Effects of age and menopause on bone density of entire skeleton in healthy and osteoporotic women

We studied 885 women to evaluate the effects of age and menopause on bone mineral density (BMD) in both healthy and postmenopausal osteoporotic subjects. The study cohort consisted of 161 healthy premenopausal women (age range 25–54 years), 357 healthy postmenopausal women (35–85 years) and 367 osteoporotic women (41–87 years). Total body and regional (spine, trunk, pelvis, arms, legs) BMD were measured with a dual-energy X-ray (DXA) device (Lunar DPX). Premenopausal BMD values remained essentially unchanged until the first half of the fourth decade, when they decreased. BMD values in both healthy postmenopausal and osteoporotic women were significantly lower than premenopausal values, and continued to decrease statistically after the onset of menopause. The highestZ-score (0.96±0.92) was found for total body BMD. HigherT-score values were found in osteoporotic than in normal postmenopausal women. In both healthy and osteoporotic postmenopausal women the best fits for BMD changes in total body, spine, trunk, arms and legs were obtained with the natural logarithm of years since menopause; only the pelvis BMD decreased linearly. Multiple regression analysis indicated that postmenopausal BMD changes in both normal and osteoporotic women were linked chiefly to body weight and years since the onset of menopause.     

Bone Mass, Bone Metabolism, Gonadal Status and Body Mass Index

Weight and gonadal status are the main determinants of bone mass in women. Because of this it is important to study which influences it more. The effect of weight (expressed as body mass index, BMI) and gonadal status of women on total-body bone mineral content (TBBMC) and regional bone mineral content (BMC) was investigated. A total of 373 normal women (mean age 48.9 ± 13.4 years) were studied: 171 postmenopausal women (mean age 59.3 ± 9.5 years; years since menopause 11.3 ± 6.7 years); 76 perimenopausal women (mean age 48.9 ± 2.2 years); and 126 premenopausal women (mean age 34.7 ± 7.4 years). In all the women, TBBMC and regional BMC were determined by dual-energy X-ray absorptiometry. Also biochemical markers of bone metabolism (total alkaline phosphatase and tartrate-resistant acid phosphatase) and serum estrone and estradiol were determined. When the women were stratified by gonadal status and BMI, thin women (BMI <20 kg/m²) had significantly lower TBBMC and regional BMC, lower gonadal steroid concentration and higher levels of biochemical markers than overweight (BMI 25–30 kg/m²) and obese (BMI >30 kg/m²) women, regardless of gonadal status. Overweight and obese women had findings suggestive of increased parathyroid activity, but greater bone mass. Weight rather than gonadal steroid concentration is the main determinant of bone mass in women regardless of gonadal status. Received: 6 July 2001 / Accepted: 15 November 2001     

Differences in mineral homeostasis, volumetric bone mass and femoral neck axis length in black and white South African women

In South Africa, appendicular and lumbar spine bone mineral density (BMD) have been found to be similar in black and white women. However, femoral BMD has been found to be higher in black than in white women. Two different techniques were used to recalculate BMD to eliminate the possible confounding influence of ethnic differences in height on areal BMD measurements. Volumetric bone mineral apparent density (BMAD) values were calculated and bone mineral content (BMC) was corrected for body and bone size. This report analyses differences in BMD (corrected for height and weight), BMAD, BMC (corrected for body and bone size), femoral neck axis length (FNAL), mineral homeostasis and bone turnover (BT) in a group of 20 to 49-year-old premenopausal (105 whites and 74 blacks) and 45 to 64-year-old postmenopausal (50 whites and 65 blacks) female South African nurses. The corrected BMD and BMC findings were congruous, showing that both pre- and postmenopausal blacks and whites have similar distal radius and lumbar spine bone mass but that whites have lower femoral neck bone mass than blacks. In contrast, BMAD findings suggest that pre- and postmenopausal whites have lower bone mass at the lumbar spine and femoral neck than blacks but similar bone mass at the distal radius to blacks. There is a greater rate of decline in BMD in postmenopausal whites than in blacks. BMD at the femoral neck was 12.1% lower in premenopausal whites and 16.5% lower in postmenopausal whites than in blacks. There was a positive association between femoral neck BMD and weight in premenopausal blacks (R ²=0.5,p=0.0001) but not in whites. Blacks had shorter FNAL than whites in both the pre- and postmenopausal groups. Blacks had lower serum 25-hydroxyvitamin D (25-(OH)D) and higher 1,25-dihydroxyvitamin D (1,25-(OH)₂D) levels than whites. There were no ethnic differences in biochemical markers of bone formation (serum alkaline phosphatase and osteocalcin) or bone resorption (urine hydroxyproline and pyridinoline), or in dietary calcium intake in either the pre- or postmenopausal groups. In the postmenopausal group, whites had higher ionized serum calcium (p=0.003), similar serum albumin, lower serum parathyroid hormone (p=0.003) and higher urinary calcium excretion (p=0.0001) than blacks. These results suggest that the higher peak femoral neck BMD in South African blacks than in whites might be determined by greater weight-bearing in blacks and that the significantly lower femoral neck BMD in postmenopausal whites than in blacks is determined by lower peak femoral neck BMD and a faster postmenopausal decline in BMD in whites. The higher incidence of femoral neck fractures in South African whites than in blacks is probably determined by the lower femoral neck BMD and longer FNAL in whites. The greater rate of decline in BMD in postmenopausal whites than in blacks is associated with an increase in urinary calcium excretion in whites. Measurement of biochemical markers of BT has not contributed to the understanding of ethnic differences in BMD and skeletal metabolism in our subjects.     

Influence of weight and seasonal changes on radiogrammetry and bone densitometry

We studied the behavior of radiogrammetric and densitometric measurements in relation to season and body weight in a group of 30 healthy premenopausal women. Measurements were made at 6-month intervals, in summer/fall when bone density increases and in winter/spring when bone density declines. Total body bone mineral content (TBBMC) and regional bone mineral content (RBMC) were measured using dual-energy X-ray absorptiometry (DXA). Metacarpal radiogrammetry was carried out with computed radiography. Weight and body mass index increased significantly in winter (P<0.05) and total body and RBMC decreased (P<0.001). The opposite occurred in summer: weight and body mass index decreased significantly (P<0.05) and total body and regional bone mineral content increased (P<0.001). Differences in TBBMC persisted when the measurement was corrected for weight (TBBMC/W) (P<0.001), but not for metacarpal cortical thickness corrected for weight. In the first measurement made there were significant relations between weight and both TBBMC (P<0.001) and metacarpal cortical thickness (P<0.005). The relation between weight and TBBMC remained significant in later measurements, but the relation between weight and metacarpal cortical thickness ceased to be significant in the second and fourth measurements. Our results show that there is an important seasonal variation in bone mass and that DXA is more sensitive than radiogrammetry in registering these changes.     

The impact of degenerative conditions in the spine on bone mineral density and fracture risk prediction

We examined the impact of degenerative conditions in the spine (osteophytosis and endplate sclerosis) and aortic calcification in the lumbar region on bone mineral content/density (BMC/BMD) measured in the spine and forearm by absorptiometry and on fracture risk prediction. The radiographs of 387 healthy postmenopausal women, aged 68–72 years, were assessed in masked fashion for the presence of osteophytosis, endplate sclerosis and aortic calcification in the region from L2 to L4. Vertebral deformities/fractures were assessed by different definitions. Osteophytes larger than 3 mm and in numbers of 3 or more resulted in a significantly (12%) higher spinal bone mass (p<0.001). Endplate sclerosis had a similar effect (p<0.001). In subjects with both degenerative conditions the BMC/BMD in the spine and forearm were significantly higher than in unaffected women (19% in the spine, 10% in the forearm;p<0.001). The spinal BMD values were significantly lower in fractured women if both degenerative conditions were absent (p<0.001), whereas fractured and unfractured women had similar values if degenerative conditions were present. Degenerative conditions did not alter the ability of forearm BMC to discriminate vertebral or peripheral fractures. Receiver operating characteristic (ROC) curves (true positive fraction versus false positive fraction) were generated for BMD of the lumbar spine and BMC of the forearm with regard to the discrimination between women with vertebral and peripheral fractures and healthy premenopausal women. The ROC curves for women without degenerative conditins were consistently above the curves for women affected by osteophytosis and endplate sclerosis in the lumbar spine (p<0.001). In conclusion, osteophytes and endplate sclerosis have a considerable influence on spinal bone mass measurements in elderly postmenopausal women and affect the diagnostic ability of spinal scans to discriminate osteoporotic women. Our data suggest that in elderly women, unless the spine is radiologically clear of degenerative conditions, a peripheral measurement procedure should be considered an alternative for assessment of bone mineral content/ensity.     

绝经后妇女骨质疏松性椎体骨折与腰椎骨密度的关系

目的探讨绝经后妇女骨质疏松性椎体骨折与腰椎骨密度的关系。方法选择骨质疏松性椎体骨折的绝经后妇女23例为骨折组,无椎体骨折的25例绝经后骨质疏松妇女为对照组。两组的年龄、绝经年限、身高、体重、体重指数差异无显著性,均行胸腰椎正侧位X线摄片。用双能X线吸收仪（DXA）测量的腰椎（L2-4）前后位骨密度（BMD）、骨矿含量（BMC）和T值。结果骨折组BMD、BMC和T值均低于对照组（P〈0.01）。结论腰椎BMD降低与绝经后妇女的骨质疏松性椎体骨折相关。绝经后骨质疏松妇女应重视BMD变化,预防椎体骨折的发生。     

Soy protein consumption and bone mass in early postmenopausal Chinese women

Recent interest has been shown in the potential beneficial effects of phytoestrogens on bone health. As the early years of menopause are a period of rapid bone loss, and the risk for osteoporosis increases substantially, the habitual intake of soy protein and isoflavones may play a role in the retardation of bone loss. This paper reports the results of the baseline cross-sectional analysis of the association between dietary soy protein intake and bone mineral density/content in a population-based study of Chinese women. The sample comprised 454 healthy Chinese women (mean age 55.1±3.57) within the first 12 years of postmenopause. We estimated the dietary intake of soy protein and isoflavones, and other key nutrients, including dietary protein and calcium, using the quantitative food frequency method. Bone mineral density (BMD) and content (BMC) at the spine, hip and total body were measured with a dual energy X-ray densitometer (Hologic 4500A). Soy protein consumption was categorized as quartiles of intake, and related to BMD values at the spine and hip, and BMC of total body. Stratified analyses were carried out among women within or at least 4 years postmenopausal. We observed few differences in BMD/BMC values among the intake quartiles in women within the first 4 years of menopause. However, among the later postmenopausal women, we noted a dose-response relationship with increasing higher BMD values at the trochanter, intertrochanter as well as the total hip and total body with increasing soy protein intake quartiles (P<0.05 from tests for trend). The BMD values differed by about 4–8% between the first and fourth soy protein intake quartiles. Though women from the fourth intake quartile had a 2.9% higher BMD value compared with those from the first intake quartile, the difference was not statistically significant. Stepwise multiple linear regression analyses showed the association between soy intake quartiles and hip BMD as well as total body BMC values remained after adjusting for body weight, which was retained in the final model. Analyses based on soy isoflavones content yielded similar results. This study demonstrated that, among women after the initial few years postmenopausal, soy protein/isoflavones intake had a modest but significant association with hip BMD as well as total body BMC. The effects of soy protein and soy isoflavones on bone health should be further explored in populations with habitual dietary soy intake.     

Monitoring estrogen replacement therapy and identifying rapid bone losers with an immunoassay for deoxypyridinoline

We have assessed urinary deoxypyridinoline (Dpd) levels by immunoassay in women who participated in a double-masked, placebo-controlled trial of the bone loss prevention effects of estrogen replacement therapy (ERT). Ninety-one women who had undergone recent surgical menopause were randomdized to receive either placebo or 0.025, 0.05 or 0.1 mg/day transdermal 17β-estradiol for 2 years. Mean Dpd levels in the postmenopausal women were significantly elevated (p<0.0001) above mean Dpd levels in a reference population of healthy, premenopausal women. Subjects in the placebo group lost 6.4% of lumbar spine bone mineral density (BMD) and 4.9% of mid-radius bone mineral content (BMC) over 2 years. Dpd levels at baseline were inversely correlated with BMD and BMC changes in the placebo group. The placebo group and subjects receiving 0.025 mg/day 17β-estradiol who had Dpd levels increased above the reference interval cut-off (mean + 2 standard deviations, 7.5 nmol/mmol) lost 2 times more bone mass than did those with Dpd levels below it. Dpd levels decreased significantly (p<0.01) from baseline at 6 months following initiation of treatment with 0.05 or 0.1 mg/day 17β-estradiol, changes that correlated with increased lumbar spine BMD and with changes in mid-radius BMC. At 12 months, Dpd levels were lower than baseline and placebo in all three treatment groups. These data suggest utility of this Dpd immunoassay in assessing changes in bone resorption induced by surgical menopause and ERT.     

Effect of bone area on spine density in Chinese men and women in Taiwan

Areal bone mineral density (BMD), the quotient of bone mineral content (BMC) divided by the projectional bone area (BA), measured with dual-energy X-ray absorptiometers (DXA), is the most common parameter used today to evaluate spinal osteoporosis. To evaluate whether gender, age, weight, and height can determine spinal BA, and to compare BA and analyze its effects on spinal density in the two genders, we measured BA and BMC, and calculated areal BMD, and the bone mineral apparent density (BMAD = BMD/√BA) of the L-2 to L-4 vertebrate of 604 female and 223 male Chinese volunteers from 20 to 70 years of age using a Norland XR-26 DXA. Standardized for height and weight, BA showed a relatively large variation and a significant increase with increasing age in both genders. On the other hand, BMC stayed unchanged in men > 50 years of age and decreased with aging in postmenopausal women. Younger men (< 51 years) had a much larger mean BA (by 15.5%) and larger mean BMC (only 10%) than that of age-matched women. As a result, younger men had a slightly and significantly lower areal BMD (by 7.1%) and a much lower BMAD (by 16%) (p < 0.0001 for both) than premenopausal women of similar age. Men had higher areal BMD and BMAD values than age-matched women only after age 50 years. Although taller body height, heavier weight, and increasing age were associated with a larger BA, these factors could not explain most of the interindividual variations in BA in both genders. Thus anteroposterior BA of lumbar vertebrate measured with DXA seems to affect the areal BMD and BMAD readings in the two genders. The larger BA caused a low BMAD and probably underestimated the true volumetric spine density in men.     

Influence of Body Mass Index on the Age-related Slope of Total and Regional Bone Mineral Content

The influence of body mass index (BMI) on T scores for total body bone mineral content (TBBMC) and regional bone mineral content (RBMC) was studied in 186 healthy women: 100 postmenopausal, 35 perimenopausal, and 51 premenopausal. The three groups were divided by BMI >25 kg/m² and BMI <25 kg/m² and the postmenopausal women were further subdivided by years since menopause (YSM): <10, 10–20, and >20. Tartrate-resistant acid phosphatase (TRAP) concentration was higher in perimenopausal and postmenopausal women with BMI <25 kg/m² (P < 0.001). T scores for TBBMC and for axial or peripheral RBMC differed (P < 0.05 in all) between women with BMI >25 kg/m² and BMI <25 kg/m². The rate of perimenopausal and postmenopausal age-related slope of BMC, as reflected in all measurements, differed with BMI. In the overall group of women, the T score for TBBMC correlated significantly with BMI (r = 0.46, P < 0.0001); this correlation increased when adjusted for age (r = 0.62, P < 0.0001). BMI correlated with TRAP only in postmenopausal women (r = 0.57, P < 0.0001). Yearly TBBMC decline was twice as high in postmenopausal women with BMI <25 kg/m² (P= 0.0004) than in those with BMI >25 kg/m²; the decline of trunk RBMC was more significant (P < 0.0001). These findings confirm the influence of BMI and gonadal status on bone mass. Received 20 February 1996 / Accepted 31 December 1996     

Interpretation of lumbar spine densitometry in women with fractures

Identification of postmenopausal women at risk of developing osteoporotic fractures is a major clinical problem. In this study the use of projected planar lumbar bone density values for individual fracture risk assessment was questioned. Osteodensitometry (DXA) results from 415 normal women, 62 women with previous vertebral compressions, and 76 women with previous low-energy fractures were analyzed, together with their body size and lumbar vertebral body size variables. The following were found: (1) Lumbar vertebral projected bone mineral areal density (BMD) and bone mineral content (BMC) of normal women correlated with body size variables (p<0.001). (2) Lumbar vertebral body size variables also correlated with body size variables (p<0.001). Logistic regression analysis of measured and derived physical variables from women without and with vertebral compression fractures (n=477) showed: (3) The best compression fracture discriminator, significantly better than BMD, was BMC divided by (H_max/165 cm)¹⁵×(D/4.35 cm)^1.5, where H_max is the body height (cm) at the menopause, and D the mean lumbar vertebral diameter of the three mid-lumbar vertebral bodies (cm). This parameter was termed BMC_corr.. ROC analysis showed: (4) At a BMC_coor. true positive ratio of 80% the corresponding uncorrected BMC or BMD true positive ratio was only 60%. The corresponding false positive ratio was 6%. Lumbar osteodensitometry could not be used to identify women with a history of peripheral low-energy fractures. (5) BMC_coor. did not, unlike BMC and BMD, correlate with body size and vertebral size variables. (6) Likewise, an observed correlation between BMC and lean body mass in a subpopulation of 116 normal women was abolished when BMC_corr. replaced BMC. We suggest that vertebral compression fracture risk limits based on BMC, corrected for individual differences in body size and vertebral body size, replace the commonly used BMD fracture risk limits. The discriminatory ability of BMC_corr. for low-energy fractures needs to be tested in a different population.This investigation was carried out as part of a collaborative study by the Danish Osteoporosis Study Group (DOPS: O. Helmer Sørensen, L. Mosekilde, P. Charles, H. Beck-Nielsen and S. Pors Nielsen).     

Familial resemblance of radial bone mass between premenopausal mothers and their college-age daughters

Summary The influences of heredity and environmental factors on radial bone mass were evaluated in 84 premenopausal mothers with their biological daughters (ages 18–22). Mid- and distal radial bone mineral content (BMC) and density (BMD) were assessed using single-photon absorptiometry. As a group, the daughters (mean age 18.6 years) had 5–10% less bone mass at both the distal and midradial sites than their mothers (mean age 44.2 years). Familial resemblance estimates showed significant relationships between mothers and daughters for mid-and distal BMC and BMD after considering the influence of body mass index (BMI). Daughters with a maternal family history of osteoporosis had 6–7% lower but nonsignificant values of mid- (P=0.086) and distal BMC (P=0.075) compared to values of women with a negative family history, whereas mothers with a positive family history had 3–4% lower (NS) values of distal and mid-BMC compared to those of mothers with a negative family history after adjustment for BMI. Multiple regression analyses showed BMI to be the most important determinant of the bone values of the mothers, and both BMI and dietary calcium intake were found to be significant for the daughters. The findings of this study suggest that hereditary contributions from the mothers play an overwhelmingly critical role in the accrual of bone mass by their daughters by ages 18–22, but that environmental influences on bone consolidation during the premenopausal decades may be more important in promoting optimal (peak) bone mass and thereby may help to delay the postmenopausal onset of osteoporotic fractures.     

Age determines longitudinal changes in body composition better than menopausal and bone status: The OFELY study

Long‐term body composition (BC) changes and their determinants have been rarely explored. We aimed to evaluate BC changes in French women from the Os des Femmes de Lyon (OFELY) cohort and to explore several determinants of those changes. At baseline, premenopausal (PreM) women (n = 145) had lower fat body mass (FM) and greater lean body mass (LM), relative skeletal muscle mass index (RASM), and total body bone mineral content (TBBMC) compared with untreated postmenopausal (PostM) women (n = 412). During a 6‐year follow‐up, LM and RASM did not change, whereas a significant increase of FM and a decrease of TBBMC were observed in PreM (n = 88) and PeriM women (n = 44; women who became PostM during the follow‐up). In untreated PostM women, FM increased, whereas LM, RASM, and TBBMC decreased (p < 0.0001). Age was a significant determinant of the changes in BC. After controlling for age, menopausal status was still a significant determinant only for changes in TBBMC. FM, LM, RASM, and TBBMC were higher in women with normal bone mineral density (BMD) compared with women with osteopenia or osteoporosis (p < 0.0001), but after adjusting for age, changes of BC were not significantly different according to the bone status. After controlling for age and menopausal status, levels of P1NP in the highest quartile were associated with a greater decrease of LM and RASM compared with lower levels. In conclusion, BC changes in French women over a 6‐year follow‐up showed a high interindividual variability. Aging may be the most important determinant of changes in body composition, rather than menopausal and bone status. © 2012 American Society for Bone and Mineral Research     

Total and regional bone mineral content in women treated with GnRH agonists

Summary Changes in bone mineral content induced by GnRH agonists were investigated by measuring total body bone mineral content (TBBM) and regional bone mineral content (BMC) (arms, legs, trunk, pelvis) and densities with dual energy X-ray absorptiometry in 25 premenopausal women before and after a 6-month treatment with gonadotropin-releasing hormone (GnRH) agonists. Biological markers of bone remodeling, estrogens, luteinizing hormone, and follicle-stimulating hormone were also measured. Weight and body mass index increased significantly after treatment (P<0.05), and TBBM, corrected for weight (TBBM/W), decreased (P<0.001). The changes in BMC that we observed ranged from +2.5% to -6.9%. The greatest decrease in regional BMC occurred in the trunk (4.4%, P<0.001), with TBBM decreasing by 2.1% (P<0.001). No significant changes were observed in the limbs. Tartrate-resistant acid phosphatase (TRAP) increased significantly after treatment (P<0.001) and a significant negative correlation between TRAP and TBBM (P<0.001) and between TRAP and estradiol (P<0.001) were observed before treatment. The lack of changes observed in the BMC of the limbs indicate that GnRH agonists cause a preferential loss of BMC in trunk osseous structures, a situation similar to that of the first years of menopause.     

Bone mineral density measured by dual-energy X-ray absorptiometry in healthy finnish women

Summary A cross-sectional study of 351 healthy Finnish women aged 20–76 years was done to establish reference values of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA). The effects of age and of several physical and lifestyle factors on BMD of the lumbar spine and proximal femur (femoral neck, trochanter, and Ward's triangle area) were investigated. Altogether 58 women were excluded from the final analysis due to significant spinal osteoarthritis or other diseases or drugs known to influence calcium or bone metabolism. The precision of the method was 0.9, 1.2, 2.7, and 2.4% in the lumbar, femoral neck, Ward's triangle and trochanter area, respectively. Lumbar BMD was increased by 30% (P<0.001) in 15 patients with osteoarthritis (21% of women 50 years or older), but it was apparently unaffected in 5 cases with aortic calcification. Except for the trochanter area, BMD diminished along with age, and this was significant after the menopause. The peak of mean BMD was observed at the age of 31–35 years in the spine and at the age of 20–25 years in the femoral neck and Ward's triangle. BMD was in a positive relationship to weight both in premenopausal and postmenopausal women and to the use of oral contraceptives in premenopausal women and to that of estrogen replacement therapy in postmenopausal women. Labors and pregnancies had a weak positive effect on BMD in premenopausal women. As compared with nonusers premenopausal women who had used alcohol showed a slightly decreased BMD of Ward's triangle. In postmenopausal women there was a positive correlation between alcohol intake and BMD.     

Normative data and percentile curves for Dual Energy X-ray Absorptiometry in healthy Indian girls and boys aged 5-17 years

For the correct interpretation of Dual Energy X-ray Absorptiometry (DXA) measurements in children, the use of age, gender, height, weight and ethnicity specific reference data is crucially important. In the absence of such a database for Indian children, the present study aimed to provide gender and age specific data on bone parameters and reference percentile curves for the assessment of bone status in 5-17 year old Indian boys and girls. A cross sectional study was conducted from May 2006 to July 2010 on 920 (480 boys) apparently healthy children from schools and colleges in Pune City, India. The GE-Lunar DPX Pro Pencil Beam DXA scanner was used to measure bone mineral content (BMC [g]), bone area (BA [cm(2)]) and bone mineral density (BMD [g/cm(2)]) at total body, lumbar spine and left femur. Reference percentile curves by age were derived separately for boys and girls for the total body BMC (TBBMC), total body BA (TBBA), lumbar spine bone mineral apparent density (BMAD [g/cm(3)]), and left femoral neck BMAD. We have also presented percentile curves for TBBA for height, TBBMC for TBBA, LBM for height and TBBMC for LBM for normalizing bone data for Indian children. Mean TBBMC, TBBA and TBBMD were expressed by age groups and Tanner stages for boys and girls separately. The average increase in TBBMC and TBBA with age was of the order of 8 to 12% at each age group. After 16 years of age, TBBMC and TBBA were significantly higher in boys than in girls (p<0.01). Maximal increase in TBBMD occurred around the age of 13 years in girls and three years later in boys. Reference data provided may be used for the clinical assessment of bone status of Indian children and adolescents.     

Idiopathic juvenile osteoporosis – an analysis of the muscle-bone relationship

Introduction Idiopathic Juvenile Osteoporosis (IJO), a disease of unknown etiology, manifests typically by pain, bone deformities and fractures. Due to limits in BMD data interpretation, evaluation of the muscle-bone functional unit has recently been proposed as a means to assess the general competence of the skeleton. The aim of this study was to evaluate skeletal status during the acute phase of IJO and during recovery from the disease in relation to muscles.Materials and methods The study population comprised 61 IJO children, including 34 girls (mean age: 13.6±3.1 years; range: 7–18) and 27 boys (14.3±3.3; 5–18 years). DXA total body (TB) and lumbar spine (S) bone mineral content (BMC) and density (BMD) were measured. Lean body mass (LBM) was employed to calculate SBMC/LBM, TBBMC/LBM, body height (BH)/LBM and LBM/body weight (BW) ratios. Previously established references for healthy controls were utilized for the calculation of Z-score values in IJO cases in respect to phase of the disease.Results IJO patients had significantly decreased Z-score values for TBBMD, SBMD, SBMC/LBM and TBBMC/LBM ratios but not for the LBM and BH/LBM or LBM/BW ratios. During the acute phase IJO girls had mean Z-scores for TBBMD and SBMD of −2.49±0.61 and −3.27±1.03, respectively, which were significantly lower than Z-scores during the recovery phase: −0.90±0.66, −1.38±0.95 (p<0.0001). IJO boys during the acute phase had Z-scores of −2.08±0.65 and −2.75±1.19 for TBBMD and SBMD, respectively, which were significantly lower than those during the recovery phase (−0.51±1.04 and −1.39±1.49; p<0.0001). Further, during the acute phase, TBBMC/LBM Z-scores of −2.95±1.15 and −2.56±1.49 were noted in girls and boys, respectively; the corresponding SBMC/LBM Z-scores were −2.66±1.07 and −2.22±1.62. During the recovery from IJO, TBBMC/LBM and SBMC/LBM Z-scores of −1.07±0.99 and −0.91±1.16 and of −1.15±1.40 and −0.68±1.45 were noted in girls and boys, respectively, and all were significantly higher than those during the acute phase (p<0.0001).Conclusions The results of this study indicate that IJO is a bone disorder characterized by an imbalanced muscle-bone relationship and fractures at onset and during the acute phase and by at least a partial recovery without bone pain and new fractures. Implementation of the BH/LBM, TBBMC/LBM and SBMC/LBM ratios to the armamentarium of pediatricians diagnosing bone disorders will provide mechanically meaningful data for diagnostic purposes and, hopefully, for proper therapeutic decisions.This study was in part financially supported by the International Osteoporosis Foundation.     

正常中国妇女前臂骨量及骨代谢生化指标及与丹麦妇女的比较

观察正常中国妇女前臂骨量和骨代谢生化指标及其与丹麦妇女的比较。对２０～８０岁，每岁５名，共３０５名正常妇女以单能Ｘ线吸收法测量非常用侧前壁１／４远端、８ｍｍ远端及超远端的骨量和骨密度。骨形成指标为血清骨钙素（ＯＣ）及碱性磷酸酶（ＡＬＰ），骨吸收指标为空腹晨两小时尿Ｉ型胶原降解物／肌酐（Ｔｙｐｅ１／Ｃｒ）和钙／肌酐（Ｃａ／Ｃｒ）。结果：绝经后比绝经前骨量明显减少，１／４远端减少１５％，８ｍｍ远端为２５％，超远端为３５％。５０岁时我国妇女骨量与丹麦相似，但５０岁后，我国妇女骨加速丢失的速度似较快。骨的加速丢失出现在绝经后１０～１５年内，此后稳定约５～１０年。在绝经的最初５年内，含松质骨较多的部位（超远端）骨丢失最多，为１６．２％。绝经后骨转换指标明显高于绝经前，与骨量呈负相关。本研究取得了正常中国妇女前臂三个部位的骨量。与丹麦妇女比较表明，东西方妇女骨量与骨代谢规律相似，但有一定差异。     

Bone density of the radius,spine, and hip in relation to percent of ideal body weight in postmenopausal women

Summary Bone mineral content (BMC) and bone mineral density (BMD) of the spine (L2–L4) and hip (at femoral neck, Ward's triangle, and greater trochanter sites) were determined by dual-photon absorptiometry (DPA), and of the radius by single-photon absorptiometry (SPA) in healthy postmenopausal women aged 40–70 years. The relationships of BMC and BMD to years since menopause were examined separately in 97 women who were above 115% of ideal body weight (IBW) and in 128 women below. The heavier women had significantly greater mean BMC and BMD at each site than did the normal-weight women. In the normal-weight women, there was a significant negative correlation between BMD and years since menopause at each measurement site except the greater trochanter. In the obese women, BMD decreased with increasing years since menopause at the radius site only and BMC declined with increasing years after menopause at the hip (femoral neck and Ward's triangle region) as well as the radius. Thus, body size is a significant determinant of BMD in this population. The pattern of loss of BMD from Ward's triangle and femoral neck regions of hip are similar to that of the spine. The BMC and BMD findings in the hip suggest that remodeling occurs at this weight-bearing site which has a favorable effect on bone strength.     

Fat mass is negatively associated with bone mineral content in Koreans

Summary

Although obesity and osteoporosis are important public health problems, the effect of fat mass on bone mass remains controversial. This study demonstrated that fat mass was inversely related to bone mineral content, and abdominal obesity was significantly associated with bone mineral content independent of total fat mass.

Introduction

Obesity and osteoporosis, two disorders of body composition, have become increasingly important public health problems throughout the world. However, the effect of fat mass on bone mass remains controversial. This study investigates the effect of fat mass and regional fat distribution on bone mass within a community-dwelling cohort.

Methods

A total of 3,042 subjects (1,284 men, 362 premenopausal women, and 1,396 postmenopausal women) were studied. Fat mass, percent fat mass, lean mass, percent lean mass, and bone mineral content (BMC) were measured by dual energy X-ray absorptiometry.

Results

Fat mass and percent fat mass decreased significantly across increasing tertiles of BMC in all three subgroups (men, premenopausal and postmenopausal women). In contrast, lean mass and percent lean mass increased significantly across tertiles of BMC in men, and a similar trend was also identified in postmenopausal women. Interestingly, although correlation analysis showed a positive association between fat mass and BMC (p?p?p?Conclusion This study demonstrated that fat mass was inversely related to BMC after removing the mechanical loading effect in Korean men and women. Moreover, abdominal obesity as measured by WC was significantly associated with BMC independent of total fat mass.