Beijing Youth Bone Mass Development Of The Situation And Investigate The Influence Factors

BackgroundOsteoporosis is a major public health issue.bone development of adolescences is an important determinant of risk for the development of osteoporosis later in life Failure to achieve peak bone mass will increase the risk of having osteoporosis. Osteoporosis is a adolescent disease which show its pathological consequence in older age. Genetic, hormonal,nutritional factors and physical exercise contribute to the regulation of bone mass, but the specific effect of these factors and the ways in which they interact with each other remain poorly understood. The survey of bone development of adolescences has only been conducted roughly, it’s necessary to conduct a detailed research on it. Diseases such as growth hormone deficiency and hypogonadotropichypogonadism are good clinical research model for study the effect of hormones on bone developmentOur objective was to systematically study the feature of bone development and its determinants of adolescences in BeiJiing, thus to provide evidence to prevent and reduce the incidence of osteoporosis.MethodWe recruit healthy adolescences aged between7-25years old,patients with GHD, HH or Turner syndrome.subjects were divided into subgroups according to their age (<11[before adolescence]、11-13[early stage of adolescence]、13-15[middle stage of adolescence]、15-18[later stage of adolescence] and>18[after adolescence].Every subject received physical examination and medical history inquiry to evaluate the developmental situation. BMD of the posteroanterior lumbar spine (LS, L1-L4)and the femoral area(including femoral neck、troch、shaft, Ward’s triangle and total area) was measured by dual-energyX-ray absorptiometry using the Lunar DPX-L dual energy absoeptiometer.The patients with GHD were treated with hGH (O.1IU/kg body weight/day) and BMD were remeasured at the end of treatment for six months.Results1.The height and BMD of healthy adolescences increased along with the increase of mean ages of subjects in different subgroups. The most obvious intergroup difference in BMD was seen between group1(age11-13)and group2(age13-15)in female subjects,group1(age11-13)and group3(age15-18)in male subjects.2.Bone density of female GHD patients didn’t decrease(Z scores of L1-4、Neck、Ward’s triangle、Troch、Shaft and Total was-1.38±3.02、-3.35±2.90、-1.47±2.47、-0.76±1.05、-0.38±2.41and-0.82±1.53,T scores of L1-4、Neck、Ward’s triangle、Troch and Total was-1.97±2.32、-1.85±0.93、-1.317±1.313、-1.17±1.18and-1.53±0.98separately,P>0.05),bone density of male GHD patients decreased(Z scores of L1-4、Neck、Ward’s triangle、Troch、Shaft and Total was-1.20±1.09、-0.83±0.83、-0.42±0.80、-0.75±0.93、-0.84±0.87and-0.76±0.87,T scores of L1-4、Neck、Ward’s triangle、Troch and Total was-3.79±0.98、-1.45±0.86、-0.77±1.11、-1.02±1.11and-1.03±0.93,separately P<0.05).Bone density of male HH patients decreased(Z scores of L1-4、Neck、Ward’s triangle、Troch、Shaft and Total was-0.94±0.77、-0.71±0.82、-0.75±0.80、-0.76±0.80、-0.81±0.76and-0.84±0.79,,P<0.05).Bone density of Turner syndrome patients decreased(Z scores of L1-4、Neck、Ward’s triangle、Troch、Shaft and Total was-0.64±0.46、-0.89±0.64、-0.83±0.66、-0.84±0.82、-0.86±0.65amd-0.81±0.69s,T scores of L1-4、Neck、Ward’s triangle、Troch and Total was-2.77±1.07、-1.95±0.83、-1.98±0.91、-1.79±0.93和-1.91±0.89separately,P<0.05).3.After been treated with rGH for six months,bone density of GHD patients increased (The differences after treatment in Z scores of L1-4、Neck、Ward’s triangle、Troch、 Shaft and Total was0.21±O.08、0.46±0.27、0.27±0.19、0.40±0.23、0.12±0.16and0.25+0.18,the differences in T scores of L1-4、Neck、Ward’s triangle、Troch and Total was0.34±0.32、0.59±0.48、0.33±0.58、0.40±0.65and0.23±0.40separately),paired t test:P<0.05.4.The results of one-sample sign test or t test of Z scores and T scores of patients with simple obesity:obese female patients P<0.05,overweight female、overweight male and obese male P>0.05.Residuals analysis of Z scores in linear regression analysis:residuals had a normal distribution but the variances were heteroscedastic and self-dependent, Scatter Diagram of Z scores and BMI didn’t suggest a linear distribution.Conclusion1.The height and BMD of healthy adolescences increased along with the increase of mean ages of subjects in different subgroups.The most obvious intergroup difference in BMD was seen between group1(age11-13)and group2(age13-15)in female subjects,group1(age11-13)and group3(age15-18)in male subjects,which suggest adolescence is critical years for bone development.2.Zscores and T scores of male GHD patients、male HH patients and Turner syndrome patients decreased (t test:P<0.05). Lack of growth hormone and sex steroids was correlated with lower bone density.3..Growth and development of GHD patients were severly retarded.After been treated with rGH for six months, the height and body mass increased significantly. After been treated with rGH for six months, Z scores of GHD patients increased(paired t test:P<0.05).4. Bone density of patients with simple obesity didn’t differ from bone density of healthy adolescences.There is no linear correlation between BMI and Z scores.