Determinants of gestational weight gain in obese pregnant women

描述（由申请人提供）：在美国，怀孕的肥胖妇女人数在过去30年中增加了一倍多。然而，妊娠前肥胖并不是唯一值得关注的原因，因为三分之二的肥胖妇女体重增加超过了2009年IOM的建议，迄今为止，控制妊娠期体重增加的尝试都失败了。为了改善肥胖孕妇的体重管理，迫切需要提供关于能量摄入和能量消耗（体力活动）的具体循证建议;这是非怀孕个体体重增加的两个主要决定因素。作为LIFE-Moms（准妈妈生活方式干预研究）的辅助研究，我们将评估80名肥胖女性在怀孕期间（13至37周）和产后12个月的能量摄入和能量消耗，这些肥胖女性随机接受强化生活方式干预以管理妊娠期体重增加。我们将检验以下假设：体重增加超过IOM指南的肥胖孕妇（“高体重者”）与妊娠期体重增加适当的孕妇（“正常体重者”）相比，在调整体重增加后，将增加能量摄入，但没有证据表明能量消耗发生变化。主要结局变量为1）使用能量平衡方法和母体能量摄入数学模型测量的妊娠期间和产后12个月的能量摄入; 2）妊娠期间的自由生活能量消耗和睡眠代谢率（绝对值，并根据母体身体成分和胎儿大小进行调整）。次要结局包括测量体力活动和底物氧化的变化，能量摄入的决定因素包括瘦素、总生长激素释放肽、肽YY、胆囊收缩素的空腹浓度，能量消耗的决定因素包括尿肾上腺素和去甲肾上腺素、T3、T4和TSH的空腹浓度。

DESCRIPTION (provided by applicant): In the U.S. the number of obese women entering pregnancy has more than doubled in the past 30 years. Pregravid obesity alone however is not the only cause for concern since two-thirds of obese women gain weight in excess of the 2009 IOM recommendations and attempts to manage gestational weight gain to date have failed. To improve weight management of obese pregnant women, there is a critical need to deliver specific evidence-based recommendations on energy intake and energy expenditure (physical activity); the two primary determinants of weight gain in non-pregnant individuals. As an ancillary study to LIFE-Moms (Lifestyle Interventions in Expectant Moms Study) we will evaluate energy intake and energy expenditure during pregnancy (13 to 37 weeks) and 12 months postpartum in 80 obese women randomized to receive an intensive lifestyle intervention to manage gestational weight gain. We will test the hypothesis that obese pregnant women with weight gain above the IOM guidelines, 'High Gainers', will have increased energy intake but no evidence for changes in energy expenditure after adjustment for the weight gained when compared to women with appropriate gestational weight gain, 'Normal Gainers'. The primary outcome variables are 1) energy intake during pregnancy and 12 months postpartum measured with the energy balance method and with a mathematical model of maternal energy intake 2) the free-living energy expenditure and sleeping metabolic rate (absolute and adjusted for maternal body composition and fetal size) during pregnancy. Secondary outcomes include measurement of changes in physical activity and substrate oxidation, determinants of energy intake including fasting concentrations of leptin, total ghrelin, peptide YY, cholecystokinin and determinants of energy expenditure including urinary epinephrine and norepinephrine, fasting concentrations of T3, T4 and TSH.