Lactation and Glucose Tolerance After GDM Pregnancy

描述(申请人提供)：哺乳对糖耐量有直接的有利影响，这种影响可能在断奶后持续存在，以防止女性发生2型糖尿病(DM)。妊娠期糖耐量异常，称为妊娠期糖尿病(GDM)，是2型糖尿病后续发展的强烈预测因素。在美国，妊娠期糖尿病的发生率约为3%-5%，每年影响135,000名妇女。在产后5年内，有妊娠期糖尿病史的女性中有20%到50%会发展成2型糖尿病。妊娠期糖尿病患者发生2型糖尿病的危险因素包括：胰岛b细胞功能障碍、孕期和产后早期糖耐量低减、糖尿病家族史、母亲肥胖、妊娠期糖尿病复发和体重增加。哺乳可以降低母亲的血糖和胰岛素水平，改善葡萄糖耐量和性情指数，表明胰岛素抵抗程度有利于细胞功能。哺乳的强度和持续时间是否降低了随后的糖尿病风险，很少被研究。以前的研究局限于哺乳的定性测量(是否哺乳)、当前状态(是与否)或一生中哺乳的月份。尚无前瞻性研究评估哺乳强度(补充喂养)和/或持续时间与妊娠晚期妊娠期糖尿病后发生2型糖尿病的关系。我们提出了一项前瞻性队列研究，将在加利福尼亚州北部的Kaiser Permanente Health Care System招募1098名最近被诊断为GDM的女性，她们在产后6-8周内没有患上2型糖尿病。女性每年将接受为期两年的2小时75克口服葡萄糖耐量测试。我们将确定与不哺乳相比，长时间高强度哺乳是否与2型糖尿病的发病率降低以及空腹和负荷后2小时血糖和胰岛素水平、胰岛素抵抗指数、体重、腰围和血浆脂联素的更有利变化有关。由于随机化是不可行的，严格评估多个潜在混杂因素的哺乳强度和持续时间控制是最有效的研究设计。这些发现对有妊娠期糖尿病病史的女性的潜在公共健康影响是巨大的，因为只有不到50%的美国女性会哺乳4个月。哺乳是一种可改变的行为，可以转化为一种实用的、低成本的干预措施，有可能加强产后干预，促进健康的饮食摄入和增加体力活动。

DESCRIPTION (provided by applicant): Lactation has immediate favorable effects on glucose tolerance that may persist after weaning to prevent development of type 2 diabetes mellitus (DM) in women. Development of glucose intolerance during pregnancy, known as gestational diabetes (GDM), is a strong predictor of subsequent development of type 2 DM. In the U.S., GDM occurs in about 3-5% of all pregnancies and affects 135,000 women per year. Within 5 years after delivery, 20 to 50% of women with previous GDM will develop type 2 DM. Risk factors for type 2 DM after GDM pregnancy include pancreatic b-cell dysfunction, severity of glucose intolerance during pregnancy and early postpartum periods, family history of DM, maternal obesity, recurrent GDM and weight gain. Lactation lowers maternal glucose and insulin levels, improves glucose tolerance and the disposition index, indicating better-cell function for their degree of insulin resistance. Whether the intensity and duration of lactation reduces subsequent risk of DM has rarely been examined. Previous studies are limited by qualitative measures of lactation (ever vs. never), current status (yes vs. no), or lifetime months of lactation. No prospective studies have assessed lactation intensity (supplemental feedings) and/or duration in relation to development of type 2 DM after recent GDM pregnancy. We propose a prospective cohort study that will enroll 1,098 women with a recent GDM diagnosis who are free of type 2 DM at 6-8 weeks postpartum in the Kaiser Permanente Health Care System in northern California. Women will be followed annually for two years to administer the 2 hr 75 g oral glucose tolerance test. We will determine whether prolonged, intensive lactation compared with no lactation is associated with a lower incidence of type 2 DM, and more favorable changes in fasting and 2-hr post load plasma glucose and insulin levels, indices of insulin resistance, body weight, waist girth and plasma adiponectin. Because randomization is not feasible, the rigorous assessment of lactation intensity and duration controlling for multiple potential confounders is the most valid study design. The potential public health impact of these findings for women with a history of GDM is substantial given that less than 50% of U.S. women lactate for four months. Lactation is a modifiable behavior that may be translated into a practical, low-cost intervention that has the potential to enhance postpartum interventions that promote healthy dietary intakes and increased physical activity.