[Correlation of pubertal timing, obesity, and body composition of children and adolescents in Chongqing City]

Wei Sheng Yan Jiu. 2016 Jul;45(4):568-573.
[Article in Chinese]

Abstract

Objective: To investigate the correlation of pubertal timing, obesity, and body composition in children and adolescents in Chongqing city, China, and the difference in physical development and body fat among male and female students during puberty.

Methods: By a purposive sampling method, 1447 primary and junior high school students( 7- 17 years old) from two 9- year coherent-style schools in the Jiulongpo district( Chongqing City) were selected as research subjects. Height, weight, waist circumference, and skinfold thickness of the subjects were measured. In addition, breastdevelopment and age at first menstruation among female students and testicular volume and pubic hair development among male students were investigated.

Results: The average age at stage Ⅱ breast development for female students was 9. 78 years, while the average age at first menstruation was 12. 32 years. The average age at stage Ⅱ testicular development for male students was 11. 50 years, while the average age at stage Ⅱ pubic hair development was 12. 62 years. The incidence of overweight in female students from the group with early pubertal timing( 18. 8%) was found to be significantly higher than that of students from the group with normal pubertal timing( 7. 7%)( χ~2= 8. 881, P = 0. 005), while the incidence of obesity in the group with early pubertal timing( 18. 7%) was found to be significantly higher than that of the group with normal pubertal timing( 1. 5%)( χ~2=40. 653, P < 0. 001). Spearman rank correlation analysis showed that early pubertal timing in female students was positively correlated with their weight( r = 0. 324, P <0. 001). The incidence of overweight in male students from the group with early pubertal timing( 17. 9%) was found to be significantly higher than that of the group with normal pubertal timing( 8. 3%)( χ~2= 5. 134, P = 0. 047). Spearman rank correlation analysis also showed a positive correlation between early pubertal timing in male students and their weight( r =0. 103, P =0. 030). All body composition indices of female students revealed the same pattern. Body composition indices of the group with early pubertal timing were greater than that of the group with normal pubertal timing, and body composition indices of the group with normal pubertal timing were greater than that of the group with late pubertal timing. The differences were statistically significant( P < 0. 001). The lean body mass index of male students from the group with early pubertal timing( 46. 718 ± 1. 186) was greater than that of the group with normal pubertal timing( 42. 114 ± 0. 437), and the lean body mass index of the group with normal pubertal timing was greater than that of the group with late pubertal timing( 37. 899 ± 0. 944). The differences were statistically significant( F =14. 870, P < 0. 001).

Conclusion: Overweight, obesity, and body composition of female students in Chongqing city, China, correlate with early pubertal timing, while overweight and lean body mass of male students correlate with early pubertal timing.

Keywords: body composition; child and adolescent; obesity; pubertal timing.

MeSH terms

  • Adolescent
  • Body Composition / physiology*
  • Body Mass Index
  • Child
  • China / epidemiology
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Menstruation
  • Overweight
  • Pediatric Obesity*
  • Puberty, Precocious*
  • Sexual Maturation / physiology*
  • Time Factors