A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Introduction. The incidence and prevalence of Type 2 diabetes mellitus has been steadily increasing over the past ten years, and is currently approximately 4.1 per 1000 12‐19 year olds in the US2. This increase has been linked to obesity and a sedentary lifestyle. Prediabetes, in the pediatric population is defined as having a fasting plasma glucose concentration ≥ 100 to 125 mg/dL or 2‐hour glucose concentration during an oral glucose tolerance test ≥ 140 mg/dL but <200 mg/dL. Aims. The goal of this study is to describe the sensitivity and specificity of hemoglobin A1c at various thresholds to identify prediabetes, as defined by impaired fasting glucose and/or impaired glucose tolerance; the population included in this study consist of obese youth referred to the Division of Endocrinology and Diabetes at Phoenix Children’s Hospital for weight‐related issues. We anticipate describing various levels of sensitivity and specificity of hemoglobin A1c in comparison with gold standard tests, such that it can be used to propel further studies to ultimately reduce the immense patient burden of fasting in the pediatric population. Methods. We conducted a retrospective cross‐sectional chart review and employed receiver operating characteristic (ROC) curve analysis of data including but not limited to hemoglobin A1c, fasting plasma glucose, and 2‐hr post‐prandial plasma glucose. The benefits of this study include the potential of reducing the patient burden of fasting prior to examination. This review will determine, if any, the potential value in being able to use hemoglobin A1c clinically to detect prediabetes in pediatric patients; determining this may provide critical information to improve the monitoring and screening of prediabetes. Conclusions. Compared to the gold standards of fasting plasma glucose and oral glucose tolerance tests, we found that hemoglobin A1c had a low sensitivity and specificity for identifying prediabetes.

The effects of a variable ratio (VR) schedule of reinforcement on exercising in obese and non-obese children were examined. Eight 11-year-old boys, four obese and four non-obese, participated as subjects. One obese and one non-obese boy served as a control for social attention and maturation effects. Three obese and three non-obese boys were individually tested five times weekly over approximately 12 weeks on a stationary bicycle. A changing-criterion design was used where 3 VR phases of 8 sessions each were followed by a 3 session mini-reversal phase and a 5 session return-to-third VP phase. Each successive criterion was increased over previous performance by approximately 15%. Implementation of the initial VR subphase produced marked increases in the rate of exercising for all children with continued acceleration until the withdrawal of reinforcement phase when rates decreased. Response rates recovered during the final VP phase where the highest rates were achieved for all subjects. Cumulative records demonstrated high stable responding with no discernible pausing for non-obese boys. In contrast, pausing and accelerating which were initially evident in the obese boys' records were eliminated with higher VR schedules. The anthropometric measures taken at the pre-experimental, post-experimental and follow-up time periods revealed that the obese boys who participated in the program gained substantially less weight than children who did not participate. There appeared to be no systematic difference in self-reported food intake between obese and non-obese children. Actometer data, as well as parents' and teachers' written and verbal reports indicated that exercise on a stationary bicycle, intermittently reinforced, as well as training parents to utilize praise and attention for exercise, appeared to increase physical activity in the natural environment. A social validation questionnaire as well as informal observation revealed that participants, parents, and teachers rated the biking program most positively.

Obesity has been linked to a wide range of health problems. Evidence suggests that overweight and obese (OW/O) women avoid or delay seeking medical care and routine health screenings, a choice that may result in poorer overall health. The objective of this study is to explore how an OW/O woman’s self-identity and her experiences in past medical encounters may affect her health-seeking behaviors. Twenty-three women who self-identified as being overweight (currently or in the past) were recruited using a flyer placed in a women’s exercise facility and through the snowball method. Each agreed to an audio-taped, in-depth, semi-structured interview. Interviews were transcribed and analyzed. This study employs multiple methods of analysis and multiple genres of representation of the data, an approach recently termed “crystallization.” Analysis of an autoethnographic narrative served as a guide for the generation of the research questions, which focused on how OW/O women conceptualize their identities in relation to their bodies, how their attitudes about their bodies may have impacted choices about seeking healthcare and their perception of their experiences within medical encounters, and what OW/O women believe to be potentially effective strategies for clinicians to adopt in caring for overweight patients. Interviews were scrutinized to identify story types using Arthur Frank’s well-established framework for the analysis of narratives of sudden life-threatening illness. Two additional story types, Reorientation and Acceptance, are proposed as potentially useful in analyzing stories of chronic health conditions. Grounded theory analysis was used to identify the factors that OW/O women perceive to contribute to their weight struggles, as well as to determine clinician attitudes and practices that OW/O women regard as effective and ineffective. Two emergent themes—othering and control—were discerned in the data and are discussed in terms of both how OW/O women are impacted by their weight and how practitioners can work to provide more effective care. An explanatory model linking social bias, personal identity, and medical interactions is proposed. Finally, a performance script is presented as a means of synthesizing and disseminating research findings.

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Made available in DSpace on 2014-06-11T19:22:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-14Bitstream added on 2014-06-13T19:49:03Z : No. of bitstreams: 1 monteiro_pa_me_prud.pdf: 943493 bytes, checksum: 0d940be631fea6afcb4784848644350e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Objetivo: Avaliar o efeito do treinamento concorrente sobre fatores de risco para a doença gordurosa não alcoólica do fígado (DGNAF) em adolescentes obesos. Metodologia: A amostra foi formada por 38 indivíduos com idade entre 12 e 15 anos. Inicialmente, classificados como obesos pelo Índice de Massa Corporal (IMC) e, posteriormente submetidos à exames bioquímicos de sangue, ultrassonografia e avaliação da composição corporal. Todas as avaliações foram realizadas antes e ao final do estudo. Os sujeitos do estudo sofreram intervenção durante 20 semanas. A Intervenção consistiu de treinamento concorrente com frequência semanal de três vezes, uma hora/dia. A análise estatística foi realizada por meio do software SPSS, versão 17.0, com significância estatística fixada em 5%. Resultados: Após a intervenção, foram observadas melhoras significantes no IMC, percentual de gordura corporal (%GC), massa gorda (MG)(kg), massa livre de gordura (MLG), Percentual de gordura de tronco (%GTronco), triglicérides (TG), colesterol total (COL), LDL-colesterol (LDL), lobo direito e esquerdo do fígado, insulinêmia... / Nonalcoholic Fatty Liver Disease (NAFLD), in obese adolescents. Methodology: The sample was composed by 38 individuals aged 12 to 15 years. Initially the obesity was classified according Body Mass index and, subsequently, blood biochemical tests, ultrasonography and measurement of body composition were assessed. All evaluations were performed before and at in the final of the intervention. They were submitted to an intervention during 20 weeks, that consisted of concurrent training, three times per week, one hour/day. Statistical analysis was performed using the SPSS software, version 17.0, with statistical significance set at 5%. Results: The BMI,% BF, MG (kg), FFM, BFtrunk%, triglycerides, total cholesterol... (Complete abstract click electronic access below)

Class of 2016 Abstract / Objectives: To determine if obese patients receiving parenteral nutrition (PN) require an increased amount of potassium, magnesium, and phosphorus electrolyte provisions compared to non-obese patients. Methods: The project design was an institutional review board-approved, retrospective, descriptive chart review. Electronic medical records and physical parenteral nutrition order cards were accessed to identify patients who met the inclusion and exclusion criteria of the study. The total amounts of potassium, phosphorous, and magnesium received by patients over the initial seven days of PN therapy were calculated. The Chi-squared and independent t-tests were utilized to evaluate the statistical significance for all nominal and interval data respectively. Results: 112 samples met the inclusion criteria of the study. There were 75 samples in the non-obese group (mean age=55.1 years, mean BMI=22 kg/m2, 53% female), and 37 samples in the obese group (mean age=57.1 years, mean BMI=33.8 kg/m2, 51% female). The daily average and seven-day totals of potassium, magnesium, and phosphorus did not significantly differ between the non-obese and obese groups (average daily potassium (P=0.6224), weekly total potassium (P=0.7551), average daily magnesium (P=0.8068), weekly total magnesium (P=0.3863), average daily phosphorus (P=0.9698), weekly total phosphorus (P=0.0603)). Conclusions: Potassium, magnesium, and phosphorus electrolyte provisions administered through PN over a week appear to be similar for both non-obese and obese patients. Our study results indicate that the same standard set for dosing initial PN electrolyte provisions in a non-obese patient may be applied to dosing similar provisions for an obese patient.

Currently no previous study has isolated the independent influence of body fat (BF) on thermoregulatory responses from the confounding biophysical factors of body mass and metabolic heat production (Hprod). Therefore, seven lean (L, BF:10.7 ± 4.1%) and seven non-lean (NL, BF:32.2 ± 6.4%) males matched for total body mass (TBM, L: 87.8 ± 8.5 kg, NL: 89.4 ± 7.8 kg; P= 0.73), cycled for 60 min in a 28.2 ±0.2˚C and 27 ± 10% RH room at i) a Hprod of 546 W; and ii) a Hprod of 7.5 W·kg lean body mass (LBM). Rectal (Tre) and esophageal (Tes) temperatures, and local sweat rate (LSR) were measured continuously; while whole body sweat loss (WBSL) was measured from 0-60 mins. At 546 W, changes in Tre (L: 0.74 ± 0.16ºC, NL: 0.83 ± 0.14ºC), mean local sweat rate (MLSR) based on an average of upper-back and forearm local sweat rates (L: 0.65 ± 0.25, NL: 0.59±0.12 mgcm-2min-1) and WBSL (L: 568 ± 28 mL, NL: 567 ± 29 mL) were similar (P>0.58). At 7.5 W·kg LBM, the L group had greater changes in Tre (L: 0.87 ± 0.16ºC, NL: 0.55 ± 0.11ºC), MLSR (L: 0.83 ±0 .38, NL: 0.41 ± 0.13 mgcm-2min-1) and WBSL (L: 638 ± 19 mL, NL: 399 ± 17 mL) (P<0.05). In conclusion, i) body fat does not independently alter thermoregulatory responses during exercise; ii) core temperature comparisons between groups differing in BF should be performed using a Hprod normalized for TBM, not LBM.

Previous studies have shown that obesity negatively affects balance during quiet standing, yet little is known about its effect on the ability to recover after a postural perturbation. The purpose of this thesis was to investigate the effects of obesity on single-step balance recovery from an incipient forward fall. Eight obese (BMI = 33.2 ± 2.4) and eight non-obese (BMI = 24.8 ± 1.8) participants were released from a static forward lean and asked to recover their balance with a single step. Lean angle was progressively increased until they could no longer recover balance with a single step. Peak joint torques and relative effort during balance recovery were calculated and compared across the groups. Obese participants achieved a smaller maximum lean angle compared to non-obese participants. During balance recovery, obese participants exhibited higher ankle plantar flexor torques and relative effort. Trends also suggested higher relative hip extensor effort in the obese. Obese adults exhibited a poorer ability to recover from a forward fall with a single step. In addition, obese adults used a higher percentage of their total hip and ankle strength compared to non-obese adults during balance recovery. This suggests that the poorer ability of recovering from a forward fall in the obese may be related to increased exertion levels during balance recovery. / Master of Science

Obesity has become a global epidemic. Healthcare cost continues to increase due to co-morbidities such as diabetes, hypertension, and coronary artery disease associated with obesity. The purpose of this project was to examine whether teaching nutritious food choices to obese African American and Hispanic females in healthy cooking demonstrations would have an effect on their dietary behavior. The holistic self-care model was used to develop healthy strategies for weight loss. The model guided the development of nutritional support, exercise, and spiritual strategies for weight reduction. African American and Hispanic females between the ages of 25 to 64 were solicited from a local faith-based organization. Criteria for inclusion were a BMI greater or equal to 30, completion of a pre- and post- 24-hour dietary journal, and a pre- and post- Mediterranean diet assessment survey. Women had to participate in 3 out of 4 cooking demonstration classes. Ten participants met the full criteria for inclusion in the data. The results of the participants' responses were totaled and a percentage value was determined for each question. Comparison of the percentages between the 2 surveys showed no change in the participants' dietary habits, except in the area of red meat consumption, which decreased by 40%. The participants' mean BMI pre-survey was 37.92 and 37.80 post-survey. Lifestyle modifications such as dietary changes have the potential to decrease the obesity rate. The positive impact of the cooking demonstrations on African American and Hispanic families includes a potential decrease in comorbidities associated with obesity. A healthy future for these population groups will depend on the health of their children, and social change can occur if children adopt the healthy lifestyle behaviors of the adults in their household.

The overall objective of this research was to investigate the status of tumor necrosis factor-?? (TNF-??), and molecules associated with its signaling, in the pathological state of hepatic steatosis. The effect of NSAID piroxicam, a cancer preventive agent also known to affect TNF-?? signaling on hepatic steatosis, was also investigated. The biological state of the tissue was assessed by examining the expression of TNF-?? signaling molecule in whole tissue, as well as in hepatic lipid raft. Lipid rafts are dynamic assemblies of cholesterol and sphingolipids, microdomains that form in the exoplasmic leaflet of the biological membranes shown to play a role in compartmentalization, modulation and integration of the cell signaling. In the present research, Zucker obese rats were used as a model of human obesity and insulin resistant state. These rats exhibit hepatic steatosis in adulthood similar to those noted in obese individuals. Female Zucker obese and lean rats (5 weeks old) were fed a semisynthetic diet with or without piroxicam (150 ppm). Zucker lean counterparts served as control. After 8 weeks of feeding, rats were euthanized and liver from each animal was collected. Liver tissue from each animal was processed for histology and biochemical analysis which included lipids and proteins (COX-1 and 2, TNF-??, TNF-RI and RII, IKK-??, I??B-?? and NF-??B). Liver histology and the level of total lipids confirmed that Zucker obese rats had hepatic steatosis, which was further augmented by piroxicam treatment. Whole tissue protein expression, using western blot, showed that the steatotic liver differed from non-steatotic livers by having lower levels of TNF-RII. TNF-RII showed a trend which was inversely proportional to the pathological state of the tissue. The obese-piroxicam liver had the lowest level of TNF-RII and lean livers had the highest (p<0.05). The total NF-??B level was higher in the obese and obese-piroxicam groups compared to the lean or lean-piroxicam groups (p<0.05). Piroxicam treatment lowered the level of NF-??B in obese and lean livers. I??B-?? was higher in obese livers than in lean livers. The nuclear level of NF-??B by western blot analysis showed the same pattern as noted in the whole tissue homogenate. However, the difference in the level between obese and lean was marked. The obese nuclei contained two to three fold higher levels of NF-??B protein than the lean liver nuclei. I??B-?? level was significantly higher in the obese liver tissues and nuclei than their lean counterparts. While transcriptionally active NF-??B was higher (p<0.05) in the obese livers than in the lean livers, the difference between obese and lean groups was not as significant as that noted for the level of NF-??B assessed by western blot. This suggests that the proportion of active NF-??B present in the nuclear fraction is much higher in the lean than in the obese nuclei. Lipid raft was extracted and identified successfully from obese and lean livers. The total caveolin and flotillin levels were significantly higher in the liver lipid rafts of the obese-piroxicam than that of the other groups. This is the group that also exhibited higher steatosis. Piroxicam treatment significantly decreased the level of caveolin in the lean liver and significantly increased the level of flotillin in the obese liver. While COX-1 was not detectable, however, the level of COX-2 and TNF-RII in lipid raft was opposite to the level noted in the whole tissue homogenate. TNFRII was highest in the obese-piroxicam lipid raft and lowest in the lean-piroxicam lipid raft. TNF-RII, COX-2, I??B-?? and NF-??B proteins were the molecules profoundly affected by the pathological state of the tissue and piroxicam treatment. This research is the first to report the presence of I??B-?? in the nuclear compartment with a higher level in the nuclei and whole tissue in the obese liver than in the lean liver. This research demonstrates that TNF-?? to NF-??B axis is altered in steatotic liver, and analysis of lipid rafts in steatotic and non-steatotic liver demonstrates that lipid rafts play a distinct role in modifying the biological availability of key proteins in the pathological state of liver steatosis.