An animal model to study complications resulting from childhood obesity is lacking. Our objective was to develop a porcine model for studying mechanisms underlying diet-induced childhood obesity. Pre-pubertal female pigs, age 35 d, were fed a high-energy diet (HED; n = 12), containing tallow and refined sugars, or a control corn-based diet (n = 11) for 16 wk. Initially, HED pigs self-regulated energy intake similar to controls, but, by wk 5, consumed more (P < 0.001) energy per kg body weight. At wk 15 and 22, pigs were subjected to an oral glucose tolerance test (OGTT); blood glucose increased (P < 0.05) in control pigs and returned to baseline levels within 60 min. HED pigs were hyperglycemic at time 0, and blood glucose did not return to baseline (P = 0.01), even 3 h post-challenge. During OGTT, glucose area under the curve was higher and insulin area under the curve was lower in HED pigs compared to controls (P = 0.001). Pigs given 6 wk of dietary intervention, consuming a control diet, marginally improved glucose area under the curve and LDL-cholesterol although insulin area under the curve was unaffected. Chronic HED intake increased (P < 0.05) subcutaneous, intramuscular, and perirenal fat deposition, and induced hyperglycemia, hypoinsulinemia, and low-density lipoprotein hypercholesterolemia; however, a 6 wk dietary intervention partially recovered a normal physiology. These data suggest pre-pubertal pigs fed HED are a viable animal model for studying childhood obesity. / Master of Science

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 90-99). Also available on the World Wide Web.

No description available.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 4 uppsatser.

Submitted in fulfillment of the requirements for Masters in Technology: Clinical Technology Durban University of Technology, 2014. / Background The metabolic syndrome (MS) is a clustering of cardiovascular (CV) risk factors and is noted to be increasing globally. Several studies have shown a link between the MS, chronic kidney disease (CKD) and end-stage renal disease (ESRD) possibly through a process of inflammation. Dialysis therapy may increase inflammation and could worsen MS and increase CV risk and diseases in ESRD patients. ESRD has been associated with increased CV disease in dialysis patients. Although there have been several reports on the prevalence of MS from the general population as well as from other specific groups, there are no known studies in South Africa on the prevalence of MS in ESRD patients on chronic dialysis therapy. The prevalence and risk factors for CV diseases are also currently unknown in the dialysis population in Cape Town. Aim The aim of this study was to determine the prevalence of MS in the dialysis population at Groote Schuur Hospital in Cape Town, to determine the effect of dialysis on MS and its traits and to evaluate CV risk in this patient group. Methods A total of 143 prevalent chronic dialysis patients who consented were used for this study. Demographic and relevant clinical details including systolic and diastolic blood pressures, waist and hip circumference and body mass index were obtained from all patients. Blood was drawn in the fasting state for assessment of full lipogram, glucose, ferritin, iron, calcium and phosphate. The metabolic syndrome was defined using the Adult Treatment Panel III (ATPIII) criteria. To determine the impact of dialysis on MS and its traits in our patients, only incident (new) patients starting dialysis were followed up for assessment of MS traits at timed intervals (at baseline, at 6 months and at 12 months) following initiation of chronic dialysis. To evaluate CV risk in this study, common traditional CV risk factors were assessed and were stratified according to number of risk factors as low ( ≤ 1), moderate (2 – 4) or high ( ≥ 4). Relevant statistical methods were used for analysis. Results Of the 143 patients in the study, 67.8% were on haemodialysis (HD) and 32.2% were on peritoneal dialysis (PD). The mean age of all the patients was 38.5 ± 10.4 years. The MS was present in 37.1% of all patients (PD – 52.2%, HD 29.9%; p = 0.015) and the frequency of increased waist circumference and hypertriglyceridaemia were significantly higher in PD patients than HD patients (p < 0.0001 and p = 0.006 respectively). Hypertension was the most prevalent MS trait in all the patients (89.5%) and was also the most prevalent trait in males (92.4%), females (85.9%) and in HD and PD patients (91.3% and 88.7% respectively). The frequency of CV risk was 3.5, 75.5 and 21.0% respectively for low, moderate and high CV risk and there was no difference in CV risk in HD and PD patients. High CV risk correlated with body mass index (BMI), increased waist circumference (WC), hyperphosphataemia, raised calcium – phosphate product, raised parathyroid hormone (PTH) and elevated C-reactive protein (p < 0.05). There was no significant change in MS prevalence or prevalence of MS traits in patients who were followed up irrespective of gender or modality of dialysis (p > 0.05) Conclusion The prevalence of the MS is higher in dialysis patients compared to the general population in South Africa and among dialysis patients, the prevalence is higher in PD than HD patients. Patients with MS have significantly higher CV risk factors than those without MS. Although dialysis therapy appear to have no significant effects on the prevalence of the MS or its traits in this study, the increased prevalence of the MS and CV risk factors may be related to the underlying disease process associated with ESRD. There is therefore an urgent need to identify and treat dialysis patients with the MS in order to reduce CV morbidity and mortality in this group of patients. Further prolonged prospective studies are needed to clarify the impact of dialysis on the MS and its traits in the ESRD population.

<p>Obesity is today a problem that has reached epidemic proportions. One of the causes of obesity is the over-consumption of energy. Fat is the most energy-dense nutrient, where the quality seems to be more important for the development of the metabolic diseases than the quantity. The fatty acid composition in serum lipid fractions can be used to mirror the dietary fat quality.</p><p>Stearoyl-CoA-desaturase (SCD) is an enzyme that converts saturated to monounsaturated fatty acids. A surrogate measure of SCD activity can be estimated as a fatty acid ratio; 16:1/16:0 (palmitoleic acid/palmitic acid) and 18:1/18:0 (oleic acid/stearic acid). The aim of this project was to investigate the intra-day variation in the SCD-ratio in humans eating a standardized diet. The results showed that triacylglycerol and nonesterified fatty acid fractions in serum lipids had a significant variance in the 16:1/16:0 ratio during the day, whereas 18:1/18:0 ratio in the same fractions did not exhibit the same pattern. In this study 16:1/16:0 ratio also seems to be a better marker than 18:1/18:0 ratio for estimating SCD activity. For further evaluation of the intra-day variation there need to be a more long-term study of the SCD-activity for a larger group of subjects.</p>

Introduction. Pima Indians living in the United States (U.S.) have the highest prevalence of type 2 diabetes mellitus in the world. Their Mexican counterparts, living a traditional lifestyle in the mountain of Sonora, Mexico, have at least five times less diabetes than the U.S. Pima Indians. The effects of a traditional lifestyle in reducing type 2 diabetes risk factors and the association of factors to type 2 diabetes were evaluated in a sample of 1211 genetically related Pima Indians living different lifestyles (224 from Mexico and 887 from U.S.). Subsets of these populations were used to address specific questions. First, differences in insulin resistance between subjects with normal glucose tolerance (194 Mexican versus 449 U.S. Pima) were evaluated. Second, the effect of physical activity and obesity explaining differences in metabolic syndrome prevalence were evaluated in 224 and 447 Mexican and U.S. Pima Indians. Third, factors associated with type 2 diabetes were evaluated in each Pima Indian population (224 from Mexico and 887 from U.S.).Methods. Demographic, physical, biochemical, and lifestyle factors were measured in 1996 in a cross-sectional study of Pima Indians 20 years of age or older living in Maycoba, Sonora Mexico and contrasted to results from a sample of U.S. Pima Indians participating in an ongoing epidemiological study that used similar methods and selection criteria. Insulin resistance was estimated by both fasting insulin and homeostasis model assessment-insulin resistance (HOMA-IR). Metabolic syndrome was defined using the Third Report of the National Cholesterol Education Program's Adult Treatment Panel III (NCEP III) criteria. Body mass index (BMI) was calculated by dividing weigh in kilograms by the square of height in meters (Kg/m2). Physical activity was measured using a questionnaire developed for the U.S. Pima Indians and adapted to the Mexican Pima Indian population. Type 2 diabetes was defined according to the 1999 WHO criteria after an oral glucose tolerance test. Multiple linear regression analysis was used to answer the first question (related to differences in insulin resistance) and multiple logistic regressions analysis to answer the second (related with differences in metabolic syndrome) and third questions (related to factors associated with type 2 diabetes).Results. Insulin resistance was much lower in the Mexican Pima Indians than in genetically related U.S. counterparts, even after controlling for differences in obesity, age and sex. In addition, the unadjusted prevalence of metabolic syndrome was 24.1% and 56.6 % in the Mexican and U.S. Pima Indians, respectively. However, most of the difference in metabolic syndrome prevalence was explained by differences in obesity and physical activity. Furthermore, in Mexican Pima Indians, type 2 diabetes was independently associated with age, fasting insulin, and waist circumference. In the U.S. Pima Indians, type 2 diabetes was associated with with age, sex, fasting insulin, total cholesterol, blood pressure and physical activity.Conclusion. The findings underscore the importance of lifestyle in the prevention of type 2 diabetes risk factors, such as insulin resistance and metabolic syndrome, even in individuals with high propensity to develop diabetes.

Motivation: Metabolic syndrome is a constellation of risk factors predisposing to coronary heart disease (CHD) and is classified as a "disease of modern civilization". Characteristics of the metabolic syndrome include abdominal obesity, increased triacylglycerol (TG) concentrations, increased small dense low-density lipoprotein(LDL) particles, decreased high-density lipoprotein cholesterol (HDL-C), hypertension, insulin resistance, inflammation, glucose intolerance and/or type 2 diabetes mellitus. Subjects with metabolic syndrome may be susceptible to oxidative stress due to their prolonged exposure to elevated glucose levels. A variety of natural antioxidants exists (e.g. glutathione, l3-carotene, vitamin C, polyphenols) that may prevent oxidative damage to biological structures. Nuts are rich sources of unsaturated fatty acids, protein, fibre, .micronutrients, phytochemicals and antioxidants. Duet o their high antioxidant content, it can, therefore, be speculated that nuts may play a role in the prevention of oxidative stress in subjects with the metabolic syndrome. Objective: - To investigate the effect of a high walnut and a high unsalted cashew nut diet on the antioxidant status of subjects with metabolic syndrome. Methods: Sixty eight subjects with diagnosed metabolic syndrome (according to the ATP III criteria) were recruited to take part in this parallel, randomized, controlled feeding trial. Subjects were mainly recruited from the North-West University, Potchefstroom Campus and surrounding areas. After a run-in period of three weeks during which the participants followed a prudent diet, subjects were randomly divided into three groups receiving either walnuts or cashew nuts (63- 108g/day)as part of a prudent diet, or continued with the prudent control diet. The intervention was followed for eight weeks. Fasting blood samples were taken at the beginning(after the three week run-in period) and at the end of the intervention. Antioxidant variables including oxygen radical absorbance capacity (ORAC), reduced glutathione (GSH)/oxidized glutathione (GSSG), diacron reactive oxygen metabolites (dRom) were measured at the beginning and the end of the intervention. C-reactive protein (CRP), fibrinogen and plasminogen activator-inhibitor activity (PAI-1a) were also measured as markers of inflammation. The antioxidant capacity and the polyphenol content of the diets and the walnuts and cashew nuts were determined at the end of the intervention. Results: A significant decrease in dRom and significant increases in GSSG, the redox status of glutathione (GSH/GSSG) and ORAC were observed in all three groups from baseline to end. GSH remained unchanged from baseline to end in all three groups. No significant differences in changes in dRom (p = 0.92), GSSG (p = 0.99), GSH/GSSG (p = 0.86), antioxidant capacity (p = 0.10) and GSH (p = 0.34) were observed from baseline to end between groups. The total polyphenol content of the walnut and control diets were similar and significantly higher than the cashew nut diet. The antioxidant capacity of the walnut and cashew nut diets showed a tendency to be higher than the control diet (p = 0.07 and p = 0.06 respectively). CRP, fibrinogen and PAI-1a concentrations did not differ significantly between groups. Conclusion No significant differences between the groups receiving walnuts, cashew nuts or no nuts were observed in GSH, GSSG, GSH/GSSG, dRom or ORAC. Therefore, there seems to be no beneficial effect of the inclusion of walnuts and cashew nuts in the diet on the antioxidant status of the participants. / Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2006.

An estimated 86 million Americans in the United States age 20 and older are classified as prediabetic. Prediabetes is defined as an individual having a higher blood sugar than normal increasing the risk for developing type 2 diabetes (T2DM). T2DM is among the top ten leading causes of death in the United States and costs an estimated 245 billion dollars annually. Interventions need to take place among patients with prediabetes in order to prevent the T2DM epidemic from compounding. This study examined the effects of a six-week low carbohydrate diet on A1C values, weight and BMI, and cardiovascular markers among patients with prediabetes. A retrospective chart review examined 1,169 patients with prediabetes that met inclusion criteria from July 2013 to April 2016. Patients had completed a six-week low carbohydrate diet program with weekly clinic visits with a nurse practitioner and followed the prescribed low carbohydrate diet. A significant difference in means was found when comparing pre A1C values (M= 5.93, SD= 0.20) and post A1C values (M= 5.57, SD= 0.25); (t (1142) = 49.3, p = 0.00), pre intervention weight (M= 227.0, SD= 52.0) and post intervention weight (M = 209.5, SD = 48.0); (t (1168) = 79.3, p = 0.00), and pre BMI (M = 36.8, SD = 7.0) and post BMI (M = 34.0, SD = 6.6); (t (1168) = 77.8, p = 0.00). Additionally, statistical significance was found for cardiovascular markers including systolic and diastolic blood pressures, total cholesterol, LDL, HDL and triglycerides. These findings suggest that a low carbohydrate diet is effective at improving metabolic risk factors for prediabetes and preventing the progression to T2DM. Low carbohydrate diets should be further examined for long term effectiveness and could be recommended to patients with prediabetes in order to reverse the epidemic of T2DM.

Background: Two-thirds of U.S. adult women are overweight or obese. High body mass index (BMI) and adult weight gain are risk factors for a number of chronic diseases, including postmenopausal breast cancer. The higher postmenopausal breast cancer risk in women with elevated BMI is likely to be attributable to related metabolic disturbances including altered circulating sex steroid hormones and adipokines, elevated pro-inflammatory cytokines, and insulin resistance. Metformin is a widely used antidiabetic drug that has demonstrated favorable effects on metabolic disturbances and as such may lead to lower breast cancer risk in obese women. Further, the anti-proliferative effects of metformin suggest it may decrease breast density, an accepted biomarker of breast cancer risk. Methods/design: This is a Phase II randomized, double-blind, placebo-controlled trial of metformin in overweight/obese premenopausal women who have elements of metabolic syndrome. Eligible participants will be randomized to receive metformin 850 mg BID (n=75) or placebo (n=75) for 12 months. The primary endpoint is change in breast density, based on magnetic resonance imaging (MRI) acquired fat-water features. Secondary outcomes include changes in serum insulin levels, serum insulin-like growth factor (IGF)-1 to insulin-like growth factor binding protein (IGFBP)-3 ratio, serum IGF-2 levels, serum testosterone levels, serum leptin to adiponectin ratio, body weight, and waist circumference. Exploratory outcomes include changes in metabolomic profiles in plasma and nipple aspirate fluid. Changes in tissue architecture as well as cellular and molecular targets in breast tissue collected in a subgroup of participants will also be explored. Discussion: The study will evaluate whether metformin can result in favorable changes in breast density, select proteins and hormones, products of body metabolism, and body weight and composition. The study should help determine the potential breast cancer preventive activity of metformin in a growing population at risk for multiple diseases.