IMPE Abstracts

Objectives: This study aimed to investigate the effect of rapid weight gain in infancy and toddler period on the incidence of central precocious puberty (CPP) using nationwide population-based data.

Methods: A total of 921,191 children (454,392 girls) who had regular health check-up by National Health Insurance Service (NHIS) during 2007-2017 were followed up until the age of 9 years old for girls (10 years old for boys) or 2020, whichever comes earlier. We calculated differences in weight z-scores from 4-6 months to 9-12 months (infancy), and from 9-12 months to 18-24 months (toddler period) using the lambda-mu-sigma method. Rapid weight gain was defined when weight z-scores increased over 0.67 standard deviation score (SDS). We subdivided the population into four groups; Group A (infancy weight gain > + 0.67 SDS, toddler period weight gain > 0 SDS), Group B (infancy weight gain > +0.67 SDS, toddler period weight gain < 0 SDS), Group C (toddler period weight gain > +0.67 SDS), and Group D (no rapid weight gain in infancy or toddler period). The diagnosis of CPP was based on the World Health Organization’s International Classification of Diseases 10^th revision. An association between rapid weight gain and CPP was assessed using Cox regression analysis.

Results: CPP was diagnosed in 691 boys and 20,654 girls (0.2% and 4.6%, respectively). The rapid weight gain was occurred in 4.3% during infancy (0.9% in Group A and 3.4% in Group B) and in 5.7% in toddler period (Group C). Compared to control group, rapid weight gain in any period had higher risk of CPP (Group A: Hazard ratio [HR] 1.42, 95% confidence interval [95% CI] 1.25-1.60) (Group B: HR 1.16, 95% CI 1.08-1.25) (Group C: HR 1.17, 95% CI 1.10-1.24).

Conclusions: Our nationwide population-based study suggests any rapid weight gain before 2 years of age contributes to increase the incidence of CPP. Weight control before toddler period should be emphasized.