Bone mineral density and its relationship with body mass index in postmenopausal women with type 2 diabetes mellitus in mainland China.

Bone mineral density (BMD) and its association with body mass index (BMI) are uncertain in postmenopausal women with type 2 diabetes mellitus (T2DM) in mainland China. This study was performed to assess this association including 1,042 postmenopausal women with T2DM and 919 non-diabetic control subjects. Bone mineral density of the posteroanterior spine and of the left hip was measured by use of dual-energy X-ray absorptiometry. Diabetic participants were divided into three groups according to BMI, i.e. low BMI (DML < 18.5 kg/m(2)), intermediate BMI (DMM 18.5-24.9 kg/m(2)), and high BMI (DMH >or= 25 kg/m(2)). The BMD values of diabetic subjects between groups exhibited a significant gradient difference, with DML < DMM < DMH. On the fitting curves, where BMD in various skeletal regions varied with age, BMDs of DML were approximately 15% lower than those of DMM, and those of DMM were approximately 10% lower than those of DMH. For prevalence and risks of osteoporosis a gradient difference was observed among diabetic groups, DML > DMM approximately control > DMH. The osteoporosis risk was higher for the hip than for the lumbar spine, especially in DML. This study indicated that postmenopausal women with T2DM had higher BMD and lower osteoporosis risk in the lumbar spine, and that lower BMI was an indicator of osteoporosis in mainland China.

Establishment of BMD reference databases for the diagnosis and evaluation of osteoporosis in central southern Chinese men.

Osteoporosis in men is an increasingly important public health problem. This study was designed to establish bone mineral density (BMD) reference databases for central southern Chinese men at multiple skeletal sites. We recruited 2433 native Chinese males for BMD assessment. Of these, 1537 were healthy volunteers (age range, 15-85 years), and 896 were suspected to have osteoporosis. BMD values were measured at the posteroanterior (PA) and lateral spine, hip, and distal forearm using a Delphi A absorptiometer. The quadratic regression model provided the best fit for age-related changes in BMD in the spine and hip. The cubic regression model was the best for describing age-related BMD changes in the distal forearm. Peak BMD in the lumbar spine, femoral neck, and total hip occurred at 15-19 years. Peak BMD at the distal forearm occurred at 40-44 years. The prevalence of primary osteoporosis in subjects ranging from 50-85 years was 4.3%-27.7% at various skeletal sites. Compared to the databases established here, the Hologic databases led to significantly higher osteoporosis detection rates. The BMD reference databases established for central southern Chinese men provide the most reliable diagnostic standards for osteoporosis detection in men of central south China.

Differences in age-related bone mass of proximal femur between Chinese women and different ethnic women in the United States.

Substantial racial differences in bone mass and bone loss rate have been reported, but the extent of the difference between native Chinese women and women of different races in the United States is not clear. We used a DXA bone densitometer to measure bone mineral density (BMD), bone mineral content (BMC), bone area (BA), and volumetric BMD (vBMD) in different regions of the proximal femur in 3614 Chinese women aged 20 years and older. Regression models were chosen to best fit the changes of these parameters with increasing age. The values in their fitted curves were determined by the Cartesian coordinate numeration system. Subsequently, we compared these fitted curves to full-matched data of non-Hispanic black, non-Hispanic white, and Mexican American women reported by the third National Health and Nutrition Examination Survey (NHANES III). We found that all fitted curves of bone mass of non-Hispanic black women were significantly higher than those of Chinese, non-Hispanic white, and Mexican American women (P = 0.000). The BMD and BMC fitted curves in various regions of the hip for non-Hispanic blacks were 22%-28% and 26%-43% higher than those for Chinese women, 8.3%-13% and 7.9%-9.5% higher than those for non-Hispanic whites, and 8.8%-10% and 13%-19% higher than those for Mexican Americans, respectively. However, when the expression of difference was transformed from BMD to vBMD at the femoral neck, the difference between Chinese and non-Hispanic black women was reduced from 22% to 18% and that between Chinese and non-Hispanic white women from 7.4% to 0.8%, but the difference increased from 3.2% to 9.6% between non-Hispanic white and Mexican American women and from 13% to 17% between non-Hispanic white and non-Hispanic black women. By the age of 80 years, the accumulated bone loss rate in various regions of the proximal femur for Chinese, Mexican Americans, non-Hispanic whites, and non-Hispanic blacks were -38.9% +/- 1.8%, -34.4% +/- 3.1%, -27.8% +/- 5.9%, and -28.4% +/- 4.8%, respectively. In conclusion, bone mass in the proximal femur of native Chinese women is significantly lower, and the bone loss rate greater, than those of non-Asian women in the United States. At the femoral neck, the vBMD of Chinese women is similar to that of non-Hispanic white women.

[Age-related change of bone biochemical markers and their relationships to mineral density in healthy Chinese men].

OBJECTIVE: To study the age-related changes of bone formation markers, i.e., serum bone alkaline phosphatase (sBAP) and serum osteocalcin (sOC), bone resorption marker, i.e., cross-linked N-telopeptides of type 1 collagen (sNTX), and bone mineral density (BMD) in healthy men. METHODS: Serum sBAP, sOC, and sNTX of 389 randomly selected males, aged 20 - 80, all of Han nationality, were measured by using enzyme-linked immunosorbent (ELISA). Dual energy X-ray densitometer was used to measure the BMD of the lumbar vertebrae, left femoral neck, Ward's triangle, and hip. The relationships of these markers to age were analyzed. RESULTS: (1) The sBAP, sOC, and sNTX were negatively correlated with age, the cubic regression model being better with age-related changes of bone biochemical markers as compared with the other regression models (R(2) = 0.013 - 0.029, P < 0.05); (2) When all subjects were stratified by 10-years, the bone biochemical marker values were the highest in the age group 20 - 29, with the sBAP of 30.9 U/L +/- 12.6 U/L, sOC of 12.6 microg/L +/- 6.2 microg/L, and sNTX of 18.2 micromol/L +/- 6.6 micromol/L; then decreased with aging and to a nadir level in the age group 50 - 59, with the sBAP of 26.9 U/L +/- 8.6 U/L, sOC of 9.2 microg/L +/- 5.3 microg/L, and sNTX of 15.6 micromol/L +/- 6.1 micromol/L. After the age of 60, sNTX increased slightly 16.0 micromol/L +/- 6.1 micromol/L, however, BAP and sOC remained stable; (3) After adjustment for age, height, weight, BMI and smoking, serum BAP was negatively correlated with BMD of multiple skeletal sites. sOC was inversely associated with BMD of multiple skeletal sites except lateral spine; and sNTX was negatively correlated with BMD of the lumbar spine and total hip. CONCLUSION: Negatively correlated with BMD, sBAP, sOC, and sNTX may be sensitive and relatively specific markers to evaluate age-related changes of bone turnover.

Age-related changes in bone biochemical markers and their relationship with bone mineral density in normal Chinese women.

Measurements of bone biochemical markers are increasingly being used to evaluate the state of bone turnover in the management of bone metabolic diseases, especially osteoporosis. However, changes in the bone turnover rate vary with age. The aim of this study was to establish the laboratory reference range of serum bone-specific alkaline phosphatase (sBAP), serum type I collagen cross-linked C-terminal telopeptide (sCTx), and urine CTx (uCTx), based on values from 665 healthy Chinese women aged 20-80 years. We measured the levels of sBAP, sCTx, serum alkaline phosphatase (sALP), and uCTx and evaluated the age-related changes and their relationship with bone mineral density (BMD) in the anteroposterior (AP) lumbar spine, hip, and left forearm. We found significant correlations between biochemical markers and age, with coefficients of determination (R (2)) of 0.358 for sBAP, 0.126 for sCTx, 0.125 for uCTx, and 0.336 for sALP. The net changes in different biochemical markers were inversely correlated with the rates of BMD loss in the AP lumbar spine. After correction for age, body weight, and height, the levels of the markers had significant negative correlations with the BMD of the AP lumbar spine, femoral neck, and ultradistal forearm. All four biochemical markers had the highest negative correlation with BMD of the AP lumbar spine (partial correlation coefficients of -0.366, -0.296, -0.290, and -0.258 for sBAP, sCTx, uCTx, and sALP, respectively). The mean and SD values of these markers in premenopausal and postmenopausal women with normal BMD values were used as the normal reference ranges. The reference ranges of sBAP, sCTx, and uCTx for pre- vs postmenopausal women were 17.3 +/- 6.23 vs 18.9 +/- 7.52 U/l, 3.18 +/- 1.49 vs 3.23 +/- 1.57 nmol/l, and 15.5 +/- 11.4 vs 16.2 +/- 12.4 nM bone collagen equivalents/mM urinary creatinine, respectively. Levels of the bone formation marker (sBAP) and bone resorption markers (sCTx, uCTx) increased rapidly in women with osteopenia or osteoporosis, indicating that they may be sensitive markers to determine the bone turnover rate in healthy Chinese women.

[Age-related changes serum levels of MMP-1 and MMP-2 in women: their relationship with bone biochemical markers and bone mineral density].

OBJECTIVE: To study the relationship between serum matrix metalloproteinase (MMP)-1, MMP-2 and bone turnover markers, bone mineral density (BMD) in Chinese women aged 20-80 years. METHODS: Serum MMP-1, MMP-2, bone alkaline phosphatase (BAP), osteocalcin (OC) and cross-linked N-telopeptide of collagen type I (NTX) were measured using ELISA. BMD were measured using DEXA in 591 women. RESULTS: (1) MMP-1 and MMP-2 were positively correlated with age (both P < 0.001). (2) Level of MMP-2 in postmenopausal women was significantly higher than that in premenopausal women (P < 0.001). (3) Significant negative relationship was found between MMP-2 and BMD, but multiple linear stepwise regression analysis showed MMP-2 was not the determinant factor of BMD. (4) Positive correlation was found between MMP-2 and BAP, OC, NTX (all P < 0.001). (5) Serum MMP-2 concentrations were significantly higher in postmenopausal osteoporotic women than in age-matched normal controls and osteopenic subjects. CONCLUSION: Circulating MMP-2 and markers of bone turnover are related and they may increase with the increase in bone-turnover. The increase of serum MMP-2 appears possibly as a concomitant event in high bone turnover state such as postmenopausal osteoporosis.

[Age-related and menopause-related changes of urinary excretion of C- and N-terminal cross-linked telopeptides of type I collagen and the relationships thereof with menopause-related bone loss].

OBJECTIVE: To study the age-related and menopause-related changes of urinary excretion of C- and N-terminal cross-linked telopeptides of type I collagen (uCTX/Cr and uNTX/Cr) and the relationships thereof with menopause state, years after menopause, bone mineral density (BMD), and menopause-related bone loss in healthy women. METHODS: ELISA was used to examine the uCTX/Cr and uNTX/Cr of 659 female volunteers aged 20 - 80 in Changsha. Dual energy X-ray absorptiometry (DXA) was used to measure the BMD of various skeletal sites, including the lumbar vertebrae (L1 - L4) at anteroposterior (AP) position, L(2) - L(4) at lateral (LAT) position, hip, and forearm. 339 postmenopausal women among the 659 subjects were divided into 3 groups, osteoporotic, osteopenic, and normal groups according to the WHO criteria of osteoporosis diagnosis. RESULTS: (1) Both the curves of uCTX/Cr and uNTX/Cr with age were fit the best by regression analysis of cubic equation. The coefficients of determination (R(2)) were 0.139 for uCTX/Cr and 0.149 for uNTX/Cr. The levels of uCTX/Cr and uNTX/Cr of the women aged > 35 increased with age. (2) The values of uCTX/Cr and uNTX/Cr were 253 mg/mol +/- 101 mg/mol Cr and 63 nmol +/- 34 nmol BCE/mmol Cr respectively in the postmenopausal women, remarkably higher than those of the premenopausal women (149 mg/mol +/- 80 mg/mol Cr and 33 nmol +/- 17 nmol BCE/mmol Cr respectively), increased by 69.5% and 93.4% respectively. The annual change rates of uCTX/Cr and uNTX/Cr were the highest within the first 5 years after menopause, and these increases were in agreement with the significant decrease of BMD at most skeletal sites by 10.8% approximately 27.6%. (3) After controlled for age and body weight, both uCTX/Cr and uNTX/Cr showed significant negative correlation with BMD (r = -0.078 to -0.283, P < 0.05 or 0.01), and there was a significant positive correlation between uCTX/Cr and uNTX/Cr. (4) The elevation of the levels of uCTX/Cr and uNTX/Cr in the osteoporotic and osteopenic postmenopausal subgroups were significantly higher than those in the postmenopausal women with normal BMD (P < 0.05 or 0.01). For example, the uCTX/Cr levels of the osteoporotic, osteopenic, and normal BMD subgroups according to the DXA results at the anteroposterior lumbar spine were 189 +/- 87, 272 +/- 108, and 366 +/- 135 mg/mol Cr respectively, while the uNTX/Cr levels were 52 +/- 22, 68 +/- 34 and 108 +/- 41 nmol BCE/mmol Cr respectively. CONCLUSION: uCTX/Cr and uNTX/Cr can be used as sensitive markers to determine the bone turnover status, which is changeable with age and menopausal status in women. They present a significantly negative correlation with BMD, and increase significantly in the postmenopausal women with osteopenia or osteoporosis, which indicates that measuring uCTX/Cr and uNTX/Cr can predict age-related and menopause-related bone loss in women.

[Relationship between polymorphism of parathyroid hormone and bone mineral density and relevant biochemical indicators in women].

OBJECTIVE: To investigate the distribution of parathyroid hormone (PTH) gene polymorphisms and the relationships of PTH gene polymorphisms with bone mass and serum bone relative biochemical markers. METHODS: Blood samples of 314 normal female volunteers, aged 20 - 80, were collected. Serum PTH, bone alkaline phosphatase (sBAP), cross-linked N-telopeptide of collagen type I (sNTX), cross-linked C-telopeptide of collagen type I (sCTX), osteoprotegerin (OPG) and leptin were determined by ELISA. Polymorphisms of PTH gene were detected by polymerase chain reaction fragment length polymorphisms (PCR-RFLP) of restriction enzyme BstBI. BMD (QDR4500A) of the anteroposterior spine (AP), supine lateral spine (Lat), and femoral neck (FN) were measured. RESULTS: (1) The genotype frequency of BB, Bb, and bb were 75.8%, 23.3% and 0.9% respectively in normal females volunteers. The frequencies of RFLP alleles B and b were 87.5% and 12.5% respectively. There was no difference in the polymorphism frequency of PTH gene between the post- and pre menopausal women. (2) There were no significant differences in the BMD of the AP, Lat, and FN and the serum biochemical markers between the BB and Bb genotypes. (3) Multiple stepwise regression analysis showed that PTH did not influence the BMD values. CONCLUSION: PTH gene polymorphism has no relationship with bone mass and serum bone biochemical markers in normal females.

Serum concentrations of MMP-1, MMP-2, and TIMP-1 in Chinese women: age-related changes, and the relationships with bone biochemical markers, bone mineral density.

BACKGROUND: Osteoblast-derived matrix metalloproteinse-1 (MMP-1), MMP-2 and tissue inhibitor of metalloproteinase-1 (TIMP-1) play a role in bone metabolism by degrading bone matrix. METHODS: We measured MMP-1, MMMP-2, TIMP-1 and associated results with age and bone metabolism in 591 Chinese women aged 20-80 y. RESULTS: Serum MMP-1, MMP-2, and TIMP-1 concentrations exhibited positive correlation with age. Serum concentrations of MMP-1 were higher in 40-69 y old women. The concentrations of MMP-2 were significantly increased in the 50-69 y olds. Serum TIMP-1 concentrations were significantly lower in women aged 30-59 y, and then these were followed by an increase at >60 y olds. We found a significant negative weaker correlation between MMP-2 and BMD. But multiple linear stepwise regression analysis showed that MMP-2 was not a determinant factor for BMD. There were significant positive correlations between MMP-2 and bone alkaline phosphatase (BAP), osteocalcin (OC), and cross-linked N-telopeptides of type I collagen (NTX). CONCLUSIONS: The serum concentrations of MMP-1, MMP-2, and TIMP-1 exhibit age-related changes, and circulating MMP-2 and bone turnover are related.

Age-related changes of serum bone alkaline phosphatase and cross-linked C-telopeptides of type I collagen and the relationship with bone mineral density in Chinese women.

BACKGROUND: Previous studies have shown that bone turnover rate changes with age. At the same time, there is no definitive research regarding age-related changes of bone turnover level and its association with bone mineral density (BMD) in Chinese mainland women. METHODS: In a cohort of 663 Chinese mainland women aged 20-70 years, serum bone alkaline phosphatase (BAP) and serum cross-linked C-telopeptides of type I collagen (sCTX) were measured to evaluate the state of bone formation and resorption, respectively. BMD was measured in the posteroanterior spine, supine lateral spine, hip and forearm using a dual-energy X-ray absorptiometry. RESULTS: The cubic polynomial regression model best fit age-related changes in serum BAP (R2=0.398, p<0.001) and sCTX concentrations (R2=0.148, p<0.001) with largest R2 from comparison 8 different regression models. Their values reached a minimal level in the 30-39 years age group, and increased dramatically in the 40-59 years groups. There was a decreasing trend of BAP in women >60 years. The levels of BAP and sCTX were inversely correlated to BMD in various skeletal regions over the entire population (r=-0.096 to -0.357, p<0.05). sCTX was a significant predictor of a T-score< or =-2.5 of BMD in postmenopausal women with sCTX levels above mean+2 SD of women aged 30-39 years compared with other postmenopausal women, which indicated by odds ratios 1.9-3.7 (p<0.05) for various skeletal regions, especially for the lateral lumbar spine (2.2, p<0.01), Ward's triangle (3.7, p<0.01), and ultradistal end of radius + ulna (2.8, p<0.001). CONCLUSIONS: Age-dependent serum BAP and sCTX were inversely correlated to BMD, and sCTX was a useful parameter for the prediction of a low T-score of BMD at skeletal sites with abundant cancellous bone in postmenopausal women.

[Relationships between circulating matrix metalloproteinase-1, -2 and metalloproteinase-1 levels and bone biochemical markers and bone mineral density in Chinese postmenopausal women].

OBJECTIVE: To study the serum matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-2 (MMP-2), and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels, and the correlations of MMP-1, MMP-2, and TIMP-1 with bone turn-over markers and bone mineral density (BMD) in aged postmenopausal Chinese women. METHODS: The serum MMP-1, MMP-2, TIMP-1, serum bone alkaline phosphatase (BAP), serum osteocalcin (OC), serum cross-linked N-telopeptides of type I collagen (NTX) of 297 Chinese female volunteers aged 48 - 89 were measured using ELISA. BMD were measured using dual energy X-ray absorptiometry in aged postmenopausal Chinese women. RESULTS: (1) There were no significant negative relationships between MMP-1, TIMP-1 and BMD and bone biochemical markers. (2) A weak negative relationships were found between MMP-2 and BMD. Adjusted by age and body weight, the correlation of MMP-2 with BMD of neck of femur and hip disappeared. (3) Positive correlations between MMP-2 and BAP, OC, NTX was found (all r = 0.193, 0.231, 0.249, P < 0.01) (4) Serum MMP-2 concentrations were significantly higher in postmenopausal women with osteoporosis (1466 microg/L +/- 313 microg/L) than in age-matched normal controls (1222 microg/L +/- 243 microg/L) and osteopenia subjects (1282 microg/L +/- 220 microg/L). CONCLUSION: There are significant correlations between serum MMP-2 and bone metabolism, and MMP-2 may increase with increases in bone-turnover. The increases of serum MMP-2 appear possibly as a concomitant event in high bone turnover state, such as postmenopausal osteoporosis.

Establishment of BMD reference curves at different skeletal sites in women, using a Cartesian coordinate numeration system.

The BMD reference curve is the reference value used for diagnosing osteoporosis and assessing bone mass changes. Its accuracy would affect the correctness of T-score and Z-score values and thus the reliability of diagnostic results. In this paper, we report the use of a new method, a Cartesian coordinate numeration system, to establish BMD reference curves at different skeletal sites in women. In a reference population of 3,919 women ranging in age from 5-85 years, we used the dual X-ray absorptiometry (DXA) bone densitometer to measure BMD at the posteroanterior spine (PA; vertebrae L1-L4), followed by a paired PA/lateral spine scan of the vertebral bodies of L2-L4, expressed in g/cm2 and g/cm3, and of the hip and forearm. We chose the cubic regression model to best fit BMD curves that varied with age at different skeletal sites. We then referred the BMD of the fitting curves established by the method of the coordinate numeration system as reference curves, compared them to BMD reference curves derived from the fitting curve equation or age cross-section, and calculated the deflection degrees of the BMD reference curves acquired from the fitting curve equation. At the PA spine, lateral spine (expressed in g/cm3), femoral neck, Ward's triangle and radius + ulna ultradistal, the reference curves calculated from the equation were significantly lower than those confirmed by the method of the coordinate numeration system; whereas, at the lateral spine (expressed in g/cm2), total hip, and radius + ulna 1/3 sites, the reference curves derived from the equation were markedly higher than those acquired from the coordinate numeration system. The differences in the two kinds of reference curves calculated by these two different methods gradually increased along with the increment in ages of the women. At the peak value of the reference curves, the BMD calculated from the equation deflected from 2.02% to -10.0% from the BMD acquired from the coordinate numeration system at different skeletal sites, and from 21.5% to -121.8% until the age of 85 years. The highest positive deflection of 65.2% existed at the lateral spine (expressed in g/cm2) and the lowest positive deflection of 21.5% at the total hip. The maximum negative deflection of -121.8% was at the radius + ulna ultradistal, and the minimum negative deflection of -32.6% at the PA spine. The BMD curve acquired from age cross-section was highly positive compared with the one derived from the coordinate numeration system (r=0.955-0.985 p=0.000) with no significant difference between them. Various analysts used such a method to obtain the coefficient of variance (CV) in BMD precision on each curve that was from 0.05-0.19%. Our study shows that the Cartesian coordinate numeration system is an accurate, precise and reliable method and can serve to reveal the serious drawbacks of using the fitting curve equation to calculate BMD. The BMD reference curves established by this coordinate numeration system maintained the authenticity of the fitting curve, whereas, using the fitting curve equation to obtain BMD reference curves at different skeletal sites led to distortion, and resulted in false increases or decreases in T-score and Z-score values.

Relationship of serum leptin with age, body weight, body mass index, and bone mineral density in healthy mainland Chinese women.

BACKGROUND: Serum leptin concentration is associated with age, fat and bone mineral density (BMD), and there are ethnic differences in physique and BMD values. The relationship between serum leptin concentration and BMD in Chinese women is presently unknown. We examined the relationship of serum leptin concentration with age, body weight, BMI and BMD in mainland Chinese women. METHODS: Serum leptin concentration in a population of 676 Chinese females, aged 20-80 years (45.4+/-14.8 years, mean+/-S.D.), was measured using an enzyme-linked immunosorbent assay (ELISA). BMD values were measured by dual-energy X-ray absorptiometry (DXA) at a number of sites: the posteroanterior lumbar spine (PA, L1-L4), lateral lumbar spine (Lat, L2-L4), hip (including the femoral neck (FN) and total hip (T-hip)), and forearm (one-third region (RU1/3) and total region (RUT)). The relationship between changes in serum leptin concentration with age, body weight, height, body mass index (BMI) and BMD values at six sites were analyzed using 10 different regression models, and the models giving the best fit were selected. RESULTS: The cubic regression model best described the changes in serum leptin concentration with age (R(2)=0.048, p<0.001) and body weight (R(2)=0.352, p<0.001), while the quadratic regression model was best for serum leptin concentration changes with BMI (R(2)=0.410, p<0.001); serum leptin concentration was not correlated with height. Serum leptin concentration was significantly higher in postmenopausal than premenopausal women (p<0.001). Serum leptin concentration was correlated with Lat BMD (R(2)=0.012, p<0.018), FN BMD (R(2)=0.006, p<0.041) and T-hip BMD (R(2)=0.013, p<0.004) in the whole population. In premenopausal women, leptin was positively associated with BMD except for Lat (R(2)=0.029-0.055, p<0.008); in postmenopausal women, leptin was also positively associated with AP, FN, T-hip BMD (R(2)=0.026-0.042, p<0.007). However, after adjusting for BMI not for body weight, there was no association between serum leptin concentration and age. Meanwhile, after adjustment for age, body weight and BMI, there was no association between serum leptin concentration and BMD values in premenopausal and postmenopausal women. CONCLUSIONS: Age-related changes in serum leptin concentration is dependent on BMI, but not a direct determinant of BMD in Chinese females.

[Serum osteoprotegrin and serum bone gamma-carboxyglutamine acid-containing protein are correlated with bone mineral density in normal women].

OBJECTIVE: To study the relationships of serum osteoprotegrin (sOPG), serum bone gamma-carboxyglutamine acid-containing protein (sBGP), and urine deoxypyridinoline (uDPD)/creatinine (Cr) with age and bone mineral density (BMD) in women. METHODS: ELISA was used to examine the sOPG, sBGP, and uDPD/Cr of 672 female volunteers aged 20-80. The BMD (QDR4500A) value of the anteroposterior lumbar spine and femoral neck were measured by DXA. RESULTS: (1) The levels of sOPG, sBGP, and uDPD/Cr in the age group of 30-39 were 2.8 pmol/L +/- 1.4 pmol/L, 5 microg/L +/- 3 microg/L, and 4.9 nmol/mmol +/- 2.5 nmol/mmol respectively, all significantly lower than those in the age groups 40-49, 50-59, and 60-69 (all P < 0.05). (2) In the age group 40-49, the values of sOPG, sBGP, and uDPD in menopausal subjects were significantly higher than those of the non-menopausal subjects (5.7 pmol/L +/- 3.1 pmol/L vs 3.4 pmol/L +/- 2.0 pmol/L, 11 microg/L +/- 5 microg/L vs 6 microg/L +/- 3 microg/L, and 6.9 nmol/mmol +/- 3.3 nmol/mmol vs 5.2 nmol/mmol +/- 3.9 nmol/mmol, all P < 0.001). (3) Age was positively correlated with sOPG, sBGP, uDPD/Cr, and BMD of anteroposterior lumbar spine and femoral neck (r = 0.130, 0.355, 0.106, -0.600, -0.545; P < 0.01). sOPG and sBGP were negatively correlated to anteroposterior lumbar spine BMD (r = -0.183, -0.108, P < 0.01; and r = -0.541, -0.441, P < 0.001). sOPG was positively correlated with sBGP and uDPD/Cr (r = 0.216 and 0.083; both P < 0.05). CONCLUSION: sOPG, sBGP, and uDPD/Cr can be used as sensitive markers to determine the bone turnover status, which is changeable with age, and menopausal status in women, and predict the bone lose prior to BMD determination by DXA.

Relationship of body surface area with bone density and its risk of osteoporosis at various skeletal regions in women of mainland China.

The aim of this study was to investigate the relationship between body surface area (BS) and bone mineral density (BMD) and the associated osteoporosis risk at various skeletal regions in women from mainland China. BMD was measured at the posteroanterior (PA) spine (L1-L4), supine lateral spine (L2-L4) including volumetric BMD (vBMD), hip including femoral neck, trochanter and total hip, and forearm, including radius + ulna ultradistal (R + UUD), 1/3 site (R + U1/3) and total region (R + UT) using a dual-energy X-ray absorptiometry (DXA) fan-beam bone densitometer (Hologic QDR 4500A) in 3418 females aged from 18 to 75 years. Data analysis revealed a positive correlation between BS and BMD at the various skeletal regions (r = 0.114-0.373, all P = 0.000), but no correlation with vBMD (r = 0.000, P = 0.934). Using the stepwise regression model, BMDs at various skeletal regions were dependent variables while height, weight, body mass index (BMI), BS and projective bone area (BA) were independent variables; BS was determined to be the most important variable that affected the PA spine, hip and forearm BMDs. Subjects were divided into three groups according to size: large BS group (LBSG), intermediate BS group (IBSG) and small BS group (SBSG). The BMD at different skeletal regions of subjects between groups exhibited a significant gradient difference, with LBSG > IBSG > SBSG, but this was not seen for vBMD. On the fitting curves where BMD varied with age at the PA spine, femoral neck, total hip and R + UUD, BMDs of LBSG were 6.93-9.29% higher than those of IBSG and 12.1-16.9 % higher than those of SBSG, whereas those of SBSG were 6.12-9.59% lower than those of IBSG at various skeletal regions, respectively. The prevalence rates and risks of osteoporosis of LBSG were significantly lower than those of SBSG and IBSG, whereas those of IBSG were obviously lower than those of SBSG at various skeletal regions, respectively, presenting a gradient difference among the three study groups, LBSG < IBSG < SBSG. Our study shows that the relationship between BS and BMD exceeds that between BMD and height or weight in women in mainland China. When areal BMD is employed, those with a larger BS have higher areal BMD and lower risks of osteoporosis while, conversely, those with a smaller BS have lower areal BMD, and therefore higher risk for osteoporosis. However, when vBMD is used, these differences diminish or even disappear.

Determination of age-specific bone mineral density and comparison of diagnosis and prevalence of primary osteoporosis in Chinese women based on both Chinese and World Health Organization criteria.

The aim of this study was to determine age-specific bone mineral density (BMD) at various skeletal regions in a native Chinese reference population, and to explore the differences in the diagnosis of primary osteoporosis and estimated prevalence of osteoporosis based on both Chinese criteria (BMD of subjects, 25% lower than the peak BMD) and WHO criteria (BMD of subjects, 2.5 SD [T-score < or = -2.5] lower than the young adult mean [YAM]). There were 3,406 subjects in our female reference population, ranging in age from 10 to 90 years. A dual-energy X-ray absorptiometry (DXA) fan-beam bone densitometer (Hologic QDR 4500A) was used to measure the BMD in subjects at the posteroanterior (PA) spine (L1-L4), supine lateral spine (L2-L4 including areal BMD [aBMD] and volumetric BMD [vBMD]), hip (including femoral neck and total hip), and radius + ulna ultradistal (R + UUD) of the forearm. Cross-sectional data analysis in stratified 5-year age intervals revealed that the peak BMD (PBMD) at various skeletal regions occurred within the age range of 30-44 years, with PBMD at the lateral spine and femoral neck occurring at 30-34 years, posteroanterior spine and total hip at 35-39 years, and ultradistal forearm at 35-44 years. The reference values of BMD (PBMD) calculated using Chinese criteria for the diagnosis of primary osteoporosis were significantly higher than the young adult mean (YAM) using WHO criteria for all skeletal regions except for the total hip, at a range of 0.9%-3.8% higher. The BMD cutoff values using Chinese criteria for the diagnosis of osteoporosis were 3.7%-10.9% higher than those using WHO criteria for various skeletal regions. The prevalence rate of primary osteoporosis according to Chinese criteria in subjects ranging from 50 to 90 years was 41.5% at the PA spine, 53.9% at the lateral spine, 34.2% at the femoral neck, 30.7% for total hip, and 51.4% at R + UUD; while according to WHO criteria, this rate was 32.1% at the PA spine, 34.9% at the lateral spine, 16.3% at the femoral neck, 18.9% for total hip, and 45.2% at R + UUD. The prevalence of primary osteoporosis according to both criteria varied with the age and skeletal region of the subjects. The prevalence of primary osteoporosis using Chinese criteria, compared with WHO criteria was 31% higher at the lumbar spine, 109% higher at the femoral neck, and 14% higher at the ultradistal forearm. In conclusion, PBMD occurs in the age range of 30-44 years in native Chinese females. The BMD reference values, BMD cutoff values, and prevalence of primary osteoporosis determined by Chinese criteria are all higher than those determined by the WHO criteria; thus, the application of Chinese criteria may overestimate the number of patients with primary osteoporosis.

[The relationships between biomarkers of age-related changes in bone turnover and bone mineral density in healthy Chinese women].

OBJECTIVE: To study the relationships of serum bone alkaline phosphatase (sBAP), serum osteocalcin (sOC) and the ratio of urine cross-linked N-telopeptide of collagen type I (uNTX)/creatine (Cr) with age and bone mineral density (BMD) in healthy women aged 20 - 80 years. METHODS: sBAP, sOC and uNTX were measured using ELISA. BMD at lumbar spine 1 - 4 anteroposterior (AP) and at femoral neck (FN) was studied using DXA (QDR 4500A) in 668 healthy women. Correlations of bone biomarkers with age and BMD were fitted in entire female population by ten kinds of regression models. RESULTS: (1) sBAP, sOC and uNTX were positively correlated with age (all P < 0.001). The cubic regression model was better fitted with age-related changes of bone biomarkers as compared with the other regression models and the coefficients of determination (R(2)) of fitting curve were 0.181 - 0.381 (P < 0.001). (2) When all subjects were stratified by 10-year age groups, the bone biomarker values during 30 - 39 years of age were the lowest, then they increased gradually to a highest level in the 50 - 59 years of age. (3) When subjects were stratified by menopause, levels of sBAP, sOC and uNTX in postmenopausal women with a low value of BMD at AP and FN were significantly higher than those in premenopausal women (all P < 0.001). (4) Positive correlation among sBAP, sOC and uNTX was found (all P < 0.001) and BMD values at AP and FN were negatively correlated with all the bone biomarkers (all P < 0.001). CONCLUSIONS: sBAP, sOC and uNTX may be the sensitive and relatively specific markers to evaluate age- and menses-dependent changes of bone turnover, but they are negatively correlated with BMD, suggesting that individuals with increased bone biomarker levels are associated with a decreased BMD value.

Establishment of BMD reference plots and determination of peak BMD at multiple skeletal regions in mainland Chinese women and the diagnosis of osteoporosis.

Osteoporosis is a major public health problem, particularly in women. Bone mineral density (BMD) reference plot is a basic, and the peak BMD (PBMD) an important, parameter in the diagnosis of osteoporosis. In order to establish reference plots of BMD at multiple skeletal sites in Chinese women and improve the diagnostic accuracy for osteoporosis, we measured BMDs at several skeletal regions in 3,378 Chinese women, aged 5-96 years, using a dual-energy X-ray absorptiometry fan-beam bone densitometer. After determining that the cubic regression model best fit all skeletal regions, we utilized the curve-fitting to establish BMD reference plots and utilized the curve-fitting equation to calculate the highest BMDs at all skeletal regions using three different methods of calculation--actual PBMD (method A), PBMD of each 5-year age group (method B), and a cross-section of age (method C). When the three methods were compared, we found significant differences among them at the majority of skeletal regions studied. When we utilized these three methods to determine the prevalence of osteoporosis in 2,120 women aged 40 years and older, except for the Ward's triangle, we observed significant differences among them at all skeletal regions. In the present study, we established new BMD reference plots at multiple skeletal regions for women of mainland China. Our findings also indicate that curve-fitting equations can be employed to calculate actual PBMDs specific to individual regions, and that the use of different methods to calculate PBMD may have a significant impact on both PBMD and the diagnosis of osteoporosis. Therefore, we suggest that a standardized method be established to calculate site-specific PBMDs based on the peak values of best-fit reference curves in appropriate age groups.