Obese children frequently present with accelerated growth and early puberty.
Objective: To examine the degree of bone maturation in children with simple obesity.
Patients and methods: One hundred eighteen boys with mean chronological age (CA) 9.9±2.2 years (313 years) and 102 girls with CA 8.4±2.0 years (312 years) with simple obesity (BMI>97th centile for age and sex) were studied. Ninety-five children were prepubertal and 125 were pubertal. Pubertal stage, body mass index (BMI), height SDS (HtSDS) were recorded. Bone age (BA) was estimated according to Greulich-Pyles standards. The difference between BA and CA (BACA) was calculated.
Results: Mean HtSDS was greater than average in both sexes (0.93±1.0 for girls and 0.74±1.1 for boys). BA was significantly greater than CA in both sexes (11.1±2.2 vs 9.9±2.2, P<0.001 for boys and 9.7±2.4 vs 8.4±2.0, P<0.001 for girls). There was a statistically significant correlation between BMI and BA for both sexes (r=0.4, P<0.001 for boys and r=0.5, P<0.001 for girls). Prepubertal and pubertal children had the same degree of bone age acceleration (BACA prepubertal 1.0±0.9 versus BACA pubertal 1.2±0.6 for boys and BACA prepubertal 1.1±1.1 versus BACA pubertal 1.3±0.9 for girls. Thirteen percent of girls and 2.1% of boys had precocious adrenarche.
Conclusions: BA is significantly accelerated in obese prepubertal and pubertal children, and is positively correlated with BMI. Obese children tend to be taller than average but as their bone maturation is more advance than CA, final height will not surpass their genetically predicted height.