The effect of adiposity on the relationship between indicators of maturity in peri-pubertal children

Although the relation between body fatness and maturation has been the subject of much research, somatic maturity as assessed by sex-specific regression equations, has yet to be investigated in a population of overweight and obese children.

To examine whether adiposity affects the relationship between somatic and skeletal maturity in peri-pubertal children and if increased adiposity is related to earlier maturation.

A total of 172 girls and boys (12.8 ± 0.9 years of age) participated in the study. Participants were categorized as normal weight (NW, < 85(th) percentile) or overweight/obese (OW/OB, ≥ 85(th) percentile) based on body mass index and matched for chronological and skeletal age. Skeletal age was assessed across the radial and ulnar epiphyses using quantitative ultrasound. Somatic maturity was assessed as years from age of peak height velocity (aPHV), estimated using prediction equations. Peripheral adiposity was determined by the sum of two skin-folds.

Years from aPHV was significantly higher (p < 0.001) in OW/OB girls, but not in OW/OB boys. Skeletal age was associated with years from aPHV in NW and OW/OB boys (r = 0.87 vs 0.86, p < 0.001) and girls (r = 0.83 vs 0.72, p < 0.001). Among peri-pubertal youth of similar chronological and skeletal age, OW/OB girls were more somatically mature than their NW peers.

It is concluded that excess peripheral adiposity in girls may affect the estimated somatic maturity, as reflected in years from aPHV.