Volumetric bone mineral density using peripheral quantitative computed tomography in Japanese women

The present study evaluated a commercial device for peripheral quantitative computed tomography (pQCT) and examined the age-related changes in normal Japanese women. The volumetric bone mineral density (vBMD) of the distal radius [integral bone mineral density (BMD_I), trabecular bone mineral density (BMD_T) and cortical with subcortical bone mineral density (BMD_SC)] was measured using pQCT (Norland-Stratec XCT960) in 617 healthy women aged 20–79 years and 75 subjects with osteoporosis aged 60–89 years who exhibited at least one vertebral fracture. The short-term precision errors in vivo (CV, %) were 1.1% for BMD_I 1.1% for BMD_T and 1.2% for BMD_SC. The correlations between pQCT and dual-energy X-ray absorptiometry measurements (Lunar DPX) of the lumbar spine werer0.8 (BMD_I, BMD_T and BMD_SC). The maximal mean vBMD values were observed between 20 and 49 years; BMD_I BMD_T and BMD_SC all showed a linear postmenopausal decline averaging 1.1% per year. The overall decreases in vBMD from the peak values in those 70–79 years were 34%, 32% and 33% in BMD_I, BMD_T and BMD_SC, respectively. The diagnostic sensitivity of osteoporosis was expressed as aT-score.T-scores using pQCT were –3.0 (BMD_I), –2.4 (BMD_T) and –2.9 (BMD_SC). Bone mineral measurement of the distal radius may be useful in the evaluation of age-related bone loss and for the diagnosis of osteoporosis.     

Discordance in lumbar bone mineral density measurements by quantitative computed tomography and dual-energy X-ray absorptiometry in postmenopausal women: a prospective comparative study

Background ContextLevel-specific lumbar bone mineral density (BMD) evaluation of a single vertebral body can provide useful surgical planning and osteoporosis management information. Previous comparative studies have primarily focused on detecting spinal osteoporosis but not at specific levels.PurposeTo compare the detection rate of lumbar osteoporosis between quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA); to explore and analyze the distribution models of QCT-derived BMD and DXA T-score at the specific levels; and to evaluate the diagnostic accuracy of level-specific BMD thresholds for the prediction of osteoporotic vertebral compression fracture (OVCF) in postmenopausal women.Study Design/SettingA comparative analysis of prospectively collected data comparing QCT-derived BMD with DXA T-score.Patient SampleA total of 296 postmenopausal women who were referred to the spine service of a single academic institution were enrolled.Outcome MeasuresQCT-derived BMD and DXA T-score at specific levels, with or without osteoporotic vertebral compression fracture.MethodsPostmenopausal women who underwent QCT and DXA within a week of admission from May 2019 to June 2022 were enrolled. The diagnostic criteria for osteoporosis recommended by the World Health Organization and the American College of Radiology were used for lumbar osteoporotic diagnosis. To evaluate differences in lumbar BMD measurements at specific levels, a threshold of T score=-2.5 and QCT-derived BMD = 80 mg/cm³ were used to categorize level-specific lumbar BMD into low and high BMD. Disagreements in BMD categorization between DXA and QCT were classified as a minor or major discordance based on the definition by Woodson. Data between QCT and DXA were visualized in a stacked bar plot and analyzed. Correlations between DXA and QCT at the specific levels were evaluated using Pearson's linear correlation and scatter plots. Curve fitting of BMD distribution, receiver operating characteristic (ROC) and area under the curve (AUC) for each single vertebral level was performed.ResultsOf the 296 patients, QCT diagnosed 61.1% as osteoporosis, 30.4% as osteopenia and 8.4% as normal. For those screened with DXA, 54.1% of the patients had osteoporosis, 29.4% had osteopenia and 16.6% had normal BMD. Diagnoses were concordant for 194 (65.5%) patients. Of the other 102 discordant patients, 5 (1.7%) were major and 97 (32.8%) were minor. Significant correlations in level-specific BMD between DXA and QCT were observed (p<.001), with Pearson's correlation coefficients ranging from 0.662 to 0.728. The correlation strength was in the order of L1 > L2 > L3 > L4. The low BMD detection rate for QCT was significantly higher than that for DXA at the L3 and L4 levels (65% vs. 47.9% and 68.1% vs 43.7, respectively, p<.001). Patients with OVCF showed significantly lower QCT-derived BMD (47.2 mg/cm³ vs. 83.2 mg/cm³, p<.001) and T-score (-3.39 vs. -1.98, p<.001) than those without OVCF. Among these patients, 82.8% (101/122) were diagnosed with osteoporosis by QCT measurement, while only 74.6% (91/122) were diagnosed by DXA. For discrimination between patients with and without OVCF, QCT-derived BMD showed better diagnosed performance (AUC range from 0.769 to 0.801) than DXA T-score (AUC range from 0.696 to 0.753).ConclusionQCT provided a more accurate evaluation of lumbar osteoporosis than DXA. The QCT-derived BMD measurements at a specific lumbar level have a high diagnostic performance for OVCF.     

Distribution of bone density and cortical thickness in the proximal femur and their association with hip fracture in postmenopausal women: a quantitative computed tomography study

Summary

The quantitative computed tomography (QCT) scans in an individually matched case–control study of women with hip fracture were analysed. There were widespread deficits in the femoral volumetric bone mineral density (vBMD) and cortical thickness of cases, and cortical vBMD and thickness discriminated hip fracture independently of BMD by dual-energy X-ray absorptiometry (DXA).

Introduction

Acknowledging the limitations of QCT associated with partial volume effects, we used QCT in an individually matched case–control study of women with hip fracture to better understand its structural basis.

Methods

Fifty postmenopausal women (55–89 years) who had sustained hip fractures due to low-energy trauma underwent QCT scans of the contralateral hip within 3 months of the fracture. For each case, postmenopausal women, matched by age (±5 years), weight (±5 kg) and height (±5 cm), were recruited as controls. We quantified cortical, trabecular and integral vBMD and apparent cortical thickness (AppCtTh) in four quadrants of cross-sections along the length of the femoral head (FH), femoral neck (FN), intertrochanter and trochanter and examined their association with hip fracture.

Results

Women with hip or intracapsular (IC) fracture had significantly (p?<?0.05) lower vBMD and AppCtTh than the controls in the majority of cross-sections and quadrants of the proximal femur, and both cortical and trabecular compartments are involved. Cortical vBMD and AppCtTh in the FH and FN were associated with hip and IC fractures independent of hip areal BMD (aBMD). The combination of AppCtTh and trabecular or integral vBMD discriminated hip fracture, whereas the combination of FH and FN AppCtTh discriminated IC fracture significantly (p?<?0.05) better than the hip aBMD.

Conclusion

Deficits in vBMD and AppCtTh in cases were widespread in the proximal femur, and cortical vBMD and AppCtTh discriminated hip fracture independently of aBMD by DXA.     

Leisure physical activity is associated with quantitative ultrasound measurements independently of bone mineral density in postmenopausal women

The purpose of this study was to assess the magnitude of the relationship between leisure physical activity and bone status as measured either by an Achilles^TM ultrasound bone densitometer (QUS) or dual-energy X-ray absorptiometry (DXA) in postmenopausal women. We studied 1162 French Canadian postmenopausal women, aged 33–84 years (mean age 58 years), for QUS parameters [broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI)] measured at the right calcaneus, and bone mineral density (BMD) measured at the lumbar spine and femoral neck. Multivariate regression analyses revealed that leisure physical activity level was an independent predictor of the heel QUS parameters and of femoral neck BMD. No such association was observed for BMD of the lumbar spine. Heel QUS parameters (BUA, SOS, SI) and femoral neck BMD adjusted for interfering covariables showed a statistically significant difference between sedentary (less than three sessions/month) and active women (three or more sessions/week) (P 0.001). Furthermore, after adjusting each heel QUS parameters for the mean lumbar spine BMD value, the association observed between leisure physical activity and QUS remained significant. These results suggest that regular leisure physical activity could influence QUS parameters, independently of BMD, and that quantitative ultrasound could be a suitable outcome measure in exercise studies in postmenopausal women.     

Gender differences in normal age-dependent patterns of radial bone structure and density: a cross-sectional study using peripheral quantitative computed tomography.

This cross-sectional study determines gender differences in the age-dependent patterns in radial trabecular bone structure using high-resolution peripheral quantitative computed tomography. The nondominant forearrns of 145 adult volunteers (57 men) were scanned and indices of trabecular structure (connectivity index [CI]; mean hole size [H(A)]; and maximum hole size [H(M)]) were determined at the ultradistal radius. The images were also analyzed to determine bone density. Men had significantly higher values for CI (p < 0.01), significantly lower values for H(A) (p < 0.01), and significantly greater bone density (p < 0.001) than women. Age-dependent patterns in normal trabecular structure also displayed gender differences. CI decreased significantly with age in both men (-0.8%/yr, p < 0.05) and women &lpar-2.2%/yr, p < 0.001); however, the rate of change was more pronounced in women (p < 0.001). Similarly, the age-related increase in H(A) (+2.2%/yr) and H(M) (+1.1%/yr) was significant in women (p < 0.01) but not in men. In both sexes, when expressed as an annual percentage of change, indices of trabecular bone structure changed to a greater extent than indices of bone density. The assessment of structural indices may improve our ability to identify individuals at risk for fractures of the distal radius.     

Accuracy of volumetric bone mineral density measurement in high-resolution peripheral quantitative computed tomography

Accurate bone mineral density (BMD) quantification is critical in clinical assessment of fracture risk and in the research of age-, disease-, and treatment-related musculoskeletal changes. The development of high-resolution peripheral quantitative computed tomography (HR-pQCT) imaging has made possible in vivo assessment of compartmental volumetric BMD (vBMD) and bone micro-architecture in the distal radius and tibia. HR-pQCT imaging relies on a polychromatic X-ray source and therefore is subject to beam hardening as well as scatter artifacts. In light of these limitations, we hypothesize that the accuracy of HR-pQCT vBMD measurement in the trabecular compartment (vBMD_trab) is not independent of bone density and geometry, but rather influenced by variations in trabecular bone volume fraction and cortical thickness. The goal of this study, therefore, was to evaluate the accuracy of HR-pQCT vBMD_trab measurement in the radius and tibia, and to determine the dependence of this measurement on geometric and densitometric parameters. Our approach was to use a series of idealized hydroxyapatite (HA) phantoms with varying densities and geometries to quantify the accuracy of HR-pQCT analysis. Two sets of custom-made HA phantoms designed to mimic the distal tibia and distal radius were manufactured. Geometric and densitometric specifications were based on a dataset of healthy volunteers and osteopenic patients. Multiple beam hardening correction (BHC) algorithms were implemented and evaluated in their ability to reduce measurement error. Substantial errors in measured vBMD_trab were found. Overestimation of vBMD_trab increased proportional to cortical shell thickness and decreased proportional to insert density. The most pronounced vBMD_trab overestimation therefore occurred in the phantoms with the lowest insert densities and highest shell thickness, where error was as high as 20 mg HA/cm³ (33%) in the radius phantom and 25 mg HA/cm³ (41%) in the tibia phantom. Error in vBMD_trab propagates to the calculation of micro-architectural measures; 41% error in vBMD_trab will produce 41% error in volume fraction (BV/TV) and trabecular thickness (Tb.Th), and 5% error in trabecular separation (Tb.Sp). BHC algorithms supplied by the manufacturer failed to eliminate these errors. Our results confirm that geometric and densitometric variations influence the accuracy of HR-pQCT vBMD_trab measurements, and must be considered when interpreting data across populations or time-points.     

The effect of calcium intake and physical activity on bone quantitative ultrasound measurements in children: a pilot study

Environmental factors, such as nutritional status, physical activity, and drug therapy, can affect bone mineralization. Our objective was to evaluate the relationship between nutritional status, physical activity, and bone mineralization as assessed by multisite quantitative ultrasound technology in children. The study group comprised 67 children, aged 6–17 years (mean, 9.4), attending a primary care clinic. Data on calcium intake and physical activity were collected using a detailed questionnaire. Speed of sound measurements were performed at the distal 1/3 radius and the midshaft tibia using Sunlight Omnisense apparatus. The reported mean calcium intake was 1105 mg/day. There was a significant difference in Z-scores at the radius and tibia between the low-and high-calcium-intake groups (P = 0.004, P = 0.035, respectively). A similar difference was found between the low-and normal-physical-activity groups (P = 0.015, P = 0.036, respectively). In this pilot study, a positive association was found between calcium intake, physical activity, and bone status, as assessed by the quantitative ultrasound technique.     

Reduced bone mineral density in postmenopausal women self-reporting premenopausal wrist fractures

Postmenopausal fractures are associated with low bone mass; however, the role of low peak bone mass in young adults in determining subsequent osteoporosis suggests that premenopausal fractures may also be relevant. We therefore sought to determine whether a self-reported previous history of premenopausal wrist and nonwrist fractures could also be associated with bone density and therefore be used to predict osteoporosis. We recruited 453 volunteer women with a median age of 64 years (range 50-83 years), with no metabolic bone disease, previous femoral neck fracture, or prevalent vertebral fracture. Bone density at the femoral neck (FN) and lumbar spine (LS) was measured using a Lunar DPX-L. As expected, the 319 women who did not report any fracture had a higher T score at LS (-0.93 +/- 1.44) than the 134 women who reported a previous fracture at any site and at any age (T score -1.60 +/- 1.21, p < 0.001). The findings for the FN were similar. Compared with fracture-free women, the women who reported a first wrist fracture before menopause now had a lower LS T score (-1.77 +/- 1.20, n = 15, p < 0.05), whereas those who reported a nonwrist fracture showed no significant decrease in their LS T score (-1.26 +/- 1.00, n = 36). When both wrist and nonwrist fractures had occurred after menopause, the T score was significantly lower. Twenty percent of the fracture-free women were osteoporosis patients. After adjusting for body weight, age, hormonal replacement therapy (HRT), and hip fracture in the family, the relative risk (RR) of osteoporosis for premenopausal wrist fractures was 2.7 (95% confidence interval 1.4-4.3) vs. 1.2 (0.7-2.4) for women with premenopausal nonwrist fractures. We conclude that self-reported premenopausal wrist fractures, but no other fractures occurring before menopause, are likely to be associated with osteoporosis at 65 years of age, and therefore constitute strong grounds for screening.     

Exercise-induced bone gain is due to enlargement in bone size without a change in volumetric bone density: a peripheral quantitative computed tomography study of the upper arms of male tennis players

Bilateral bone characteristics of the humerus (proximal, shaft, and distal sites) and radius (shaft and distal sites) in 12 former Finnish national-level male tennis players (mean age 30 years) and their 12 age-, height-, and weight-matched controls were measured with peripheral quantitative computed tomography (pQCT). The pQCT variables analyzed were bone mineral content (BMC), total cross-sectional area of bone (Tot.Ar), cross-sectional area of the marrow cavity (M.Cav.Ar), cortical bone (Co.Ar) and trabecular bone (Tr.Ar), volumetric density of cortical (Co.Dn) and trabecular (Tr. Dn) bone, cortical wall thickness (Co.Wi.Th), bone strength index (BSI), and principal moments of inertia (I(min) and I(max)). In the players, significant side-to-side differences, in favor of the dominant (playing) arm, were found in BMC (ranging 14%-27%), Tot.Ar (16%-21%), Co.Ar (12%-32%), BSI (23%-37%), I(min) (33%-61%), and I(max) (27%-67%) at all measured bone sites, and in Co.Wi.Th. (5%-25%) at the humeral and radial shafts, and distal humerus. The side-to-side M.Cav.Ar difference was significant at the proximal humerus (19%) and radial shaft (29%). Concerning the players' Co.Dn and Tr.Dn, the only significant side-to-side difference was found in the Co.Dn of the distal humerus, with the playing arm showing a slightly smaller Co.Dn than the nonplaying arm (-2%). In controls, significant dominant-to-nondominant side differences were also found, but with the majority of the differences being rather small, and significantly lower than those of the players. In conclusion, despite the large side-to-side differences in BMC, the volumetric bone density (Co.Dn, Tr.Dn) was almost identical in the dominant and nondominant arms of the players and controls. Thus, the players' high playing-arm BMC was due to increases in the Tot.Ar, M.Cav.Ar, Co.Ar, and CW.Th. In other words, the playing arm's extra bone mineral, and thus increased bone strength, was mainly due to increased bone size and not due to a change in volumetric bone density. These upper arm results may not be generalized to the entire skeleton, but the finding may give new insight into conventional dual-energy X-ray absorptiometry (DXA)-based bone density measurements when interpreting the effects of exercise on bone.     

Bone structure and volumetric density in young adults born prematurely: a peripheral quantitative computed tomography study

Prematurity is known to be associated with reduced bone mineral density (BMD) in childhood, but whether this condition has long-term detrimental consequences on adult bone structure is not known. In this study, we measured with peripheral quantitative computed tomography (pQCT) the total bone cross-sectional area, cortical area and wall thickness, cortical and trabecular density, and a density-weighed polar section modulus as a bone strength index (BSI) at distal and shaft sites of right radius and tibia in a group of 40 prematurely born, otherwise normally developed and healthy young adults (17 women and 23 men, aged 18 to 27 years) and compared their data to corresponding data obtained from a group of 42 control subjects born term (20 women and 22 men, aged 18 to 28 years). Body height and weight were similar in both groups, but the preterm group had significantly lower BSI values at distal sites of tibia (approximately -16%) and radius (approximately -13%) and at tibial shaft (approximately -11%) as compared to control group. In the weight-bearing tibia, BMC was lower and the lower BSI values were mainly due to smaller total bone cross-sectional area. For unknown reason, this prematurity-associated detrimental effect seemed to concern more men than women. In contrast, prematurity was not associated with volumetric trabecular and cortical densities at any measured bone site while the typical sex differences in bone density were observed. We conclude that prematurity is associated with somewhat smaller cross-sectional bone dimensions in terms of body size in young adulthood. Due to the cross-sectional design, this study could not reveal specific reasons but they may pertain to nutrition during the neonatal period and living habits in general.     

Bone densities and bone size at the distal radius in healthy children and adolescents: a study using peripheral quantitative computed tomography

Peripheral quantitative computed tomography (pQCT) has the ability to improve the diagnostic utility of densitometry in children and adolescents, because bone size and volumetric bone mineral density (vBMD) can be measured independently. Nevertheless, detailed reference data are lacking. We therefore performed pQCT (XCT-2000 scanner, Stratec, Inc., Pforzheim, Germany) at the distal radius in 371 healthy children, adolescents, and young adults (185 males and 186 females, ages 6-23 years) and in 107 of their parents (19 men and 88 women, ages 29-40 years). Total vBMD, trabecular, and "cortical + subcortical" vBMD as well as cross-sectional area (CSA) were determined at the "4% site" of the distal radius. This location was defined as the site whose distance to the most distal portion of the growth plate or to the radial articular surface corresponded to 4% of the forearm length. In both genders, total vBMD remained stable between 6 and 15 years of age and then increased by 30% in girls and by 46% in boys. Regarding pubertal development, total vBMD remained almost constant throughout pubertal stages 1-4 and thereafter increased in both genders. Trabecular vBMD did not change with age in girls, whereas in boys an increase with age of about 10% was noted after 15 years of age. Males had higher trabecular vBMD than females. This gender difference increased from 6% in prepubertal children to 23% in adults. The variation with age and pubertal stage in "cortical + subcortical" vBMD-cort was similar to that of total vBMD. CSA roughly doubled between 6 and 15 years of age in both genders. In conclusion, the availability of this reference material will provide a basis for the use of pQCT in the assessment of pediatric bone diseases.     

Abnormal bone quality versus low bone mineral density in adolescent idiopathic scoliosis: a case-control study with in vivo high-resolution peripheral quantitative computed tomography

Background contextAdolescent idiopathic scoliosis (AIS) is associated with low bone mass that could persist into early adulthood and is an important prognostic factor for curve progression. Previous studies were confined to areal bone mineral density measurement that was a two-dimensional investigation for a three-dimensional structure. Evaluation of volumetric BMD (vBMD) and other bone quality parameters are important for gaining in-depth understanding of the etiopathogenesis of AIS.PurposeThe objective of this study was to carry out direct in vivo measurement of bone quality in AIS using high-resolution peripheral quantitative computed tomography (HR-pQCT) and compare the correlation of bone quality with osteopenia between AIS and control subjects.Study design/settingA case-control study.Patient sampleNewly diagnosed AIS girls (n=112) and non-AIS girls (n=115) between 11 and 13 years.Outcome measuresAreal bone mineral density of bilateral femoral necks and HR-pQCT of the nondominant distal radius were performed.MethodsAreal bone mineral density of femoral necks was measured by dual-energy X-ray absorptiometry. Subjects were classified into the osteopenic (Z score less than or equal to ?1) and nonosteopenic (Z score more than ?1) groups. Bone quality parameters, including bone morphometry, trabecular bone microarchitecture, and vBMD, were measured by HR-pQCT (XtremeCT; Scanco Medical, Zurich, Switzerland).ResultsIn AIS, the osteopenic group had lower measurements in cortical area, cortical thickness, average vBMD, compact bone vBMD, trabecular vBMD, trabecular bone volume to tissue volume ratio, and trabecular thickness compared with nonosteopenic AIS subjects. In contrast, among the non-AIS controls, the osteopenic group had lower measurements only in bone morphometry, average vBMD, and compact bone vBMD but not in trabecular vBMD and all other trabecular bone microarchitecture parameters.ConclusionsThis is the first study using HR-pQCT to compare the correlation of bone quality with osteopenia in AIS and non-AIS subjects. It provides new insights and highlights the unique bone quality profile with predominant changes in the trabecular compartment in association with osteopenia being notably only detected in the AIS subjects. Further studies in this area are warranted for defining the metabolic nature and biomechanical sequelae of derangement in bone mass and bone quality and their roles in the etiopathogenesis of AIS.     

Spinal bone mineral assessment in postmenopausal women: A comparison between dual X-ray absorptiometry and quantitative computed tomography

We compared quantitative computed tomography (QCT) and dual X-ray absorptiometry (DXA) with respect to their ability to discriminate subjects with and without prevalent vertebral fractures. In 240 post-menopausal women (mean age 63.7±6.9 years) lateral spine radiographs (T4-L4) were reviewed for the presence of vertebral fracture. Using a semiquantitative technique to grade the severity of vertebral deformities, we classified fractures as mild, moderate or severe (grade 1 to 3, respectively). Postero-anterior DXA (PA-DXA) and lateral DXA (L-DXA) measurements (L2–4) as well as QCT measurements of the lumbar spine (T12-L3 or L1–14) were obtained in all women. Seventy-two women were diagnosed with at least one fracture, and of these 40 were graded as mild. Comparing normal women with fractured women, we found the area under the receiver operating characteristics (ROC) curves to be greatest for QCT (0.81), followed by L-DXA (0.72) and PA-DXA (0.65). The differences among all three techniques were significant. Comparing the normal women with women having only mild fractures, the areas under the ROC curves were 0.79, 0.73 and 0.63 for QCT, L-DXA and PA-DXA, respectively. Significant differences existed between QCT and PA-DXA as well as between L-DXA and PA-DXA. Logistic regression analysis also revealed the highest age-adjusted odds ratios for QCT (3.67; 2.25–5.97) while L-DXA and PA-DXA showed substantially lower odds ratios (2.00; 1.39–2.87, and 1.54; 1.11–2.15, respectively). We conclude that low bone density as measured by QCT, PA-DXA or L-DXA is significantly associated with the prevalence of vertebral fractures. Of the methods studied, QCT of trabecular bone offered the best discriminatory capability. L-DXA proved to be superior to PA-DXA in its diagnostic sensitivity, particularly in women with mild fracture. Mild vertebral fractures are associated with decreased spinal bone density and may be regarded as osteoporotic deformities.     

Sarcopenia in premenopausal and postmenopausal women with osteopenia, osteoporosis and normal bone mineral density

Sarcopenia, the decline of muscle mass with age, causes impaired gait, disability and falls. It may therefore increase the risk of fracture for osteoporotic women. The aims of this study were to determine the prevalence of sarcopenia in osteopenic and osteoporotic women, and to determine if hormone replacement therapy (HRT), diet, or physical activity (PA) has a role in the prevention of sarcopenia. One hundred and thirty-one premenopausal and 82 postmenopausal (54 taking HRT) healthy women (17–77 years) volunteered for the study. Body composition was measured by dual X-ray absorptiometry (DXA). Sarcopenia was defined as a relative skeletal muscle index (RSMI) (appendicular skeletal muscle mass divided by height) below 5.45 kg/m². Osteopenia was defined by a densitometric t -score for bone mineral density (BMD) (g/cm²) below –1.0 and osteoporosis by a t -score below –2.5. Nutrient intake was assessed using 3-day food records and physical activity (PA) was measured using the Baecke Physical Activity Questionnaire. Pearson chi-squared, independent t -tests, simple correlation and multiple regression were used to analyze the data. In premenopausal osteopenic women the prevalence of sarcopenia was 12.5%. In postmenopausal women it was 25% for those with osteopenia, and 50% for those with osteoporosis. PA was independently related to RSMI (=0.222, p =0.0001), but diet and HRT were not. After adjusting for PA, RSMI was not significantly related to BMD. These data suggest that the relationship between RSMI, BMD and risk of osteoporosis may largely be mediated through participation in PA. Sarcopenia screening simultaneous to BMD examinations by DXA, may be of value in identifying osteoporotic women with sarcopenia, a group that may be most in need of exercise interventions to increase muscle and BMD.     

Decreased tibial bone strength in postmenopausal women with aseptic loosening of cemented femoral implants measured by peripheral quantitative computed tomography (pQCT)

Aseptic loosening after total hip arthroplasty is related to bone loss of the operated leg. The aim of the present study was to investigate the effect of aseptic loosening on volumetric bone mineral density (vBMD) and bone geometry in the operated leg, in postmenopausal women with a loosened cemented femoral implant using peripheral quantitative computed tomography (pQCT). We matched 12 postmenopausal women with aseptic loosening of cemented femoral implant, with 12 women without aseptic loosening (control group) according to age, BMI, and years from operation. All patients underwent pQCT of both tibias, DXA of the lumbar spine, and determination of biochemical markers of bone turnover. pQCT values in the control group as well as the nonoperated legs between groups had no significant difference. In the aseptic loosening group, there was significant reduction of cortical vBMD (cort vBMD) at 14% and 38% sites (cortical site), cortical thickness at 38% site, and of polar stress strength index (SSIp) at 14% site (transition zone) in the operated compared with the nonoperated leg. Similarly, there was significant reduction of cort vBMD at 14% and 38% sites and total vBMD and trabecular vBMD (trab vBMD) at the 14% site in the operated legs between the two groups. The aseptic loosening group had increased osteocalcin and serum collagen cross-linked N- and C-telopeptides (sNTX and sCTX) levels compared with controls. Aseptic loosening is associated with significant decrease of cortical and trabecular vBMD, and impairment of bone geometry and strength only in the operated leg. Increased bone turnover probably represents a local phenomenon, and is not associated with systemic skeletal disease.     

Differences in hip quantitative computed tomography (QCT) measurements of bone mineral density and bone strength between glucocorticoid-treated and glucocorticoid-naïve postmenopausal women

Chronic treatment with glucocorticoids (GCs) leads to significant bone loss and increased risk of fractures. In chronically GC-treated patients, hip fracture risk is nearly 50%. The purpose of this investigation was to determine if there are differences in the quantities of trabecular and cortical bone and bone strength of the hip between GC-treated osteoporotic patients and controls. Methods: Study subjects were GC-treated osteoporotic postmenopausal women, and controls were postmenopausal women, recruited for separate clinical trials. Quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA) of the hip were obtained from all subjects. QCT outcome variables measured included total, cortical, and trabecular BMD of hip subregions (femoral neck and trochanter) and total hip. In addition, finite element modeling (FEM) was performed on a subset of 19 cases and 38 controls, matched on age (± 5 years), weight (± 5 kg), and history of hormone replacement (>1 year use) to assess failure load in stance and fall loading conditions. Generalized linear models were used to adjust the QCT variables for covariates between groups. Multiple regression was performed to identify independent predictors of bone strength from the QCT variables. Results: Compared with controls, GC-treated subjects were significantly (p<0.05) younger, weighed less, and had more years of hormone replacement. QCT of the hip in GC-treated subjects for total femoral integral, cortical, and trabecular BMD averaged 4.9–23.2% (p<0.002) less than controls, and similar results were seen by hip subregion including the trochanter and femoral neck. DXA of the total hip was 17% lower in GC subjects than controls (p<0.05). Compared with controls, FEM failure load in GC subjects was 15% (p<0.05) and 16% (p=0.07) lower for stance and fall loading conditions, respectively. Multiple regression analysis demonstrated that a combination of QCT measures was correlated with bone strength as measured by FEM. Conclusions: Chronic GC treatment in postmenopausal women resulted in significantly decreased BMD of the hip, measured by QCT, with loss of both trabecular and cortical bone. In addition, GC treatment decreased bone strength as determined by FEM. The reduced cortical and trabecular bone mass in the hip may contribute to the disproportionately high hip fracture rates observed in GC-treated subjects.This work was supported by grants from the NIH 1R01AG05407, 1R01AR40431, 1R01AR46197, the Doris Duke Clinical Research Fellowship (CRF) Program for Medical Students (#20000684) K24AR048841-02 and the Rosalind Russell Arthritis Foundation.     

Leisure-time physical activity and rate of bone loss among peri- and postmenopausal women: a longitudinal study.

We examined the association between continuous leisure-time physical activity and the change in bone mineral density (BMD) and bone mineral content (BMC) in a population-based random sample of 1873 peri- and postmenopausal women. Leisure-time physical activities were registered with self-administered questionnaires in 1989 and 1994, and with an assisted questionnaire in 1995-1997. BMD and BMC were measured from lumbar vertebrae L2-4 and left femoral neck using dual-energy X-ray absorptiometry (DXA) in 1989-1991 and 1994-1997. During the average 5.6 year follow-up, annual loss of lumbar BMC was 124 mg (311 vs. 435 mg, p = 0.036) and annual loss of lumbar BMD was 1.22 mg/cm(2) (4.15 vs. 5.37 mg/cm(2), p = 0.21) smaller among women with regular (at least 1 h each week) weight-bearing leisure-time exercise compared with sedentary women. The advantage was even larger in women with walking or jogging as their only regular weight-bearing leisure-time exercise; that is, their annual loss of lumbar BMC was 180 mg (272 vs. 452 mg, p = 0.022), and annual loss of lumbar BMD was 2.78 mg/cm(2) (2.96 vs. 5.74 mg/cm(2), p = 0.029) smaller than in sedentary women. Continuous leisure-time physical activity did not have any association with loss of BMC or BMD in the femoral neck Physical activity during 12 months before the last bone densitometry was not associated with loss of BMC or BMD at any site. Our results suggest that regular weight-bearing exercise diminishes lumbar bone loss, but might be ineffective in the prevention of femoral osteoporosis among peri- and early postmenopausal women.