Table 2.

Distribution of measurements for pubertal development by puberty status^* among children aged 7–9 years (n 219), Ewha Birth & Growth Cohort study, Republic of Korea

	Early puberty		Average puberty
	Median or n	IQR or %	Median or n	IQR or %	P value†
Boys (n 103)	n 22		n 81
Testosterone (ng/dl)‡	5·59	3·37–8·71	5·45	3·24–8·00	0·453
High testosterone level (≥25 ng/dl)§,||	1	4·6	2	2·5	0·518
Girls (n 116)	n 28		n 88
Oestradiol (pg/ml)‡	15·00	7·40–37·75	7·45	4·90–10·65	<0·001
High oestradiol level (≥15 pg/ml)§,¶	15	53·6	8	9·1	<0·0001

IQR, interquartile range.

^*Early puberty is defined as a subject who reached Tanner stage 2 or greater based on clinician-reported Tanner stage assessments.

^† P value obtained from Wilcoxon rank-sum test for non-parametric value and Fisher’s exact test for differences in frequency.

^‡Values are median and IQR.

^§Values are n and %.

^||The cut-off for testosterone refers to the study by Potau et al.^{( 16 )}.

^¶The cut-off for oestradiol refers to the study by Prété et al. ^{( 17 )}.