Biodemographic Tools for Investigating Postpartum Amenorrhea

用于调查产后闭经的生物人口统计学工具

• 批准号: 7384984
• 负责人: DARRYL J HOLMAN
• 金额: $ 24.06万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7384984
• 关键词: Amenorrhea; Anovulation; Bangladesh; Behavior; Biological Assay; Birth Intervals; Breast Feeding; C-Peptide; Child; Class; Condition; Contraceptive Agents; Data; Data Set; Developed Countries; Developing Countries; Development; Discipline of Nursing; Effectiveness; Endocrine; Fertility; Frequencies; Future; Goals; Guatemala; Health; Heterogeneity; Hormones; Hydrocortisone; Hypothalamic structure; Infant; Insulin-Like Growth Factor I; Investigation; Java; Laboratories; Left; Length; Leptin; Maintenance; Maternal Behavior; Measurement; Measures; Menstrual fluid; Menstruation; Metabolic; Metabolic Control; Metabolic Marker; Methods; Modeling; Natural Fertility; Neurologic; Nurses; Nutritional status; Ovarian; Ovarian Cycles; Pathway interactions; Patient Self-Report; Pattern; Population; Postpartum Period; Probability; Prospective Studies; Public Health; Questionnaires; Relative (related person); Reproduction; Research; Sampling; Series; Specimen; Statistical Models; Stimulus; Subgroup; Testing; Time; Triiodothyronine; Urine; Woman; Women' s Health; Work; Workload; base; field study; hazard; health economics; improved; nutrition; prospective; reproductive axis; response; socioeconomics; tool; urinary

DESCRIPTION (provided by applicant): In populations that approximate conditions of natural fertility, the period of lactational infecundability is one of the most important and the most variable components of birth intervals, lasting from a few months to several years. Breastfeeding acts to suppress hypothalamic function which, in turn, suppresses the reproductive axis. A debate has emerged in the last decade over the mechanism by which breastfeeding suppresses hypothalamic activity. One hypothesis proposes a direct neurological pathway in response to nursing intensity. The alternative hypothesis is that hypothalamic function is suppressed in response to the metabolic load of breastfeeding. For this project, we develop and evaluate two classes of biodemographic tools for investigating the mechanisms of lactational amenorrhea. First, we will develop new endocrine tools for assessing metabolic load for large population-based field projects. We will develop and validate assays for urinary leptin, C-peptide, T3, and IGF-I. Second, we develop two new models of lactational amenorrhea. We extend the mixture model of Ford and Kim (1987) to include time-varying covariates modeled on the hazard of resumption of menses in each subgroup and the probability of subgroup membership. We also propose a new three-state stochastic model that may represent more realistically the underlying mechanisms of lactational amenorrhea. These tools will be applied to three existing longitudinal data sets in order to evaluate their potential for a more targeted study. The statistical tools will be used to examine the relative effects of nutrition (assessed by anthropometric measures), nursing behavior, maternal workload and other health and socioeconomic variables on the time to resumption of menses in two of the studies (the Ngaglik study from Java and the INCAP study in Guatemala). A third 9-month study from Bangladesh includes urine specimens collected from breastfeeding women. Specimens will be assayed for urinary leptin, C-peptide, T3, IGF-I, and cortisol (using an existing assay). The effects of endocrine markers and nursing behavior on the maintenance of PPA will be examined by statistically fitting the new models to these observations. Relevance: In many developing settings the contraceptive effects of nursing contribute significantly to birth spacing. This project will develop tools and provide preliminary analyses to disentangle how the metabolic load of nursing and the frequency and duration of nursing suppress reproduction. The results will be important for understanding and projecting effects of improvements in women's health, nutrition, and work patterns on the duration to return of full fecundity. The resulting endocrine tools will also be useful for other large-scale (field) studies that require measurement of relative metabolic load.

描述（由申请人提供）：在近似自然生育能力条件的人群中，乳酸无可性性的时期是最重要，最可变的出生间隔成分之一，持续了几个月至几年。母乳喂养起来抑制下丘脑功能，进而抑制生殖轴。在过去的十年中，关于母乳喂养抑制下丘脑活性的机制已经出现了辩论。一个假设提出了针对护理强度的直接神经系统途径。另一种假设是，下丘脑功能因母乳喂养的代谢负荷而受到抑制。对于这个项目，我们开发和评估了两类生物人口统计学工具，以研究泌乳闭经的机制。首先，我们将开发新的内分泌工具，用于评估大型基于人群的现场项目的代谢负荷。我们将开发和验证尿瘦素，C肽，T3和IGF-I的测定法。其次，我们开发了两种新的泌乳闭经模型。我们将福特和金（1987）的混合模型扩展到包括时变的协变量，该协变量建立在每个亚组中恢复月球的危害以及亚组成员资格的概率上。我们还提出了一个新的三态随机模型，该模型可能更现实地代表泌乳闭经的潜在机制。这些工具将应用于现有的三个纵向数据集，以评估其对更有针对性的研究的潜力。统计工具将用于检查营养的相对影响（通过人体测量措施评估），护理行为，孕妇工作量以及其他健康和社会经济变量对两项研究的恢复月经的时间（Java的Ngaglik研究以及在Guatemala中的INCAP研究）。孟加拉国的第三次9个月研究包括从母乳喂养女性那里收集的尿液标本。标本将用于尿液瘦素，C肽，T3，IGF-I和皮质醇（使用现有测定）。内分泌标记物和护理行为对维持PPA的影响将通过统计上的新模型与这些观察结果进行检查。相关性：在许多开发环境中，护理的避孕作用对出生间距产生了重大贡献。该项目将开发工具并提供初步分析，以解除护理的代谢负荷以及抑制繁殖的频率和持续时间。结果对于理解和预测妇女健康，营养和工作模式的改善对全部繁殖力的持续时间的效果至关重要。所得的内分泌工具也将用于其他需要测量相对代谢负荷的大规模（现场）研究。