bone mineral density ( bmd ) , a measure of the mineral content of bones , is a criterion for 
 clinical diagnosis of osteoporosis ; it is also used to assess responses to treatments , 
 including rates of bone loss and gain . osteoporosis is approximately five times more common 
 in females than in males . by age 50 , because bone mass decreases by 50% within 5  years after menopause , they are highly 
 susceptible to osteoporosis ; thus , measures to prevent osteoporosis in females prior to the 
 onset of menopause are of vital importance1 . due to the increasing aging population in today s society , the number of patients with 
 osteoporosis is increasing , with consequent increases in the frequency of spinal or hip 
 joint fractures due to decreased bmd and bone mass . therefore , bmd examinations are 
 important for preventing fractures and providing interventions to improve bmd . moreover , 
 appropriate measures based on accurate bmd measurements enable the early prevention and 
 treatment of osteoporosis - related complications2 . to prevent osteoporosis , bone and body health moreover , various factors may also affect bmd , such as weight , body fat , and muscle 
 mass4 . radiographic bmd measurement is 
 considered an important tool for diagnosing osteopenia and determining the effect of 
 therapy5 . among the many methods , 
 dual - energy x - ray absorptiometry ( dxa ) is the most sensitive and appropriate standard 
 method6 . the vertebrae and hip joints 
 are typically measured since they represent important areas that affect both morbidity and 
 mortality . cancellous bone is present in the vertebral body , which makes it useful for 
 assessing treatment response , and it offers greater accuracy for recreating a patient s 
 posture compared to measurements in the hip joint area7 . vertebral bmd may be elevated in older patients due to arterial 
 calcification and degenerative changes ; in such cases , bmd measurements of the hip and 
 lumbar areas taken laterally via dxa can offer more accurate results . femoral bmd is 
 generally measured from four areas : the proximal femoral neck , the entire hip area , the 
 condyle , and ward s triangle . the proximal femoral neck and condyle are composed of cortical 
 and cancellous bone , respectively7 . the t - score , a measure often used in bmd measurements , is typically expressed as mean  
 standard deviation based on comparisons to maximum mean bmd found in young , healthy adults 
 of the same ethnicity and gender . relative to t - scores of young , healthy adults , measured 
 t - scores are defined as follows : normal if 1.0 , osteopenia if 1.0 to 2.5 , and 
 osteoporosis if < 2.5 ( shin , 2006 ) . z - scores , another measure , are unlike the t - score in 
 that they represent a value that is relative to the mean bmd of a healthy control group of 
 the same age , gender , and ethnicity7 . previous studies on bmd have reported t - scores as being useful for measuring osteoporotic 
 fractures and changes in morphological characteristics of the proximal femur8 , as well as comparing correlations of 
 vertebral and femoral bmd according to fractures in elderly patients with osteoporosis9 . however , few studies have examined the 
 correlations between vertebral and femoral values in groups with different bmds . therefore , the present study used t - scores , which are reportedly highly associated with the 
 risk of fracture7 , to assess the 
 correlations between vertebral and femoral values in three groups classified as normal , with 
 osteopenia , and with osteoporosis based on their bmd levels to provide clues for the 
 accurate diagnosis of bmd and prevention of problems associated with decreased bmd . the subjects included 314 adult female patients who underwent a bmd examination at  k  
 hospital in daegu ( south korea ) through july 2015 . the patients were in their 40s ( n=32 ) , 
 50s ( n=115 ) , 60s ( n=98 ) , and 70s ( n=69 ) . patients with a history of orthopedic surgical 
 treatment or spinal and/or femoral injury or diseases were excluded from the study . after 
 the measurements , 114 , 144 , and 56 subjects were assigned to the osteoporosis , osteopenia , 
 and normal groups based on their bmd scores . all of them understood the purpose of this 
 study and gave their written informed consent before experimental involvement . the study was 
 performed according to the principles of the declaration of helsinki , and ethical approval 
 was granted by local committee of the institution review board of the university 
 hospital . prior to bmd testing , hospital medical records were used to determine test and surgical 
 history , and subjects received detailed explanations of the objectives , methods , and time 
 required for the testing . each examinee changed into an examination gown and was then placed 
 in the supine position on the center of the examination table with a rectangular sponge 
 supporting the legs and the waist contacting the examination table . a dpx - bravo ( ge , healthcare lunar , pa , usa ) instrument was used to measure bmd via dxa . the 
 measurement areas included lumbar vertebrae 14 , the femoral neck , ward s triangle , and the 
 femoral trochanter . values from the first and second lumbar vertebrae , which have the 
 highest frequency of fracture , were excluded , and bmd values from lumbar vertebra 3 ( l3 ) 
 were used9 . based on computer analysis , t - scores that showed the rate relative to the reference value 
 of a normal person ( peak reference ; % ) were used and bmd measurement from each region were 
 classified according to world health organization definitions as normal ( t - scores1 ) , 
 osteopenia ( 1>t - scores>2.5 ) , and osteoporosis ( t - scores2.5 ) . subjects were 
 assigned to the normal , osteopenia , and osteoporosis groups accordingly , and their lumbar 
 and femoral bmd values were compared10 . analyses of test results and correlations were performed using spss statistics for windows 
 version 17.0 ( spss inc . , descriptive statistics were used to assess the 
 subjects general characteristics , while one - way analysis of variance was performed to 
 examine inter - group differences in bmd . pearson s correlation analysis was performed to 
 analyze the vertebral and femoral bmd measurements . comparisons of general patient characteristics among the three groups showed that the 
 osteoporosis group had the highest mean age and lowest mean height and weight . among the 314 
 subjects , the rate of females with osteopenia or osteoporosis was very high ( table 1table 1.general subject characteristicsgroupage ( years)height ( cm)weight ( kg)number of patients ( % ) normal54.2156.860.256 ( 17.8)osteopenia58.9157.158.1144 ( 45.8)osteoporosis67.4151.953.1114 ( 36.3 ) ) . comparison of t - scores revealed significant inter - group differences in 
 measurements from the l3 , femoral neck , ward s triangle , and trochanter ( p<0.05 ) ( table 2table 2.t - scores according to body partsnormalosteopeniaosteoporosisl30.72  0.891.01  0.932.57  1.16**femoral neck0.38  0.870.77  0.841.90  0.90**ward s triangle0.31  1.021.15  0.912.10  0.85**femoral trochanter0.90  1.010.22  0.871.17  0.81****p<0.01 ) . pearson s correlation coefficients analysis revealed correlations between 
 vertebral and femoral bmd , with the normal group showing significant differences and 
 positive correlations in the l3 , femoral neck , ward s triangle , and trochanter measurements 
 ( p<0.05 ) . in the osteopenia group , the l3 , femoral neck , and trochanter measurements 
 differed significantly ( p<0.05 ) , with positive correlations that were weaker than those 
 in the normal group . in the osteoporosis group , the l3 measurements were negatively 
 correlated with those of the femoral neck and ward s triangle and positively correlated with 
 femoral trochanter measurements ; however , the differences were not statistically significant 
 ( table 3table 3.pearson correlation coefficients between body partsfemoral neckward s trianglefemoral trochanternormal l30.278 * 0.294 * 0.271*osteopenia l30.192 * 0.0760.222*osteoporosis l30.0550.0290.118*p<0.05 ) . osteoporosis is a metabolic bone disease that increases the risk of fracture due to reduced 
 bmd ; it also leads to social problems such as increased medical costs11 , 12 . the use of bmd 
 measurements for diagnosing osteoporosis was first reported by camerun and sorrenson13 ; since that time , bmd measurements of the 
 lumbar region , hip joint area , and distal radius region have been generally utilized for the 
 early detection and treatment of osteoporosis . in the present study , the analysis of bmd measurements according to the general 
 characteristics of the 314 study participants revealed high rates of osteopenia and 
 osteoporosis . these findings were consistent with those of the study by compston14 , which reported that bmd begins to 
 decrease in the 30s to early 40s , resulting in an increasing number of patients with 
 osteoporosis , with increasing age , and a study by ito et al.15 , which reported maximum bmd in the mid-30s and a decreasing trend 
 thereafter with a particularly drastic decrease in females around menopause . moreover , an 
 analysis of groups according to bmd showed that the osteoporosis group had the lowest mean 
 body weight , consistent with previous studies that reported decreasing bmd with decreasing 
 body weight16 , 17 . inter - group comparisons of t - scores showed significant differences 
 among the l3 , the femoral neck , ward s triangle , and the femoral trochanter . moreover , 
 groups with a lower mean bmd tended to have a higher mean age . this observation was 
 consistent with the results of a study by cho et al.18 that assessed bmd by age group , which showed the biggest difference 
 in bmd between those in their 60s and those in their 70s . bmd measurements of the l3 and 
 femoral trochanter are typically used for early detection and treatment of osteoporosis19 , while ward s triangle results in poor 
 value readings or accuracy due to its small size20 . moreover , the correlations between ward s triangle and bmd become 
 weaker with increasing subject age9 . in 
 the present study , the l3 , femoral neck , and femoral trochanter had high t - scores in bmd 
 measurements , while the values for ward s triangle were relatively low , a finding consistent 
 with the results of precedent studies . in the present study , the rate of patients with osteopenia or osteoporosis was high , 
 demonstrating the need for preventing and treating osteoporosis in females as they age . these findings were consistent with those of the study by lane et al.21 , which showed that a reduction in bmd by one standard 
 deviation in each category was associated with a 1.53-fold increase in the rate of 
 fractures , with fracture rates of 30% for < 2.5 sd , which was defined as the threshold at 
 which consultation and treatment were necessary . similarly , bechanan et al.22 suggested that bmd values of 
 70100  mg / cm required immediate preventive measures and 
 values<70  mg / cm required active prevention and treatment . in the bmd correlation analysis by measurement area , the normal group showed l3 t - scores 
 that were significantly correlated with those of the femoral neck , ward s triangle , and the 
 femoral trochanter . meanwhile , the l3 t - scores in the osteopenia group were correlated with 
 those of the femoral neck and trochanter . these findings suggest that these values can be 
 surmised from other locations when an accurate bmd test can not be performed due to testing 
 area limitations . however , the l3 t - scores in the osteoporosis group were not correlated 
 with those of the femoral neck , ward s triangle , and femoral trochanter , a finding similar 
 to results from a study by choi et al.23 
 that found that the correlation between vertebral and hip joint bmd declined with increasing 
 age . furthermore , all three groups showed the highest correlation between lumbar and 
 trochanter t - scores , consistent with the findings of a precedent study that showed the 
 lumbar and trochanter bmd measurements were highly correlated , likely because the ossein of 
 the trochanter has characteristics similar to those of the trabecular bone9 . the limitations of the present study include the fact that it included females only ; thus , 
 the results can not be generalized to males and children . other limitations include not 
 considering differences in bmd according to age ; using only t - scores , showing results that 
 are inconsistent with bmd diagnosis using z - score or bmd ; and not considering other factors , 
 such as muscle or fat mass , that can also affect bmd . therefore , future studies should also 
 consider other factors that can affect bmd ; these investigations should also be more 
 broad - based to enhance the value and generalizability of our findings .
[ purpose ] this study assessed vertebral and femoral bone mineral density in adult 
 females . 
 [ subjects and methods ] a total of 314 females in their 40s to 70s were divided 
 into normal , osteopenia , and osteoporosis groups and their vertebral and femoral bone 
 mineral densities were compared . 
 [ results ] comparisons of t scores revealed significant 
 differences among measurements of the third lumbar vertebra , femoral neck , ward s 
 triangle , and femoral trochanter . 
 pearson correlation coefficients were used to assess 
 differences between the vertebral and femoral measurements , and significant differences 
 and positive correlations were observed among third lumbar vertebra , femoral neck , ward s 
 triangle , and femur trochanter in the normal group . 
 [ conclusion ] females in the normal , 
 osteopenia , and osteoporosis groups showed significant differences in their third lumbar 
 vertebrae . 
 the lack of significant differences among measurements in the osteoporosis 
 group in this study suggests that patients with osteoporosis require careful and accurate 
 diagnosis .