Background: Liver is a vital organ that plays a major role in glucose production and regulationthroughout the body (Musso et al., 2012). Liver disease has long been linked with insulin resistance (IR), dating back to 1906 (Megyesi et al., 1967). IR has been found to be prevalent in a range of liver diseases, including chronic Hepatitis C Virus (HCV), hemochromatosis, and alcoholic liver disease (Goswami et al., 2014). Liver disease is highly prevalent in the United States population with 30 million people (or one out of ten Americans) suffering from some type of liver disease (Peery et al., 2015). Although research demonstrates a significant relationship between liver disease and IR, the University of Arizona (UA) hepatology clinic does not currently screen liver disease patients for IR. Homeostatic model assessment for insulin resistance (HOMA-IR) score is used to study IR in non-insulin resistant population. HOMA-IR score is calculated using formula fasting plasma glucose (mmol/l) times fasting serum insulin (mU/l) divided by 22.5 (Bonora et al., 2002). Low HOMA-IR (HOMA< 2.0) values indicate high insulin sensitivity, whereas high HOMA-IR (HOMA> 2.0) values indicate low insulin sensitivity (insulin resistance) (Bonora et al., 2002). Objective: The purpose of this quality improvement (QI) project is to show the prevalence of IR in euglycemic liver disease patients at the UA hepatology clinic by using their HOMA-IR scores as a screening tool. By screening euglycemic liver disease patients for IR based on their HOMA-IR score, providers at the UA hepatology clinic can prevent liver disease progression and complications associated with IR early on. By doing so, the providers can improve the quality of care for liver disease patients. An essential part of calculating HOMA-IR is the availability of labs (serum glucose and serum insulin). A part of this QI project is to determine if the UA hepatology clinic has necessary labs to calculate HOMA-IR for euglycemic liver disease patients. A related matter is whether there is a correlation between liver disease patients' HOMA-IR score and Model for End-stage Liver Disease (MELD) score. If there is a direct correlation between HOMA-IR and MELD scores, providers can identify severity and progression of liver disease in euglycemic liver disease patients. Design: A case control retrospective study. Study Questions: 1) Do UA Hepatology clinic providers order sufficient labs (fasting plasma glucose and fasting plasma insulin) to calculate HOMA-IR in euglycemic patients? 2) What is the prevalence of IR in euglycemic liver patients indicated by HOMA-IR score? 3) Is there any correlation between HOMA-IR score and MELD score in euglycemic liver disease patients? Participants: Data will be collected from 1000 liver disease patients' at the UA hepatologyclinic, a tertiary level referral center. Settings: Banner University Medical Center (UMC) in Tucson, Arizona from January 1, 2011 until December 31, 2014. Measurements: HOMA-IR score using serum fasting glucose and serum fasting insulin levels laboratory values. MELD score to identify the severity of liver disease in euglycemic liver disease patients. Results: Among 1000 patients, 506 (60.5%) were found to have a previous diagnosis of T2DMand 395 (39.5 %) were euglycemic liver disease patients (Figure 1). Out of the 395 euglycemic liver disease patients, 217 (55%) participants were found to have both insulin level and glucose11level in their charts; 178 (45%) euglycemic liver disease patients were missing either insulin level or glucose level needed to calculate HOMA-IR score (Figure 2). Of the 217 euglycemic liver disease patients, 54.8% of had HOMA-IR> 2 and 45.2% patients had HOMA-IR<2 (Figure 3). The Pearson Correlation between HOMA-R>2 and MELD scores was 0.092 and the significance value using 2-tailed was 0.321 (Table 4). Conclusion: The results showed a significant high prevalence of IR in euglycemic patients with HOMA-IR score> 2 (54.8%) compare to those patients with HOMA-IR score<2 (45.2%). Furthermore, about 178 (45%) euglycemic liver disease patients were missing either insulin level or glucose level needed to calculate HOMA-IR score. This is a significant number of patients missing important labs to identify them as high risk for IR. This QI project identified HOMA-IRas an important screening tool that should be used both in hepatology clinics and primary healthcare settings. Use of such tool will lead to improved quality of care for euglycemic liver disease patients.

The purpose of this investigation was to expand the evaluation of Normal Weight Obesity (NWO) and its association with insulin resistance using a nationally representative sample of U.S. adults. A cross-sectional study including 5,983 subjects was conducted. Body fat percentage was assessed using dual energy X-ray absorptiometry (DXA). Expanded Normal Weight Obesity (eNWO) categories (pairings of BMI and body fat percentage classifications) were determined by standard cut-points for BMI and the gender specific median for body fat percentage. Homeostatic Model Assessment-Insulin Resistance (HOMA-IR) levels were used to index insulin resistance. Mean ± SE values were as follows: BMI: 27.9 ± 0.2 (women) and 27.8 ± 0.1 (men); body fat percentage: 40.5 ± 0.2 (women) and 27.8 ± 0.2 (men); HOMA-IR: 2.04 ± 0.05 (women) 2.47 ± 0.09 (men). HOMA-IR differed systematically and in a dose-response fashion across all levels of the eNWO categories (F = 291.3, P < 0.0001). As BMI levels increased, HOMA-IR increased significantly and within each BMI category, higher levels of body fat were associated significantly with higher levels of HOMA-IR. Both high BMI and high body fat percentage are strongly related to insulin resistance. In this study, insulin resistance increased incrementally according to BMI levels primarily and body fat levels secondarily. Consequently, due to the costs associated with precisely measuring body fat, and the accuracy of using BMI independently, we recommend that BMI be used in its standard form to predict insulin resistance and not be supplemented with an estimate of body fat.

Submitted by admin tede (tede@pucgoias.edu.br) on 2017-02-06T17:10:02Z No. of bitstreams: 1 RENATA MACHADO PINTO.pdf: 1879389 bytes, checksum: 1e831384ae5ac2534e9b7187fd6e1ae5 (MD5) / Made available in DSpace on 2017-02-06T17:10:02Z (GMT). No. of bitstreams: 1 RENATA MACHADO PINTO.pdf: 1879389 bytes, checksum: 1e831384ae5ac2534e9b7187fd6e1ae5 (MD5) Previous issue date: 2014-03-26 / The worldwide prevalence of obesity has increased at an alarming rate in all age groups. Although it has been described some rare obesity syndromes caused by mutations in single genes, the highest proportion of obesity results from an interaction between variants in multiple genes (susceptible genotype) and a favorable environment (plenty of calories and lack of physical activity). Classically, it has been studied genes involved in the control of intake, energy expenditure and the metabolism of glucose and lipids. In the last decade the discovery of numerous substances secreted by adipocytes among them hormones and inflammatory cytokines opened a new research front. The “Reward Deficient Syndrome” (RDS) is characterized as a hypodopaminegic state that predisposes to obsessive-compulsive behavior and impulsivity. Obesity is part of the RDS, as the individual overeats as a manner to compensate de dopamine defect. In this context, this study was designed to investigate the relationship between childhood onset obesity and polymorphisms of the tumor necrosis factor alpha (TNF alpha) and the Dopamine D2 Receptor (DRD2). Our research is a case control study that included 105 children, being 55 obese and 50 normal weight (control group). Peripheral blood samples were collected for the determination of lipid profile, glucose and insulin levels, and for the evaluation of the genetic polymorphisms of TNF- gene (G308A) and DRD2 (Taq1 - C32806T), by ARMS-PCR and RFLP-PCR, respectively. Genetic variants of the SNP G308A TNF- failed to confirm a participation in weight gain in children. The A1 allele (T) of the Taq1 polymorphism in the DRD2 gene was associated with an increase in childhood obesity and higher BMI of the parents, corroborating some data of the literature. Our results showed for the first time that the A1 allele is associated with Total Cholesterol 70 mg/dl, minor levels of triglycerides and a relative risk of 1.5 for HOMA ß secretion. Understanding how genetic variations affect the tendency to become or remain obese is an important step in understanding the mechanisms that lead to obesity. / A prevalência mundial da obesidade tem aumentado a um ritmo alarmante em todos os grupos etários. Embora tenham sido descritas algumas síndromes raras de obesidade causadas por mutações em genes individuais, a maior proporção de obesidade resulta de uma interação entre variantes em vários genes (genótipo suscetível) e um ambiente favorável (abundância de calorias e falta de atividade física). Classicamente, tem-se estudado genes envolvidos no controle da ingestão, do gasto de energia e do metabolismo da glicose e lipídios. Na última década a descoberta de numerosas substâncias secretadas pelos adipócitos, entre elas hormônios e citocinas inflamatórias abriu uma nova frente de pesquisa. A "Síndrome de Deficiência de Recompensa" (RDS) é caracterizada como um estado hipodopaminérgico que predispõe a comportamentos obsessivo-compulsivos e impulsividade. A obesidade é parte da RDS, já que o indivíduo come demais como uma forma de compensar o defeito nos níveis de dopamina. Neste contexto, o presente estudo foi desenhado para investigar a relação entre a obesidade de início na infância e polimorfismos do fator de necrose tumoral alfa (TNF- ) e do Receptor D2 de dopamina (DRD2). Nossa pesquisa é um estudo de caso-controle que incluiu 105 crianças, sendo 55 obesas e 50 eutróficas (grupo controle). Amostras de sangue periférico foram colhidas para a determinação do perfil de lipídios, glicemia e os níveis de insulina, e para a avaliação dos polimorfismos do gene do TNF - (G308A) e DRD2 - C32806T), por ARMS - PCR e PCR - RFLP, respectivamente. Variantes genéticas do SNP G308A do TNF- não conseguiu confirmar uma participação no ganho de peso em crianças. O alelo A1 (T) do polimorfismo Taq1A do gene DRD2 foi associado a um aumento da obesidade infantil e IMC superior dos pais, corroborando alguns dados da literatura. Os nossos resultados mostram pela primeira vez que o alelo A1 está associado a colesterol total , a menores níveis de triglicérides, e confere um risco relativo de 1,5 para HOMA ß proteção contra a secreção de insulina prejudicada. A compreensão de como variações genéticas afetam a tendência de tornar-se ou permanecer obeso é um passo importante na compreensão dos mecanismos que levam à obesidade.

O acúmulo de tecido adiposo visceral (TAV) está relacionado com a piora da sensibilidade à insulina (SI) e, por isso, tem sido hipotetizado que a retirada de parte deste depósito, lipectomia (L), poderia melhorar este quadro. No entanto, a L pode ocasionar um aumento compensatório ou uma regeneração do tecido retirado. Para investigar se a L e o exercício afetam ou não a SI e a adiposidade, 36 ratos machos Wistar foram submetidos à dieta hiperlipídica e divididos em 4 grupos: LT (treinado), LS (sedentário), FT (falso operado) e FS, sendo submetidos à L e/ou treinamento aeróbio. O peso corporal e consumo de ração foram medidos semanalmente. A glicemia de jejum e tolerância à glicose foram avaliados pré e pós-intervenções. Índice HOMA, adiposidade e expressão gênica (mRNA) PPAR, PPAR e TNF- e expressão protéica do PGC1- foram analisados pós-intervenções. O grupo L apresentou maior consumo de ração após L (p<0,05). Foi verificada pior tolerância à glicose no grupo LS (p<0,03) e diminuída insulina de jejum nos grupos LT e FT (p<0,00). O grupo LT apresentou melhor SI (p<0,04). Não houve diferença na adiposidade dos animais (p>0,1). Os grupos LT e FS apresentaram maior expressão gênica do PPAR no TAV comparados aos LS e FT, já no músculo o LT apresentou menor expressão gênica comparado ao FS (p<0,05). O grupo LS apresentou maior mRNA do TNF- comparado aos demais grupos (p<0,05) e maior expressão protéica de PGC1- que o grupos LT e FS (p<0,05). Nossos resultados demonstram que o treinamento melhorou a ação da insulina e em associação à L melhorou a SI. Além disso, a L ocasionou aumento no consumo de ração que pode ter colaborado com a recuperação da adiposidade neste grupo / Increased visceral adipose tissue (VAT) may account for the impairment in peripheral and hepatic insulin sensitivity (IS). It has been hypothesized that the partial removal of VAT known as lipectomy (L) could result in the improvement, while a re-growth of the excised tissue and/or a compensatory growth of non-excised depots seem to occur. To investigate whether or not VAT removal and exercise affect IS and adiposity 36 male Wistar rats were fed a high-fat diet and assigned to 4 experimental groups: EL (exercised), ES (sham-lipectomized), CL (control-sedentary), and CS; animals were submitted to L and/or exercise training. Body weight and food intake were recorded weekly. Fasting glucose and glucose tolerance were assessed pre and post-interventions. HOMA Index, body fat content, PPAR, PPAR e TNF- mRNA and PGC1- protein expression were assessed post-interventions. L group showed increased food intake post-L (p<0,05). CL group presented worsening on glucose tolerance (p<0,03). ET and ES showed lower fast insulin (p<0,00) and EL group showed better IS (p<0,04). There were no significant difference on body fat (p>0,1). EL and CL groups showed higher PPAR mRNA on VAT compared to CL and ES, EL showed decreased PPAR mRNA on skeletal muscle compared to CS (p<0,05). CL group showed greater TNF- mRNA (p<0,05) and greater PGC1- protein expression compared to EL and CS (p<0,05). Our results showed that short-term swimming training improved insulin action and, in association with L improve IS. Moreover, lipectomy has induced increased food intake which may be related with an increase in adiposity at this group

Made available in DSpace on 2016-08-10T10:38:47Z (GMT). No. of bitstreams: 1 RENATA MACHADO PINTO.pdf: 1879389 bytes, checksum: 1e831384ae5ac2534e9b7187fd6e1ae5 (MD5) Previous issue date: 2014-03-26 / The worldwide prevalence of obesity has increased at an alarming rate in all age groups. Although it has been described some rare obesity syndromes caused by mutations in single genes, the highest proportion of obesity results from an interaction between variants in multiple genes (susceptible genotype) and a favorable environment (plenty of calories and lack of physical activity). Classically, it has been studied genes involved in the control of intake, energy expenditure and the metabolism of glucose and lipids. In the last decade the discovery of numerous substances secreted by adipocytes among them hormones and inflammatory cytokines opened a new research front. The Reward Deficient Syndrome (RDS) is characterized as a hypodopaminegic state that predisposes to obsessive-compulsive behavior and impulsivity. Obesity is part of the RDS, as the individual overeats as a manner to compensate de dopamine defect. In this context, this study was designed to investigate the relationship between childhood onset obesity and polymorphisms of the tumor necrosis factor alpha (TNF alpha) and the Dopamine D2 Receptor (DRD2). Our research is a case control study that included 105 children, being 55 obese and 50 normal weight (control group). Peripheral blood samples were collected for the determination of lipid profile, glucose and insulin levels, and for the evaluation of the genetic polymorphisms of TNF- gene (G308A) and DRD2 (Taq1 - C32806T), by ARMS-PCR and RFLP-PCR, respectively. Genetic variants of the SNP G308A TNF- failed to confirm a participation in weight gain in children. The A1 allele (T) of the Taq1 polymorphism in the DRD2 gene was associated with an increase in childhood obesity and higher BMI of the parents, corroborating some data of the literature. Our results showed for the first time that the A1 allele is associated with Total Cholesterol 70 mg/dl, minor levels of triglycerides and a relative risk of 1.5 for HOMA ß secretion. Understanding how genetic variations affect the tendency to become or remain obese is an important step in understanding the mechanisms that lead to obesity. / A prevalência mundial da obesidade tem aumentado a um ritmo alarmante em todos os grupos etários. Embora tenham sido descritas algumas síndromes raras de obesidade causadas por mutações em genes individuais, a maior proporção de obesidade resulta de uma interação entre variantes em vários genes (genótipo suscetível) e um ambiente favorável (abundância de calorias e falta de atividade física). Classicamente, tem-se estudado genes envolvidos no controle da ingestão, do gasto de energia e do metabolismo da glicose e lipídios. Na última década a descoberta de numerosas substâncias secretadas pelos adipócitos, entre elas hormônios e citocinas inflamatórias abriu uma nova frente de pesquisa. A "Síndrome de Deficiência de Recompensa" (RDS) é caracterizada como um estado hipodopaminérgico que predispõe a comportamentos obsessivo-compulsivos e impulsividade. A obesidade é parte da RDS, já que o indivíduo come demais como uma forma de compensar o defeito nos níveis de dopamina. Neste contexto, o presente estudo foi desenhado para investigar a relação entre a obesidade de início na infância e polimorfismos do fator de necrose tumoral alfa (TNF- ) e do Receptor D2 de dopamina (DRD2). Nossa pesquisa é um estudo de caso-controle que incluiu 105 crianças, sendo 55 obesas e 50 eutróficas (grupo controle). Amostras de sangue periférico foram colhidas para a determinação do perfil de lipídios, glicemia e os níveis de insulina, e para a avaliação dos polimorfismos do gene do TNF - (G308A) e DRD2 - C32806T), por ARMS - PCR e PCR - RFLP, respectivamente. Variantes genéticas do SNP G308A do TNF- não conseguiu confirmar uma participação no ganho de peso em crianças. O alelo A1 (T) do polimorfismo Taq1A do gene DRD2 foi associado a um aumento da obesidade infantil e IMC superior dos pais, corroborando alguns dados da literatura. Os nossos resultados mostram pela primeira vez que o alelo A1 está associado a colesterol total , a menores níveis de triglicérides, e confere um risco relativo de 1,5 para HOMA ß proteção contra a secreção de insulina prejudicada. A compreensão de como variações genéticas afetam a tendência de tornar-se ou permanecer obeso é um passo importante na compreensão dos mecanismos que levam à obesidade.

O acúmulo de tecido adiposo visceral (TAV) está relacionado com a piora da sensibilidade à insulina (SI) e, por isso, tem sido hipotetizado que a retirada de parte deste depósito, lipectomia (L), poderia melhorar este quadro. No entanto, a L pode ocasionar um aumento compensatório ou uma regeneração do tecido retirado. Para investigar se a L e o exercício afetam ou não a SI e a adiposidade, 36 ratos machos Wistar foram submetidos à dieta hiperlipídica e divididos em 4 grupos: LT (treinado), LS (sedentário), FT (falso operado) e FS, sendo submetidos à L e/ou treinamento aeróbio. O peso corporal e consumo de ração foram medidos semanalmente. A glicemia de jejum e tolerância à glicose foram avaliados pré e pós-intervenções. Índice HOMA, adiposidade e expressão gênica (mRNA) PPAR, PPAR e TNF- e expressão protéica do PGC1- foram analisados pós-intervenções. O grupo L apresentou maior consumo de ração após L (p<0,05). Foi verificada pior tolerância à glicose no grupo LS (p<0,03) e diminuída insulina de jejum nos grupos LT e FT (p<0,00). O grupo LT apresentou melhor SI (p<0,04). Não houve diferença na adiposidade dos animais (p>0,1). Os grupos LT e FS apresentaram maior expressão gênica do PPAR no TAV comparados aos LS e FT, já no músculo o LT apresentou menor expressão gênica comparado ao FS (p<0,05). O grupo LS apresentou maior mRNA do TNF- comparado aos demais grupos (p<0,05) e maior expressão protéica de PGC1- que o grupos LT e FS (p<0,05). Nossos resultados demonstram que o treinamento melhorou a ação da insulina e em associação à L melhorou a SI. Além disso, a L ocasionou aumento no consumo de ração que pode ter colaborado com a recuperação da adiposidade neste grupo / Increased visceral adipose tissue (VAT) may account for the impairment in peripheral and hepatic insulin sensitivity (IS). It has been hypothesized that the partial removal of VAT known as lipectomy (L) could result in the improvement, while a re-growth of the excised tissue and/or a compensatory growth of non-excised depots seem to occur. To investigate whether or not VAT removal and exercise affect IS and adiposity 36 male Wistar rats were fed a high-fat diet and assigned to 4 experimental groups: EL (exercised), ES (sham-lipectomized), CL (control-sedentary), and CS; animals were submitted to L and/or exercise training. Body weight and food intake were recorded weekly. Fasting glucose and glucose tolerance were assessed pre and post-interventions. HOMA Index, body fat content, PPAR, PPAR e TNF- mRNA and PGC1- protein expression were assessed post-interventions. L group showed increased food intake post-L (p<0,05). CL group presented worsening on glucose tolerance (p<0,03). ET and ES showed lower fast insulin (p<0,00) and EL group showed better IS (p<0,04). There were no significant difference on body fat (p>0,1). EL and CL groups showed higher PPAR mRNA on VAT compared to CL and ES, EL showed decreased PPAR mRNA on skeletal muscle compared to CS (p<0,05). CL group showed greater TNF- mRNA (p<0,05) and greater PGC1- protein expression compared to EL and CS (p<0,05). Our results showed that short-term swimming training improved insulin action and, in association with L improve IS. Moreover, lipectomy has induced increased food intake which may be related with an increase in adiposity at this group

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-21T13:54:37Z No. of bitstreams: 1 aecioflaviomeirellesdesouza.pdf: 588675 bytes, checksum: 84d528796e59a48f1e76239e179980a4 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-22T15:30:38Z (GMT) No. of bitstreams: 1 aecioflaviomeirellesdesouza.pdf: 588675 bytes, checksum: 84d528796e59a48f1e76239e179980a4 (MD5) / Made available in DSpace on 2016-07-22T15:30:38Z (GMT). No. of bitstreams: 1 aecioflaviomeirellesdesouza.pdf: 588675 bytes, checksum: 84d528796e59a48f1e76239e179980a4 (MD5) Previous issue date: 2011-10-10 / Objetivos: verificar a prevalência de resistência insulínica (RI) em portadores de hepatite crônica C não diabéticos e analisar o impacto da mesma sobre os parâmetros laboratoriais e histológicos. Sujeitos e métodos: foram incluídos no estudo 82 pacientes e amostras de sangue foram coletadas para determinação de glicose, perfil lipídico, ALT, AST, ferritina, HOMA-IR, carga viral e genótipo do VHC. HOMA-IR superior a 2,5 foi considerado resistência insulínica. Resultados: RI foi observada em 27% dos pacientes e foi associada a idade, circunferência abdominal e índice de massa corpórea. Quando comparado a pacientes sem RI, aqueles com HOMA-IR superior a 2,5 apresentaram graus mais acentuados de fibrose hepática e atividade necroinflamatória, maiores níveis de aminotransferases e esteatose hepática mais freqüente. Conclusões: É comum a presença de RI em portadores de hepatite crônica C e esta tem como resultado a acentuação da fibrose hepática induzida pelo vírus da hepatite C. DESCRITORES: Hepatite crônica C, fibrose hepática, resistência insulínica, HOMA-IR / Objectives: To determine the prevalence of insulin resistance (IR) in patients nondiabetic with chronic hepatitis C and analyze the impact of insulin resistance on laboratory and histology parameters. Subjects and methods: The study included 82 patients and blood samples were collected for glucose, lipid profile, CRP, ferritin, ALT, AST, HOMA-IR, viral load and HCV genotype. HOMA-IR greater than 2.5 were considered insulin resistance. Results: Insulin resistance was observed in 27% of patients and was associated with age, waist circumference and body mass index. When compared with patients without RI those with insulin resistance had more pronounced stage of hepatic fibrosis and necroinflammatory activity, higher levels of aminotransferases and liver steatosis more frequently. Conclusions: It is often the presence of insulin resistance in patients with chronic hepatitis C and this has resulted in the exacerbation of liver fibrosis induced by HCV.

<p>Insulin resistance has shown to be a precursor to a number of lifestylerelated chronic diseases and abnormalities in adults and is affected by a number of factors including genetics, age, physical activity and acute exercise, diet, obesity, body fat distribution and medication. Physical activity has shown to have marked effects on improving sensitivity to insulin though various physiological mechanisms, and numerous correlation studies have identified a relationship between these two variables, suggesting the beneficial role of exercise on insulin resistance.&nbsp / This study aimed to identify a relationship between current levels of physical activity, physical fitness and insulin resistance in adults between the ages of 35 and 65 years of age residing in a northern suburb community in Cape Town. A total of 186 volunteers participated in this study ranging from healthy individuals to those with diagnosed chronic conditions. Insulin resistance (determined by the homeostasis model assessment of insulin resistance), physical activity (measured by the Global Physical Activity Questionnaire) and five health-related physical fitness tests were measured. The five components included body composition, determined by body mass index and waist circumference, the 3-minute cardiorespiratory step test, the handgrip&nbsp / muscle strength test, one-minute crunches for muscle endurance and the sit-and-reach flexibility test. Spearman correlation was used to identify the relationships between the homeostasis model assessment of insulin resistance, age, body composition and physical activity and fitness.Results showed that body mass index and waist circumference were the only two variables which produced significant correlations with the homeostasis model assessment of insulin resistance (p &lt / 0.019). No physical activity or fitness data produced significant scores with the homeostasis model assessment of insulin resistance. Body mass index in men was the only significant predictor of HOMA-IR and explained 37% of the variance in insulin resistance, whereas in women, only waist circumference was related to HOMA-IR, but explained less than 16% of the variance. Associations between reported MET-minutes from the Global Physical Activity Questionnaire and the four fitness tests indicated significance with handgrip strength (&rho / = 0.17 / p =0.039), one-minute crunches (&rho / = 0.18 / p = 0.024) and sit-and-reach flexibility (&rho / = 0.17 / 0.034). This study has shown that body composition is an important component in influencing insulin resistance therefore physical activity interventions should be targeted at increasing physical activity levels and reducing body weight.</p>

No description available.

<p>Insulin resistance has shown to be a precursor to a number of lifestylerelated chronic diseases and abnormalities in adults and is affected by a number of factors including genetics, age, physical activity and acute exercise, diet, obesity, body fat distribution and medication. Physical activity has shown to have marked effects on improving sensitivity to insulin though various physiological mechanisms, and numerous correlation studies have identified a relationship between these two variables, suggesting the beneficial role of exercise on insulin resistance.&nbsp / This study aimed to identify a relationship between current levels of physical activity, physical fitness and insulin resistance in adults between the ages of 35 and 65 years of age residing in a northern suburb community in Cape Town. A total of 186 volunteers participated in this study ranging from healthy individuals to those with diagnosed chronic conditions. Insulin resistance (determined by the homeostasis model assessment of insulin resistance), physical activity (measured by the Global Physical Activity Questionnaire) and five health-related physical fitness tests were measured. The five components included body composition, determined by body mass index and waist circumference, the 3-minute cardiorespiratory step test, the handgrip&nbsp / muscle strength test, one-minute crunches for muscle endurance and the sit-and-reach flexibility test. Spearman correlation was used to identify the relationships between the homeostasis model assessment of insulin resistance, age, body composition and physical activity and fitness.Results showed that body mass index and waist circumference were the only two variables which produced significant correlations with the homeostasis model assessment of insulin resistance (p &lt / 0.019). No physical activity or fitness data produced significant scores with the homeostasis model assessment of insulin resistance. Body mass index in men was the only significant predictor of HOMA-IR and explained 37% of the variance in insulin resistance, whereas in women, only waist circumference was related to HOMA-IR, but explained less than 16% of the variance. Associations between reported MET-minutes from the Global Physical Activity Questionnaire and the four fitness tests indicated significance with handgrip strength (&rho / = 0.17 / p =0.039), one-minute crunches (&rho / = 0.18 / p = 0.024) and sit-and-reach flexibility (&rho / = 0.17 / 0.034). This study has shown that body composition is an important component in influencing insulin resistance therefore physical activity interventions should be targeted at increasing physical activity levels and reducing body weight.</p>