Background We aimed to investigate the effects of overweight and obesity on bone age (BA), predicted adult height (PAH) and glucose metabolism in children and adolescents. Methods Chinese boys aged 5–15 years who were overweight or obese were recruited for the study. Clinical characteristics, including height, weight, body mass index (BMI), BA, PAH and homeostatic model assessment of insulin resistance (HOMA-IR), were recorded. Spearman’s rank-order correlation was used to analyse associations between BA, PAH, HOMA-IR and BMI z-scores. Receiver-operating characteristic (ROC) curves were generated to evaluate the diagnostic value of the BMI z-score. Results Data from 130 males (n=43, overweight; n=87, obese) were collected. The median BA of the cohort was significantly higher than the chronological age: 12.00 (IQR: 11.00 to 13.00) versus 10.67 (IQR: 9.50 to 12.00; p=0.000). PAH was significantly lower than mid-parental height: −0.28±0.81 versus 0.10±0.60 (p=0.000). The prevalence of BA advancement, PAH impairment and insulin resistance was 52.3% (67/128), 22.6% (28/124) and 61.3% (49/80), respectively. BA advancement and HOMA-IR positively correlated with BMI z-score (Spearman’s coefficients r s =0.495, p=0.000 and r s =0.343, p=0.002, respectively). No significant association was found between PAH impairment and BMI z-score ( r s =0.045, p=0.622). The ROC curves showed that the area under the curve for the BMI z-score of BA advancement and insulin resistance was 0.741 and 0.622, respectively. The sensitivity and specificity for BA advancement with a cut-off of 2.40 SD score (SDS) were 0.567 and 0.820, and for insulin resistance with a cut-off of 2.40 SDS, were 0.571 and 0.645. Conclusions Approximately half of the included children had advanced BA, one-fifth of them had PAH impairment and two-thirds exhibited insulin resistance. Advanced BA and HOMA-IR were positively correlated with the BMI z-score. A BMI z-score above 2.40 SDS may indicate BA advancement and insulin resistance.
Sun et al. (Sun,) studied this question.