Master of Science / Food Science / Fadi Aramouni / Little in vivo research on glycemic index (GI) values or the digestive impact of sorghum based food products currently exists. Because sorghum is a gluten-free grain, its utilization in the United States is growing, especially in baking applications. Information on how sorghum affects blood sugar levels would be beneficial as new products emerge because glycemic effect has an impact on human health and in controlling diabetes. The objective of this study was to determine the GI of a sorghum muffin, and compare this value to the GI of muffins made from commonly consumed grains in the United States. The effects of particle size and damaged starch on GI were also studied. GI values were determined for muffins made from white sorghum, corn, brown rice, whole wheat, and all-purpose flours. All muffin formulations were composed of flour, water, baking powder and salt. To determine the GI, weighed portions of muffin containing 20g of available carbohydrates were eaten on separate occasions by eight healthy volunteers (ages 18-40) after an overnight fast (10 hours). Each muffin was administered twice. Two capillary blood samples were taken at 0 (fasting), 30, 45, 60, 90 and 120 minutes after consumption and averaged. Blood glucose curves were constructed from mean blood glucose values. The GI was calculated by dividing the incremental area under the curve for the test food (muffin) by that for the standard (20g dextrose drink) and multiplying by 100. The GI for the muffins was calculated as the mean from the respective average GIs of the 8 volunteers. The data indicated that sorghum flour milled at particle size < 400 um resulted in the lowest GI of 32 ± 16.8. These findings should assist in development of lower GI sorghum foods.

O Diabetes Mellitus (DM) é uma doença metabólica que implica em altas incidências de mortalidade e morbidade. A hiperglicemia crônica é responsável pelo surgimento de inúmeras complicações em longo prazo nestes pacientes. Atualmente, é recomendado por diretrizes internacionais que pacientes com DM sejam monitorados e manejados em seu tratamento a partir dos níveis de hemoglobina glicada (A1C). A A1C é formada por reações não enzimáticas de glicação na hemoglobina, refletindo a glicemia dos últimos 120 dias. A A1C possui forte associação com os desfechos clínicos no DM e apresenta uma excelente padronização de seus métodos analíticos. Contudo, diversas situações clínicas podem interferir falsamente em seus níveis e prejudicar a interpretação de seus resultados, como em anemias (carenciais ou hemolíticas), hemoglobinopatias, gravidez, doença renal crônica, etc. Por outro lado, a albumina glicada (AG) é uma frutosamina formada por glicações na albumina e reflete uma glicemia média de cerca de 2 a 3 semanas. A AG não é influenciada pela concentração de outras proteínas no plasma e também não sofre interferência pelas condições que afetam a A1C. Este marcador tem sido fortemente avaliado como uma ferramenta alternativa para a A1C, a partir da análise de seus níveis por um novo método enzimático descrito em 2002. Estudos tem demonstrado uma forte associação entre estes dois marcadores e grande semelhança em predizer as complicações do DM. Entretanto, a AG se mostra melhor para avaliar flutuações nos níveis de glicose e a resposta ao tratamento terapêutico. Neste trabalho, foi avaliado o desempenho analítico de dois kits enzimáticos de AG e realizado uma comparação entre os métodos, encontrando excelentes resultados. Ainda, foi determinado o intervalo de referência para os níveis de AG em brasileiros saudáveis. A forte correlação encontrada entre AG e A1C demonstra que a AG pode ser um teste útil para o controle glicêmico no DM, principalmente quando a A1C não é recomendada. / Diabetes Mellitus is a metabolic disease with high incidence rates of mortality and morbidity. Chronic hyperglycemia is responsible for several long-term complications in these patients. Currently, international guidelines recommend that glycemic monitoring in DM should be performed by glycated hemoglobin (A1C) levels, to provide a correct clinical conduction. A1C is relative to non-enzymatic glycation reactions in hemoglobin and reflects the glucose levels from the last 120 days. It is well established the great association between A1C and clinical outcomes in DM, besides, its analytical methods present an excellent standardization. However, some conditions may influence and imply misinterpretation in A1C results, such as anemia, hemoglobinophaties, pregnancy, chronic renal disease, etc. On the other hand, glycated albumin (GA) is a fructosamine produced by glycation reactions in albumin and it reflects a mean glycemia at around 2 to 3 weeks. GA is not influenced by the concentrations of other plasma proteins, as well as by those conditions that interfere in A1C. GA has been strongly evaluated as an alternative marker to A1C, through its quantitative measurement by an enzymatic methodology described in 2002. Recent studies have demonstrated a high association between GA and A1C and a great similarity between these tests in predicting DM future complications. Nevertheless, GA has showed be better to assess the glucose fluctuations in blood and the response to treatment. This study evaluated the analytical performance of two GA enzymatic kits and also executed a methods comparison, and found excellent results. Also, we established the reference range for GA levels in healthy Brazilians. The high correlation found between GA and A1C indicates that GA could be a useful test for glycemic control in DM, especially when A1C is unreliable.

Orientador: Célia Regina Nogueira / Resumo: Os hormônios tireoidianos (HTs) são fundamentais para o crescimento e desenvolvimento de vários órgãos e tecido. A fonte de HTs é a glândula tireoide, que faz parte do eixo hipotálamo-hipófise-tireoide e produz, principalmente, triiodotironina (T3) e tiroxina (T4). A disfunção tireoidiana é frequentemente associada com mudanças no apetite e peso corporal, que levam a alterações em parâmetros metabólicos, desempenhando papel importante na regulação do metabolismo e do tecido adiposo. A relação entre obesidade e distúrbios na tireoide vem sendo muito estudada, porem ainda não é bem estabelecida. A Organização Mundial de Saúde (OMS) reconhece a obesidade como um importante problema de saúde pública, que afeta crianças, adolescentes e adultos. Com embasamento na literatura, a partir dos modelos estudados pelo nosso grupo e a fim de ampliar as pesquisas nesta área, o objetivo do nosso estudo foi avaliar a influência do hormônio tireoidiano sobre o perfil nutricional, metabólico e hormonal de ratos obesos. Foram utilizados Ratos Wistar machos, com 60 dias, foram distribuídos em dois grupos: controle (C; n=24) e obeso (OB; n=24). Os ratos C receberam ração padrão e os OB ração ocidental. Posteriormente, na 43º semana após o início das dietas os animais de ambos os grupos foram realocados em 2 novos grupos para início do tratamento hormonal, formando neste momento 4 grupos experimentais (C; n=12, CT; n=12, OB; n=12, OBT; n=12). A gordura corporal total foi realizada pela somatória do... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Thyroid hormones (HTs) are key to the growth and development of various organs and tissue. The source of HTs is the thyroid gland, which is part of the hypothalamicpituitary-thyroid axis and produces, mainly, triiodothyronine (T3) and thyroxine (T4). Thyroid dysfunction is often associated with changes in appetite and body weight, leading to changes in metabolic parameters, playing an important role in the regulation of metabolism and adipose tissue. The relationship between obesity and thyroid disorders has been much studied but is still not well established. The World Health Organization (WHO) recognizes obesity as an important public health problem that affects children, adolescents, and adults. The objective of our study was to evaluate the influence of thyroid hormone on the nutritional, metabolic and hormonal profile of obese rats, based on the models studied by our group and in order to broaden the research in this area. Male Wistar rats, 60 days old, were used in two groups: control (C; n = 24) and obese (OB; n = 24). C rats received standard ration and Western rations. Later, at the 43rd week after the beginning of the diets, the animals of both groups were relocated into 2 new groups to start the hormonal treatment, forming at this moment 4 experimental groups (C; n = 12, CT; n = 12, OB; n = 12, OBT; n = 12). The total body fat was performed by the sum of the epididymal, retroperitoneal, visceral deposits and the obesity defined by the adiposity index. The nutrition... (Complete abstract click electronic access below) / Mestre

[Truncated abstract] Type 1 Diabetes is emerging as a significant public health problem faced by nearly every country in the world. It has major economic and social implications with considerable burden of illness. Approximately 140,000 Australians have been diagnosed with T1DM with an annual increase in incidence rate of 3% per year, comparable to the overall global increase. The management of T1DM requires insulin therapy which places considerable burden on the patient and their carers. Coping with daily insulin injections, dietary changes, modification of physical activity and vigilant monitoring of blood glucose levels, will impact on patient?s quality of life. The optimum goal for the treatment of type 1 diabetes is to safely achieve near-normal glycaemia and failure to maintain this goal accelerates the progression of the devastating long term complications of diabetes. Unfortunately attempts to achieve near normal glycaemia are limited by the risk of excessive lowering of blood glucose levels and hypoglycaemia remains a major barrier to strict glucose control of diabetes. In general this thesis focuses on two fundamental issues related to the epidemiology of severe hypoglycaemia. Namely, methodological consideration when analysing prospective observational data and application of the most robust methodology. A prospective open cohort study of the Princess Margaret Hospital diabetes clinic established in 1992, with 99% case ascertainment was used. This hospital is the only paediatric referral centre for type 1 diabetes and every child diagnosed in the state of Western Australia is treated at this centre. ... The results of this study showed that severe hypoglycaemia remains a major problem and recent approaches to therapy may be allowing a degree of improved control without the expected increased risk of severe hypoglycaemia. The study in chapter 7 investigates genetic risk factors related to severe hypoglycaemia. A significant relationship where the presence of the iv deletion (D) allele of the angiotensin-converting enzyme (ACE) increases risk of severe hypoglycaemia has been reported. This study concludes that the presence of D allele of the ACE gene does not predict a significantly higher risk of severe hypoglycaemia. In an attempt to optimize glycemic control, patients may suffer multiple episodes of severe hypoglycaemia which can adversely affect quality of life as well as educational and intellectual disadvantage. The study in chapter 8 investigates the factors related to recurrent severe hypoglycaemia. A rigorous and informative time-to-event approach is used to account for within child correlation, staggered enrolment and timevarying covariates. This allows important risk factors to change over time. Preschool children have an increased risk of experiencing recurrent severe hypoglycaemia. The findings of this thesis highlights the importance of selecting appropriate analytical methodology to identify risk factors associated with severe hypoglycaemia and also to dismiss factors that had previously been thought to be important. This will help in formulating management plans in order to limit the impact of severe hypoglycaemia.

The present study aimed to examine factors that predict glycemic control in Hispanic youths. Secondary aims included developing and evaluating Spanish translations of three measures commonly used in research with youths with type 1 diabetes and examining factors associated with diabetes self-management in this population. Data was collected at three sites through interviews, questionnaires, and medical chart review. Participants included 117 Hispanic diabetic youths (10 to 17 years old) and their caregiver. 15% of the youths who participated were born outside of the continental U.S. and 57% were first generation born in the U.S. Translations of the Diabetes Self-Management Profile, Diabetes Social Support Questionnaire-Family version, and the Family Environment Scale?s Organization subscale had adequate reliability and showed evidence of concurrent validity. Primary analyses indicated that parent education, occupation, and household income are all significant predictors of glycemic control in Hispanic youth. In addition, global ratings of diabetes self-management on the DSMP predicted control in this population. Family factors did not contribute directly to glycemic control after controlling for sociodemographic and disease variables. However, older age, more acculturation, and language barriers were associated with poorer self-management. Additionally, family support and organization significantly contributed to self-management.

Research investigating the effects of pre-exercise meals with varying glycemic indices on exercise performance in intermittent sports is scarce. This study determined whether whole foods of low glycemic index (GI) resulted in a metabolic and performance advantage, in comparison to high GI foods, when eaten prior to extended intermittent cardiovascular exercise, such as tournament soccer play. Consenting trained participants (10 males, 4 females, 25.8 ± 7.3 y) completed two simulated soccer tournaments separated by at least seven days. Each testing day included two 90-minute soccer matches separated by a three hour break. Using a randomized cross-over design, low-GI, lentil-based meals (GI~42) or high-GI, potato-based meals (GI~78) matched for caloric value were consumed two hours prior to and then within one hour after the first soccer match. Blood glucose, lactate, insulin, free fatty acids, and respiratory gases were measured throughout the post-prandial and testing periods. Ratings of perceived exertion (RPE) and gastrointestinal symptoms were also recorded. Performance was measured by the distance covered during five one-minute sprints, separated by two minute and thirty second rest intervals, at the end of each match. Peak post-prandial blood glucose was higher (p<0.05) in the high-GI trial (8.9 ± 2.2 molL-1 [SD]) compared to the low GI trial (5.9 ± 1.3 mmolL-1) as was insulin prior to the start of exercise (19.4 ± 2.0 versus 9.2 ¬± 1.3 umolL-1, p<0.05). Blood lactate levels were significantly higher (p<0.05) at the end of the second match during the high-GI trial (6.1 ± 1.2 mmolL-1) compared to the low-GI trial (2.5 ± 0.4 mmolL-1). Breath-by-breath analysis showed lower (p<0.05) carbohydrate oxidation during the low-GI trials compared to the high-GI at the start of the first soccer match (p<0.05). Subjects reported greater feelings of hunger during the high-GI trial versus greater feelings of fullness during the low-GI trial (p<0.05), but RPE during the low-GI (14.1 ± 0.3) was similar to the high-GI meal (14.2 ± 0.3). Sprint distance was not significantly different between treatments (p=0.27). Overall, these findings suggest that lentil-based, low-GI foods are a comparable alternative to traditional high-GI pre-exercise meals, as they result in similar performance outcomes but improved metabolic profiles. Over the long-term, improving metabolic conditions during exercise may be beneficial to the health of athletes.

Research investigating the effects of pre-exercise meals with varying glycemic indices on exercise performance in intermittent sports is scarce. This study determined whether whole foods of low glycemic index (GI) resulted in a metabolic and performance advantage, in comparison to high GI foods, when eaten prior to extended intermittent cardiovascular exercise, such as tournament soccer play. Consenting trained participants (10 males, 4 females, 25.8 ± 7.3 y) completed two simulated soccer tournaments separated by at least seven days. Each testing day included two 90-minute soccer matches separated by a three hour break. Using a randomized cross-over design, low-GI, lentil-based meals (GI~42) or high-GI, potato-based meals (GI~78) matched for caloric value were consumed two hours prior to and then within one hour after the first soccer match. Blood glucose, lactate, insulin, free fatty acids, and respiratory gases were measured throughout the post-prandial and testing periods. Ratings of perceived exertion (RPE) and gastrointestinal symptoms were also recorded. Performance was measured by the distance covered during five one-minute sprints, separated by two minute and thirty second rest intervals, at the end of each match. Peak post-prandial blood glucose was higher (p<0.05) in the high-GI trial (8.9 ± 2.2 molL-1 [SD]) compared to the low GI trial (5.9 ± 1.3 mmolL-1) as was insulin prior to the start of exercise (19.4 ± 2.0 versus 9.2 ¬± 1.3 umolL-1, p<0.05). Blood lactate levels were significantly higher (p<0.05) at the end of the second match during the high-GI trial (6.1 ± 1.2 mmolL-1) compared to the low-GI trial (2.5 ± 0.4 mmolL-1). Breath-by-breath analysis showed lower (p<0.05) carbohydrate oxidation during the low-GI trials compared to the high-GI at the start of the first soccer match (p<0.05). Subjects reported greater feelings of hunger during the high-GI trial versus greater feelings of fullness during the low-GI trial (p<0.05), but RPE during the low-GI (14.1 ± 0.3) was similar to the high-GI meal (14.2 ± 0.3). Sprint distance was not significantly different between treatments (p=0.27). Overall, these findings suggest that lentil-based, low-GI foods are a comparable alternative to traditional high-GI pre-exercise meals, as they result in similar performance outcomes but improved metabolic profiles. Over the long-term, improving metabolic conditions during exercise may be beneficial to the health of athletes.

The aim was to determine whether the dietary glycemic index (GI) related to coronary heart disease (CHD) risk and whether oxidized LDL could explain this relation. Nine prospective cohorts of GI or glycemic load (GL) associations were pooled in a meta-analysis and showed an increased risk of CHD for high GI (near significant at RR=1.13, 95%CI; 1.00-1.26) and GL diets (significant at RR=1.40, 95%CI; 1.17-1.68), both with significant evidence of heterogeneity (P<0.07). Sera from 151 type 2 diabetics who completed a 6-month trial of a low GI diet demonstrated no treatment difference in measures of oxidative damage. However, when data from both treatments were pooled, oxidized LDL as a marker of CHD risk inversely related to low GI carbohydrate intake. We conclude that GI and GL relate to CHD and oxidative damage to LDL may explain part of this association.

Gestational Diabetes Mellitus develops in 3.7-18% of Canadian women, and can cause serious maternal-fetal complications. Low-GI foods have been shown to increase β-cell function in subjects with impaired glucose tolerance. Theoretically, this effect should improve glucose tolerance and reduce the risk of gestational hyperglycemia. Thus, we aimed to explore the effects of a low-GI diet on glucose challenge test (GCT) results in women at risk for GDM. Women were randomized to receive education during pregnancy focused on incorporation of low- or medium- to high-GI foods. Key foods were provided to assist compliance. Information was obtained from medical records and questionnaires. Ninety-four (94) women completed the study. After adjustment for confounding variables, there was no significant difference in GCT values between intervention groups. Results suggest that low-GI foods do not affect blood glucose control during pregnancy.

Gestational Diabetes Mellitus develops in 3.7-18% of Canadian women, and can cause serious maternal-fetal complications. Low-GI foods have been shown to increase β-cell function in subjects with impaired glucose tolerance. Theoretically, this effect should improve glucose tolerance and reduce the risk of gestational hyperglycemia. Thus, we aimed to explore the effects of a low-GI diet on glucose challenge test (GCT) results in women at risk for GDM. Women were randomized to receive education during pregnancy focused on incorporation of low- or medium- to high-GI foods. Key foods were provided to assist compliance. Information was obtained from medical records and questionnaires. Ninety-four (94) women completed the study. After adjustment for confounding variables, there was no significant difference in GCT values between intervention groups. Results suggest that low-GI foods do not affect blood glucose control during pregnancy.