Includes bibliographical references and index.

abstract: This study examined the effect of consuming pinto, black, and dark red kidney beans with white rice in comparison to a white rice only control meal on the glycemic response of adults with type 2 diabetes (T2D). These bean and rice combinations are part of many traditional diets. Seventeen subjects with T2D treated by diet and/or metformin were randomly assigned to 4 treatments: white rice (control), pinto beans/rice, black beans/rice, and dark red kidney beans/rice. All treatments were portioned by weight and matched for available carbohydrate content of &sim; 50 grams. Capillary whole blood samples were collected at baseline and at 30, 60, 90, 120, 150 and 180 minutes posttreatment and assessed for glucose concentration using the YSI Stat Plus Analyzer. Net change glucose responses were significantly lower for the pinto, black, and dark red kidney bean and rice meals than control at 90, 120 and 150 minutes posttreatment (P < 0.05). Incremental area under the curve (iAUC) values were also significantly reduced for the bean/rice meals containing pinto (P < 0.01) and black beans (P < 0.05) in contrast to the rice control. Results suggest that the combination of whole beans and rice may be beneficial to those with T2D to assist with blood glucose management. / Dissertation/Thesis / M.S. Nutrition 2011

AN ABSTRACT OF THE THESIS OF Rebecca Startzer, for the Master of Science degree in Community Nutrition, presented on November 6, 2008, at Southern Illinois University Carbondale. TITLE: A PILOT STUDY ON THE EFFECT OF A COMMUNITY-BASED LIFESTYLE INTERVENTION FOR MIDDLE SCHOOL STUDENTS WHO ARE "AT RISK" FOR TYPE 2 DIABETES MAJOR PROFESSOR: Dr. Sharon Peterson The prevalence of childhood Type 2 Diabetes Mellitus (T2DM) has increased by 33% over the last 15 years (Kaufman, 2002). With the growing number of adolescents with T2DM, it is important to identify adolescents who are "at risk" for T2DM and develop programs to help delay or prevent T2DM. Our pilot study, "R .U. A. Healthy Kid?" sought to examine the relationship of middle school students "at risk" for T2DM and lifestyle factors, including family meals, physical activity, and "screen time" in an effort to reduce their risk through a community-based intervention. At baseline a significant negative correlation was found between "screen time" levels and fruit (p= 0.041) and vegetable (p = 0.046) intake and a significant positive correlation between "screen time" levels and physical activity levels (p=0.006). At three months, a significant positive correlation was found between family meals at home and vegetable intake increased (p=0.024) and a significant positive correlation between family meal frequency increased and physical activity levels (p=0.047). From baseline to three months, frequency of family meals at home decreased (p=0.021). From this study, it could be concluded that improving "at risk" adolescent's behaviors related to family meals, physical activity, and "screen time" levels are critical while developing successful interventions for adolescents "at risk" for T2DM.

Previous studies have shown that overweight and obesity in youth and adolescents is one of the leading risk factors for developing Type 2 diabetes mellitus (T2DM). Besides being "at–risk” for T2DM, the possibility also exists for development of major psychological issues. Thus, overweight adolescents who are "at–risk” for T2DM may have increased levels of emotional eating, and poor self–esteem and body image. The design of this pilot study ("R. U. A Healthy Kid”) was a prospective cohort of 17 free–living middle school students "at–risk” for T2DM. Each participant was previously screened and found to have three or more risk factors for T2DM. The intervention targeted four main topics: Family Meals, Healthy Snacks, Physical Activity and "Unique U” (emotional eating, self–esteem, body image and stress management). The "Unique U” component forms the basis of the current study. After three months in the program, participants’ self–esteem significantly increased since the beginning of the program. Many relationships were found between self–esteem, body image, stress and emotional eating questions. Community– based lifestyle interventions that include issues such as improving self–esteem, body image, stress and emotional eating are critical in helping adolescents who are "at–risk” for T2DM.

Diabetes is a global epidemic that has unfortunately been significantly increasing in number of cases annually. It is currently the 7th leading cause of death in the United States and leads to many further complications including cardiovascular disease, neuropathy, retinopathy, and kidney failure. With the increase in Western dietary patterns there has been a subsequent rise in both obesity and diabetes. In fact, type 2 diabetes makes up 90% of diabetes cases and is, in most cases, preventable with lifestyle changes and weight loss. The aim of this review is to look at the option of a plant-based diet as a means of prevention and treatment for type 2 diabetes. In order to understand type 2 diabetes the basics of pathophysiology, risk factors, statistic, complications and current treatments is discussed. Based on an analysis of a low-fat, plant-based diet compared to current conventional type 2 diabetes treatments there is evidence that a vegan diet increases insulin sensitivity, decreases body weight, lowers cardiovascular risk factors, and decreases need for oral antidiabetic treatments. A review of the efficacy of a plant-based diet for treatment and prevention of type 2 diabetes is also discussed in-depth. Further studies may be helpful to validate adopting a low-fat, plant-based diet in treatment of type 2 diabetes. Overall, it is important for physicians to address the individual needs of their patients and allow for the option of lifestyle changes with adequate guidance and support.

Genome Wide Association Studies (GWASs) have identified variants associated with disease that promise to deliver insights into disease aetiology. However, because many GWAS variants lie in non-coding genomic regions, it is difficult to define the genes and pathways underlying a GWAS signal. The possibility of linking GWAS variants to molecular traits, combined with the development of high throughput assays, has motivated the mapping of molecular quantitative trait loci (QTLs), genetic associations with molecular traits such as gene expression (eQTLs) and DNA methylation (mQTLs). The Finland-United States Investigation of NIDDM (FUSION) tissue biopsy study is motivated by the desire to understand the molecular pathogenesis of Type 2 diabetes (T2D), a complex disease where the vast majority of the ~100 independent GWAS loci occur in non-coding regions. To elucidate the molecular mechanisms underlying these signals, we collected skeletal muscle biopsies, a T2D-relevant tissue, from 318 extensively phenotyped individuals who exhibit a range of glucose tolerance levels. From these biopsies, we generated genotype, gene expression, and DNA methylation information, enabling us to directly measure the effects of T2D on molecular traits, and to link non-coding T2D GWAS loci to candidate molecular targets. In this thesis, I present a catalogue of genetic effects on gene expression and DNA methylation. I use this catalogue firstly, to reveal basic biology of the genetic regulators of skeletal muscle molecular traits, and secondly, to identify molecular traits that are relevant to T2D, glycemic, and other complex traits. In regards to basic biology, I characterise the broader genomic context of QTLs by calculating the enrichment of QTLs in chromatin states across a diverse panel of cell/tissue types. I also identify key skeletal muscle transcription factors (TFs) and classify them as activators or repressors by aggregating the effects of QTLs predicted to perturb TF binding sites. In addition, I characterise the properties of methylation sites associated with gene expression and use inference models to dissect these methylation-expression relationships, classifying cases where the genetic effect is mediated by methylation, expression, or is independent. I also integrate molecular trait genetics with complex traits. First, I perform a conditional analysis, mapping GWAS variants for T2D and glycemic traits to molecular traits, prioritising disease relevant skeletal muscle molecular traits. Second, recognising QTLs may also be specific to a disease state or environmental context, I leverage the rich phenotyping of participants to map genotype by environment (GxE) effects on gene expression—eQTLs that exhibit effects specific to an environmental context. Altogether, these analyses form a thorough survey of the genetic regulators of skeletal muscle expression and DNA methylation, and provide an important resource for interpreting complex diseases.

Glucocorticoid excess as a result of Cushing’s syndrome or pharmacological treatment can result in the development of obesity and type 2 diabetes mellitus (T2DM). The reactivation of cortisone to cortisol is catalysed by 11βHSD1 which is expressed widely but notably in adipose tissue and liver. Studies have shown dysregulation of cortisol in these tissues with obesity potentially promoting the development of T2DM. Inhibition of 11βHSD1 has been attempted as a novel treatment for T2DM with observed improvement in glycaemic control, body weight and blood pressure. The efficacy of such agents has been disappointing with few reaching phase 2 trials. With recent evidence of bidirectional activity of 11βHSD1 in vivo it becomes apparent that dysregulation may occur at an intracellular rather than tissue level. In this thesis I address several key outstanding questions concerning the physiology and regulation of 11βHSD1 including: 1. Whether combined therapy with metformin alters 11βHSD1 activity and obscures the efficacy of 11βHSD1inhibitors; 2. Whether the contribution of 11βHSD1 to local cortisol concentrations has been under-estimated by considering total rather than free cortisol turnover; and 3. Whether recycling between cortisol and cortisone in adipose tissue and skeletal muscle in obesity is a neglected feature of 11βHSD1 biochemistry and function. Eight obese healthy men with and without type 2 diabetes were recruited to a randomised placebo controlled cross over trial. They received 4 weeks treatment with metformin and placebo. Participants with T2DM additionally received gliclazide as a further control. Using the deuterated tracer D4-cortisol 11βHSD1 activity was measured. Metformin treatment increased whole body 11βHSD1 in both groups postulated as a result of improved insulin sensitivity. 11βHSD1 is located within cells and so contributes to free tissue cortisol concentrations but perhaps less so to total (protein-bound) cortisol in plasma. It has been shown that 11βHSD1 contributes almost half of total circulating cortisol concentrations at rest. This measurement relied upon blood sampling during steady state deuterated cortisol (D4-cortisol) infusion with measurements of total (free plus protein bound) cortisol which may have underestimated true 11βHSD1 activity. This was therefore investigated by comparing 11βHSD1 activity as calculated using total compared with free cortisol tracer enrichments. Equilibrium dialysis was performed separating free from bound portions in plasma samples taken from healthy volunteers who received D4-cortisol infusion. Analysis revealed similar measurements of 11βHSD1 activity using free compared with total cortisol implicating rapid turnover of glucocorticoids between the free and bound pools. On first discovery 11βHSD1 was seen to be a dehydrogenase enzyme in vitro. Later work recognised reductase activity in vivo and up until recently 11βHSD1 has been viewed as a predominantly reductase enzyme. As with other enzymes in the same family, the ability to catalyse both reductase and dehydrogenase depends upon the availability of substrate and co substrate. Whether dysregulation of 11βHSD1 in the settings of obesity and T2DM is the result of alteration in directionality at a cellular level is not known. Firstly bidirectional activity of 11βHSD1 was confirmed in vitro using HEK-293 cells stably transfected with 11βHSD1. The influence of obesity and acute perturbation with hyperinsulinaemia was subsequently investigated in vivo in a random order cross over single blinded case control study involving ten normal weight and ten obese healthy male volunteers. D4-cortisol and deuterated cortisone (D2-cortisone) were infused for the measurement of reductase and dehydrogenase activity of 11βHSD1 respectively with measurements taken across forearm muscle and abdominal subcutaneous adipose tissue. Across whole body, lean and obese individuals displayed similar 11β-reductase and 11β-dehydrogenase activity. Across tissue, 11β-reductase and 11β-dehydrogenase activity was different from zero across adipose tissue in obese individuals and across skeletal muscle in lean individuals providing further evidence of tissue specific differences in 11βHSD1 with obesity. With the addition of hyperinsulinaemia, reductase and dehydrogenase activity was somewhat increased in lean individuals although there was no statistically significant difference between lean and obese individuals. Across tissue there was a trend for obese individuals to display increased 11β-reductase activity across adipose tissue with hyperinsulinaemia. Comparing the rates of reductase and dehydrogenase activity revealed predominantly reductase activity across tissue in obese and dehydrogenase activity in lean individuals. The development of direction specific inhibitors targeting reductase activity by 11βHSD1 may prove efficacious for the treatment of obesity. In conclusion, 11βHSD1 acts as a bidirectional enzyme in vitro and in vivo. Overall directionality of enzyme activity is altered in a tissue specific manner in the setting of obesity. We have shown that this intracellular regulation of cortisol is reflected equally in the metabolically active free pool and total plasma pool. The efficacy of 11βHSD1 inhibitors as novel agents for the treatment of T2DM and coexisting obesity is not diminished by co-prescription with metformin but may prove more efficacious through the development of reductase specific inhibitors.

Increasingly chronic liver disease is being acknowledged as a complication of type 2 diabetes, in particular non-alcoholic fatty liver and non-alcoholic fatty liver disease. Rates of non-alcoholic fatty liver are higher in people with type 2 diabetes than in the general population, with prevalence rates believed to be between 40-70%. Given the aging Scottish population and the obesity driven diabetes epidemic, the problem of chronic liver disease is likely to increase. Despite this there has been little investigation into the natural history of nonalcoholic fatty liver disease and the risks of clinically significant chronic liver disease in community based cohorts because diagnosis has been heavily reliant on liver biopsy. The use of liver biopsy is limited in both research and clinical practice due to its associated high mortality (1/1000) and morbidity and also due to practical limitations (sampling variability, semi-quantitative scoring systems). As a result the use of non-invasive markers of liver injury (non-specific liver injury, steatosis, steatohepatitis, liver fibrosis and surrogates of advanced portal hypertension) are rising, in the diagnosis of chronic liver disease, however, their utility in both community cohorts and patients with type 2 diabetes has not been widely studied. The aims of the studies presented in the thesis, using the Edinburgh Type 2 Diabetes Study, were: (i) to describe the distributions of a range of non-invasive markers of steatohepatitis and liver fibrosis in older people with type 2 diabetes, their relationship with metabolic and liver disease risk factors, and to compare the agreement of different non-invasive markers of hepatic fibrosis; (ii) to determine the frequency (prevalence and incidence) of and risk factors for clinically significant chronic liver disease in people with type 2 diabetes; and (iii) to determine the importance of chronic liver disease as a risk factor (or risk marker) for cardiovascular mortality or morbidity in type 2 diabetes. Prior to undertaking this work I undertook a detailed systematic review of the literature relating to the use of non-invasive markers of hepatic fibrosis to inform the choice of markers used in the study. Examination of a wide range of potential markers of steatohepatitis and liver fibrosis found varied relationships with diabetes history. Most commonly, elevated markers of steatohepatitis and liver fibrosis were associated with older age and higher body fat measures. However, most of these relationships between liver markers and body fat measures lost statistical significance when limiting the population to only those with hepatic steatosis and/or non-alcoholic fatty liver disease. There were marked differences in the associations between different liver fibrosis markers and potential diabetes and metabolic risk factors, suggesting that these markers are not actually measuring the same underlying “fibrosis” condition. There was poor correlation between the five markers of liver fibrosis studied. Using the top vigintile (5%) of each marker resulted in excellent agreement on the absence of advanced liver disease but poor agreement on the presence of advanced liver disease. The prevalence of clinically significant CLD (defined as cirrhosis, HCC or gastrooesophageal varices) was 2.2% - 0.9% diagnosed prior to enrolment with an additional 1.4% identified by study investigations. Over nearly 6 years of follow-up, only 1.4% of the cohort developed incident clinically significant CLD. Higher levels of systemic inflammation, steatohepatitis and hepatic fibrosis markers were associated with both unknown prevalent and incident clinically significant chronic liver disease. Less than half of participants developing incident significant disease were identified as high risk by the study investigations. Abnormal liver enzymes were statistically significantly associated with incident cases, however the presence of hepatic steatosis was not. There were 372/1033 (36.0%) patients with prevalent CVD and 319 (30.9%) with prevalent CAD at baseline. After mean follow-up of 4.4 years there were 44/663 incident CVD events, including 27 CAD events. There were 30/82 CVD related deaths. However, risk of dying from or developing CVD was no higher in subjects with steatosis than in those without. There was also no statistically significant relationship between CVD and steatohepatitis or liver fibrosis. The only statistically significant relationship between CVD and any liver markers was with GGT (prevalent CVD, OR 1.28, p=0.007; incident CAD, OR 2.35, p=0.042), suggesting that in our study population, CLD may have little effect on the development of, or mortality from, CVD. In conclusion, the potential for using non-invasive biomarkers to diagnose clinically significant chronic liver disease in type 2 diabetes remains limited, however chronic liver disease is a significant problem in older people with type 2 diabetes and is frequently undiagnosed.

maria.cristina.rc2690@gmail.com / Article / Introduction: There is limited and controversial information regarding the potential impact of depression on glycemic control. This study aims to evaluate the association between depression and poor glycemic control. In addition, the prevalence of depression and rates of poor glycemic control were determined. Methods: Cross-sectional study performed in the endocrinology unit of two hospitals of ESSALUD in Peru. The outcome of interest was poor glycemic control, evaluated by glycated hemoglobin (HbA1c: < 7% versus ≥ 7%), whereas the exposure of interest was depression defined as 15 or more points in the Patient Health Questionnaire-9 tool. The association of interest was evaluated using Poisson regression models with robust standard errors reporting prevalence ratios (PR) and 95% confidence intervals (95% CI) adjusting for potential confounders. Results: A total of 277 participants, 184 (66.4%) males, mean age 59.0 (SD: 4.8), and 7.1 (SD: 6.8) years of disease were analyzed. Only 31 participants (11.2%; 95% CI: 7.5%–14.9%) had moderately severe or severe depression, whereas 70 (25.3%; 95% CI 20.3%–30.8%) had good glycemic control. Depression increased the probability of having poor glycemic control (PR = 1.32; 95% CI 1.15–1.51) after adjusting for several potential confounders. Conclusions: There is an association between depression and poor glycemic control among type 2 diabetes patients. Our results suggest that early detection of depression might be important to facilitate appropriate glycemic control and avoid further metabolic complications. / We would like to thank Dr Viviana Ulloa who helped us to access data and T2D patients, and Dr Percy Mayta- Tristan for revising initial versions of the manuscript. AB-O is supported by Wellcome Trust Research Training Fellowship in Public Health and Tropical Medicine (Grant number 103994/Z/14/Z). / Revisión por pares

Genome wide association studies (GWAS) have transformed the study of the heritability of complex diseases such as type 2 diabetes (T2D), with the current tally of established risk loci close to ninety. Each of these loci has the potential to offer novel insights into the biology of this disease, and opportunities for clinical exploitation. However, the complexity of T2D has often frustrated efforts to achieve these functional and translational advances. This thesis aims to delve into the functional characterisation of two known susceptibility loci, KLF14 and ADCY5, and describe findings relevant to disease pathology. KLF14 and ADCY5 are two loci associated with T2D predisposition working through disparate mechanisms. Variants at the maternally imprinted KLF14 locus are associated with measures of insulin resistance and expression data has implicated KLF14 as a master regulator of genes in adipose tissue. In contrast, variation at the ADCY5 locus is associated with impaired beta cell function, high fasting glucose, and low birth weight suggesting ADCY5 is having an effect on insulin secretion. In this thesis, ENU mouse models of these two genes are investigated functionally to elucidate more about the pathology of common human variation at these loci. A mouse model was derived with an ENU point mutation at Adcy5 Y1064C. Phenotyping of this model revealed improved oral glucose tolerance, and secretion studies from isolated islet cells demonstrated impaired glucagon secretion from mice homozygous for the Y1064C mutation in the presence of adrenaline. These results suggest that Adcy5 is involved in glucagon regulation in the alpha cell. The Adcy5 Y1064C confers a protective effect against hyperglycaemia in mouse indicating that the T2D risk allele at the ADCY5 locus in humans may have the opposite direction of effect. A mouse model containing the ENU point mutation Klf14 R238L predicted to be disruptive to KLF14 protein function showed no significant difference in body weight, measures of insulin resistance, or blood cholesterol. However, expression of several genes associated in trans with variation near KLF14 in humans was changed in adipose tissue and skeletal muscle when the R238L mutation was inherited maternally compared to mice which had inherited the mutation paternally or carried two wild type alleles. This result suggests a mechanism by which Klf14 is regulating genes across metabolic tissues.