EARLY LIFE HEIGHT TRAJECTORIES AND LATE CHILDHOOD ADIPOSITY IN MEXICAN CHILDREN

Background and objectives: In Mexico, childhood obesity is a major public health concern, with a current prevalence of 34.4 % in school-aged children classified as overweight or obese. Previous research suggests that poor growth during early childhood may increase the risk of obesity, but others have reported that the rate of growth is more important than size at birth or early nutritional status. Therefore, the objective of this study was to determine if distinct trajectories of growth are associated with body fat mass (FM) in late childhood. Methods: Study participants were a sub-sample that participated in the 8-10 y follow up of the POSGRAD study, a double- blind, randomized, placebo-controlled trial of prenatal DHA supplementation. Sex-specific height latent class trajectories were derived from 11 measures of height from birth to 5 years of age using MPlus v.7.3. Body composition and anthropometric measures were obtained between ages 8-10 years. Body composition was estimated using validated equations for Mexican children based on the measures from a tetrapolar bioimpedance analyzer (Impedimed DF50). Multivariate linear regression was used to determine the relationship between growth trajectory classes and FM (kg) in late childhood, controlling for current body weight (kg), SES (low, med and high), parity and maternal education. All statistical analyses were conducted with STATA 14. Results: 255 girls and 281 boys and were included. Two height latent classes were identified in girls [low (58%) and high (42%)] and three classes in boys [low (17%), medium (51%) and high (32%)]. Mean FM in girls (high and low) and boys (high, medium, low) per class were 12.66 kg and 8.99 kg and 10.76 kg, 8.97 kg and 8.39 kg, respectively. In girls, there were no significant associations between classes and FM. In boys, relative to the intermediate growth class, the low class had higher FM β = 0.69 kg, 95% CI (0.26 - 1.11) and the high class had lower FM in late childhood β = -0.40 kg, (-0.76 - -0.05). Conclusions: Among boys, more rapid growth in early childhood is associated with lower adiposity in late childhood compared to children who grew slower.