Associations of built and social neighborhood environment variables with pediatric BMI z-score and changes in BMI z-score

Abstract

Introduction: Child obesity remains a major public health challenge and neighborhood environments could have a significant role in driving the epidemic. However existing evidence on the impact of neighborhoods on child obesity remains inconclusive. I conducted a systematic literature review of longitudinal studies analyzing the associations between built and social neighborhood environment exposures and pediatric weight. I also conducted a cross-sectional and longitudinal study of these exposures’ associations with BMI z-score using geographically linked electronic heath records (EHR) from a large sample of urban-dwelling, predominantly African American children. Methods: The literature search included six databases searched over 2011 to 2017. Thirty-one longitudinal studies met the inclusion criteria. Information on the study populations, exposure and outcome measures, and main results were extracted. To conduct the cross-sectional and longitudinal analyses I used a pediatric integrated EHR database of children residing in Philadelphia from 2007-2016. I used a generalized estimating equation to analyze the cross-sectional associations between built and social neighborhood environment variables with BMI z-score. I also examined synergisms between built and social environment variables. I used a fixed effects model to analyze the associations between a change in the neighborhood environment with a change in BMI z-score. In both analyses I examined whether associations were modified by age, sex, neighborhood SES, or population density. Results: Most longitudinal studies of the relationship between the built and social environment are prospective cohort studies conducted in high income western countries. The literature review showed that higher access to greenness, parks, and physical activity facilities were associated with less weight gain and lower obesity incidence. The literature also showed that increases in crime were associated with increases in BMI and higher obesity incidence. Cross-sectional analyses showed that higher greenness and Walk Score® were associated with lower BMI z-scores. Higher access to healthy food and physical activity facilities was associated with higher BMI z-scores. I did not find synergisms between built and social environment exposures. Longitudinal analyses showed that increases greenness and safety were associated with decreases in BMI z-score. The effects of safety were stronger in younger children than older children. Increases in social cohesion were associated with increases in BMI z-score and this effect was stronger in boys than in girls. Conclusions: Greenness and safety are associated with decreases in weight in children. Further research is needed to understand associations between changes in healthy food stores, physical activity facilities, urban form, and social cohesion with changes in pediatric BMI.%%%%Ph.D., Epidemiology – Drexel University, 2019