Childhood Obesity Alters Growth Trajectory With Minimal Effect on Definitive Height

Childhood obesity was associated with an atypical height for age and growth velocity, despite a normal final height, according to study results published in the Journal of Clinical Endocrinology & Metabolism.

Investigators evaluated the effects of obesity on height for age, height velocity, and the effect of weight loss on long-term height growth among children and adolescents with obesity.

A prospective study was conducted including patients aged 3 to 18 years who were enrolled in the Swedish Childhood Obesity Treatment Register (BORIS) between 1998 and 2020.

Anthropometric data was collected periodically at clinical visits. Obesity was determined by body mass index (BMI) for age and sex (BMI z score). Individuals were categorized according to degree of obesity, with class I and class II corresponding to a BMI of 30 and 35 kg/m², respectively. Patients with pathological growth disorders were excluded from the study.

Primary study outcomes included the impact of obesity on height and growth velocity, as well as the outcome of obesity treatment on growth velocity. Appropriate height for sex and age was compiled according to the national Swedish reference and used for comparison; growth velocity was similarly compared with a reference population of Swedish children of average maturity.

Obesity treatment outcome, defined as the difference between BMI z score at 1-year follow-up and initial BMI score, was stratified into “poor treatment outcome” (increase in BMI z score), “intermediate treatment outcome” (reduction in BMI z score of 0-0.24 units) and “good treatment outcome” (reduction in BMI z score of ≥0.25 units).

A total of 27,997 children and adolescents were included in the study, with a mean age of 10.2±3.6 years and a mean BMI z score of 2.8 ±0.5 units (55% class I obesity and 45% class II obesity).

Individuals with class II obesity were, on average, taller than those with class I obesity until age 16 for boys and age 15 for girls; however, no difference in height z score was observed thereafter (P >.05). No significant association was found between birth weight for gestational age and height z score.

Boys and girls with class II obesity were found to grow faster relative to their peers with class I obesity until 10 years of age, at which point those with class II obesity were found to have a lower height velocity than individuals with class I obesity.

An inverse relationship was found between the degree of obesity and growth spurt, with a reduced growth spurt found among those with class I obesity and virtually absent among those with class II obesity; these findings were more pronounced among boys than girls.

Compared with the reference population, peak growth velocity among those with obesity and severe obesity occurred at an earlier age; height gain at peak growth velocity was also lower among those with obesity when compared with the reference group.

Of note, individuals aged 3 to 5 years with good treatment outcomes grew more slowly when compared against those with poorer outcomes. Conversely, those aged 10 to 13 years with good treatment outcomes grew faster than those with poorer treatment outcomes.

The lack of data on parental height and age at onset of obesity was cited as a potential study limitation.

The study authors concluded, “Neither modest nor severe obesity is associated with altered final height. Successful obesity treatment does not harm, but rather normalizes, the growth velocity pattern.”

This article originally appeared on Endocrinology Advisor