Lamichhane Archana P, Crandell Jamie L, Jaacks Lindsay M, Couch Sarah C, Lawrence Jean M, Mayer-Davis Elizabeth J
From the Department of Nutrition, Gillings School of Global Public Health (APL), the Department of Nutrition, Gillings School of Global Public Health and School of Medicine (EJM-D), and the Departments of Nursing and Biostatistics (JLC), University of North Carolina, Chapel Hill, NC; the Department of Nutritional Sciences, University of Cincinnati Medical Center, Cincinnati, OH (SCC); the Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA (JML), and the Hubert Department of Global Health, Emory University, Atlanta, GA (LMJ).
Am J Clin Nutr. 2015 Jun;101(6):1278-85. doi: 10.3945/ajcn.114.103747. Epub 2015 May 6.
Improved glycated hemoglobin (Hb A1c) delays the progression of microvascular and macrovascular complications in individuals with type 1 diabetes (T1D). We previously showed that higher baseline intakes of n-3 (ω-3) fatty acids and leucine are associated with preserved β cell function 2 y later in youth with T1D.
In the current study, we extend this work to explore the longitudinal associations of nutritional factors with Hb A1c in youth with T1D.
We included 908 T1D youth with baseline and follow-up Hb A1c measurements. Nutritional factors assessed at baseline were as follows: breastfeeding status and timing of complimentary food introduction; intakes of leucine, carbohydrates, protein, fat, and fiber estimated from a food-frequency questionnaire (FFQ); and plasma biomarkers for vitamins D and E, eicosapentaenoic acid (EPA), and docosahexaenoic acid. We fit linear regression models adjusted for baseline Hb A1c, sociodemographic variables, diabetes-related variables, time between baseline and follow-up visits, saturated fat, physical activity, and for FFQ-derived nutrients, total calories. The vitamin D model was further adjusted for season and body mass index z score.
The mean ± SD age and diabetes duration at baseline was 10.8 ± 3.9 y and 10.1 ± 5.8 mo, respectively. A total of 9.3% of participants had poor Hb A1c (value ≥9.5%) at baseline, which increased to 18.3% during follow-up (P < 0.0001). Intakes of EPA (β = -0.045, P = 0.046), leucine (β = -0.031, P = 0.0004), and protein (β = -0.003, P = 0.0002) were significantly negatively associated with follow-up Hb A1c after adjustment for confounders. Intake of carbohydrates was significantly positively (β = 0.001, P = 0.003) associated with follow-up Hb A1c after adjustment for confounders.
Several nutritional factors may be associated with Hb A1c during early stages of disease progression in youth recently diagnosed with T1D. In addition to the overall role of major macronutrients such as carbohydrates and protein, leucine and n-3 fatty acid intakes, such as of EPA, may be important for long-term glycemic control.
糖化血红蛋白（Hb A1c）水平的改善可延缓1型糖尿病（T1D）患者微血管和大血管并发症的进展。我们之前的研究表明，较高的n-3（ω-3）脂肪酸和亮氨酸基线摄入量与T1D青少年2年后β细胞功能的保留有关。
在本研究中，我们扩展了这项工作，以探讨营养因素与T1D青少年Hb A1c的纵向关联。
我们纳入了908名有基线和随访Hb A1c测量值的T1D青少年。在基线时评估的营养因素如下：母乳喂养状况和辅食引入时间；通过食物频率问卷（FFQ）估计的亮氨酸、碳水化合物、蛋白质、脂肪和纤维摄入量；以及维生素D、维生素E、二十碳五烯酸（EPA）和二十二碳六烯酸的血浆生物标志物。我们拟合了线性回归模型，对基线Hb A1c、社会人口统计学变量、糖尿病相关变量在基线和随访之间的时间、饱和脂肪、身体活动以及FFQ衍生营养素、总热量进行了调整。维生素D模型进一步根据季节和体重指数z评分进行了调整。
基线时的平均±标准差年龄和糖尿病病程分别为10.8±3.9岁和10.1±5.8个月。共有9.3%的参与者在基线时Hb A1c水平不佳（值≥9.5%），随访期间这一比例增至18.3%（P<0.0001）。在对混杂因素进行调整后，EPA摄入量（β=-0.045，P=0.046）、亮氨酸摄入量（β=-0.031，P=0.0004）和蛋白质摄入量（β=-0.003，P=0.0002）与随访时的Hb A1c显著负相关。在对混杂因素进行调整后，碳水化合物摄入量与随访时的Hb A1c显著正相关（β=0.001，P=0.003）。
在新诊断为T1D的青少年疾病进展早期，几种营养因素可能与Hb A1c有关。除了碳水化合物和蛋白质等主要宏量营养素的总体作用外，亮氨酸和n-3脂肪酸摄入量（如EPA）可能对长期血糖控制很重要。
