Abstract P379: Adiposity Tracking and Its Heritability: A Longitudinal Study of Rural Chinese Children and Adolescents
Objectives: Examine adiposity tracking and estimate its heritability in a large prospective cohort of pre-pubertal and pubertal rural Chinese children.
Methods: This report included 1317 children and adolescents from the Anqing region of China, aged 6 to 18 years at baseline, who also completed follow-up visit 6 years later. Anthropometric measures included body mass index (BMI), waist circumference (WC), total body fat (TBF), percent body fat (%BF), trunk fat (TRF), and percent trunk fat (%TRF). Adiposity measures were obtained by dual-energy X-ray absorptiometry (DEXA). Locally weighted nonparametric smoothing function (SAS LOESS, SAS Institute, Cary, NC, USA) were used to describe (1) “tracking” of adiposity measurements from baseline to 6-year follow-up, and (2) gender differences in the growth of adiposity measurements across age. Structural equation modeling was used to estimate the heritability of tracking using the software Mx.
Results: All anthropometric measures, except for %TRF, tracked significantly from baseline to follow-up in both genders. The middle baseline tertile, in general, had the lowest degree of tracking. Subjects in a high baseline tertile for BMI, TBF, %TBF, WC, and TRF were significantly more likely to be in the high tertile of TBF, %TBF, TRF at the follow-up. There was no good predictor for %TRF. Gender and pubertal status did not affect tracking, for TBF in females, and WC in the older age-group. The genetic correlation of BMI=0.60 (0.46-0.72); TBF=0.43 (0.29-0.55); %TBF=0.37 (0.23-0.50); WC=0.35 (0.11-0.56); TR=0.41 (0.27-0.54); and %TR=0.33 (0.07-0.59).
Conclusion: The strong tracking of adiposity measures in this pediatric population underscores the importance of closely monitoring individuals with high BMI or adiposity over time; those in the medium tertile should also be monitored for upward trend due to their “mobility”. Only BMI showed a strong genetic correlation between baseline and followup, suggesting that environmental changes can influence adiposity depots. Our data raises the possibility that individuals at risk of adult obesity can be identified at early age so that early intervention can be initiated to prevent or mitigate obesity and related complications.
- © 2012 by American Heart Association, Inc.