The relationship between maternal allostatic load and demographic characteristics within different ethnic populations and different federal-level poverty groups

Open Access
Author:
Wang, Rong
Graduate Program:
Public Health Sciences
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
March 10, 2015
Committee Members:
  • Vernon Michael Chinchilli, Thesis Advisor
Keywords:
  • allostatic load
  • demographics
  • ethnicity
  • federal-level poverty
Abstract:
Background: The purpose of this study is to investigate the relationship between maternal allostatic load, a measure of the cumulative toll of chronic stress, and demographic characteristics within different ethnic populations and different federal-level poverty groups, which provides some foundational research prior to investigating the association of maternal allostatic load with the outcome of a subsequent pregnancy. Methods: This study is a part of a large study conducted by the Community and Child Health Network (CCHN). The CCHN allostatic load data set includes 10 objective biomarkers taken at the T2M visit (six months postpartum) and the T3M visit (12 months postpartum) for the mothers. The linear mixed-effects model was used to analyze the differences of all maternal allostatic load variables between the T2M visit and the T3M visit. Next, principal component analysis was applied to summarize the variability across maternal allostatic load variables in different ethnicity and poverty level groups and to do variable reduction. Finally, regression analysis was invoked to determine the relationship between maternal allostatic load variables and demographic variables within different ethnicity and poverty level groups. Results: From the linear mixed-effects regression analysis, there were significant differences on total cholesterol between the T2M visit and the T3M visit in poor Hispanic group (Difference=-9.9, SE=4.6, p=0.03), in the rich White group (Difference=-8.5, SE=3.7, p=0.02), and in the middle White group (Difference=-29.9, SE=7.2, p<0.0001). Principal component analysis identified two principal components of the biomarkers of maternal allostatic load. The first principal component was total cholesterol and the second principal component can be explained as a weighted average of systolic blood pressure and diastolic blood pressure. The comparisons of each allostatic load variable between different groups by ethnicity and poverty level at the T3M visit showed the only difference of mid-arm circumference between the middle Africa-American group and the middle White group after performing Hochberg step-down procedure (Difference=8.6, 95% Confidence Limits: 3.8-13.3, p=0.0004). The group wise comparisons of overall allostatic load variables at the T3M visit showed no statistical significance. Conclusions: There were no differences on most allostatic load biomarkers among 18 to 40 years old women within different ethnicity and poverty level groups while accounting for education, recruitment location, and age as covariables.