Browsing by Subject "Diabetes"
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Item Antipsychotic drug utilization patterns and treatment-emergent diabetes: a methodological comparison of incidence using a claims database(2006) Yang, Min; Barner, JAmie C.The study purposes were to: 1) examine antipsychotic utilization trends; and 2) evaluate relationships between antipsychotic utilization and treatment-emergent diabetes when methodologies varied while controlling for covariates. Claims databases from North and South Texas Veterans Administration (1993-2004) were used to identify adults newly initiated on antipsychotics. For Purpose 2, only patients with no previous diabetes were eligible. Seven models were created based on the following methodological variations: 1) study designs (retrospective cohort and case-control); 2) treatment exposure assignment (intent-totreat (ITT) and as-treated (AT)); and 3) statistical approaches (propensity scoring, standard and conditional logistic regression, and Cox proportional hazards function). Covariates included: demographics, general health comorbidities, mental health comorbidities, drug utilization patterns, treatment duration, medication re-exposure, and treatment initiation year. Regarding Purpose 1, from 1997-2003, antipsychotic utilization shifted from first to second generation, with olanzapine and risperidone most frequently prescribed. Monotherapy was the predominant utilization pattern with switching and combination therapy used infrequently. Of the eligible patients (N=8,949) for Purpose 2, regardless of variations in methodologies of the seven tested models (eight models were proposed), there were no significant differences in diabetes risk among patients who were: 1) initiated on SGAs compared to those on FGAs; 2) initiated on olanzapine compared to those on risperidone; and 3) exposed to olanzapine or quetiapine compared to those exposed to FGAs. Inconsistent results among the seven models were observed when comparisons were made between: 1) patients initiated on quetiapine compared to those on risperidone; and 2) patients exposed to risperidone compared to those exposed to FGAs. Differences occurred among the following methods: ITT retrospective cohort and ITT case-control; and AT retrospective cohort and AT case-control. With respect to antipsychotic utilization, results of the various models using different methodologies were largely consistent.Item Beneficial effects of dietary L-arginine supplementation to diabetic rats(Texas A&M University, 2004-09-30) Kohli, RiplaDiabetic rats exhibit decrease in plasma arginine, NO synthesis and tetrahydrobiopterin in endothelial cells (EC). Treatment with L-arginine may be beneficial for enhancing NO synthesis in diseases associated with endothelial dysfunction. However, little is known about the mechanism responsible for the stimulatory effect of arginine on endothelial NO synthesis. We hypothesized that dietary arginine supplementation increases BH4 for NO synthesis in EC of diabetic rats, thereby preventing endothelial dysfunction. In experiment I, streptozotocin (STZ) induced-diabetic male Sprague Dawley (SD) rats (a model of type-I diabetes) were individually pair-fed a casein-based diet on the basis of feed intake (per kg body weight) of non-diabetic SD rats. Addition of arginine-HCl or alanine to drinking water for the rats were adjusted daily to ensure isonitrogenous provision per kg body weight. In non-diabetic rats, arginine supplementation increased plasma arginine (144%), plasma insulin (44%), EC arginine (88%), EC BH4 (106%) and EC NO synthesis (80%), compared with alanine treatment. In diabetic rats, arginine supplementation reduced body weight loss (36%), and plasma glucose (54%), and increased plasma arginine (110%), plasma insulin (209%), EC arginine (173%), EC BH4 (128%) and EC NO synthesis (125%), compared with alanine treatment. In experiment II, male Zucker diabetic fatty (ZDF) rats (a model of type-II diabetes) were individually pair-fed a Purina 5008 diet on the basis of feed intake by alanine-treated diabetic rats (per kg body wt). Addition of arginine-HCl or alanine to drinking water for the rats was adjusted daily to ensure isonitrogenous provision per kg body weight. Arginine supplementation to ZDF rats did not affect plasma glucose and insulin, reduced epidididmal fat (30%), abdominal fat (43%) and body weight gain (18%), and increased plasma arginine (273%), EC arginine (197%), EC BH4 (120%) and EC NO synthesis (122%), compared with alanine-treated ZDF rats. These results show that dietary L-arginine supplementation increases BH4 and NO synthesis in EC of both STZ-diabetic and ZDF rats. Strikingly, arginine treatment prevented hyperglycemia in STZ-diabetic SD rats and reduced obesity in ZDF rats. Collectively, results demonstrate that oral administration of arginine is beneficial for both type-I and type-II diabetic rats.Item Blood Sugar and Brothers' Voices: An Exploratory Study Of The Self-Care Management Experiences of African-American Men Living With Type 2 Diabetes(2013-07-23) Sherman, Ledric DSelf-care is the key to living a long and healthy life for people with diabetes. Yet numerous studies show that self-care is far from optimal. This has resulted in attempts to understand the progress underlying self-care behavior in the efforts of mediating more effectively. While there are an abundance of studies focusing on African-American women and diabetes management, there is a considerable gap in health education literature regarding the self-care management experiences of African-American men living with type 2 diabetes. The management and impact of type 2 diabetes on the sense of self, lifestyle, and significant others of the African-American man are not clearly comprehended. Therefore, the purpose of the study was to explore the knowledge, beliefs, and self-care management practices of African American men living with type 2 diabetes. This was an exploratory study utilizing qualitative methodology to understand the knowledge, beliefs, and existing self-care management practices of up to 50 African-American men, ages 18-70, living with type 2 diabetes. Participants had one-on-one semi structured interviews with the primary investigator. The instruments that were used consisted of two parts: one was a self-administered paper/pencil questionnaire to collect socio-demographic information. The second was a semi-structured interview. The study significance was to identify and understand the barriers to type 2 diabetes management and how they had an adverse influence on self-care. A combination of high barriers, poor daily self-care, management, and knowledge possibly put those with type 2 diabetes at an elevated risk for subordinate self-care management. Barriers had a role in reality and diabetes researchers and educators are charged with recognizing the complications of what individuals with type 2 diabetes need to do improve and enhance their health. The study findings revealed that the participants labored with managing their diabetes and some counted on their own potential or performance, as well as the encouragement of their family, extended family, neighbors, and friends. Also, many of the participants had a unified theme in that regarding self-care management, having type 2 diabetes affected those in their surrounding environment, not just the person living with the illness. In conclusion, the study findings suggest that future diabetes research and education among African-American men should give attention to male masculinity and the powerful influence it has on utilizing preventive health services. The limited amount of African-American men included in empirical type 2 diabetes research could help explain the under addressed barriers and complexities to positive self-care management.Item Depression in patients with diabetes : risk factors, medication-taking behaviors, and association with glycemic control(2010-12) Suehs, Brandon Thomas; Lawson, Kenneth Allen, 1952-; Smith, Tawny Bettinger; Barner, Jamie C.; Crismon, Miles L.; Garcia, Alexandra A.This study evaluated the epidemiological relationship between diabetes and incident depression, as well as antidepressant medication utilization among indigent care patients diagnosed with diabetes. Medical data for 2,886 subjects receiving care in a public indigent care provider network were utilized for this study. Diagnoses of diabetes, depression, and other comorbid medical conditions were identified from the electronic medical record. Prescription claims data from the clinic pharmacy network were used to evaluate medication-taking behaviors. Clinical laboratory data were extracted, as available, from the electronic clinic records. After controlling for the influence of age, gender, race/ethnicity, marital status classification, and Charlson score, a diagnosis of diabetes was associated with a 42 percent reduction in odds of new-onset depression (p = 0.021). In the a priori analysis of factors associated with new-onset depression among diabetic patients, none of the risk factors evaluated were associated with incident depression at a statistically significant level. Post-hoc exploratory analyses revealed that female gender and White non-Hispanic race/ethnicity were associated with increased odds of a prevalent diagnosis of depression among diabetic patients. Patients with diabetes were more likely to be prescribed selective serotonin reuptake inhibitors (SSRIs) as their initial antidepressant medication compared to non-SSRIs. Diagnosis of diabetes was not associated with antidepressant switch, discontinuation, or 6-month antidepressant adherence; however, diagnosis of diabetes was associated with a higher level of 12-month antidepressant adherence (p = 0.024). Diagnosis of diabetes was also associated with a higher level of 3-month antidepressant persistence (p = 0.004), but not 12-month persistence. There were no statistically significant relationships observed between initial class of antidepressant medication prescribed and any of the medication-taking behaviors evaluated. For subjects with available data (n = 106), glycemic control was evaluated in terms of hemoglobin A1c. Increased antidepressant medication adherence was associated with higher hemoglobin A1c values during follow-up. Results suggest that prevalent diabetes is associated with a reduced risk of diagnosis of new-onset depression in indigent care patients. Further research is necessary to evaluate the effect that chronic comorbid medical conditions such as diabetes may have on antidepressant medication-taking behaviors, and the relationship between antidepressant exposure and glycemic control.Item Depressive symptoms, behavioral health risk factors, and physical illness among older Mexican Americans(2010-12) Talavera-Garza, Liza; Holahan, Charles J.; Bigler, Rebecca S.; Iscoe, Ira; Ramirez, Manuel; Warner, David C.This study utilized data from the Hispanic Established Populations for Epidemiologic Studies of the Elderly (H-EPESE) at two different time points, seven years apart, to examine the relationship between physical illness and depressive symptoms in elderly Mexican Americans. The two physical illnesses studied are coronary artery disease and type II diabetes due to their high prevalence among Mexican Americans. The relationship between physical illness and depressive symptoms is examined longitudinally and prospectively, in both directions. In addition, the relationship between depressive symptoms and three behavioral health risk factors: alcohol use, cigarette smoking, and physical inactivity, at baseline is examined. The roles of gender, acculturation, nativity, and locus of control are examined as moderators of the key relationships studied. Additionally, self-rated health at baseline is examined as a predictor of physical illness and mortality at follow-up.Item Designing for lived experience : a suite of tools for people with Type 1 diabetes(2014-05) Kinbarovsky, Jesse Israel; Catterall, Kate; Gorman, Carma; Stuckey, HeatherDiabetes is a chronic, patient-managed illness. Type 1 diabetics must maintain near-constant awareness of their blood sugar levels and perform frequent medical interventions in order to remain alive and healthy. Research has shown that symptoms of poor treatment adherence manifest both physically and emotionally. While a great deal has been written about, and many products designed for, treatment of physiological symptoms and outcomes, far less has been written about, and even fewer products designed to address, the emotional experience of the type 1 diabetic. Yet the emotional effects of chronic illness have been well documented, including the effects of blood glucose variation on mood (Penckofer, 2012) and increased comorbid depression among diabetics (Anderson, 2001). For my thesis project, I have created a connected system of physical and digital tools called the t1D Suite that addresses the unique emotional needs of people with diabetes, thereby bridging the gap between life-giving treatment and life-enriching experience.Item Diabetes and streptozotocin-induced alterations in the rat myocardial [beta]-adrenoceptor system(Texas Tech University, 1985-08) Ramanadham, SasankaDiabetogenic agent streptozotocin (STZ) was used to induce diabetes in male Sprague-Dawley rats. A single i.v. administration of the drug resulted in marked hyperglycemia, glycosuria, polyuria, polydipsia, and hyperphagia. The diabetic state was found to be associated with alterations in cardiovascular tissue responsiveness and sensitivity. Vascular alterations Thoracic aortic strips isolated from STZ-treated animals were found to be less responsive to calcium, relative to control animals. However sensitivity to the a-agonists, norepinephrine and methoxamine, was unchanged. In contrast to aorta, tail arteries were similar in responsiveness to calcium and supersensitive to the contractile effects of the a-agonists. The supersensitivity was found to be associated with decreased tissue norepinephrine content. This indication of neuropathy suggested that both pre- and post-junctional alterations influence sensitivity of the tail artery to a-agonists in STZ-diabetic animals. Myocardial alterations Basal rate of spontaneously beating atria and maximum chronotropic responses to isoproterenol were lowered after STZ treatment. Sensitivity to the B-agonist however, was not affected. Right ventricular tissue isolated from STZ-treated animals was found to be subsensitive to the inotropic effects of isoproterenol. The subsensitivity phenomenon was found to be accompanied by decreased myocardial B-adrenoceptor density, increased basal developed force, and supersensitivity to calcium. Detailed characterization of the subsensitivity phenomenon revealed that it was independent of (a) age of the animal, (b) duration of diabetes up to six months, (c) direct cardiotoxic effects of STZ, (d) resting tension, (e) frequency of stimulation, (f) changes in heart norepinephrine content, (g) BDF, and (h) supersensitivity to calcium. Inotropic responses obtained with methoxamine, an adenylate cyclase (AC)-independent agonist; glucagon, a receptor- and AC dependent agonist; and forskolin, a direct activator of AC; provided indirect evidence for a "defect" in the ability of isoproterenol to activate AC, via B-adrenoceptor stimulation, in hearts obtained from STZ-treated animals. This defect was linked to (1) decreased B-adrenoceptor density and (2) decrease in the high affinity state population of the B-adrenoceptor. Since the high affinity state of the receptor is a necessary intermediate for AC activation and myocardial contraction, it might be proposed that the decreased population of receptors in this state after STZ treatment contributes to the development of inotropic subsensitivity to isoproterenol. It is further proposed that the down-regulation of receptor population is related to an increase in circulating epinephrine levels, which were evident in diabetic animals. It might also be proposed that myocardial inotropic subsensitivity to B-stimulation is an important factor contributing to heart failure seen among diabetic patients.Item Diabetes management and personal interests(Texas Tech University, 1984-12) Havins, William HowardProblems in the management of Type I Diabetes Mellitus have been addressed in previous literature using models of psychopathology. It is suggested that the use of models of psychopathology in investigations of diabetes management problems is inappropriate since the use of such models is predicated on the assumption that poor diabetes management is indicative of psychopathology. The present study sought to determine if a model of normal behavior, developed by John L. Holland (1973), could better explain problems in diabetes management. The present study attempted to gather data from 240 male and 240 female diabetes patients by seeking the participation of 143 physicians in five states. Twenty-seven physicians agreed to participate in the study, offering to gather data from a total 4651 patients (1065 patients per month). Seven physicians actually returned completed data (N = 99; male = 50, female = 49). Data gathered from each subject included a single glycosylated hemoglobin measure, a blood test that gives an estimate of individuals' levels of diabetes management for the previous 90-120 days, done on the same day that patients completed copies of Holland's "Self-Directed Search" (1977), a paper-and-pencil type interest inventory that assesses individuals' interests and self-estimates of skills and abilities in each of the six areas included in Holland's theory of personality (1973). Because of the small amount of data received from physicians, present data were analyzed and compared to data from a pilot study (Havins, Winer, Wysocki, Bourgeois & Varma, 1982) to determine if relationships between glycosylated hemoglobin measures and patients' scores on the "Self-Directed Search" were consistent. These relationships were not found to be consistent between samples. On the basis of the present comparisons there is no support for the idea that Holland's theory of normal behavior can explain problems in Type I diabetes mellitus management. Reasons for failure to find such a relationship are discussed.Item Eating frequency and obesity and metabolic disease risk in Hispanic youth(2016-05) House, Benjamin T.; Davis, Jaimie Nicole; Bray , Molly S; Pasch , Keryn N; Ranjit, Nalini; Forman, Michele RThe objective of this study was to analyze the relationship between eating frequency and adiposity and associated metabolic disease risk. The main hypothesis was that increased eating frequency compared to infrequent eating frequency would be related to reduced adiposity and metabolic disease markers, as well as healthier dietary and physical activity behaviors in Hispanic youth. For this investigation four cross-sectional analyses were performed in Hispanic youth age 8-19 y with a combined sample size of 1185. Three of the studies completed included gold standard measures of dietary intake, body composition, metabolic parameters, physical activity, and specific fat distribution. The forth included a questionnaire filled out by over 700 Hispanic college freshmen age 18-19 y at the University of Texas at Austin. The first two analyses included two separate cohorts of overweight or obese minority youth ages 8-18 y (n=185 and n=191)1,2. Frequent Eaters (4.0 eating occasions (EOs) per day) compared to Infrequent Eaters (2.4 EOs per day) consumed more calories per day (p≤0.01), ate more often (p≤0.01), consumed less calories per EO (p≤0.01), yet exhibited lower visceral adipose tissue (p=0.03), BMI (p≤0.01), waist circumferences (p≤0.01), fasting insulin (p=0.02), HOMA-IR values (p=0.02), and lower triglycerides (p≤0.01), and higher beta cell function (p=0.01) and acute insulin response (p=0.02). To date, these were the first studies investigating eating frequency and adiposity and metabolic disease risk in Hispanic youth. We know minority youth tend to eat less often than Non-Hispanic Whites and that first year college students are particularly susceptible to weight gain and poor overall health. Given this combined with our previous findings and that in Hispanic high school graduates were more likely to be enrolled in college than NHW or blacks, we wanted to further explore this high risk population as they transitioned to college. We conducted a large cross-sectional study with 709 Hispanic college freshmen that completed a questionnaire to identify eating frequency, physical activity levels and reported height and weight. We found eating frequency to be positively related to moderate to vigorous physical activity (MVPA), but not overweight or obesity prevalence. Also, those who ate 4 or more times per day were 2.5 times more likely to spend at least 150 minutes in MVPA per week compared to those who ate 2 or less times per day. We further brought in 100 of the 709 in for extensive in-person testing in which 92 subjects had complete data. We found frequent eaters ate 44% more often (p≤0.01) and consumed 27% less calories per eating occasion (p≤0.01), while consuming 21% more kcals per day (or 445 less kcals per day) (p≤0.01) compared to infrequent eaters. Frequent eaters had 8% lower BMIs (p=0.02), 60% lower BMI z-scores (p=0.03), 21% lower visceral adipose tissue (p=0.03), 26% lower subcutaneous adipose tissue (p=0.03), and 8% higher total body fat (p=0.04) compared to infrequent eaters. These findings suggest that increased eating frequency is related to decreased obesity and metabolic disease risk in Hispanic youth and Hispanic college freshmen, despite increases in energy intake. Additionally, in a very large and exclusively Hispanic college freshmen population eating frequency was related to self-reported increases in physical activity. Thus, increasing eating frequency may be a viable public health message among Hispanic youth and Hispanic college students, yet more research is needed to understand the potential mechanisms and investigate a causal relationship.Item Effect of diabetes on composition and metabolism of heart lipids(Texas Tech University, 1980-08) Paulson, Dennis JNot availableItem Effects of hypertension and diabetes mellitus on cognitive functioning: A profile analytic approach(Texas Tech University, 2009-08) Clark, Joy HumphreysResearch studies have demonstrated a relationship between several cardiovascular risk factors and decreased performance on cognitive tasks. In particular, recent research has suggested a strong effect of hypertension and diabetes mellitus on neuropsychological performance, particularly in certain cognitive domains, in both cognitively normal and demented individuals. Findings have been mixed, however, with some studies showing significant effects and others demonstrating none. Despite widely differing methodologies, all previous studies have had one thing in common: the examination of mean-group differences in performance on individual cognitive tests. The current study, conversely, investigated possible differences in neuropsychological profiles across several cognitive measures between cognitively normal individuals with and without hypertension and/or diabetes, as well as between individuals diagnosed with Alzheimer's disease with or without either condition. While effects of hypertension and diabetes on cognitive functioning were found in specific cognitive domains, current analyses did not find overall profile differences.Item Evaluation of a pharmacist-led medication management program in high-risk diabetic patients: impact on clinical outcomes, medication adherence, and pharmacy costs(2009-12) Hanson, Kristin Anne; Wilson, James P.; Rascati, Karen L.; Godley, Paul J.; Browne, Barry A.Diabetes mellitus is a group of metabolic disorders caused by a relative or absolute lack of insulin. Currently, 23.6 million Americans have diabetes. Diabetes can lead to serious microvascular and macrovascular complications, such as cardiovascular disease, blindness, kidney disease, lower-limb amputations, and premature death. Due to the potential cardiovascular complications and the high prevalence of co-morbid hypertension and/or hyperlipidemia in patients with diabetes, diabetes management should include close monitoring of blood glucose, blood pressure, and cholesterol levels. Medical management of diabetic patients is costly; approximately 1 in every 10 health care dollars is currently spent treating diabetes. Studies have shown that in chronic conditions such as diabetes, increased medication use results in demonstrable improvements in health outcomes, reduced hospitalization rates, and decreased direct health care costs. To date no studies have evaluated the impact of a pharmacist-led intervention on diabetic medication adherence. The purpose of this investigation was to analyze the impact of a pharmacist-led medication management program on medication adherence and pharmacy costs and to evaluate clinical measures of diabetes, hypertension, and hyperlipidemia. This study was a quasi-experimental, longitudinal, pre-post study, with a control group. Scott & White Health Plan (SWHP) patients with diabetes (type 1 or type 2), poor glycemic control (most recent A1C >7.5%), and living within 30 miles of participating pharmacies were invited to participate in the intervention which consisted of monthly appointments with a clinical pharmacist and a co-payment waiver for all diabetes medications and testing supplies. A total of 118 patients met study inclusion criteria and were enrolled in the intervention between August 2006 and July 2008. Intervention patients were matched on sex and age to SWHP patients with poor diabetes control living more than 30 miles from a participating pharmacy. To measure the impact of the intervention, medical and pharmacy data were evaluated for one year before and after the study enrollment date. A significant difference was seen in the percentage of patients with type 1 diabetes in the intervention group (14) and the control group (3). The medication management program significantly improved A1C levels in intervention patients relative to controls (-1.1% vs. 0.6%) and was more effective in lowering A1Cs in type 2 diabetics than type 1 patients. Although the generalized linear model did not show that the intervention significantly improved the percentage of patients achieving the ADA goal A1C of <7% compared to controls, the multivariate logistic regression, which controlled for factors such as diabetes type, showed that patients participating in the intervention were 8.7 times more likely to achieve the A1C goal. Persistence with diabetic medications and the number of medications taken significantly increased in the intervention group; however, adherence rates, as measured by medication possession ratio (MPR), did not significantly improve relative to controls. The expenditure on diabetic medications and testing supplies increased substantially more in the intervention group than in the control group. The percentage of patients adherent with antihypertensive medications (MPR ≥80%) increased from 76% to 91% in the intervention group and decreased from 68% to 63% in the control group (P<0.05); no significant difference in blood pressure control was observed. For hyperlipidemia medications, adherence and persistence increased and pharmacy costs decreased in both groups, likely due to the introduction of the first generic HMG-CoA reductase inhibitor into the market during the study period. Future research is needed on the impact of the intervention on medical resource utilization and costs.Item Evaluation of the impact of cardiovascular safety concerns of thiazolidinediones on the utilization of oral antidiabetic drugs(2011-05) Bui, Cat Nguyen; Rascati, Karen L.; Wilson, James P.; Godley, Paul J.; Prasla, KarimThe overall objective of this study was to evaluate the impact of cardiovascular safety concerns on the utilization of the thiazolidinediones (TZDs), pioglitazone and rosiglitazone, and other oral antidiabetic drugs. In May 2007, a meta-analysis was published that found a potential increased risk of myocardial infarction (MI) associated with TZDs, particularly with rosiglitazone. A two-year retrospective study of patients diagnosed with type 2 diabetes (ICD9 250.xx) using prescription and medical databases from the Scott & White Health System (SWHS) was conducted. Patients aged 18 or older who were continuously enrolled with SWHS from 2006 to 2008 and had high adherence (Medication Adherence Ratio ≥80%) for either pioglitazone or rosiglitazone during the pre-safety warning period (May 2006- April 2007) were included. Patients were followed through the post-safety warning period (May 2007 - October 2008) or occurrence of event (discontinuation of index TZD drug). Patients who discontinued their index TZD drug by April 2008 were identified if they had a prescription filled for a new oral antidiabetic drugs (OADs), and followed until October 2008 or occurrence of event (discontinuation of new OAD). Cox proportional hazards models were used to assess the rate of and time to discontinuation of index TZD and new OAD with adjustment of age, gender and Charlson Comorbidity Index (CCI). A total of 531 patients (58 percent male; mean age [SD] = 61 [9.1] years) were included in the final analysis, 255 and 276 patients in the rosiglitazone and pioglitazone groups, respectively. The rate of discontinuation for the pioglitazone and rosiglitazone groups began to separate within 90 days of the index event (meta-analysis published in May 2007). In the pioglitazone group, the rate of discontinuation was significantly lower than in the rosiglitazone group ( HR = 0.56; 95% CI = 0.47, 0.67). A total of 21 patients did not experience discontinuation of their index medication. Among patients receiving a new OAD after discontinuing their index TZD (N = 95 rosiglitazone and N = 33 pioglitazone patients), there was no statistical significant in the rate of discontinuing their new OAD between the rosiglitazone and pioglitazone groups (HR = 0.98; 95% CI = 0.61, 1.59). However, patients who received metformin/sulfonylurea combinations had a lower rate of discontinuation compared to patients who received sulfonylureas (HR = 0.38; 94% CI = 0.21, 0.66). The analysis showed the cardiovascular safety concern of TZDs had a significant impact on the utilization of oral antidiabetic drug utilization.Item Incident coronary atherosclerosis, unstable angina, non-ST-segment elevation myocardial infarction or ST-segment elevation myocardial infarction in type 2 diabetes : is mean glycated hemoglobin a good predictor?(2010-12) Owusu, Yaw Boahene; Lawson, Kenneth Allen, 1952-; Barner, Jamie C.; Jokerst, Jason R.; Lopez, DebraBackground: Glycated hemoglobin is the indicator of long-term diabetes control and a value below 7 percent is recommended by the American Diabetes Association (ADA) to reduce cardiovascular complications. Diabetic patients have a two- to four-fold risk of cardiovascular disease and approximately two-thirds of diabetic patients die as a result of cardiovascular complications. Three large prospective randomized controlled long-term trials within the last decade reported no significant reduction in cardiovascular complications in type 2 diabetic patients by intensive glycemic control. To the author's knowledge, no known retrospective studies have examined the association between mean serial glycated hemoglobin and coronary atherosclerosis (CA) or acute coronary syndromes (ACS). Objective: This study was designed to determine the association between mean serial glycated hemoglobin with incident CA or ACS in type 2 diabetic patients after controlling for age, gender, hypertension, low density lipoprotein cholesterol (LDL-C), microalbuminuria, aspirin use, statin use, insulin use, tobacco use, and body mass index (BMI). Methods: The study was a retrospective cohort database analysis using the Austin Travis County CommUnityCare[trademark] clinics' electronic medical record for the time period between October 1, 2004 and September 30, 2009. The primary outcome of the study was the incidence of CA or ACS and the primary independent variable was glycated hemoglobin (<7% vs. [greater than or equal to]7%). The study subjects included type 2 diabetic patients aged 30 to 80 years with at least one glycated hemoglobin value per year for a minimum of two consecutive years. Study subjects were excluded if CA or ACS occurred within six months of the index date (i.e., first glycated hemoglobin). Logistic regression analysis was used to address the study objective. Results: Overall, 3069 subjects met the study inclusion criteria with a mean follow-up period of approximately two years. Two percent (N=62) of the subjects had incident CA or ACS. After controlling for age, gender, hypertension diagnosis, LDL-C, microalbuminuria, aspirin use, statin use, insulin use, tobacco use and BMI, there was no significant association (OR=1.026, 95% CI=0.589-1.785, p=0.9289) between mean serial glycated hemoglobin and the incident diagnosis of CA or ACS. Increasing age (OR=1.051, 95% CI=1.025-1.077, p<0.0001), male gender (OR=1.855, 95% CI=1.105-3.115, p=0.0195) and normal weight (normal or underweight compared to obese: OR=0.122, 95% CI=0.017-0.895, p=0.0438) were significantly associated with incident CA or ACS. Conclusions: Mean serial glycated hemoglobin (comparing [greater than or equal to]7% to <7%) was not significantly associated with CA or ACS over a mean follow-up period of approximately two years. Until more evidence becomes available, clinicians and diabetic patients should target glycated hemoglobin level below or close to 7 percent as recommended by the ADA soon after diagnosis while concomitantly controlling nonglycemic risk factors of cardiovascular disease (statin use, aspirin use, blood pressure control, smoking cessation and life style modification), to reduce their long-term risk of incident CA or ACS.Item Intravenous closed-loop glucose control in type I diabetic patients(2007-05) Farmer, Terry Glen, 1979-; Edgar, Thomas F.; Peppas, Nicholas A., 1948-Models describing glucose homeostasis were developed. A pharmacokinetic model describing the kinetic rates of appearance and disappearance of glucose, amino acids, fatty acids, insulin, glucagon, epinephrine, and glucagon-like peptide-1 was developed, and a physiologically-based model describing the dynamics of these species in the brain, liver, kidneys, muscle tissue, adipose tissue, gut, pancreas, and adrenal medullae was developed. Because sufficient data was not readily available, parameter estimation for the models was not performed. Parameter estimation was investigated by using one- and two-compartment insulin models to generate test data with known parameter values and investigating the effectiveness of a nonlinear least squares algorithm with respect to estimating the actual parameter values. Parameter estimation was strongly dependent on the initial guess of the parameter set, and confidence intervals were found to be ±100% of the estimated parameter value. The use of dynamic sensitivity equations in conjunction with a stiff differential equation solver resulted in the parameters of the one-compartment model being accurately estimated with confidence intervals less than 10%. The twocompartment parameters were not able to be accurately estimated within confidence limits, but all parameter sets from the estimation fit the test data very strongly. Explicit closed-loop control was simulated by incorporating feedback control, feedforward control, combined feedforward/feedback control, and model predictive control into three patient models describing glucose and insulin kinetics. No controller was able to keep the minimal model glucose below 14 mmol/L in response to a 50 g oral glucose disturbance without also resulting in hypoglycemia. Sorensen model and Hovorka model simulations predicted that proportional control is able to mimic the healthy pancreas response to a 50 g oral glucose disturbance and 30 minutes of moderate exercise. A model describing swelling and release dynamics for a pH-responsive cationic hydrogel was developed using the quasi steady-state assumption for particle swelling. The response of implicit closed-loop control system was simulated using the minimal model. Physical constraints imposed on diffusion coefficients and the collapsed particle radius results in complete insulin depletion in less than 1 minute, rendering the hydrogel system infeasible for intravenous implicit closed-loop glucose control.Item Model and analysis: Diabetes and obesity(2007-12) Al-Hashmi, Sam; Martin, Clyde F.; Drager, Lance D.The thesis is a further revision of a mathematical model based upon Sorensen’s progress and Alvehag’s modification under Dr Clyde Martin. The intention of the model is to address the aspect of regulating glucose concentration with in the body from a control theory point of view. The chosen method of simulation is based upon the pharmacokinetic approach; and our revision main aspect is to address the effect free fatty acid (FFA) in the blood. This is a necessary step since the primary role of the model is to establish a mathematical model simulating the behavior of a type II diabetic patient. Type II diabetes can be classified into categories; such early stages of type II diabetes and fully developed type II diabetes. The thesis emphasis on the affect of insulin resistance by including a sub-model of adipose tissue; hence creating a further understanding to the behavior of a healthy human body under induced insulin resistance, or obese individuals, or early stages of a type II diabetic patient. The thesis remains lacking the ability to simulate the unique behavior of impaired insulin secretion. Further research is needed to be able to fully simulate the response of early stages type II diabetic patients and follow the progress into a fully type II diabetic patients.Item The effects diabetes has on the neurovascular system during exercise(2016-05) Brown, Ashlyn Victoria; Stone, Audrey J.; Castelli, DarlaThe autonomic nervous system is responsible for the involuntary control of most visceral organs. This system greatly influences the neurovascular and cardiovascular systems while at rest and during exercise. Central command, the baroreflex, and the exercise pressor reflex are the three systems that are responsible for the distribution of blood during exercise. Specifically, the exercise pressor reflex plays a dominant role during exercise because it is influenced by metabolic and mechanical factors that affect the vasculature health. Diabetes mellitus is a metabolic disease that can alter the way these systems function within the body. The effects of neural damage and exercise-induced hypoglycemia have been thought to be the sources behind the changes seen in the exercise pressor reflex. Currently, not a lot of research has been done on the exact mechanisms behind the changes of the exercise pressor reflex in diabetes; therefore, the explanations to these alterations are unknown. Thus, the purpose of this report is to develop a hypothesis for the effects of diabetes on the autonomic control of exercise, specifically the exercise pressor reflex.Item The relation between family functioning and psychological adjustment in children with asthma and children with diabetes(Texas A&M University, 2007-04-25) Fontaine, Eve NicoleThe goals of this study were to evaluate the relationships among family functioning, psychological adjustment, and health-related quality of life in children with asthma and children with diabetes. A secondary goal of this study was to examine the relations between illness severity, psychological adjustment, and health-related quality of life in the children with asthma. Participants included 41 children with asthma and 109 children with diabetes, and one primary caregiver of each child. Questionnaires were given to children to assess their levels of anxiety, depression, and health-related quality of life. Questionnaires pertaining to parenting stress, family functioning, and psychological adjustment also were completed by the participating primary caregiver. Results suggested these two groups of children do not differ in their psychological adjustment, family functioning, or health-related quality of life. Normal levels of anxiety and depression were reported, which both supports and contradicts current research in this area. Additionally, parenting stress mediated the relationship between family cohesion and parent-reported depression in children with diabetes; however, this result was not obtained in the children with asthma. In children with diabetes, significant relationships were found between self-reported anxiety and parenting stress and between parent-reported anxiety and health-related quality of life. Additionally, parent-reported depression was significantly related to parenting stress, health-related quality of life, and family cohesion. Self-reported depression was significantly predicted by health-related quality of life. In children with asthma, health-related quality of life significantly predicted self-reported anxiety and parenting stress was significantly related to parentreported depression. Illness severity did not predict psychological adjustment or healthrelated quality of life in children with asthma.Item Use of antihypertensive agents and the incidence of Type 2 diabetes: a retrospective analysis(2004) Vincze, Gábor; Barner, Jamie C.The effect of major antihypertensive medications on blood glucose and newonset diabetes was assessed using medical data from the Central Texas Veterans Health Care System (CTVHCS). Veterans were followed for an average of 3.6 years (total of 51,549 person-years) between 1995 and 2004. The average age of the participants (N=11,187) was 60.7 (SD: 12.7) years; the majority (78.7%) were =50 years of age, White (73.8%) males (95.3%). Commonly used antihypertensive therapies appeared to increase veterans’ blood glucose levels significantly more than what was observed in the control group; i.e., patients who were not treated with medications. The only exception was beta-blocker therapy, which showed similar effect to the control group. Presence of impaired glucose tolerance, higher BMI, “high risk” therapies, and dyslipidemia at baseline significantly increased the risk of developing diabetes. Non-thiazide ‘diuretics’ were associated with the highest risk as indicated by a hazard rate of 1.48 (95% CI: 1.21-1.80). Statistically significant, protective effect was found with ‘alpha-blocker’ therapy: 23 percent reduced risk to develop diabetes (95% CI:0.63-0.93). When ‘dual’ and ‘three or more therapies’ were included into the model, the effect of ‘alpha-blockers’ became non-significant (p=0.196); whereas ‘ACEI’ and ‘CCB’ therapies became significantly associated with an increased risk for diabetes (p-values: 0.003 and 0.008, respectively). The corresponding hazard rates were 1.29 (95% CI: 1.09-1.53) and 1.26 (95% CI: 1.06- 1.50), respectively. The simultaneous use of three or more antihypertensives appeared to be protective against the development of new-onset diabetes (hazard rate: 0.60; 95% CI: 0.43-0.83; p=0.002). This finding conflicts with the majority of previous studies and may have been the result of selection bias (also called “channeling”), in which patients with higher baseline ris k to develop diabetes were “channeled” towards ACEIs and CCBs and away from beta-blockers. Several animal and small clinical trials showed the beneficial effect of ACEIs on carbohydrate metabolism, so our findings might have been the result of confounding by uncontrolled risk factors, such as genetic predisposition for diabetes, lifestlyle habits, and other unmeasured biological differences.