Indiana University-Purdue University Indianapolis (IUPUI) / Medication adherence remains a problem among Type-2 diabetes (T2D) patients despite availability of effective treatments. Three analyses of extant data sets were conducted to examine barriers to using medication as prescribed as an alternate method to assess medication adherence: 1) development and psychometric evaluation of the Murage-Marrero-Monahan-Medication barriers (4M) scale to assess patients’ perceived barriers; 2) patient demographic factors associated with barriers to using medication as prescribed, and 3) the association between patients’ perceived barriers to medication use and cardiovascular disease (CVD) risk factor control.Twelve focus groups and a cross-sectional study of 362 T2D patients contributed to develop and evaluate psychometric properties of the 4M scale. A cross-sectional survey of 964 T2D patients was used for the other two studies. Analysis of covariance identified demographic factors associated with reported barriers. Multivariable logistic regression was used to identify barriers associated with CVD risk factors (glucose, blood pressure and lipids) categorized as either poor or good control. Exploratory factor analysis with Varimax rotation resulted in a 19-item 4M scale with acceptable psychometric properties. As a five-domain (or single-domain) structure, coefficient alpha ranged from 0.70 to 0.83 (0.92). Both structures demonstrated discriminant validity and known-group validity. Age was inversely associated with all identified barriers while income was inversely associated with poor communication with providers and side effects. A unit increase in the overall barrier mean score on the 4M scale was associated with 92% increase in the odds of having poor control of two or more CVD risk factors compared to good control of all three risk factors (adjusted OR=1.92, 95% CI: 1.16–3.17; p<0.05). The 4M scale demonstrated acceptable psychometric properties in assessing barriers to using medication among T2D patients. Poor medication adherence has been previously associated with CVD risk. In this study, greater barriers were associated with poorer control of CVD risk factors making barriers a potential alternative to medication adherence, whose current assessment methods are limited. The 4M scale has the advantage to identify specific barriers inhibiting medication use that can facilitate patient-provider discussions and the development of targeted interventions. / Some parts of this dissertation work were jointly funded by Program Announcement 04005 from the Centers for Disease Control and Prevention (Division of Diabetes Translation) and the National Institute of Diabetes and Digestive and Kidney Diseases. The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the funding agency(s).

Indiana University-Purdue University Indianapolis (IUPUI) / Diabetes mellitus is a group of related metabolic diseases that share a common pathological mechanism: insufficient insulin signaling. Insulin is a hormone secreted from pancreatic β cells that promotes energy storage and consequently lowers blood glucose. In contrast, the hormone glucagon, released by pancreatic α cells, plays a critical complementary role in metabolic homeostasis by releasing energy stores and increasing blood glucose. Restoration of β cell mass in diabetic patients via β cell regeneration is a conceptually proven approach to finally curing diabetes. Moreover, in situ regeneration of β cells from endogenous sources would circumvent many of the obstacles encountered by surgical restoration of β cell mass via islet transplantation. Regeneration may occur both by β cell self-duplication and by neogenesis from non-β cell sources. Although the mechanisms regulating the β cell replication pathway have been highly investigated, the signals that regulate β cell neogenesis are relatively unknown. In this dissertation, I have used zebrafish as a genetic model system to investigate the process of β cell neogenesis following insulin signaling depletion by various modes. Specifically, I have found that after their ablation, β cells primarily regenerate from two discrete cellular sources: differentiation from uncommitted pancreatic progenitors and transdifferentiation from α cells. Importantly, I have found that insulin and glucagon play crucial roles in controlling β cell regeneration from both sources. As with metabolic regulation, insulin and glucagon play counter-balancing roles in directing endocrine cell fate specification. These studies have revealed that glucagon signaling promotes β cell formation by increasing differentiation of pancreas progenitors and by destabilizing α cell identity to promote α to β cell transdifferentiation. In contrast, insulin signaling maintains pancreatic progenitors in an undifferentiated state and stabilizes α cell identity. Finally, I have shown that insulin also regulates pancreatic exocrine cell development. Insufficient insulin signaling destabilized acinar cell fate and impairs exocrine pancreas development. By understanding the roles of pancreatic hormones during pancreas development and regeneration can provide new therapeutic targets for in vivo β cell regeneration to remediate the devastating consequences of diabetes.

Includes publications published as a result of ideas developed in this thesis, inserted at end. / "April 2005" / Includes bibliographical references (leaves 210-242) / 242 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines goal setting in people with diabetes as part of chronic disease management in a rural setting. The studies were performed in Eyre Peninsula with a significant (10-20%) Aboriginal population. / Thesis (M.D.)--University of Adelaide, Dept. of General Practice, 2005

Type 2 diabetes is still rapidly on the rise today, affecting 10.5% of individuals in the United States between the ages 45 to 64 and 18.4% of those between the ages of 65 to 74. In the past two decades, type 2 diabetes has doubled in all age groups. Many adults with type 2 diabetes experience difficulty managing their blood sugars, which can result in a range of further complications. One of the newest treatment options on the market today is a glucagon-like peptide-1 (GLP-1) receptor agonist, Bydureon. Similar to Byetta, Bydureon has a main ingredient of exenatide. It offers once a week dosing as opposed to twice-a-day, which may be more appealing to patients. The purpose of this study was to examine the efficacy of a newly FDA released medication, Bydureon, once weekly dosage in adults with type 2 diabetes. A descriptive, comparative, retrospective study of 35 patients evaluated efficacy by examining Hgb A1C and body mass index in adults with type 2 diabetes at baseline and 3 months after Bydureon was prescribed. Data were collected by a chart review of records in a primary care practice. Results demonstrated a statistically significant difference between baseline to 3 month means in both Hgb A1C (t (34)= -3.05, p=.0044) and BMI (t (34) = -2.86, p = .0072) for patients using Bydureon. Health care providers need to individualize the patients’ plans of care to address multifactorial areas of their diabetes care and provide them with an opportunity to successfully meet their goals. Practitioners must be knowledgeable about the treatment options available, including the newer GLP-1 receptor agonist, Bydureon and its efficacy for adults with type 2 diabetes.

Embarking on a quest to uncover the shared experiences of Latinos with diabetes in the Central San Joaquin Valley is the principal issue discussed in this body of work. Diabetes is estimated to become a serious public health problem, with a current estimate of more than 30 million already afflicted. Engaging in participant-observation at a local clinic serving patients in a Diabetes Education Program and semi-structured interviews with Latinos attending the program, this research explores cultural experiences of diabetes. The primary aim of this research is to answer how health education information is accepted and interpreted based on cultural definitions of diabetes to inform diabetes management strategies.