Enhancing Carbohydrate Quality in Diabetes Management

由于糖尿病并发症的程度直接关系到糖尿病的控制水平，目前的糖尿病治疗方案越来越重视通过使用更密集的胰岛素方案和碳水化合物计数来维持接近正常的血糖。虽然建议适量使用单糖，但碳水化合物的来源或质量目前并不被视为养生法的组成部分。然而，越来越多的证据表明，血糖指数较低的碳水化合物可能会降低餐后高血糖，并改善整体血糖控制。根据HHS-USDA 2005年美国饮食指南，这样的饮食将包括从营养密集型全食--全谷物、水果、蔬菜和豆类--中更多地摄入碳水化合物。 两项试点研究为指导这一研究计划的发展提供了数据。2004年夏天进行了一项试点研究，以调查在糖尿病营地环境中实施低血糖指数饮食的可行性和可接受性。Camp提供了一个理想的环境，向年轻人介绍较低的血糖指数饮食，因为对食物的接触受到控制，并提供足够数量的食物来评估一系列食物的可接受性。参加糖尿病夏令营的7至15岁的年轻人以每日交替交叉设计的方式获得标准糖尿病夏令营菜单和较低血糖指数糖尿病夏令营菜单。从青年和工作人员那里获得了对营地餐饮和零食的满意程度，并进行了餐食消费观察。其他数据是通过焦点小组和食物模式和偏好的自我报告收集的。膳食计划和血糖监测数据来自营地记录。 2006年夏天进行了一项试点研究，利用连续血糖监测测试了青年糖尿病患者对低血糖指数膳食和高血糖指数膳食的血糖反应。在这项研究中，患有糖尿病的青少年参加了为期5天的连续血糖监测，在此期间，他们在有组织的诊所环境和家庭环境中分别接受了低血糖指数和高血糖指数膳食。记录食物摄入量、胰岛素和血糖自我监测。分析正在进行中，包括比较平均血糖、漂移和变异性。 一系列焦点小组研究了1型糖尿病儿童家庭对健康饮食的看法，以指导行为干预的发展，并将在即将到来的疗效试验中进行测试。焦点小组分别与儿童、青少年和父母一起进行。此外，还进行了一项横断面观察性研究，评估与饮食摄入量相关的潜在可修改因素。收集的数据包括儿童和父母的饮食摄入量、家庭饮食模式、食物可获得性、营养知识、父母和孩子对健康饮食的信念(例如，障碍、结果预期、自我效能)，以及父母和同龄人对健康饮食的模范。 正在计划进行一项行为干预的有效性试验，旨在增加来自低血糖、营养密集的全食来源的碳水化合物的消费。预计这项研究将提供对指导糖尿病患者饮食指南至关重要的数据。研究结果将促进人们对以下方面的理解：1)旨在增加全谷物、水果、蔬菜和豆类消费的青少年糖尿病行为干预的有效性；2)行为变化的中介和调节因素；以及3)饮食变化的生理影响。糖尿病患者的饮食建议必须考虑到饮食改变的潜在好处，以及实施这些建议的可行性、可接受性和预期的困难。到目前为止，研究主要依靠实验操作或传统的饮食教育来实现饮食改变，因此提供的信息很少用于指导自由生活个体的临床实践。因此，这项研究的结果将解决目前知识库中缺乏的领域。

Because degree of diabetes complications is directly linked to level of diabetes control, current diabetes regimens are placing increasing emphasis on maintenance of near-normal glycemia through the use of more intensive insulin regimens and carbohydrate counting. While moderation in the use of simple sugar is recommended, the source or quality of carbohydrate is not currently considered an integral part of the regimen. However, a growing body of evidence indicates that carbohydrates with a lower glycemic index may reduce postprandial hyperglycemia and improve overall glycemic control. Such a diet would consist of greater consumption of carbohydrate from nutrient-dense whole foods - whole grains, fruits, vegetables, and legumes - in accordance with the HHS-USDA 2005 Dietary Guidelines for Americans. Two pilot studies have provided data to guide the development of this program of research. A pilot study was conducted during the summer of 2004 to investigate the feasibility and acceptability of implementing a low glycemic index diet in the diabetes camp setting. Camp provides an ideal setting to introduce youth to a lower glycemic index diet, because exposure to foods is controlled, and a sufficient number of meals are served to assess acceptability across a range of foods. Youth ages 7 to 15 attending a diabetes summer camp were served standard diabetes camp menus and lower glycemic index diabetes camp menus in a daily alternating cross-over design. Measures of satisfaction with the camp meals and snacks were obtained from youth and staff, and observations of meal consumption were conducted. Additional data were collected via focus groups, and self-report of food patterns and preferences. Meal plans and blood glucose monitoring data were obtained from camp records. A pilot study was conducted during the summer of 2006 testing blood glucose response to low and high glycemic index meals in youth with diabetes using continuous blood glucose monitoring. In this study, youth with diabetes participated in 5 days of continuous blood glucose monitoring during which they received both low and high glycemic index meals both in a structured clinic setting and in the home environment. Food intake, insulin, and blood glucose self-monitoring were recorded. Analyses are in progress, and include comparison of mean blood glucose, excursions, and variability. A series of focus groups addressed perceptions of healthful eating among families of children with type 1 diabetes to guide development of a behavioral intervention to be testing in the upcoming efficacy trial. The focus groups were conducted separately with children, adolescents, and parents. In addition, a cross-sectional observational study assessing potential modifiable factors associated with dietary intake was conducted. Data collected include child and parent dietary intake, family eating patterns, food availability, nutrition knowledge, parent and child beliefs regarding healthful eating (e.g., barriers, outcome expectations, self-efficacy), and parent and peer modeling of healthful eating. Planning is underway for the conduct of an efficacy trial of a behavioral intervention designed to increase consumption of carbohydrates from lower glycemic, nutrient dense, whole food sources. It is anticipated that this research will provide data that are critical for guiding dietary guidelines for persons with diabetes. Findings will advance understanding of: 1) the efficacy of behavioral interventions for youth with diabetes designed to increase consumption of whole grains, fruits, vegetables, and legumes; 2) mediators and moderators of behavior change; and 3) physiological effects of dietary change. Dietary recommendations for persons with diabetes must take into account both the potential benefits dietary change, as well as the feasibility, acceptability, and expected difficulty of implementing such recommendations. Studies to date have relied primarily on either experimental manipulation or traditional dietary education to achieve dietary change, and so provide little information to guide clinical practice with free-living individuals. Thus, findings from this study will address areas that are currently lacking in the knowledge base.