Department of Nutrition, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, MA, USA.
J Nutr. 2021 Dec 3;151(12):3801-3810. doi: 10.1093/jn/nxab302.
The postpartum period is a critical transition period when exposures to protective factors such as breastfeeding can have long-lasting health impact. Studies have suggested downregulating effects of breastfeeding on stress biomarkers such as cortisol but have not explored the way breastfeeding interacts with allostatic load, a multisystem indicator of chronic stress.
We aimed to examine the association between breastfeeding and maternal allostatic load among women within 2 y postpartum using nationally representative data.
A cross-sectional analysis of 10 waves of data from the NHANES (1999-2018) was conducted in a sample of 1302 women aged ≥18 y who provided information on breastfeeding through the reproductive health questionnaire. Clinical and empirical allostatic load scores (range: 0-10; higher numbers associated with increased risk) were derived for each participant based on 10 biomarkers reflecting metabolic, cardiovascular, and immune health. Multiple linear regression tested associations between breastfeeding and allostatic load, adjusting for maternal age, race and ethnicity, education, poverty level, and survey wave.
Breastfeeding had a significant inverse association with allostatic load in unadjusted and adjusted models. Controlling for age, race and ethnicity, education, poverty level, and survey wave, breastfeeding women had a 0.36-point lower clinical allostatic load score than nonbreastfeeding women (β = -0.36, SE = 0.11; 95% CI: -0.59, -0.14; P = 0.002) and a 0.44-point lower empirical allostatic load score (β = -0.44, SE = 0.15; 95% CI: -0.74, -0.14; P = 0.005).
Our study suggests that breastfeeding is protective of maternal stress and provides a more comprehensive picture of breastfeeding's influence on multiple body systems, exemplifying physiological benefits beyond effects on single biomarkers. However, limitations of cross-sectional data and non-classification of breastfeeding duration, mode, and intensity should be considered when interpreting these findings, and further research to address the role of breastfeeding and allostatic load is needed.
产后是一个关键的过渡期，在此期间，如母乳喂养等保护因素可能会对健康产生持久的影响。研究表明，母乳喂养对皮质醇等应激生物标志物有下调作用，但尚未探索母乳喂养与身体压力负荷（一种慢性应激的多系统指标）相互作用的方式。
我们旨在使用全国代表性数据，在产后 2 年内的女性中，检验母乳喂养与产妇身体压力负荷之间的关联。
使用 NHANES（1999-2018 年）的 10 个波次的数据进行横断面分析，纳入了 1302 名年龄≥18 岁的女性，她们通过生殖健康问卷提供了母乳喂养信息。根据 10 个反映代谢、心血管和免疫健康的生物标志物，为每位参与者计算临床和经验性身体压力负荷评分（范围：0-10；分数越高，风险越高）。多元线性回归检验了母乳喂养与身体压力负荷之间的关联，调整了母亲的年龄、种族和民族、教育程度、贫困水平和调查波次。
在未调整和调整模型中，母乳喂养与身体压力负荷呈显著负相关。在控制了年龄、种族和民族、教育程度、贫困水平和调查波次后，与非母乳喂养女性相比，母乳喂养女性的临床身体压力负荷评分低 0.36 分（β=-0.36，SE=0.11；95%CI：-0.59，-0.14；P=0.002），经验性身体压力负荷评分低 0.44 分（β=-0.44，SE=0.15；95%CI：-0.74，-0.14；P=0.005）。
我们的研究表明，母乳喂养对产妇压力具有保护作用，并提供了一个更全面的视角，说明母乳喂养对多个身体系统的影响，体现了除对单一生物标志物的影响之外的生理益处。然而，在解释这些发现时，应考虑横断面数据的局限性以及母乳喂养持续时间、方式和强度的非分类，并需要进一步研究来确定母乳喂养和身体压力负荷的作用。
