An Evaluation Of The Bone Mineral Content And Bone Mineral Density Among Children From 6 To 18 Years Old In Chongqing

Objective:To investigate the bone mineral content and bone mineral density among children from 6 to 18 years old in Chongqing; to evaluate the relationships between BMD or BMC vs race, age, sex, weight, height and puberty stage; at the same time to establish reference database for bone mineral content(BMC) and density(BMD) in children.Methods:1334 healthy and normally developing children aged 6 to 18 years old(687 female,647 male) in Chongqing were sampled with stratified cluster sampling. The investigation items included the measurement of height, weight, breast development(girls) and testicular volume by orchidometer(boys), which evaluated using the criteria of Tanner. DXA scans were performed using Hologic bone densitometers(QDR 4500 Discovery Wi),the posterior-anterior spine, femur neck and total hip were the selected skeletal sites. SPSS 17.0 of statistical software was used for data analysis.Results:1. All bone parameters increased progressively with age. In girls, an obvious increase in BMD and BMC of L1-L4, LS, femur neck and total hip was observed at 11 to 14 years, 12 to 13 years growing fastest, after the age of 15, speeding slowly. In boys, an obvious increase in BMD and BMC at L1-L4, LS, femur neck and total hip was observed at 12 to 16 years, 15 to 16 years growing fastest, after the age of 16, appeared a plateau.2. Regions of the BMC and BMD were growth with the increase of pubertal stage. After puberty development, the bone mass increased significantly, which fastest during TannerⅡ-Ⅲ, and slower at Tanner Ⅴ.3.Regions of the BMC and BMD had no sex difference at 6 to 9 years, at 12 to 13 years girls’ were higher, at 16 to 18 years boys’ were higher. The BMC of L1-L4 and LS had no sex difference at Tanner stageⅠ, at TannerⅣ-Ⅴ boys’ higher than girls’. Boys’ BMC and BMD of FN and total hip werw higher at Tanner stage Ⅳ-Ⅴ。4. The bone parameters of most groups were correlated with height and weight in most age groups.5. All bone parameters of participants were lower than those of Mexicans, non-Hispanic whites and non-Hispanic blacks. The BMD of lumbar spine of Chongqing children was significant lower than that of the Thai. When compared with Changsha children, the BMD of total lumbar spine and hip were higher in Chongqing children at most groups.Conclusions:We report the normative data of BMC and BMD(L1-L4, total LS, femur neck and total hip) measured by DXA(Hologic) in Chongqing children aged 6 to 18 years. At the same time, we should take ethnic, age, sex, weight, height, puberty state,calcium or vitamin D intakes into account.