Low body weight and its association with bone health and pubertal maturation in Chinese girls.
OBJECTIVE
To investigate the prevalence of low body weight in Beijing pubertal girls and to establish the cut-off for body mass index (BMI) for underweight for Chinese pubertal girls.


METHODS
Cross-sectional study.


METHODS
Three socioeconomic areas (rural, suburban and urban) in Beijing, China.


METHODS
Random sample of 1214 adolescent girls aged 12-14 y from 13 middle schools.


RESULTS
Using a modified Chinese reference, the rate of low body weight (BMI<18) was 32.2% (95% CI 29.6-34.8%). Compared with desirable weight girls (BMI=18-21), girls with low body weight had a lower bone age, delayed breast and pubic hair development, a lower rate of menarche, lower distal one-third radius and ulna bone mineral content (BMC), bone mineral density and bone width. Logistic regression showed that BMI was one of the predictors of one-third ulna BMC after adjustment for confounding variables. When comparing BMI<18 vs BMI=18-21, the risk of BMC being less than the median increased by 82% (odds ratio 1.82, 95% CI 1.06-3.13). Thinness and stunting rates assessed by WHO recommended cut-offs are also reported.


CONCLUSIONS
High prevalence of low body weight (BMI<18) was found to be a major health problem among Beijing pubertal girls. BMI<18 is confirmed as the cut-off for delayed general growth and development for Chinese girls and for screening girls at risk of lower bone mineral status.
Du
X
X
Department of Food Science and Technology, University of New South Wales, Australia. xdu@vetsci.usyd.edu.au
Greenfield
H
H
Fraser
D R
DR
Ge
K
K
Zheng
W
W
Huang
L
L
Liu
Z
Z
D000293:Adolescent; D015992:Body Mass Index; D001835:Body Weight; D015519:Bone Density; D002648:Child; D002681:China; D005260:Female; D006801:Humans; D016015:Logistic Models; D008572:Menarche; D009752:Nutritional Status; D011627:Puberty; D011884:Radius; D012016:Reference Values; D013851:Thinness; D014457:Ulna; D014944:World Health Organization