Adiposity Status, Trajectories, and Earlier Puberty Onset: Results From a Longitudinal Cohort Study

Context: Adiposity is associated with earlier puberty onset in girls, but such an association among boys is controversial. Objective: To estimate the association of prepubertal adiposity status, trajectories, and the earlier puberty onset based on a cohort study. Methods: A total of 1322 children were included in 2017 (mean age of 8.1 [+ or -] 0.6 years for girls and 9.1 [+ or -] 0.6 years for boys) and were followed every 6 months until October 2020. Anthropometric profiles, including BMI, WC, and body composition indicators, were used to determine adiposity status. Group-based trajectory modeling was used to identify trajectory groups of anthropometric profiles. Testicular volume for boys and breast stage for girls were clinically assessed. Pubertal development was assessed through clinical inspection and palpation by using The Tanner rating map and Prader orchidometer. Covariate information was obtained through questionnaires. Results: Childhood adiposity was associated with increased risk of earlier puberty onset. Body composition was more sensitive to earlier puberty onset than BMI and WC. Boys and girls with high-level body fat percentage had increased risk of earlier puberty onset compared with those with low-level body fat percentage. However, boys and girls with high-level FFM (fat-free mass)/FM (fat mass) had a decreased risk of earlier puberty onset compared with those with low-level FFM/FM. High-level trajectories of rapid increase in anthropometric profiles, in addition to FFM/FM, were also significantly associated with higher risk of earlier puberty onset. Conclusion: Prepubertal adiposity and distinct trajectories were associated with earlier puberty onset. It is important to maintain healthy adiposity status to prevent earlier puberty onset in children. Key Words: adiposity status, overweight and obesity, trajectory, body fat, puberty onset, pubertal timing Abbreviations: BMI, body mass index; FFM, fat-free mass; FFMI, fat-free mass index; FM, fat mass; FMI, fat mass index; HI, high-increasing; LI, low-increasing; LMI, low-to-moderate-increasing; MHI, moderate-to-high-increasing; PBF, percentage of body fat; RR, risk ratio; WC, waist circumference.