TY - JOUR
T1 - Stunting mediates the association between small-for-gestational-age and postneonatal mortality
AU - Oddo, Vanessa M.
AU - Christian, Parul
AU - Katz, Joanne
AU - Liu, Li
AU - Kozuki, Naoko
AU - Black, Robert E.
AU - Ntozini, Robert
AU - Humphrey, Jean
N1 - Publisher Copyright:
© 2016 American Society for Nutrition.
PY - 2016
Y1 - 2016
N2 - Background: In sub-Saharan Africa, one-third of all births are small for gestational age (SGA), and 4.4 million children are stunted; both conditions increase the risk of child mortality. SGA has also been shown to increase the risk of stunting. Objective: We tested whether the association between SGA and postneonatal mortality is mediated by stunting. Methods:Weusedlongitudinaldata fromchildrenaged6wk to24mo (n = 12,155) enrolled in the ZVITAMBO(Zimbabwe Vitamin A for Mothers and Babies) trial. HIV exposure was defined based on maternal HIV status at baseline. SGA was defined as birthweight < 10th percentile of the INTERGROWTH-21st (International Fetal and Newborn Growth Consortium for the 21st Century) standards. We used a standard mediation approach by comparing the attenuation of the risk when the mediator was added to the model.We used Cox proportional hazardsmodels first to regress SGA on postneonatal mortality, controlling for age. Stunting (length-for-age z score < 22) was then included in the model to test mediation. Results: Approximately 20% of children were term SGA, and 23% were stunted before their last follow-up visit. In this cohort, 31% of children were exposed to HIV; the HIV-exposed group represented a pooled group of HIV-infected and HIV-exposed but uninfected children. Postneonatal mortality was significantly higher among children born SGA (HR: 1.5; 95% CI: 1.3, 1.7). This association was attenuated and not statistically significant when stuntingwas included in themodel, suggesting a mediation effect (HR: 1.1; 95%CI: 0.91, 1.3). When stratified by HIV exposure status, we observed a significant attenuation of the risk, suggesting mediation, only among HIV-exposed children (model 1, HR: 1.3; 95% CI: 1.1, 1.6; model 2, HR: 1.1; 95% CI: 0.88, 1.3). Conclusions: This analysis aids in investigating pathways that underlie an observed SGA-mortality relation and may inform survival interventions in undernourished settings.
AB - Background: In sub-Saharan Africa, one-third of all births are small for gestational age (SGA), and 4.4 million children are stunted; both conditions increase the risk of child mortality. SGA has also been shown to increase the risk of stunting. Objective: We tested whether the association between SGA and postneonatal mortality is mediated by stunting. Methods:Weusedlongitudinaldata fromchildrenaged6wk to24mo (n = 12,155) enrolled in the ZVITAMBO(Zimbabwe Vitamin A for Mothers and Babies) trial. HIV exposure was defined based on maternal HIV status at baseline. SGA was defined as birthweight < 10th percentile of the INTERGROWTH-21st (International Fetal and Newborn Growth Consortium for the 21st Century) standards. We used a standard mediation approach by comparing the attenuation of the risk when the mediator was added to the model.We used Cox proportional hazardsmodels first to regress SGA on postneonatal mortality, controlling for age. Stunting (length-for-age z score < 22) was then included in the model to test mediation. Results: Approximately 20% of children were term SGA, and 23% were stunted before their last follow-up visit. In this cohort, 31% of children were exposed to HIV; the HIV-exposed group represented a pooled group of HIV-infected and HIV-exposed but uninfected children. Postneonatal mortality was significantly higher among children born SGA (HR: 1.5; 95% CI: 1.3, 1.7). This association was attenuated and not statistically significant when stuntingwas included in themodel, suggesting a mediation effect (HR: 1.1; 95%CI: 0.91, 1.3). When stratified by HIV exposure status, we observed a significant attenuation of the risk, suggesting mediation, only among HIV-exposed children (model 1, HR: 1.3; 95% CI: 1.1, 1.6; model 2, HR: 1.1; 95% CI: 0.88, 1.3). Conclusions: This analysis aids in investigating pathways that underlie an observed SGA-mortality relation and may inform survival interventions in undernourished settings.
KW - HIV
KW - Mediation
KW - Postneonatal mortality
KW - Small for gestational age
KW - Stunting
UR - http://www.scopus.com/inward/record.url?scp=84995495108&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84995495108&partnerID=8YFLogxK
U2 - 10.3945/jn.116.235457
DO - 10.3945/jn.116.235457
M3 - Article
C2 - 27733526
AN - SCOPUS:84995495108
SN - 0022-3166
VL - 146
SP - 2383
EP - 2387
JO - Journal of Nutrition
JF - Journal of Nutrition
IS - 11
ER -