This cross-sectional investigation of 6,931 U.S. adults examined the relationship between sitting time and insulin resistance. A primary objective was to evaluate how this relationship was mediated by the following variables: age, sex, race, year of assessment, cigarette smoking, physical activity, body mass index (BMI), and waist circumference. Self-reported sitting time, measured in minutes per day, was the exposure variable. Insulin resistance, indexed by the homeostatic model assessment of insulin resistance (HOMA-IR), was the outcome variable. Data were used from the 2011-2018 National Health and Nutrition Examination Survey (NHANES). Results showed a strong, positive association between sitting time and insulin resistance after adjusting for age, sex, race, and year of assessment (F = 13.3, p < 0.0001). Further controlling for cigarette smoking and physical activity did not alter the significance of the relationship. Adding BMI to the demographic covariates weakened the relationship but did not nullify it; however, the association was no longer significant after adjusting for differences in waist circumference (F = 1.39, p = 0.2563). Overall, waist circumference was a powerful mediating variable between sitting time and insulin resistance.

INTRODUÇÃO: O vírus da hepatite C (VHC) é a maior causa de hepatite crônica em todo o mundo. É um vírus hepatotrópico e linfotrópico que está associado a diversas manifestações extra-hepática que tem sido associada à infecção pelo VHC. A presença de RI nos pacientes com hepatite C está implicada em pior resposta ao tratamento antiviral com interferon, na progressão da fibrose hepática, na instalação da esteatose e maior risco de carcinoma hepatocelular. O método mais comumente utilizado para o diagnóstico da RI é o índice HOMA-IR (homeostasis model assessment). OBJETIVOS: Avaliar a frequência de resistência à insulina e os fatores associados em pacientes infectados com o vírus da hepatite C. MÉTODOS: Incluídos 202 pacientes infectados pelo VHC e não diabéticos em estudo transversal realizado no ambulatório de hepatites virais do DMIP- HCFMUSP de março de 2010 a fevereiro de 2012. Foram avaliados dados demográficos, antropométricos, bioquímicos (incluindo HOMA-IR) e dados de estudo anatomopatológico do fígado. Os pacientes foram divididos em dois grupos: resistentes à insulina (HOMA-IR >= 3) e não resistentes à insulina (HOMA-IR < 3). Esses grupos foram submetidos à análise uni e multivariada (regressão logística), para ajuste dos fatores de confusão. RESULTADOS: Dos pacientes incluídos no estudo, 87 (43,1%) eram do sexo masculino e 115 (56,9%) do sexo feminino. A média de idade foi de 49,65 anos. O fator de risco mais frequente para aquisição da VHC foi a transfusão sanguínea. O genótipo 1 foi o mais frequente (77,2%), seguido pelo genótipo 3 (18,3%). Trinta e três pacientes (16,3%) apresentaram grau de fibrose avançado (3 e 4). Noventa e cinco pacientes (47%) apresentaram algum grau de esteatose. Cinquenta e dois pacientes (25,74%) apresentaram HOMA-IR >= 3. Entre os pacientes infectados pelo VHC genótipo 1 (n = 156), encontramos 41 pacientes (26,3%) com resistência à insulina; entre os pacientes com genótipo 3 (n = 37), encontramos 10 pacientes (27,0%) com HOMA-IR >= 3. Encontramos associação positiva entre índice de massa corpórea maior ou igual a 25 kg/m2, presença de esteatose hepática e presença de resistência à insulina. Atividade necroinflamatória e esteatose hepática foram fatores independentes associados à fibrose hepática. CONCLUSÕES: Considerando a prevalência e as implicações clínicas da resistência à insulina, são necessários mais estudos para se conhecer a melhor abordagem para os pacientes resistentes à insulina nos pacientes com hepatite C crônica / BACKGROUND: Hepatitis C virus (HCV) is the leading cause of chronic hepatitis worldwide. It is a hepatotropic and lymphotropic virus that is associated with several extrahepatic manifestations. Insulin resistance (IR) is an extrahepatic manifestations that have been associated with HCV infection. The presence of IR in patients with hepatitis C is implicated in poor response to antiviral therapy with interferon, in the progression of liver fibrosis, the installation of steatosis and increased risk of hepatocellular carcinoma. The most commonly used method for the diagnosis of IR is the HOMA-IR (homeostasis model assessment). OBJECTIVES: To assess the frequency of insulin resistance and associated factors in patients infected with hepatitis C. METHODS: The sample comprised 202 non-diabetic patients infected with HCV and non-diabetic study performed in the outpatient clinic of the viral hepatitis DMIP-HCFMUSP between March 2010 and December 2011. We evaluated demographic, anthropometric, biochemical (including HOMA-IR) data and histological features of of the liver. The patients were divided into two groups: insulin resistant (HOMA-IR >=3) and non-insulin resistant (HOMA-IR < 3). These groups were subjected to univariate and multivariate analysis (logistic regression) to adjust for confounding factors. RESULTS: Of the patients studied, 87 (43.1%) were male and 115 (56.9%) females. The mean age was 49.65 years. The most common risk factor for acquisition of HCV was blood transfusion. Genotype 1 was the most frequent (77.2%), followed by genotype 3 (18.3%). Thirty-three patients (16.3%) had advanced fibrosis (3 and 4). Ninety-five patients (47%) had some degree of steatosis. Fifty-two patients (25.74%) had HOMA-IR >= 3. CONCLUSIONS: Among patients infected with HCV genotype 1 (n = 156), we found 41 patients (26.3%) with insulin resistance, among patients with genotype 3 (n = 37), we found 10 patients (27.0% ) with HOMA-IR >= 3. We found a positive association between body mass index greater than or equal to 25 kg/m2, presence of hepatic steatosis and presence of insulin resistance. Necroinflammatory activity and hepatic steatosis were independent factors associated with liver fibrosis. CONCLUSIONS: Given the prevalence and clinical implications of insulin resistance, further studies are needed to know the best approach for insulin resistant patients with chronic hepatitis C

INTRODUÇÃO: O vírus da hepatite C (VHC) é a maior causa de hepatite crônica em todo o mundo. É um vírus hepatotrópico e linfotrópico que está associado a diversas manifestações extra-hepática que tem sido associada à infecção pelo VHC. A presença de RI nos pacientes com hepatite C está implicada em pior resposta ao tratamento antiviral com interferon, na progressão da fibrose hepática, na instalação da esteatose e maior risco de carcinoma hepatocelular. O método mais comumente utilizado para o diagnóstico da RI é o índice HOMA-IR (homeostasis model assessment). OBJETIVOS: Avaliar a frequência de resistência à insulina e os fatores associados em pacientes infectados com o vírus da hepatite C. MÉTODOS: Incluídos 202 pacientes infectados pelo VHC e não diabéticos em estudo transversal realizado no ambulatório de hepatites virais do DMIP- HCFMUSP de março de 2010 a fevereiro de 2012. Foram avaliados dados demográficos, antropométricos, bioquímicos (incluindo HOMA-IR) e dados de estudo anatomopatológico do fígado. Os pacientes foram divididos em dois grupos: resistentes à insulina (HOMA-IR >= 3) e não resistentes à insulina (HOMA-IR < 3). Esses grupos foram submetidos à análise uni e multivariada (regressão logística), para ajuste dos fatores de confusão. RESULTADOS: Dos pacientes incluídos no estudo, 87 (43,1%) eram do sexo masculino e 115 (56,9%) do sexo feminino. A média de idade foi de 49,65 anos. O fator de risco mais frequente para aquisição da VHC foi a transfusão sanguínea. O genótipo 1 foi o mais frequente (77,2%), seguido pelo genótipo 3 (18,3%). Trinta e três pacientes (16,3%) apresentaram grau de fibrose avançado (3 e 4). Noventa e cinco pacientes (47%) apresentaram algum grau de esteatose. Cinquenta e dois pacientes (25,74%) apresentaram HOMA-IR >= 3. Entre os pacientes infectados pelo VHC genótipo 1 (n = 156), encontramos 41 pacientes (26,3%) com resistência à insulina; entre os pacientes com genótipo 3 (n = 37), encontramos 10 pacientes (27,0%) com HOMA-IR >= 3. Encontramos associação positiva entre índice de massa corpórea maior ou igual a 25 kg/m2, presença de esteatose hepática e presença de resistência à insulina. Atividade necroinflamatória e esteatose hepática foram fatores independentes associados à fibrose hepática. CONCLUSÕES: Considerando a prevalência e as implicações clínicas da resistência à insulina, são necessários mais estudos para se conhecer a melhor abordagem para os pacientes resistentes à insulina nos pacientes com hepatite C crônica / BACKGROUND: Hepatitis C virus (HCV) is the leading cause of chronic hepatitis worldwide. It is a hepatotropic and lymphotropic virus that is associated with several extrahepatic manifestations. Insulin resistance (IR) is an extrahepatic manifestations that have been associated with HCV infection. The presence of IR in patients with hepatitis C is implicated in poor response to antiviral therapy with interferon, in the progression of liver fibrosis, the installation of steatosis and increased risk of hepatocellular carcinoma. The most commonly used method for the diagnosis of IR is the HOMA-IR (homeostasis model assessment). OBJECTIVES: To assess the frequency of insulin resistance and associated factors in patients infected with hepatitis C. METHODS: The sample comprised 202 non-diabetic patients infected with HCV and non-diabetic study performed in the outpatient clinic of the viral hepatitis DMIP-HCFMUSP between March 2010 and December 2011. We evaluated demographic, anthropometric, biochemical (including HOMA-IR) data and histological features of of the liver. The patients were divided into two groups: insulin resistant (HOMA-IR >=3) and non-insulin resistant (HOMA-IR < 3). These groups were subjected to univariate and multivariate analysis (logistic regression) to adjust for confounding factors. RESULTS: Of the patients studied, 87 (43.1%) were male and 115 (56.9%) females. The mean age was 49.65 years. The most common risk factor for acquisition of HCV was blood transfusion. Genotype 1 was the most frequent (77.2%), followed by genotype 3 (18.3%). Thirty-three patients (16.3%) had advanced fibrosis (3 and 4). Ninety-five patients (47%) had some degree of steatosis. Fifty-two patients (25.74%) had HOMA-IR >= 3. CONCLUSIONS: Among patients infected with HCV genotype 1 (n = 156), we found 41 patients (26.3%) with insulin resistance, among patients with genotype 3 (n = 37), we found 10 patients (27.0% ) with HOMA-IR >= 3. We found a positive association between body mass index greater than or equal to 25 kg/m2, presence of hepatic steatosis and presence of insulin resistance. Necroinflammatory activity and hepatic steatosis were independent factors associated with liver fibrosis. CONCLUSIONS: Given the prevalence and clinical implications of insulin resistance, further studies are needed to know the best approach for insulin resistant patients with chronic hepatitis C

Objective: To identify whether perceived stress is a risk-factor for higher cortisol levels and greater insulin resistance in Type 2 diabetic patients, using data from participants with and without diabetes in the National Survey of Midlife Development in the United States (MIDUS), specifically MIDUS II, Project 4. The following hypotheses were tested: (H1a) greater perceived stress would be associated with higher cortisol for Type 2 diabetic participants, (H1b) the perceived stress/cortisol relationship would be stronger for people with Type 2 diabetes than for those without it, (H2) greater perceived stress would be associated with higher Homeostatic Model Assessment-Insulin Resistance (HOMA-IR, insulin-resistance) for Type 2 diabetic participants, (H3a) subjective well-being would moderate the perceived stress/insulin resistance relationship for Type 2 diabetic participants, and (H3b) depression would moderate the perceived stress/insulin resistance relationship for Type 2 diabetic participants. Method: MIDUS, a longitudinal study of over 7,000 American adults, explores biopsychosocial factors that could contribute to variance in mental/physical health. Only complete data were utilized. Type 2 participants (n=115) consisted of 54 males and 62 females ranging in age from 36 to 81 years. Non-diabetic participants (n=1097) consisted of 470 males and 627 females ranging in age from 34 to 84 years. Results: None of the predicted relationships were statistically significant. Waist to hip ratio was significantly related to insulin resistance (r = .31, p = .001). Conclusions: Future studies should collect information about the type and duration of stressors in addition to perceptions about stress for those with Type 2 diabetes.

Background: Muscular strengthening activity (MSA) has been shown to be inversely associated with insulin resistance (IR). The associations between quartiles of the homeostatic model assessment of insulin resistance (HOMA-IR) and self-reported MSA in a nationally representative sample of euglycemic U.S. adults were examined. Methods: Sample included adult participants (≥20 years of age [n=2,543]) from the 1999-2004 National Health and Nutrition Examination Survey (NHANES). HOMA-IR was categorized into quartiles based on every 25th percentile. No MSA was the dependent variable. Results: Following adjustment for covariates, those with HOMA-IR values in third (p Conclusions: Having a higher HOMA-IR value is associated with greater odds of reporting no MSA in euglycemic U.S. adults.

Background: African-Americans are a vulnerable population group with disproportionately elevated rates of type 2 Diabetes Mellitus (DM). Resistant starch is a promising food ingredient that has the potential to reduce the risk factors involved in the development of type 2 DM. To date, there is a dearth of published research studies on the effect of resistant starch on African-Americans who are at increased risk for type 2 DM. Objective: The major objective of this study was to determine if daily consumption of approximately twelve grams of high-maize™ 260 resistant starch (RS) added to bread improved glucose homeostasis by monitoring changes in fasting plasma glucose, fructosamine, hemoglobin A1c, insulin, glucagon-like peptide-1, C-reactive protein, homeostasis model assessment insulin resistant (HOMA- IR) and beta-cell function (HOMA-Beta), serum acetate, propionate, and butyrate levels. Design: A fourteen-week, randomized, double-blind, within-subject crossover design feeding study was carried out in African-American males (n=8) and females (n=7) at increased risk for type 2 DM who resided in Southwest Virginia. All participants consumed bread containing added RS or control bread (no added RS) for six-weeks. RS and control bread feedings were separated by a two-week washout period. Results: Fasting Plasma Glucose (FPG) levels were significantly lower (P = 0.0179) after six-week control bread feedings compared to baseline. FPG levels were also significantly lower (P < 0.0001) after two-week washout period than at baseline. FPG levels were significantly higher (P < 0.0001) after six-week resistant starch bread feeding than at washout. FPG levels due to consumption of resistant starch versus control bread approached significance (P = 0.0574). Fructosamine levels were significantly lower (P = 0.0054) after control bread and resistant starch bread (P < 0.0012) consumption compared to baseline. No significant differences were found in fructosamine levels due to resistant bread intake versus control (P = 0.9692). Mean baseline HbA1c levels were 6.9% (n=15). This value was slightly lowered to 6.79% (n=14) at the end of the fourteen-week study, although statistical significance was not found. Mean ± standard errors for HbA1c values were 6.9% ± 0.18% and 6.9% ± 0.14% at baseline for the sequence groups, resistant starch first (n=7) and control treatment first (n=8) groups, respectively. Mean± standard error HbA1c values were 6.7%± 0.27% and 6.9% ± 0.27% at the conclusion of fourteen-week study for sequence groups, resistant starch first group (n=7) and control treatment first group, respectively. Baseline mean and standard errors C-reactive Protein (CRP) levels for male and female combined results were 0.62 ± 0.16 mg/dL (n=15). Mean CRP levels were 0.53 ± 0.12 mg/dL for resistant starch bread and 0.64 ± 0.21 mg/dL for control bread feeding periods. No significant differences were found for treatment, gender, or sequence effects for C-reactive protein levels during the fourteen-week study (P > 0.05). Mean HOMA-IR levels following six-week resistant starch and control bread consumption decreased to normal values (> 2.5), although no significant differences were found for treatment (P = 0.5923). Conclusions: Eighty-seven grams of Hi- maize™ 260 Resistant Starch added to baked loaves of bread consumed by a free-living African-American population at increased risk for type 2 diabetes did not consistently show significance in all clinical indicators and biochemical markers assessed. On the basis of the evidence in this study we do not have evidence that this amount of resistant starch in this population's diet will prevent the onset of diabetes. However, results are suggestive that higher levels of resistant starch in a more controlled experiment could reduce clinical risk factors for type 2 diabetes. / Ph. D.