Ns grouped by sex. As shown in Tables 2, 441 boys and 407 girlsNs grouped

Ns grouped by sex. As shown in Tables 2, 441 boys and 407 girls
Ns grouped by sex. As shown in Tables 2, 441 boys and 407 girls had entered puberty. By using the probit analysis to calculate the quartiles of the decimal age of each Tanner stage for girls’ breast and boys’ testis, the subjects were grouped into three groups: early puberty, on-time puberty, and delayed puberty. Over one eighth of the boys (12.7 ) were PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/25681438 classified as early puberty, nearly three quarters of boys (70.3 ) were on-time puberty, and 17.0 were regarded as experiencing delayed puberty. Approximately one fifth of girls (19.7 ) were experiencing early puberty, 38.0 of girls developed on-time, and 42.3 of girls were developing later than others. The percent ofHe et al. BMC Public Health (2017) 17:Page 4 ofTable 1 Characteristics of Study ParticipantsNutlin-3a chiral manufacturer indicators Age (Mean ?SD) School Urban school Village school Grade Grade two Grade three Grade four Grade seven Grade eight Anthropometric Height (cm) Weight(kg) Triceps skinfold (mm) Subscapular skinfold (mm) 147.57 ?13.84 142.37 ?14.59 41.81 ?13.70 6.60 ?3.04 5.03 ?3.22 38.12 ?13.72 7.54 ?3.29 5.86 ?2.70 7.72 ?3.74 109 225 221 227 203 102 181 204 421 361 333 357 Boys (n = 782) 11.72 ?2.09 Girls (n = 690) 11.02 ?2.Body compositions compared to timing of pubertyAs shown in Table 4, BD, BF, FM and FFM of boys had no significant difference among different timing of puberty group (all P > 0.05). But all indicators in the delayed puberty were significantly lower than in the ontime puberty and the early puberty girls, except for BD had the opposite result (all P < 0.017).Suprailiac skinfold (mm) 5.14 ?3.28 Body compositions BD(kg/L) BF FM(kg) FFM(kg) 1.07 ?0.01 12.51 ?3.35 5.49 ?3.12 36.47 ?11.1.06 ?0.01 15.43 ?4.44 5.66 ?3.40 32.74 ?11.BD: body density, BF: percentage of body fat, FM: fat mass, FFM: fat-free mass, BMI: body mass indexearly and delayed puberty girls was significantly higher than boys (P = 0.007, P < 0.001, separetely), and the percent of on-time puberty girls was significantly lower than boys (P < 0.001).Association between obesity, overweight and PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/27488460 puberty timingThe prevalence of obesity and overweight in boys and girls in different pubertal groups were presented in Table 3. There were significant differences in the distribution of fat levels (normal weigh, overweight, obesity) among different pubertal groups in different sex (boys:2 = 10.639, P = 0.031,girls:2 = 63.232, P = 0.000).Table 2 Chi-square test of timing of puberty between boys and girlsBoys (n = 441) Early puberty On-time puberty Delayed puberty 56 (12.7 ) 310 (70.3 ) 75 (17.0 ) Girls (n = 407) 80 (19.7 ) 155 (38 ) 172 (42.3 ) 2 7.609 88.673 65.389 P 0.007 <0.001 <0.Discussion This study examined how children's fat levels (obesity and overweight) and body compositions varied with respect to timing of puberty development based on the evaluation of breast development in girls and the volume of each testis in boys according to the Tanner stage standard. Although the mechanism of association between obesity and early puberty in girls remains to be elucidated, the relationship between obesity and early puberty are consistent. Obesity and overweight are positively correlated with early puberty [4?, 27, 28]. This study also found that there were significant differences in the distribution of overweight and obesity among the groups of early puberty, on-time puberty, and delayed puberty. In boys, the relationship is still controversial. Wang [4] examined the influence of early sexual maturation on fat in 1520 US bo.