Breastfeeding Is Inversely Associated with Allostatic Load in Postpartum Women: Cross-Sectional Data from Nationally Representative US Women

ABSTRACT Background 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. Objective We aimed to examine the association between breastfeeding and maternal allostatic load among women within 2 y postpartum using nationally representative data. Methods 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. Results 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). Conclusions 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.

Associations Between Breastfeeding and Postpartum Allostatic Load: NHANES 1999–2016

Objectives Current evidence suggests breastfeeding has a modulating effect on maternal stress. We aimed to examine the association between breastfeeding and maternal allostatic load, a marker of chronic stress and adverse health, among women within one year postpartum, using nationally representative data. We hypothesized that women who were breastfeeding had lower allostatic load compared to women who were not breastfeeding. Methods A cross sectional analysis of nine waves of data from the National Health and Nutrition Examination Survey (NHANES 1999–2016) was conducted on a sample of 1203 women >18 years old, within their first year postpartum, who provided information on breastfeeding status through the reproductive health questionnaire. An allostatic load score (range 0–10) was derived for each participant based on ten biomarkers reflecting metabolic, cardiovascular, and immune health. Simple linear regression was used to test bivariate associations between potential confounders and allostatic load. Confounders were then incorporated into multiple linear regression models. The final model tested associations between breastfeeding and allostatic load, adjusting for maternal age, race/ethnicity, education, and poverty status. Results Our findings showed that breastfeeding had a significant inverse association with allostatic load in unadjusted and adjusted models. Furthermore, controlling for age, race/ethnicity, education, and poverty status, we found that breastfeeding women had 0.2727 points lower allostatic load score than non-breastfeeding women (ß = −0.2727, SE = 0.0958, P = 0.0045). Conclusions Our study suggests breastfeeding is protective of maternal stress, demonstrating an inverse association with allostatic load among women during the first year postpartum. Our results provide a more comprehensive picture of breastfeeding's influence on multiple body systems, exemplifying physiological benefits beyond effects on single biomarkers. Funding Sources No funding was used to support this study.

Abstract P121: Multidimensional Allostatic Load Score Directly Associates With Coronary Artery Disease Burden in Psoriasis

Introduction: Psoriasis is a chronic inflammatory skin disease associated with accelerated development of asymptomatic coronary artery disease (CAD) by coronary computed tomography angiography (CCTA). Allostatic load score is a multidimensional measure related to chronic stress which incorporates cardiovascular, metabolic and inflammatory indices. To better understand the physiologic impact of chronic stress in psoriasis, we studied the association between allostatic load score and subclinical CAD. Hypothesis: We hypothesized that allostatic load score would associate with coronary artery disease burden beyond traditional risk factors in an ongoing psoriasis cohort study. Methods: Consecutive psoriasis patients (n=275) underwent CCTA for assessment of coronary artery disease burden (QAngio, Medis). Allostatic load score was determined using established methods (see Table 1 footnote). The association between coronary artery disease burden and allostatic load score was characterized by multivariable regression (STATA 12). Results: Psoriasis patients were middle-aged, predominantly male and white, with low cardiovascular risk by Framingham risk score and moderate-severe psoriasis severity (Table 1) . Allostatic load score associated with total coronary burden (β=0.39; p<0.001) and non-calcified coronary burden (β=0.40; p<0.001) in unadjusted analyses. In multivariable models, allostatic load score was still associated with total coronary burden (β=0.30; p<0.001) and non-calcified coronary burden (β=0.31; p<0.001) independent of race, Framingham risk score and waist-hip ratio. Conclusions: Allostatic load score positively associated with both total and non-calcified coronary artery burden beyond traditional risk factors, suggesting multisystem physiologic dysregulation related to chronic stress may drive subclinical atherosclerosis in psoriasis. Efforts to understand stress effects and its reduction are critical in this population at high-risk for cardiovascular disease.

Abstract P301: Differences in Stress Related Behavior According to Age of Immigration: Insight From the Africans in America Study

Background: Adjusting to the stress of life in the United States is associated with unhealthy assimilation behaviors, such as cigarette smoking and alcohol consumption. Allostatic load score (ALS) is a measure of the accumulative effect of stress due to overactivation of the hypothalamic-pituitary-adrenal (HPA) and sympathetic adrenal medullary (SAM) axes. It is unknown if stress related behaviors vary according to whether immigration occurred as a child (<18y) or as an adult (≥18y). Objective: Our goal was to measure stress by ALS in 382 African-born blacks living in the Washington, DC metropolitan area (age 39±10y, range 20 to 65y) and compare social and behavioral factors in Africans who migrated to the United States as children versus as adults. Methods: ALS was calculated using 10 biomarkers from the 3 physiological systems affected by the HPA and SAM axes: cardiovascular (systolic BP, diastolic BP, pulse, cholesterol, HDL, homocysteine), metabolic (BMI, A1C, albumin) and inflammatory (hsCRP). One point was assigned if a variable was determined to be in the high-risk range and 0 if not. High-risk was defined by being in the highest quartile for the population distribution of each variable, except for albumin and HDL, which required the lowest quartile. Results: Of the 382 enrollees, 18% (68/382) came to the United States as children and 82% (314/382) were adults. Compared to adulthood immigrants, childhood immigrants were younger (31±9 vs. 41±10y, P <0.001) and had been in the United States longer (22±9 vs.11±10y, P <0.001). After adjusting for age, ALS was similar in the child and adult immigrants (2.6±0.02 vs.2.6±0.01, P =0.84). Alcohol intake was higher in immigrants who came as children than immigrants who came as adults (40% vs. 25%, P =0.02). Cigarette smoking, sedentary behavior and number of meals outside of the home all tended to be higher in the childhood immigrants ( P <0.2). In addition, childhood immigrants were more likely to self-identify as African-Americans than Africans (16% vs. 7%, P =0.05). Conclusion: Independent of whether Africans came to the United States as children or adults, degree of stress as measured by ALS is similar. However, Africans who arrived as children were more likely to develop unhealthy assimilation behaviors. Whether these behaviors are due to longer duration of stay in the United States or a generational difference remains to be determined.