Association of BMI with Linear Growth and Pubertal Development.

Objective: The aim of this study was to investigate the relationship of BMI with subsequent statural growth among children born in the era of the obesity epidemic.

Methods: Among 18,271 children from Belarus (n = 16,781, born 1996 to 1997) and the United States (n = 1,490, born 1999 to 2002), multivariable linear and ordinal logistic regression was used to analyze associations of BMI z score from infancy to adolescence with subsequent standardized length and height velocity, standing height and its components (trunk and leg lengths), and pubertal timing.

Results: The prevalence of early adolescent obesity was 6.2% in Belarus and 12.8% in the United States. In both Belarusian and US children, higher BMI z scores in infancy and childhood were associated with faster length and height velocity in early life, while higher BMI z scores during middle childhood were associated with slower length and height velocity during adolescence. Associations with greater standing height and trunk length and earlier pubertal development in adolescence were stronger for BMI z scores at middle childhood than BMI z scores at birth or infancy.

Conclusions: These findings in both Belarus and the United States support the role of higher BMI in accelerating linear growth in early life (taller stature and longer trunk length) but earlier pubertal development and slower linear growth during adolescence.