Motivation: The metabolic syndrome is characterized by a group of risk factors for cardiovascular disease (CVD) that includes obesity, dyslipidemia, high blood pressure, insulin resistance, glucose intolerance or non-insulin dependant diabetes mellitus, pro-thrombotic state and pro-inflammatory state. The NHANES I11 study showed the prevalence of this syndrome to be 24.0% in men and 23.4% in women in the USA. These figures translate to more than 47 million US residents having the metabolic syndrome. In the THUSA (acronym for Transition and Health in the Urbanization of South Africans) study in South Africa it was found that 12% and 28.4% of men and women, respectively, of the black population of the North West Province had three or more disturbances characterizing this syndrome. Therefore, it is evident that the metabolic syndrome is a health problem not only for developed countries but also for developing countries. As a result, this syndrome has been identified as a target for dietary therapies to reduce the risk of CVD and type 2 diabetes. Epidemiological studies have consistently demonstrated an inverse association between nut consumption and coronary heart disease (CHD) morbidity and mortality in different population groups. Nut consumption may not only offer protection against heart disease, but also increase longevity. Recently, the benefits of nuts consumption were acknowledged by the U.S. Food and Drug Administration when they approved a qualified health claim that eating nuts (1.5 ounces/day ≈ 42.8 g/day) may reduce the risk of CHD. In this regard, the most comprehensively studied mechanism involved the favourable lipid lowering effects of nuts. There is, however, a lack of data in the literature regarding the effect of nuts on the metabolic syndrome. Objective: The main objective of this study was to examine the effects of a high walnut diet and a high unsalted cashew nut diet on markers of the metabolic syndrome in humans. In order to provide a foundational body of evidence for the aforementioned, a secondary objective included conducting a systematic review that investigates the effects of nuts on the lipid profile. Methods: The main project consisted of a controlled feeding trial with a parallel, randomized controlled study design on participants having the metabolic syndrome. Sixty-four subjects having this syndrome (29 men, 35 women) with a mean (±SD) age of 45±10 y and who met with the selection criteria were all fed a 3-week run-in control diet. After this period, participants were grouped according to gender and age and then randomized into three groups, namely, those that received a controlled feeding diet including walnuts (20% energy (E), 60-100g/day; protein:carbohydrate:fat=18:42:40%E). or unsalted cashew nuts (20%E 66- 1 15g/day; protein:carbohydrate:fat=l9:44:37%E) or no nuts (protein:carbohydrate:fat=20:47:33%E) for 8 weeks. The participants' physical activity and weight were maintained for the duration of the study. For the systematic review. human intervention trials that investigated the independent effects of nuts on lipid concentrations were included. Medline and Web of Science databases were searched from the start of the database to August 2004 and supplemented by cross-checking reference lists of relevant publications. These papers received a rating based upon the methodology as it appeared in the publication. No formal statistical analysis was performed due to the large differences in study designs of the dietary intervention trials. The main outcome measures for the systematic review, were percentage differences between treatment and control groups for total blood cholesterol (TC), low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDL-C) and triacyglycerols (TG). Results: Regarding the main objective, we found that both the walnut and unsalted cashew nut intervention diets had no significant effect on the lipid profile, serum fructosamine, insulin, insulin sensitivity, insulin resistance, serum high sensitivity C-reactive protein, blood pressure and serum uric acid concentrations when compared to the control dict. All three groups experienced highly significant increases in serum insulin concentrations when comparing the baseline to end (P<0.05). In turn, insulin resistance increased while insulin sensitivity decreased in all three groups. Plasma glucose concentrations increased significantly in the cashew nut group compared to the control group (P<0.05). By contrast, serum fructosamine was unchanged in the cashew nut group while the control group had significantly increased concentrations of this short-term marker of glycaemic control. The literature search for the systematic review yielded 41 5 publications. After screening, 23 nut studies were included in the review with most of these studies including heart-healthy diets. The majority of the studies were short (4-6 weeks) with only one study lasting 6 months. The number of subjects in most of the studies was sufficient to study the effects on TC and LDL-C but not for HDL-C and TG. The results of three almond (50-100g/day), two peanut (35-68g/day), one pecan nut (72g/day) and four walnut (40-84g/day) studies showed convincing evidence for a lipid lowering effect of TC between 2-1 6% and LDL-C between 2- 19%, when compared to their control diets. Currently, there are indications from inadequately designed intervention studies that hazelnuts (lg/day/kg body weight) and pistachios (20%E) may have a lipid lowering effect. At this stage the evidence for macadamia nuts is less convincing. Furthermore, it is apparent that the components in nuts further reduce TC and LDL-C concentrations beyond the effects predicted by equations based solely on dietary fatty acid profiles. Conclusions: In the controlled feeding trial, subjects displayed no improvement in the markers of the metabolic syndrome after following a walnut or unsalted cashew nut diet compared to a control diet while maintaining body weight (8 weeks). Finally, we suspect that the dramatic increase in insulin resistance may have masked the protective effects of the walnut and cashew nut diets in our subjects with the metabolic syndrome Further research is warranted before a consensus can be reached. From the systematic review it was concluded that the consumption of ≈50-100g (≈1.5-3.5 servings) of nuts five or more times/week as part of a heart-healthy diet with total fat content (high in mono- and /or polyunsaturated fatty acids) of ≈ 35% of energy may significantly decrease TC and LDL-C in normo- and hyperlipidemic individuals. Recommendations: A similar nut controlled feeding trial with some form of calorie restriction, should be done on participants having the metabolic syndrome. Future research should use randomized controlled studies with larger sample sizes and longer duration to investigate the effects of nuts on HDL-C and TG concentrations. Also, studies should investigate the effects on the lipid profile of mixed nuts and those individual nuts not yet considered. In addition, the unique nutrient and non-nutrient composition of nuts requires further research in order to elucidate the possible mechanisms responsible for the LDL-C lowering effect / Thesis (Ph.D. (Nutrition))--North-West University, Potchefstroom Campus, 2005.

The prevalence of obesity in both the developed and developing world have increased, which leads to diverse health outcomes and is placing a heavy burden on the economy. Abdominal obesity proved to be one of the main features in predicting metabolic and cardiovascular disease (CVD) risk and may be the link that unifies the metabolic syndrome (MS) through pro-inflammatory pathways. While the pathogenesis of the MS and each of its components are complex and not well understood, abdominal obesity remains the mechanism that relates to increased lipolysis causing the liver to increase blood glucose and very low lipoprotein output. This in turns leads to raised blood glucose, triglycerides, low-density lipoprotein cholesterol (LDL-C), blood pressure and inflammatory markers (C-reactive protein, interleukin-6 and tumor necrosis factor-a) and decreased high-density lipoprotein cholesterol (HDL-C). Prevention of the metabolic syndrome and treatment of its main characteristics are now considered of utmost importance in order to combat the increased CVD risk and all-cause mortality. Decreasing sedentary behaviour through regular physical activity is a key element in successful treatment of obesity through an increase in energy expenditure, but the ability to decrease low-grade systemic inflammation may be an even greater outcome. Aims The aims of this study was firstly, to determine by means of a literature review, how obesity could be related to a state of chronic systemic inflammation (increased CRP and IL-6). Secondly to determine whether physical activity could serve as a suitable method to decrease inflammation associated with obesity and related disorders. Thirdly to determine if abdominal obesity is a predictor of the metabolic syndrome and CVD and finally, to determine if measures of obesity can predict risk for the metabolic syndrome and CVD risk. Methods For this review study, a computer-assisted literature search were utilized to identify research published between 1990 and 2005. the following databases were utilized for the search: NEXUS, Science Direct, PubMed and Medline. Keywords related to obesity (abdominal obesity, overweight), metabolic syndrome (insulin resistance syndrome, dysmetabolic syndrome, syndrome X), cardiovascular disease (coronary heart disease, coronary artery disease), cardiovascular risk factors (hypertension, dyslipidemia, diabetes mellitus, physical activity), inflammatory markers (CRP, IL-6, chronic low-grade inflammation) and physical activity (fitness, exercise and training) were included as part of the search, including the references identified by previous reviewers (not identified as part of the computerized literature search). Results and conclusions Several research studies concluded that obesity could be an inflammatory disorder due to low-grade systemic inflammation. Adipose tissue is known to be a sectretory organ producing cytokines, acute phase reactants and other circulating factors. The synthesis of adipose tissue TNF-a could induce the production of IL-6, CRP and other acute phase reactants. CRP is a acute phase reactant, synthesized primarily in hepatocytes and secreted by the liver in response to a variety of inflammatory cytokines of which IL-6 and TNF-a are mainly involved. CRP increases rapidly in response to trauma, inflammation and infection. Thus, enhanced levels of CRP can be used as a marker of inflammation. Several studies of large population cohorts provide evidence for an inverse, independent dose-response relation between plasma CRP concentration and level of physical activity in both men and women. Trends for decreased IL-6, TNF-a and CRP concentrations were linear with increasing amounts of reported exercise in most of the research studies, physical activity proved effective in lowering measures of adiposity (BMI, WHR, WC and percentage body fat) and obesity related inflammatory markers (CRP & IL-6). Thereby indicating a potential anti-inflammatory effect. In the studies reviewed in this article abdominal obesity is identified as a predictor and independent risk factor for CVD in both men and women. High levels of deep abdominal fat have also been correlated with components of the metabolic syndrome, glucose intolerance, hyperinsulinemia, hypertension, diabetes, increases in plasma triglyceride levels and a decrease in HDL-C levels (dyslipidemia) in many of the studies. Prospective epidemiological studies have revealed that abdominal obesity (determined by WC and WHR) conveys an independent prediction of CVD risk and is more relevant compared to general obesity (determined by BMI). Abdominal fat has been linked to metabolic risk factors like high systolic blood pressure, atherogenic dyslipidemia, with increased serum TG and decreased HDL-C, and glucose intolerance. Although magnetic resonance imaging (MRI) and computerized tomography (CT) have been used successfully in many studies to measure adipose compartments of the abdomen (subcutaneous and visceral fat), anthropometrical measures like WHR and WC have been proven to be an effective measure in predicting the metabolic syndrome. WC has also been included in the metabolic syndrome definitions of the WHO, ATP Ill and new IDF. / The prevalence of obesity in both the developed and developing world have increased, which leads to diverse health outcomes and is placing a heavy burden on the economy. Abdominal obesity proved to be one of the main features in predicting metabolic and cardiovascular disease (CVD) risk and may be the link that unifies the metabolic syndrome (MS) through pro-inflammatory pathways. While the pathogenesis of the MS and each of its components are complex and not well understood, abdominal obesity remains the mechanism that relates to increased lipolysis causing the liver to increase blood glucose and very low lipoprotein output. This in turns leads to raised blood glucose, triglycerides, low-density lipoprotein cholesterol (LDL-C), blood pressure and inflammatory markers (C-reactive protein, interleukin-6 and tumor necrosis factor-a) and decreased high-density lipoprotein cholesterol (HDL-C). Prevention of the metabolic syndrome and treatment of its main characteristics are now considered of utmost importance in order to combat the increased CVD risk and all-cause mortality. Decreasing sedentary behaviour through regular physical activity is a key element in successful treatment of obesity through an increase in energy expenditure, but the ability to decrease low-grade systemic inflammation may be an even greater outcome. Aims The aims of this study was firstly, to determine by means of a literature review, how obesity could be related to a state of chronic systemic inflammation (increased CRP and IL-6). Secondly to determine whether physical activity could serve as a suitable method to decrease inflammation associated with obesity and related disorders. Thirdly to determine if abdominal obesity is a predictor of the metabolic syndrome and CVD and finally, to determine if measures of obesity can predict risk for the metabolic syndrome and CVD risk. Methods For this review study, a computer-assisted literature search were utilized to identify research published between 1990 and 2005. the following databases were utilized for the search: NEXUS, Science Direct, PubMed and Medline. Keywords related to obesity (abdominal obesity, overweight), metabolic syndrome (insulin resistance syndrome, dysmetabolic syndrome, syndrome X), cardiovascular disease (coronary heart disease, coronary artery disease), cardiovascular risk factors (hypertension, dyslipidemia, diabetes mellitus, physical activity), inflammatory markers (CRP, IL-6, chronic low-grade inflammation) and physical activity (fitness, exercise and training) were included as part of the search, including the references identified by previous reviewers (not identified as part of the computerized literature search). Results and conclusions Several research studies concluded that obesity could be an inflammatory disorder due to low-grade systemic inflammation. Adipose tissue is known to be a sectretory organ producing cytokines, acute phase reactants and other circulating factors. The synthesis of adipose tissue TNF-a could induce the production of IL-6, CRP and other acute phase reactants. CRP is a acute phase reactant, synthesized primarily in hepatocytes and secreted by the liver in response to a variety of inflammatory cytokines of which IL-6 and TNF-a are mainly involved. CRP increases rapidly in response to trauma, inflammation and infection. Thus, enhanced levels of CRP can be used as a marker of inflammation. Several studies of large population cohorts provide evidence for an inverse, independent dose-response relation between plasma CRP concentration and level of physical activity in both men and women. Trends for decreased IL-6, TNF-a and CRP concentrations were linear with increasing amounts of reported exercise in most of the research studies, physical activity proved effective in lowering measures of adiposity (BMI, WHR, WC and percentage body fat) and obesity related inflammatory markers (CRP & IL-6). Thereby indicating a potential anti-inflammatory effect. In the studies reviewed in this article abdominal obesity is identified as a predictor and independent risk factor for CVD in both men and women. High levels of deep abdominal fat have also been correlated with components of the metabolic syndrome, glucose intolerance, hyperinsulinemia, hypertension, diabetes, increases in plasma triglyceride levels and a decrease in HDL-C levels (dyslipidemia) in many of the studies. Prospective epidemiological studies have revealed that abdominal obesity (determined by WC and WHR) conveys an independent prediction of CVD risk and is more relevant compared to general obesity (determined by BMI). Abdominal fat has been linked to metabolic risk factors like high systolic blood pressure, atherogenic dyslipidemia, with increased serum TG and decreased HDL-C, and glucose intolerance. Although magnetic resonance imaging (MRI) and computerized tomography (CT) have been used successfully in many studies to measure adipose compartments of the abdomen (subcutaneous and visceral fat), anthropometrical measures like WHR and WC have been proven to be an effective measure in predicting the metabolic syndrome. WC has also been included in the metabolic syndrome definitions of the WHO, ATP Ill and new IDF. / Thesis (M.A. (Human Movement Science))--North-West University, Potchefstroom Campus, 2006.

No description available.

Activation of inducible nitric oxide synthase (iNOS) and oxidative stress have been shown to be associated with compromised cardiovascular function in streptozotocin (STZ)-induced type 1 diabetes. The aim of the project is to investigate cardiovascular abnormalities in a rat model of type 2 diabetes (Zucker diabetes fatty or ZDF rats) and two models of metabolic syndrome (fructose-fed rats and Zucker obese rats), and to provide direct evidence linking iNOS and oxidative stress to abnormal cardiovascular function in these disorders. Blood pressure, cardiac contractility, cardiac index, regional flow, vascular resistance and venous tone were measured in diseased as well as normal rats. Biochemical analyses such as activities of iNOS, immunostaining of iNOS and western-blot analysis of iNOS in the heart tissue were carried out. The results showed that cardiac contractile response to dobutamine was compromised in the ZDF rats, and this was associated with increased myocardial protein expression as well as activity of iNOS. The formation of peroxynitrite was increased in the heart tissue of the ZDF rats. Selective inhibition of iNOS by 1400W (N-3-aminomethyl-benzyl-acetamidine) did not alter responses to dobutamine in the control rats, but augmented the contractile effects of dobutamine in the diabetic rats. The regional blood flow was altered in the ZDF rats, and iNOS played a negligible role in regulating regional flow in the ZDF rats. Although venous response to noradrenaline was also altered in the Zucker obese rats, NOS may not be involved in venous tone regulation. Anti-oxidative treatment with N-acetylcysteine inhibited the development of insulin resistance, blood pressure elevation and the increase of 8-isoprostane formation in the fructose-fed rats. We conclude that heart function is compromised and regional blood flow is altered in the ZDF rats. Activation of iNOS plays an important role in suppressing heart dysfunction but does not affect regional blood flow. In Zucker obese rats with metabolic syndrome, iNOS may not be involved in changes of venous function. Oxidative stress is associated with both abnormality of heart dysfunction in type 2 diabetes (by formation of peroxynitrite due to iNOS activation) and development of hypertension and insulin resistance in metabolic syndrome.

The aim of this work - to estimate an association of metabolic syndrome (MS) with ischemic heart disease (IHD) in middle-aged Kaunas population and to propose the model for preventing prevalence of MS. Material and methods. Analysis was performed for 1336 persons aged 35-64 years (603 men and 733 women) - the participants of health survey which has been carried out according to the MONICA study protocol. MS was defined by Adult Treatment Panel III criteria for the presence of three or more from five components: central obesity (waist circumference >102/88 cm (men/women)); fasting plasma glucose ≥6.1 mmol/l; triglycerides ≥1.7 mmol/l; high density lipoprotein cholesterol <1.04/1.3 mmol/l (men/women); systolic/diastolic blood pressure ≥130 and/or 85 mmHg. IHD was diagnosed as previous myocardial infarction, angina pectoris or ischemic changes in electrocardiogram. Lifestyle habits were evaluated using frequency questionnaire. The relationship between MS and IHD in consideration of age and smoking habits was estimated using logistic regression. Results. Prevalence of MS in the study population was 19.4 percent for men and 26.3 percent for women. Prevalence of MS among men and women increased with age. Hypertension was the most frequent component of MS (64.1 percent for men and 54.2 percent. for women). The rate of IHD was 14.3 percent for men and 19.4 percent for women. Risk of IHD in subjects with MS in comparing to subjects without MS was higher: odds ratio 1.98 (95 percent... [to full text]

The increasing prevalence of abdominal obesity worldwide poses a serious public health problem and hence, presents a target for research designed to improve the assessment or treatment of abdominal obesity. Specifically, the first study in this thesis investigated the influence of age and gender on visceral (VAT) and abdominal subcutaneous adipose tissue (ASAT) for a given waist circumference (WC) in 481 men and women varying widely in age and BMI. Significant gender differences in VAT and ASAT for a given WC were observed, however, only the relationship between WC and VAT was substantially influenced by age. The second study examined whether the associations between VAT, ASAT and the metabolic syndrome (MetS) were altered depending on measurement methodology used to assess VAT and ASAT. The odds ratio (OR) for MetS was higher for total VAT volume (OR=7.26) and the partial volumes at T12-L1 (OR=7.46) and L1-L2 (OR=8.77) compared to the classic L4-L5 (OR=3.94) measurement. The OR for MetS was not substantially different among the ASAT measures (OR~2.6). Measurement site for VAT, but not ASAT, has a substantial influence on the magnitude of the association with MetS. The third study examined the independent associations between VAT, ASAT, liver fat and all-cause mortality in 291 men (97 decedents and 194 controls, mortality follow-up of 2.2±1.3 years). In a model including VAT, ASAT, liver fat, age, and length of follow-up, only VAT (1.93 [1.15-3.23]) remained a significant predictor of mortality. We concluded that VAT is a strong, independent predictor of all-cause mortality in men. The purpose of the final study was to determine the effect of aerobic exercise dose (energy expenditure) on WC in sedentary, overweight/obese postmenopausal women (n=424). The women were randomly assigned to a control group or one of three aerobic exercise groups that exercised at energy expenditures of 4-, 8-, or 12-kcal/kg body weight/week. By comparison to control, there were significant reductions in WC in the exercise groups (~3 cm, P <0.05), which were independent of weight loss. However, the amount of exercise performed was not associated with reductions in WC in a dose dependent manner. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2007-05-17 19:24:06.777

No description available.

No description available.

Atypical antipsychotics (AAPs) are associated with metabolic sequelae including risk of type 2 diabetes. Evidence points to a weight-gain independent and direct drug effect on glucose homeostasis. While the exact mechanisms remain elusive, the heterogeneous binding profiles of AAPs likely include receptors involved in glucose metabolism. We aimed to clarify weight-gain independent mechanisms of AAP-induced alterations in insulin secretion. Deconstruction of the receptor binding profiles of these agents was done using representative antagonists and the hyperglycemic clamp. We assessed the acute effects of several selective receptor antagonists on glucose metabolism, namely prazosin, idazoxan, MDL100907, SB242084 and WAY100635. Prazosin and MDL100907, selective α1 and 5HT2A antagonists, respectively, caused significant decreases in both insulin and C-peptide secretion. A decreased glucose infusion rate and disposition index was also found in the prazosin group. Antagonism of the α1 and 5HT2A receptors may be involved in AAP-induced glucose dysregulation, however, the responsible mechanisms remain unknown.

Atypical antipsychotics (AAPs) are associated with metabolic sequelae including risk of type 2 diabetes. Evidence points to a weight-gain independent and direct drug effect on glucose homeostasis. While the exact mechanisms remain elusive, the heterogeneous binding profiles of AAPs likely include receptors involved in glucose metabolism. We aimed to clarify weight-gain independent mechanisms of AAP-induced alterations in insulin secretion. Deconstruction of the receptor binding profiles of these agents was done using representative antagonists and the hyperglycemic clamp. We assessed the acute effects of several selective receptor antagonists on glucose metabolism, namely prazosin, idazoxan, MDL100907, SB242084 and WAY100635. Prazosin and MDL100907, selective α1 and 5HT2A antagonists, respectively, caused significant decreases in both insulin and C-peptide secretion. A decreased glucose infusion rate and disposition index was also found in the prazosin group. Antagonism of the α1 and 5HT2A receptors may be involved in AAP-induced glucose dysregulation, however, the responsible mechanisms remain unknown.