Determinants of rapid weight gain in a cohort of children in the first six months of life

Abstract

Objective  To evaluate the influence of genetic, gestational, birth, and socioeconomic factors on Rapid Weight Gain (RWG) in children between birth and six months.

Methods  This is a cohort study with 267 children, information on individual and sociodemographics was obtained from the medical record. RWG was identified when the z-score difference in weight-for-age between two child assessments was > +0.67. The rs9939609 was assessed by Real-Time Polymerase Chain Reaction Taqman. The exploratory analysis of the cumulative incidence rate curves of RWG used the Kaplan-Meier, as well as the Log-Rank test to perform comparisons between the groups. To estimate the hazard ratio, the Cox semi-parametric model was used, to verify the quality of the fit of the proposed model the generalized Cox-Snell residuals were used.

Results  The RWG between birth and six months was 31.84% and the incidence rate was estimated to be 2.31 cases/1000 person-days. The children who were born with inadequate weight or low weight had 1.88 times the risk of having RWG between birth and six months. In multivariate analysis, a higher risk of RWG in the first six months of life was found for children who were born weighing < 3000 g and whose mothers were overweight/obese in the pregestational phase, adjusted for the variables sex, rs 9939,609 and paternal education, rs9939609 was not associated with RWG.

Conclusions  Children with lower birth weight and with mothers overweight/obese before pregnancy presented a higher risk of RWG in the first six months and rs 9939,609 was not associated with RWG.

Keywords
Birth weight; Infant; Weight gain; Polymorphism; Risk factors