Timing, velocity, and magnitude of pubertal changes in body composition: a longitudinal study

Pubertal changes in body composition significantly influence future health, with links to various diseases. This study aimed to evaluate the weight changes, fat-free mass (FFM), and body fat mass (BFM) during pubertal growth in Korean children and adolescents.

We utilized mixed longitudinal data, employing bioelectrical impedance analysis for 4641 height measurements (2204 boys, 2437 girls) from 361 individuals (170 boys, 191 girls) aged 7-18 years. Utilizing the Superimposition by Translation and Rotation (SITAR) model, a shape-invariant growth curve model, reference curves for height, weight, and body composition change velocities were estimated.

Korean boys experience peak weight velocity (PWV) at an average age of 12.41 years, with a rate of 8.19 kg/year, peak fat-free mass velocity (PFFV) at 12.70 years (7.60 kg/year), and peak body fat mass velocity (PBFV) at 9.69 years (2.67 kg/year). Korean girls show PWV at 11.28 years (6.33 kg/year), PFFV at 11.13 years (4.86 kg/year), and PBFV at 12.33 years (2.72 kg/year). Positive correlations exist among the ages of peak height velocity, PWV, PFFV, and PBFV.

This research represents the groundbreaking application of the SITAR model in analyzing changes in body composition during pubertal growth in Korean children and adolescents.

This study utilized the SITAR model to analyze longitudinal changes in the body composition of the general pediatric population in Korea across pre- and post-pubertal stages, addressing overlooked aspects in cross-sectional studies. Examining growth parameters, including size (mean mass), tempo (timing), and velocity (compression and expansion) for each body component, revealed positive correlations among ages at peak velocities for various body composition parameters. This study can be employed for further investigations that compare the tempo, size, and velocity of various body composition parameters in pediatric disease cohorts and the general population.