Selenoprotein P and growth outcomes
SE, LBW
SEPP1, unlike serum and WBSe, showed positive associations with infant birth weight in unadjusted and adjusted models, although results for statistical significance were not consistent across models. Based on our findings, a per unit increase in VC blood SEPP1 was associated with a large increase in birth weight, with estimates ranging between 43 and 82 g between unadjusted and adjusted models. Risk for LBW in our analyses was marginal, with WBSe in VC blood suggesting a protective effect per unit increase in concentrations, although results were non-significant.We did not see significant or consistent associations between LAZ at any age time point and SEPP1 in maternal delivery plasma samples in unadjusted models. We did observe small positive increases in LAZ scores in adjusted models at birth when examining SEPP1 concentrations in VC blood, and associations were significant after accounting for covariates in adjusted models. Effect estimates suggest a stronger association between VC SEPP1 and LAZ at birth up to 2 years of age. These associations, although similar in magnitude, were not significant at 12 and 24 months of age.Non-significant positive associations were observed between WAZ and SEPP1 in maternal delivery samples at birth. Significant associations were observed between SEPP1 in VC blood and WAZ. We used uncontrolled longitudinal hierarchical models and found a mean WAZ at birth to be −1·1 (SE 0·1), Weight-for-length and head circumference for age z-score were not associated with SEPP1 in maternal delivery and/or VC blood. We did note that the overall risk for SGA and LBW was marginally lower per unit increase in SEPP1 in both maternal delivery and VC blood; however, these relationships were not significant. Across the different biomarkers, we did note shifts in the direction of trends across the different age points at which growth outcomes were measured.