The concordance between ultrasonographic stage of breast and Tanner stage of breast for overweight and obese girls: a school population-based study

In this study, we evaluated the concordance between the ultrasonographic stage of breast (US B) and Tanner stage of breast (TS B) for overweight and obese girls based on a school population study.We conducted multistage, stratified cluster, and random-proportional sampling and ultimately included 221 girls (aged 6-10 years).This study revealed that the concordance was poor (accuracy=0.19 (95% confidence interval: 0.14, 0.25)) between US B and TS B among the 221 participants. When our subjects were stratified by weight, we observed a weak association between US B and TS B in the thin/normal weight group (r=0.34, p=0.001) but not in the overweight (r=0.097, p=0.38) or obese groups (r=-0.19, p=0.206), and as the body mass index (BMI) z-score increased, the overestimation ratio of TS B increased. US B manifested a positive correlation with breast bud diameter (BD) (r=0.885, p<0.001), follicle-stimulating hormone (r=0.235, p=0.009), and luteinizing hormone (r=0.192, p=0.037), but this was not the case with TS B.As the BMI z-score increased, the correlation between the two methods declined, and the overestimation ratio of TS B increased. US B is an objective and quantitative method used to evaluate breast development, and whether BD might replace US B as a routine diagnostic method to evaluate breast development in clinical practice needs to be confirmed in larger-sample studies.