the patients had increased waist circumference. Among evaluated metabolic parameters, there was a higher prevalence of metabolic syndrome (MS) in patients with HOMA-IR>2.5, with no statistical difference in relation to BMI between studied groups. Values of liver enzymes and serum ferritin were significantly higher in patients with this marker of IR, who had a higher prevalence of non-alcoholic steatohepatitis (NASH) and advanced liver fibrosis. In the multivariate analysis, the clinical diagnosis of MS, hyperferritinemia and the presence of NASH in the liver biopsy were the factors independently associated with the presence of altered HOMA-IR. CONCLUSION: HOMA-IR values >2.5 identify patients with NAFLD with distinct clinical and metabolic characteristics and with a greater potential for disease progression, which validates this parameter in the identification of patients with MAFLD.

IS HOMEOSTASIS MODEL ASSESSMENT FOR INSULIN RESISTANCE >2.5 A DISTINGUISHED CRITERIA FOR METABOLIC DYSFUNCTION-ASSOCIATED FATTY LIVER DISEASE IDENTIFICATION? / O modelo de avaliação da homeostase para resistência à insulina >2,5 é um critério distinto para a identificação da doença hepática gordurosa associada à disfunção metabólica?

ABSTRACT Background Insulin resistance (IR), assessed by different criteria, is an important factor in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). More recently with the characterization of this metabolic dysfunction-associated fatty liver disease (MAFLD), one of the proposed criteria for this diagnosis has been the determination of the homeostasis model assessment-insulin resistance (HOMA-IR). Objective: The purpose of this study was to evaluate the relationship of HOMA-IR>2.5 with clinical, metabolic, biochemical and histological data obtained in non-diabetic patients diagnosed with NAFLD by liver biopsy. Methods: Cross-sectional, retrospective study was carried out with data from 174 adult individuals of both genders with non-diabetics NAFLD, without obvious signs of portal hypertension. The body mass index (BMI) was classified according to the World Health Organization (1998), and the metabolic syndrome by the criteria of NCEP-ATP-III. Biochemical tests were evaluated using an automated method and insulinemia through immunofluorometric assay. Histological findings were classified according to Kleiner et al. (2005). Results: The mean age of the studied population was 53.6±11.2 years, with 60.3% being female. The average BMI was 30.3 kg/m2 and 75.9% of the patients had increased waist circumference. Among evaluated metabolic parameters, there was a higher prevalence of metabolic syndrome (MS) in patients with HOMA-IR>2.5, with no statistical difference in relation to BMI between studied groups. Values of liver enzymes and serum ferritin were significantly higher in patients with this marker of IR, who had a higher prevalence of non-alcoholic steatohepatitis (NASH) and advanced liver fibrosis. In the multivariate analysis, the clinical diagnosis of MS, hyperferritinemia and the presence of NASH in the liver biopsy were the factors independently associated with the presence of altered HOMA-IR. Conclusion: HOMA-IR values >2.5 identify patients with NAFLD with distinct clinical and metabolic characteristics and with a greater potential for disease progression, which validates this parameter in the identification of patients with MAFLD.

RESUMO Contexto A resistência à insulina (RI), avaliada por diferentes critérios, é um fator importante na patogênese da doença hepática gordurosa não alcoólica (DHGNA). Mas, recentemente, com a caracterização desta disfunção metabólica associada com a doença hepática gordurosa (DGH), um dos critérios propostos para este diagnóstico tem sido a determinação do modelo de avaliação da homeostase-resistência à insulina (HOMA-IR). Objetivo: O objetivo deste estudo foi avaliar a relação do HOMA-IR> 2,5 com dados clínicos, metabólicos, bioquímicos e histológicos obtidos em pacientes não diabéticos diagnosticados com DHGNA por biópsia hepática. Métodos Estudo transversal, retrospectivo, com dados de 174 indivíduos adultos de ambos os sexos com DHGNA não-diabética, sem sinais evidentes de hipertensão portal. O índice de massa corporal (IMC) foi classificado de acordo com a Organização Mundial da Saúde (1998) e a síndrome metabólica pelos critérios do NCEP-ATP-III. Os exames bioquímicos foram avaliados pelo método automatizado e a insulinemia por imunofluorometria. Os achados histológicos foram classificados de acordo com Kleiner et al. (2005). Resultados: A média de idade da população estudada foi de 53,6±11,2 anos, sendo 60,3% do sexo feminino. O IMC médio foi de 30,3 kg/m2 e 75,9% dos pacientes apresentaram circunferência da cintura aumentada. Entre os parâmetros metabólicos avaliados, houve maior prevalência de síndrome metabólica (SM) em pacientes com HOMA-IR >2,5, sem diferença estatística em relação ao IMC entre os grupos estudados. Os valores das enzimas hepáticas e da ferritina sérica foram significativamente maiores nos pacientes com este marcador de RI, que apresentaram maior prevalência de esteato-hepatite não alcoólica (EHNA) e fibrose hepática avançada. Na análise multivariada, o diagnóstico clínico de SM, hiperferritinemia e a presença de EHNA na biópsia hepática foram os fatores independentemente associados à presença de HOMA-IR alterado. Conclusão: Valores de HOMA-IR >2,5 identificam pacientes com DHGNA com características clínicas e metabólicas distintas e com maior potencial de progressão da doença, o que valida esse parâmetro na identificação de pacientes com DHG.

OBSTRUCTIVE SLEEP APNEA SYNDROME RISK IN PATIENTS WITH NON-ALCOHOLIC FATTY LIVER DISEASE IS ASSOCIATED WITH OBESITY AND PRESENCE OF NASH.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common form of liver disease and refers to a wide spectrum of histological abnormalities ranging from simple steatosis (HE) to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis and hepatocellular carcinoma. OBJECTIVE: To assess the risk of obstructive sleep apnea syndrome (OSAS) and relating it to demographic, biochemical and histological data in patients with non-alcoholic fatty liver disease. METHODS: Cross-sectional cohort study in individuals with biopsy-proven NAFLD. Anthropometric and biochemical parameters, presence of metabolic syndrome and insulin resistance were evaluated. The Berlin Questionnaire (BQ) was applied to assess the risk of apnea and a food record was requested. Based on the BQ, participants were classified as high or low risk for OSAS. In the correlation of sleep apnea with the severity of NAFLD, presence of nonalcoholic steatohepatitis (NASH) and the degree of liver fibrosis were evaluated. Statistical analysis used the chi-square test, Student's t and bivariate logistic regression; values were expressed as mean ± standard deviation. This research project was approved by the Ethics Committee. RESULTS: Regarding the parameters evaluated, significant differences were observed between the groups in terms of body mass index (BMI), waist and neck circumference. In the histological evaluation, patients classified as high risk were more likely to have fibrosis and NASH. In bivariate regression, the BMI, presence of fibrosis and steatohepatitis in the biopsy were independently associated with an elevated risk of the syndrome. CONCLUSION: A high prevalence of risk for OSAS was observed in the studied group, with a higher risk being independently associated with BMI and presence of steatohepatitis, suggesting that it is a factor associated with the severity of the disease.

P2X7 receptor-nitric oxide interaction mediates apoptosis in mouse immortalized mesangial cells exposed to high glucose / A interação do receptor P2X7 com o óxido nítrico medeia a apoptose em células mesangiais imortalizadas de camundongos expostas a níveis elevados de glicose

Abstract Introduction: Diabetes mellitus (DM) is a chronic disease characterized by hyperglycemia that leads to diabetic nephropathy (DN). We showed that P2X7, a purinergic receptor, was highly expressed in DM; however, when oxidative stress was controlled, renal NO recovered, and the activation of this receptor remained significantly reduced. The aim of this study was to assess the influence of NO on the P2X7 and apoptosis in mouse immortalized mesangial cells (MiMC) cultured in high glucose (HG) medium. Methods: MiMCs were cultured with DMEM and exposed to normal glucose (NG), mannitol (MA), or HG. Cell viability was assessed by an automated counter. Supernatants were collected for NO quantification, and proteins were extracted for analysis of NO synthases (iNOS and eNOS), caspase-3, and P2X7. Results: Cell viability remained above 90% in all groups. There was a significant increase in the proliferation of cells in HG compared to MA and NG. NO, iNOS, caspase-3, and P2X7 were significantly increased in HG compared to NG and MA, with no changes in eNOS. We observed that there was a strong and significant correlation between P2X7 and NO. Discussion: The main finding was that the production of NO by iNOS was positively correlated with the increase of P2X7 in MCs under HG conditions, showing that there is a common stimulus between them and that NO interacts with the P2X7 pathway, contributing to apoptosis in experimental DM. These findings could be relevant to studies of therapeutic targets for the prevention and/or treatment of hyperglycemia-induced kidney damage to delay DN progression.

Resumo Introdução: Diabetes mellitus (DM) é uma doença crônica caracterizada por hiperglicemia levando à nefropatia diabética (ND). Mostramos que P2X7, um receptor purinérgico, foi altamente expresso na DM; entretanto, quando o estresse oxidativo foi controlado, o NO renal recuperou-se, e a ativação deste receptor permaneceu significativamente reduzida. Este estudo objetivou avaliar a influência do NO no P2X7 e a apoptose em células mesangiais imortalizadas de camundongos (CMiC) cultivadas em meio de glicose elevada (GE). Métodos: CMiCs foram cultivadas em meio DMEM e expostas à glicose normal (GN), manitol (MA), ou GE. A viabilidade celular foi avaliada por contador automático. Sobrenadantes foram coletados para quantificação de NO, e foram extraídas proteínas para análise de NO sintases (iNOS e eNOS), caspase-3, e P2X7. Resultados: A viabilidade celular permaneceu acima de 90% em todos os grupos. Houve aumento significativo na proliferação de células na GE comparado com MA e GN. NO, iNOS, caspase-3 e P2X7 foram significativamente aumentados na GE comparados com GN e MA, sem alterações na eNOS. Observamos que houve correlação forte e significativa entre P2X7 e NO. Discussão: O principal achado foi que a produção de NO pela iNOS foi positivamente correlacionada com aumento de P2X7 em CMs sob condições de GE, mostrando que existe um estímulo comum entre eles e que o NO interage com a via do P2X7, contribuindo para apoptose na DM experimental. Estes achados podem ser relevantes para estudos de alvos terapêuticos para a prevenção e/ou tratamento de danos renais induzidos por hiperglicemia para retardar a progressão da ND.

O risco de síndrome de apneia obstrutiva do sono em pacientes com doença hepática gordurosa não alcoólica está associado à obesidade e à presença de NASH / Obstructive sleep apnea syndrome risk in patients with non-alcoholic fatty liver disease is associated with obesity and presence of nash

ABSTRACT Background: Non-alcoholic fatty liver disease (NAFLD) is the most common form of liver disease and refers to a wide spectrum of histological abnormalities ranging from simple steatosis (HE) to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis and hepatocellular carcinoma. Objective: To assess the risk of obstructive sleep apnea syndrome (OSAS) and relating it to demographic, biochemical and histological data in patients with non-alcoholic fatty liver disease. Methods: Cross-sectional cohort study in individuals with biopsy-proven NAFLD. Anthropometric and biochemical parameters, presence of metabolic syndrome and insulin resistance were evaluated. The Berlin Questionnaire (BQ) was applied to assess the risk of apnea and a food record was requested. Based on the BQ, participants were classified as high or low risk for OSAS. In the correlation of sleep apnea with the severity of NAFLD, presence of nonalcoholic steatohepatitis (NASH) and the degree of liver fibrosis were evaluated. Statistical analysis used the chi-square test, Student's t and bivariate logistic regression; values were expressed as mean ± standard deviation. This research project was approved by the Ethics Committee. Results: Regarding the parameters evaluated, significant differences were observed between the groups in terms of body mass index (BMI), waist and neck circumference. In the histological evaluation, patients classified as high risk were more likely to have fibrosis and NASH. In bivariate regression, the BMI, presence of fibrosis and steatohepatitis in the biopsy were independently associated with an elevated risk of the syndrome. Conclusion: A high prevalence of risk for OSAS was observed in the studied group, with a higher risk being independently associated with BMI and presence of steatohepatitis, suggesting that it is a factor associated with the severity of the disease.

RESUMO Contexto: A doença hepática gordurosa não alcoólica (DHGNA) é a forma mais comum de doença hepática e se refere a um amplo espectro de anormalidades histológicas que variam de esteatose simples a esteato-hepatite não alcoólica (EHNA), fibrose, cirrose e carcinoma hepatocelular. Objetivo: Avaliar o risco de síndrome da apneia obstrutiva do sono (SAOS) e relacioná-lo com dados demográficos, bioquímicos e histológicos em pacientes com doença hepática gordurosa não alcoólica. Métodos: Estudo de coorte transversal em indivíduos com DHGNA comprovada por biópsia. Foram avaliados parâmetros antropométricos e bioquímicos, presença de síndrome metabólica e resistência à insulina. O Questionário de Berlim (QB) foi aplicado para avaliar o risco de apneia e um registro alimentar foi solicitado. Com base no QB, os participantes foram classificados como de alto ou baixo risco para SAOS. Na correlação da apneia do sono com a gravidade da DHGNA, avaliou-se a presença de EHNA e o grau de fibrose hepática. Na análise estatística foram utilizados: o teste qui-quadrado, t de Student e regressão logística bivariada; os valores foram expressos como média ± desvio padrão. Este projeto de pesquisa foi aprovado pelo Comitê de Ética. Resultados: Em relação aos parâmetros avaliados, foram observadas diferenças significativas entre os grupos em relação ao índice de massa corporal (IMC), cintura e circunferência do pescoço. Na avaliação histológica, os pacientes classificados como de alto risco tiveram maior chance de apresentar fibrose e EHNA. Na regressão bivariada, o IMC, a presença de fibrose e esteato-hepatite na biópsia foram independentemente associados a um risco elevado da síndrome. Conclusão: Observou-se alta prevalência de risco para SAOS no grupo estudado, sendo o maior risco associado de forma independente ao IMC e à presença de esteato-hepatite, sugerindo que seja um fator associado à gravidade da doença.

P2X7 receptor-nitric oxide interaction mediates apoptosis in mouse immortalized mesangial cells exposed to high glucose.

INTRODUCTION: Diabetes mellitus (DM) is a chronic disease characterized by hyperglycemia that leads to diabetic nephropathy (DN). We showed that P2X7, a purinergic receptor, was highly expressed in DM; however, when oxidative stress was controlled, renal NO recovered, and the activation of this receptor remained significantly reduced. The aim of this study was to assess the influence of NO on the P2X7 and apoptosis in mouse immortalized mesangial cells (MiMC) cultured in high glucose (HG) medium. METHODS: MiMCs were cultured with DMEM and exposed to normal glucose (NG), mannitol (MA), or HG. Cell viability was assessed by an automated counter. Supernatants were collected for NO quantification, and proteins were extracted for analysis of NO synthases (iNOS and eNOS), caspase-3, and P2X7. RESULTS: Cell viability remained above 90% in all groups. There was a significant increase in the proliferation of cells in HG compared to MA and NG. NO, iNOS, caspase-3, and P2X7 were significantly increased in HG compared to NG and MA, with no changes in eNOS. We observed that there was a strong and significant correlation between P2X7 and NO. DISCUSSION: The main finding was that the production of NO by iNOS was positively correlated with the increase of P2X7 in MCs under HG conditions, showing that there is a common stimulus between them and that NO interacts with the P2X7 pathway, contributing to apoptosis in experimental DM. These findings could be relevant to studies of therapeutic targets for the prevention and/or treatment of hyperglycemia-induced kidney damage to delay DN progression.

Relationship between short and long-term glycemic variability and oxidative stress in type 1 diabetes mellitus under daily life insulin treatment.

OBJECTIVE: The purpose of this study was to investigate the heterogeneity of the association between glycemic variability and oxidative stress markers in T1DM patients under daily life insulin treatment. METHODS: We studied, in a cross-sectional analysis, 76 T1DM patients without clinical chronic diabetes complications and 22 healthy individuals. Were evaluated the short-term glycemic variability (STGV), long-term glycemic variability (LTGV), oxidative stress markers [8-isoprostaglandin-F2α (Ur-8-iso-PGF2α), nitric oxide (NO), thiobarbituric acid reactive substances (TBARS) and erythrocytes reduced/oxidized glutathione (GSH/GSSG)] and biochemical dosages (glycaemia, HbA1c, lipidogram, albuminuria). RESULTS: Plasmatic NO was positively associated with LTGV (last year average of HbA1c) (8.7 ± 1.6% or 71 ± 18 mmol) (rS: 0.278; p: 0.042). Plasmatic TBARS, erythrocytes GSH/GSSH and Ur-8-iso-PGF-2α didn't show correlation with glycemic variability. GSH/GSSG was inversely correlated with LDL-cholesterol (rS: - 0.417; p: 0.047) and triglycerides (rS: -0.521; p: 0.013). Albuminuria was positive correlated with age (rS: 0.340; p: 0.002), plasmatic NO (rS: 0.267; p 0.049) and TBARS (rS: 0.327; p: 0.015). CONCLUSION: In daily life insulin treatment, young T1DM patients have higher plasmatic NO than healthy subjects. However, the correlation between glycemic variability and oxidative stress markers is heterogeneous. Lipid profile and albuminuria are associated with different oxidative stress markers. These data collaborate to explain the controversial results in this issue.

Relationship between short and long-term glycemic variability and oxidative stress in type 1 diabetes mellitus under daily life insulin treatment

ABSTRACT Objectives: The purpose of this study was to investigate the heterogeneity of the association between glycemic variability and oxidative stress markers in T1DM patients under daily life insulin treatment. Subjects and methods: We studied, in a cross-sectional analysis, 76 T1DM patients without clinical chronic diabetes complications and 22 healthy individuals. Were evaluated the short-term glycemic variability (STGV), long-term glycemic variability (LTGV), oxidative stress markers [8-isoprostaglandin-F2α (Ur-8-iso-PGF2α), nitric oxide (NO), thiobarbituric acid reactive substances (TBARS) and erythrocytes reduced/oxidized glutathione (GSH/GSSG)] and biochemical dosages (glycaemia, HbA1c, lipidogram, albuminuria). Results: Plasmatic NO was positively associated with LTGV (last year average of HbA1c) (8.7 ± 1.6% or 71 ± 18 mmol) (rS: 0.278; p: 0.042). Plasmatic TBARS, erythrocytes GSH/GSSH and Ur-8-iso-PGF-2α didn't show correlation with glycemic variability. GSH/GSSG was inversely correlated with LDL-cholesterol (rS: - 0.417; p: 0.047) and triglycerides (rS: −0.521; p: 0.013). Albuminuria was positive correlated with age (rS: 0.340; p: 0.002), plasmatic NO (rS: 0.267; p 0.049) and TBARS (rS: 0.327; p: 0.015). Conclusion: In daily life insulin treatment, young T1DM patients have higher plasmatic NO than healthy subjects. However, the correlation between glycemic variability and oxidative stress markers is heterogeneous. Lipid profile and albuminuria are associated with different oxidative stress markers. These data collaborate to explain the controversial results in this issue.

Assessment of fructose overload in the metabolic profile and oxidative/nitrosative stress in the kidney of senescent female rats.

The aging process is a complex phenomenon that leads the body to several changes, affecting its integrity and resulting in chronic pathologies, which compromises health and quality of life of elderly people. Animals supplemented with fructose have been used as an experimental model for induction of insulin resistance. The objective of this study was to evaluate the metabolic effects and the levels of oxidative/nitrosative stress in the kidney of senescent rats with a high fructose intake. The animals were allocated into 4 groups: young control (Y), aged control (A), young fructose (YF) and aged fructose (AF). Groups Y and A received water and groups YF and AF received fructose (100g/L) in the water, both ad libitum. After 12weeks of high fructose intake, the animals were sacrificed to collect their kidneys, blood and the thoracic aorta. The results are presented as mean±SE, analyzed by the One-Way ANOVA test with Newman-Keuls post-test; significant at p<0.05. The fructose overload caused metabolic dysfunctions and insulin resistance, confirming the efficacy of the chosen model. In this study, we observed a body weight gain in the studied groups (except in the elderly fructose group), and an increase in general caloric intake, diuresis and adipose tissue; insulin resistance, increased fasting glucose, triglycerides and cholesterol in the fructose groups. We also found a loss of renal function, increased oxidative/nitrosative stress and inflammation, and a reduction of antioxidants and a lower vasodepressor response in the studied groups, especially those who consumed fructose. In summary, our data showed that aging or high fructose intake contributed to the increase of oxidative/nitrosative stress in animals, demonstrating that at the dose and the period of fructose treatment utilized in this study, fructose was not able to aggravate several aspects which were already altered by aging. We believe that the high fructose intake simulates most of the effects of aging, and this understanding would be useful to prevent or minimize many of the alterations caused by this condition.

Short-term l-arginine supplementation attenuates elevation of interleukin 6 level after resistance exercise in overweight men.

BACKGROUND AND AIM: l-Arginine (l-arg) supplementation and resistance exercise can induce changes in inflammatory and anti-inflammatory cytokines; however, it has not been investigated in obese hypertensive men. This study examines the effects of short-term l-arg supplementation and acute resistance exercise (AREX) on cytokine levels in obese hypertensive men. METHODS: Eight obese hypertensive men aged 46 ± 6 yrs. with an average body weight of 92.56 ± 9.9 kg and a BMI of 31.68 ± 2.18 kg/m2 participated in a randomized, double-blinded, crossover study. The patients were distributed into exercise groups based on the type of supplementation (6 g/day of placebo or l-arg for 7 days). Supplementation periods were separated by a seven-day washout period. The AREX regimen consisted of eight exercises with an exercise intensity of 60% of 1 repetition maximum. The interleukins IL-1ra, IL-6, and IL-10 and the IL-6/IL10 ratio were determined at rest, immediately after exercise and 1 h after exercise sessions. RESULTS: IL-1ra levels exhibited a significant difference both immediately and 1 h after exercise when the l-arg and placebo groups were compared (P < 0.05). IL-6 levels increased significantly after exercise in the placebo group compared with the l-arg group (P < 0.05). The placebo group showed a decrease in the IL-10 levels 1 h after exercise compared with resting levels (P < 0.05). The IL-6/IL-10 ratio showed a statistically significant increase in the placebo group after exercise compared to the l-arg group (P < 0.05). CONCLUSIONS: LARG supplementation attenuates the cytokine increase after AREX, in particular peak IL-6 levels decrease and exercise induced decreases in IL-10 levels are attenuated.