Biomedical subjects

F Duboeuf

Publications and source records attributed to F Duboeuf.

At least 19 recordsLinked to original sources

PubMed2005

Quantitative ultrasound parameters as well as bone mineral density are better predictors of trochanteric than cervical hip fractures in elderly women. Results from the EPIDOS study.

RATIONALE: Hip fractures can be separated into cervical and trochanteric fractures. Trochanteric fractures have been associated with up to twice the short-term mortality of cervical fractures in the elderly. There is also evidence suggesting that the mechanisms are different. Evidence from the literature remains limited on the predictive power of bone mineral density (BMD) and quantitative ultrasounds (QUS) for both types of hip fractures. METHODS: 5703 elderly women aged 75 years or more, who were recruited from the voting lists in the EPIDOS study, and had baseline calcaneal ultrasounds (QUS) and DXA measurements at the hip and the whole body, were analyzed in this paper. Among those, 192 hip fractures occurred during an average follow-up of 4 years, 108 cervical and 84 trochanteric fractures. RESULTS: Femoral neck, trochanteric and whole body BMD were able to predict trochanteric hip fracture (RR's and 95% CI were, respectively, 3.2 (2.4-4.2); 4.8 (3.5-6.6); and 2.8 (2.2-3.6)) more accurately than cervical fractures (respectively, 2.1 (1.7-2.7); 2.3 (1.8-3.0); 1.2 (1.0-1.6)). All ultrasound parameters, SOS, BUA, and stiffness index (SI) were significant predictors of trochanteric (RR's respectively 3.0 (2.2-4.1), 2.5(2.0-3.1), and 3.5(2.6-4.7)) but not cervical fractures. After adjustment for femoral neck or trochanteric BMD ultrasound parameters were still significant predictors of trochanteric fracture, and stiffness tended to be a better predictor of trochanteric fractures than either BUA or SOS with a relative risk of 2.25 (1.6-3.1). CONCLUSIONS: A significant decrease of all bone measurements, BMD and QUS, was highly predictive of trochanteric fractures, whereas a decrease of femoral neck and trochanteric BMD were only associated with a slight increase in cervical fracture risk and a low total body BMD or QUS parameters were not significant predictors of cervical fractures. In women who sustained a hip fracture, the decrease of BMD and QUS values increases the risk of trochanteric fracture as compared to cervical fracture. Trochanteric fractures were mostly a consequence of a generalized low BMD and QUS, whereas other parameters might be involved in cervical fractures.

Aged↗

PubMed2005

Structural determinants of hip fracture in elderly women: re-analysis of the data from the EPIDOS study.

Hip fracture is the most disastrous osteoporotic fracture, characterized by high mortality, morbidity and institutionalization for the patient and by high economic costs for the health care system. The morphology of the upper part of the femur can influence the risk of hip fracture, e.g., a longer femoral neck is associated with a higher risk of cervical fractures, but not trochanteric ones. In this study, we evaluated the prediction of hip fracture risk by morphological parameters estimated from DXA measurements, and we compared their predictive value for cervical and trochanteric fractures in elderly women by reanalyzing previously published data (Duboeuf et al. J Bone Miner Res 1997 12 1895). This nested case-control study was performed in 232 elderly community-dwelling women from the EPIDOS cohort, including 65 women who sustained a hip fracture. After adjustment for confounding variables, women who sustained a cervical fracture had lower areal bone mineral density (aBMD), lower cortical thickness and a higher average buckling ratio (P<0.005 for all) as well as longer femoral neck (P<0.01) than controls. Women who sustained a trochanteric fracture had lower aBMD, lower cortical thickness and higher buckling ratio than controls (P<0.0001) and than women who sustained a cervical fracture (P<0.05). Their bending resistance (cross-sectional moment of inertia-CSMI, section modulus) was significantly lower in comparison with controls (P<0.05-0.001). A decrease in aBMD, cortical thickness, CSMI and section modulus as well as an increase in buckling ratio were predictive of all hip fractures (OR -1.42-2.46 per 1 SD, P<0.05-0.0001), but the ORs for all structural parameters were markedly higher for trochanteric than for cervical fractures. CSMI and section modulus were predictive of trochanteric, but not cervical fractures. However, aBMD was strongly correlated with the CSA, cortical thickness and buckling ratio (r2>0.74), which suggests that they convey the same information. CSMI and section modulus correlated with aBMD more weakly, but their OR lost statistical significance after adjustment for aBMD. In conclusion, low femoral neck aBMD, CSA and cortical thickness as well as a high buckling ratio are associated with the higher risk of hip fracture, especially trochanteric ones. These indices are highly correlated with aBMD and convey the same message. The calculated CSMI and section modulus predict trochanteric fractures, but not cervical fractures, and their statistical significance is lost after adjustment for aBMD, indicating that they reflect mainly aBMD, not mechanical properties. Thus, the independent contribution of the external diameter of the femoral neck to the risk of hip fracture cannot be reliably estimated by this technique.

Absorptiometry, Photon↗

PubMed2005

Assessment of vertebral fracture using densitometric morphometry.

Diagnosis of vertebral fracture is critical for management of osteoporosis, as existence of such deformities substantially increases the risk of subsequent fracture. Thus, accurate and precise techniques allowing detection of such deformities are essential to clinicians. So far, this detection has been performed by spinal lateral X-rays. More advanced techniques have recently been developed, based on dual energy X-ray absorptiometry (DXA). This review describes these different techniques and discusses the effectiveness of the DXA technique to assess vertebral deformities compared to X-ray. The use of DXA detection of vertebral fracture for clinical practice and clinical trials is discussed. Specifically, vertebral morphometry using DXA provides an excellent specificity, with moderate sensitivity. The major limitation of the DXA vertebral assessment is the poor quality of images of thoracic vertebrae. The clinical utility of vertebral morphometry using densitometry may help screening patients with vertebral fracture, but technological improvements are necessary to improve image quality.

Absorptiometry, Photon↗

PubMed2004

Biochemical markers of bone formation reflect endosteal bone loss in elderly men--MINOS study.

In the skeleton of elderly men, two opposite activities occur: bone loss at the endosteal envelope, which increases bone fragility, and periosteal apposition, which improves bending strength of bone. Both may contribute to serum bone formation markers although they have an opposite effect on bone fragility. The aim of this study was to determine if circulating bone formation markers reflect periosteal bone formation and endosteal bone remodelling in 640 men aged 55-85 years belonging to the MINOS cohort. We measured biochemical markers of bone formation (osteocalcin, bone alkaline phosphatase, N-terminal extension propeptide of type I collagen) and bone resorption (urinary and serum beta-isomerised C-terminal telopeptide of collagen type I, total and free deoxypyridinoline). Parameters of bone size (cross-sectional surface of third lumbar vertebral body measured by X-ray, projected areas of total hip, femoral neck, radius and ulna measured by dual-energy X-ray absorptiometry) increased with age (r = 0.20-0.32, P < 0.0001). In contrast, parameters related to bone loss (areal bone mineral density [aBMD], volumetric bone mineral density [vBMD] and cortical thickness) and determined mainly by bone resorption, decreased with ageing (r = -0.14 to -0.23, P < 0.005-0.0001). Men in the highest quartile of bone resorption markers had lower aBMD (3.8-10.2%, P < 0.05-0.0001), lower vBMD (3.9-13.0%, P < 0.05-0.0001), and lower cortical thickness (1.5-9.6%, P < 0.05-0.0001) than men in the lowest quartile. Markers of bone resorption were not significantly associated with estimates of bone size at any skeletal site. Markers of bone formation were not associated with estimates of periosteal formation after adjustment for covariates. In contrast, men in the highest quartile of the bone formation markers had significantly lower aBMD (4.0-11.7%, P < 0.05-0.0001), lower vBMD (4.2-16.3, P < 0.05-0.0001) and lower cortical thickness (4.0-7.4%, P < 0.05-0.0001) than men in the lowest quartile. In summary, serum levels of bone formation markers are negatively correlated with the estimates of endosteal bone loss. In contrast, they disclose no association with parameters reflecting periosteal apposition. Thus, in elderly men, bone formation markers reflect endosteal bone remodelling, probably because of the coupling between resorption and formation activities. In contrast, they do not reflect the periosteal bone formation, probably because the periosteal surface is smaller and has a slower remodelling rate than the endosteal surface.

Absorptiometry, Photon↗

PubMed2004

Dramatic decrease of innervation density in bone after ovariectomy.

Recent studies have demonstrated that bone is highly innervated and contains neuromediators that have functional receptors on bone cells. However, no data exist concerning the quantitative changes of innervation during bone loss associated with estrogen withdrawal. To study the involvement of nerve fibers in the regulation of bone remodeling, we have evaluated the modifications of innervation in a classical in vivo model of osteopenia in rats, ovariectomy (OVX). Skeletal innervation was studied by immunocytochemistry using antibodies directed against specific neuronal markers, neurofilament 200 and synaptophysin, and the neuromediator glutamate. Sciatic neurectomy, another model of bone loss due to limb denervation and paralysis, was used to validate our quantitative image analysis technique of immunostaining for nerve markers. Female Wistar rats at 12 wk of age were sham-operated (SHAM) or ovariectomized (OVX). Bone mineral density measurement and bone histomorphometry analysis of tibiae 14 d after surgery demonstrated a significant bone loss in OVX compared with SHAM. We observed an important reduction of nerve profile density in tibiae of OVX animals compared with SHAM animals, whereas innervation density in skin and muscles was similar for OVX and control rats. Quantitative image analysis of immunostainings demonstrated a significant decrease of the percentage of immunolabeling per total bone volume of neurofilament 200, synaptophysin, and glutamate in both the primary and secondary spongiosa of OVX rats compared with SHAM. These data indicate for the first time that OVX-induced bone loss in rat tibiae is associated with a reduction in nerve profile density, suggesting a functional link between the nervous system and the bone loss after ovariectomy.

Animals↗

PubMed2004

Does follow-up duration influence the ultrasound and DXA prediction of hip fracture? The EPIDOS prospective study.

While the potential of quantitative ultrasound (QUS) in the management of osteoporosis has been accepted, its interaction with follow-up time has never been investigated. The aim of our study is to prospectively evaluate the influence of follow-up time on the prediction of hip fracture by ultrasound parameters in the elderly as compared to bone mineral density (BMD) and to establish a long-term fracture prediction model. In the multicenter prospective study EPIDOS, 5898 Caucasian healthy women, aged 75 and over, had femoral dual-energy X-ray absorptiometry (DXA) and heel ultrasound measurements at baseline. A survey of fracture occurrence was conducted every 4 months. Statistical analyses were performed for three different average lengths of follow-up, namely, 1.5, 2.5 and 3.5 years. Relative risks per standard deviation decrease (RR) and the area under the receiver operating characteristic (AUC) curves were given. Estimates of the long-term hip fracture prediction by DXA and QUS were extrapolated. During an average of 3.5 years follow-up, 227 women sustained their first non-traumatic hip fracture. For the three categories of follow-up, low values of both calcaneal ultrasound and hip BMD were associated with a significant increased risk of hip fracture [e.g. ultrasound Stiffness index RR = 2.8 (2.1-3.8), 2.1 (1.7-2.6) and 1.9 (1.7-2.3) for 1.5, 2.5 and 3.5 years of follow-up, respectively]. The combination of femoral neck BMD with the Stiffness showed an improvement of the hip fracture prediction model. Using extrapolation, the prediction of hip fracture by the Stiffness remained significant up to 7.5 years [RR = 1.2 (1.03-1.41)], whereas the limit of significance was reached at 10 years for the femoral neck BMD [RR = 1.25 (1.04-1.52)]. Our results indicate that the Stiffness tends to be the best short- and long-term predictor of hip fracture among ultrasound parameters. This paper provides additional information on the long-term prediction of hip fracture, which has always been an important issue in routine clinical practice as it influences the management of the disease. Our model should give a relatively good estimation of the fracture risk prediction at 5 years with the ultrasound and 10 years for the femoral neck BMD.

Absorptiometry, Photon↗

PubMed2004

Trabecular alveolar bone microarchitecture in the human mandible using high resolution magnetic resonance imaging.

OBJECTIVES: Cancellous bone microarchitecture in the mandible can influence the success of dental implant osseointegration. The aims of this study were to explore the feasibility of two-dimensional (2D) high resolution magnetic resonance imaging (MRI) for the evaluation of trabecular bone architecture and to compare architecture parameters derived from MR images between different areas in the mandible, and between sex and dental status. METHODS: 45 mandibular bone specimens (8 mm thickness) were cut from 15 fresh cadavers. MR images were obtained at 2 T using a multislice 2D spin-echo sequence. After MR image binarization, histomorphometry parameters, i.e. bone area fraction (BAF), specific perimeter (La), trabecular bone width (Tb.Wi), trabecular bone separation (Tb.Sp) and trabecular network anisotropy (R), were computed from the mean intercept length. The angle between trabeculae and tooth axis and the Euler-Poincaré characteristics (EPCs) were also computed. RESULTS: BAF, Tb.Wi and R were significantly higher in male specimens compared with female specimens, whereas Tb.Sp was significantly lower. The apparent Tb.Wi was found to be significantly higher in dentate specimens compared with edentulous ones. The highest anisotropy, corresponding to the smallest R value, was seen in the incisal specimens. The preferential orientation of the trabeculae was close to perpendicular to the tooth axis, especially in the molar specimens. CONCLUSION: BAF, La, Tb.Wi, Tb.Sp and R, the most variable parameters, may potentially have a relationship with the biomechanical competence of trabecular bone and play a role both in primary stabilization of dental implant and the time needed before loading.

Absorptiometry, Photon↗

PubMed2003

Speed of sound measurements of the third metacarpal bone in young exercising thoroughbred racehorses.

The purpose of this longitudinal in-field study was to evaluate the influence of exercise, age, and gender on superficial cortical bone of the third metacarpal bone (MC III) in young Thoroughbreds by measuring speed of sound (SOS) values with an axial transmission technique (Omnisense, Sunlight Ltd, Israel). Both MC III of 75 racehorses, 2 to 4 years old, were monitored with SOS measurements in 5- to 7-week intervals during a 9- month physical exercise period. Medical data and training programs (slow gallop, canter, and high-speed work) of each horse were recorded. SOS measurements began before 2-year-old horses started high-speed training. SOS values of the dorsal aspect of MC III were significantly lower in comparison with values obtained at the lateral and the medial aspect of MC III, and SOS values were inversely correlated with measurement cycles. Significant limb-associated differences in dorsal MC III SOS values were observed at measurement cycles 2, 3, and 4. SOS values obtained at the lateral and medial aspect of MC III increased with age. SOS values obtained at the dorsal aspect of MC III, decreased with age. Mares had significantly higher SOS values at the dorsal aspect of MC III, when compared with corresponding values in stallions. In 2-year-old Thoroughbreds SOS values of the dorsal MC III were significantly different between cycles 1 and 2, between cycles 3 and 4, and between cycles 4 and 5. Three-year-old horses showed significant differences between SOS values of the dorsal MC III obtained at cycles 3 and 4. Training intensities did not significantly influence SOS values. The results indicate that young exercising Thoroughbred racehorses have age-, gender-, and measurement-cycle-dependent variations in SOS values of MC III, which probably reflect adaptive variations in superficial cortical bone properties of MC III.

Age Factors↗

PubMed2003

Equine third metacarpal bone assessment by quantitative ultrasound and dual energy X-ray absorptiometry: an ex vivo study.

The purpose of this ex vivo study was to analyse two commonly established methods of mechanical bone property assessment for application in horses: Quantitative ultrasound (QUS), which depends on the bone's density and Young's modulus, and dual energy X-ray absorptiometry (DXA), which depends on the areal bone mineral density (BMD). The third metacarpal bone (MC III) of horses was selected as examination region for practical reasons. An interrelationship between QUS- and DXA-values was examined. Both MC III of eleven randomly selected equine cadavers were divided in nine regions of interest (ROI). A multi-site QUS device was used for axial transmission speed of sound (SOS) measurements and a DXA device was used for BMD evaluation. Full cortical thickness BMD (FcBMD), overall aspect BMD and 4 mm cortical border slice BMD (4 mmBMD) were evaluated. In addition, each ROI of one MC III was measured 10 times to determine QUS- and DXA-measurement precision. SOS values and BMD values obtained at different aspects of MC III were different (P < 0.001). FcBMD and overall BMD obtained at different levels were different (P < 0.001). SOS data correlated with FcBMD-, overall BMD- and 4 mmBMD-data at various ROI. FcBMD-, overall BMD- and 4 mmBMD-data were strongly correlated. The intra-operator coefficient of variation was 1.3% for SOS-measurements and ranged between 1.94 and 10.3% for BMD-measurements. Multi-site axial transmission QUS as well as DXA can be used to precisely measure bone characteristics of MC III in horses. However, both techniques do not measure the same bone properties. It is therefore concluded, that QUS and DXA techniques are complementary for application in horses.

Absorptiometry, Photon↗

PubMed2002

The impact of osteoporosis on quality-of-life: the OFELY cohort.

Although the long-term outcomes of osteoporosis (Op) such as fracture, kyphosis, and pain are well known, the physical, psychological, and social consequences, beyond fracture and pain, are less clear. The Osteoporosis-targeted Quality-of-life (OPTQoL) questionnaire aimed at assessing the physical difficulty, fears, and adaptations to one's daily life was developed as a cross-sectional instrument to characterize the burden of Op within a community. The purpose of this study was to assess the impact of Op and related factors on community women participating in the OFELY study in France. Femoral neck bone mineral density (BMD) and OPTQoL questionnaire data were collected from women randomly selected from a large insurance company. Data were obtained for 756 women (mean age 59 years, range 36-92), most of whom were white. Women were classified into five groups based on the extent of physical manifestations and family history of Op. Women who had prior fractures, height loss, and/or kyphosis or both reported greater physical difficulty, more adaptations to their lives, and greater fears than women reporting no such changes. Scores on the Physical Difficulty domain, however, did not differ significantly based on BMD alone (BMD T score <or=2.5), after controlling for age and self-reported arthritis. The negative impact of Op on quality-of-life (QoL) seems to be more related to the physical manifestations of Op than to bone density levels. Recognition of the impact of Op-related factors on QoL may help health-care providers more fully appreciate the importance of prevention and treatment.

Adult↗

PubMed2002

Association between a functional interleukin-6 gene polymorphism and peak bone mineral density and postmenopausal bone loss in women: the OFELY study.

Genetic factors play an important role in determining bone mass and several genes are involved in this process. Interleukin-6 (IL-6) is a candidate gene for regulation of bone mineral density (BMD) and it has been suggested recently that novel IL-6 -174 G/C allelic variants may be associated with peak BMD in young men and with bone resorption in elderly women. In this study, we assessed the relationships between IL-6 gene polymorphism, peak BMD, rate of postmenopausal BMD loss, and bone turnover in women. BMD was measured by dual-energy X-ray absorptiometry in 255 healthy premenopausal women, aged 31-57 years. BMD loss at the forearm was measured over 4 years in 298 healthy untreated postmenopausal women, 50-88 years (mean 64 years). We also measured levels of serum osteocalcin, bone alkaline phosphatase, and N-propeptide of type I collagen for bone formation and three markers of bone resorption, including urinary and serum C-terminal cross-linking telopeptide of type I collagen and urinary N-terminal telopeptide of type I collagen, in both pre- and postmenopausal women at baseline. In premenopausal women we found a significant association between IL-6 genotypes and BMD at the whole body (analysis of variance [ANOVA], p = 0.03), femoral neck (p = 0.03), trochanter (p = 0.014), Ward's triangle (p = 0.03), and total hip (p = 0.006), with subjects having the CC genotype showing 3%-7% higher BMD levels than their GG counterparts. However, after matching women with CC and GG genotypes for body height the differences decreased (2%-4%), and were no longer significant (p = 0.10-0.23). In postmenopausal women the mean rate of loss at the ultradistal radius was significantly associated with IL-6 genotypes (ANOVA, p = 0.049), with women having the CC genotype showing a significantly greater rate of bone loss (p < 0.05) compared with their GC and GG counterparts. After adjustment for weight changes, the difference in the rate of ultradistal radius bone loss between genotypes decreased and was not significant (p = 0.06 for CC vs. GG). A similar trend was observed for distal radius bone loss (p = 0.10, ANOVA), but not for the middle radius. We found no significant association between genotypes, bone turnover markers in premenopausal women, and either bone turnover or BMD in postmenopausal women. We conclude that this new functional IL-6 polymorphism was weakly associated with level of peak BMD and the rate of forearm trabecular postmenopausal bone loss in this cohort of healthy French women. IL-6 genotypes accounted only for a small proportion of the interindividual variation of both peak BMD and rate of bone loss and were not significant after adjustment for height and changes in body weight, respectively, suggesting that part of the effect may have been due to the differences in body size. Larger long-term studies are necessary to assess adequately the relationships between IL-6 genotype, rate of bone loss, and risk of fracture.

Adult↗

PubMed2002

Increased bone resorption in moderate smokers with low body weight: the Minos study.

Tobacco was found to be a risk factor for osteoporosis, mainly in postmenopausal women. We studied the effect of smoking on bone mineral density (BMD) and bone turnover in a cohort of 719 men, aged 51-85 yr, composed of 83 current smokers, 405 former smokers, and 231 men who never smoked. Most current and former smokers were moderate smokers (median, 10 cigarettes/d). Current smokers were younger, thinner, and drank more coffee and more alcoholic beverages. After adjustment for age, body weight, alcohol intake, and caffeine intake, current and former smokers had similar BMD, except at the forearm. Former smokers had lower BMD compared with never-smokers at most skeletal sites. Men who had smoked more than 7120 packs (third quartile) had lower BMD of total hip (P < 0.01) and distal forearm (P = 0.03) compared with men in the 2 lower tertiles. In the 3 groups, levels of bone formation markers did not differ. After adjustment for confounding variables, levels of urinary markers of bone resorption (beta-isomerized C-terminal telopeptide, free and total deoxypyridinoline) were higher in the current smokers than in former smokers and never-smokers. Concentrations of T, total 17beta-E2, and androstenedione were higher, whereas that of 25-hydroxyvitamin D was lower, in current smokers. When men were divided according to tertiles of body weight, increased bone resorption, decreased BMD and biochemical indexes of secondary hyperparathyroidism were observed in current smokers in the lowest tertile of body weight (<75 kg) compared with the never-smokers, but not in men in the two highest tertiles of body weight. Current smokers had a higher prevalence of vertebral deformities after adjustment for age and body weight (13% vs. 5%; P < 0.005). In summary, in moderate smokers with low body weight (<75 kg), increased bone resorption, not matched by increased bone formation, results in decreased BMD and an increased prevalence of vertebral deformities. In this group, low serum 25-hydroxyvitamin D and secondary hyperparathyroidism may explain, at least partly, the effect of tobacco on bone turnover. In former smokers, bone resorption is not increased, but BMD remains lower compared with that in never-smokers.

Aged↗

PubMed2002

[Dosimetry and bone densitometry: examples of LUNAR IQ and HOLOGIC 4500A].

Patient dosimetry related to two bone densitometer units from different manufacturers (LUNAR IQ and HOLOGIC 4500A) were evaluated using the parallel beam technique and thermoluminescence from Ca (SO4)/Dy. The radiation dose measured for a phantom of 18 cm in thickness was 0,11 mGy (+/- 0,004) at a maximum current of 3 mA for the LUNAR IQ unit in the high-resolution mode. The radiation dose is 0,28 mGy (+/- 0,011) for the HOLOGIC 4500A unit used at 2,5 mA in the high resolution-mode. These results obtained by thermoluminescence of the Ca (SO4)/Dy are in favor of the LUNAR IQ unit. However, dosimetry must be weighted against image quality.

Absorptiometry, Photon↗

PubMed2001

Bioavailable estradiol may be an important determinant of osteoporosis in men: the MINOS study.

During recent years, experimental data, case reports, and epidemiological studies have suggested an important role for estradiol in bone metabolism in men. In a cohort of 596 men, aged 51-85 yr, we measured bone mineral density (BMD) of the lumbar spine, hip, total body, and forearm; serum levels of sex steroid hormones [total and free testosterone, total estradiol (17betaE(2)), bioavailable estradiol (bio-17betaE(2)), androstenedione, and sex hormone-binding globulin]; and markers of bone turnover [serum osteocalcin, bone alkaline phosphatase, N-terminal extension propeptide of type I collagen, and beta-isomerized C-terminal telopeptide of collagen type I (betaCTX)], as well as urinary excretion of betaCTX and deoxypyridinoline (DPyr). An age-related decrease was found for bio-17betaE(2) (r = -0.16; P < 0.001), free testosterone (r = -0.25; P < 0.001), free testosterone index (r = -0.32; P < 0.001), and androstenedione (r = -0.22; P < 0.001), but not for total 17betaE(2) or total testosterone. 17betaE(2) and bio-17betaE(2), but not other hormones, were correlated with BMD after adjustment for age and body weight. In men with a bio-17betaE(2) level in the lowest quartile, the average BMD was lower than in men having a bio-17betaE(2) level in the highest quartile by 6.6-8.7% according to the site of measurement, which corresponded to 0.45-0.65 SD. In age- and body weight-adjusted models, bio-17betaE(2), but not other hormones, was negatively correlated with bone markers (e.g., osteocalcin: r = -0.14; P < 0.001; urinary betaCTX: r = -0.20; P = 0.0001; DPyr: r = -0.14; P < 0.001). In men with the lowest concentration of bio-17betaE(2) (first quartile), the concentrations of markers of bone turnover were higher by 11-35% (or 0.4-0.7 SD) than in men having the highest bio-17betaE(2) level (upper quartile). In men in the lowest quartile for bio-17betaE(2) and in the highest quartile for urinary DPyr or betaCTX, the BMD of total hip and that of distal forearm were 8% and 10% lower than in men in the highest quartile for bio-17betaE(2) and in the lowest quartile for DPyr or ssCTX. In the age- and body weight-adjusted multiple regression models, bio-17betaE(2) contributed significantly to the explanation for the variability in all markers. In summary, we found in a cross-sectional analysis of a cohort of men that low levels of bio-17betaE(2) are associated with high bone turnover and low BMD. These data suggest that the age-related decrease in bio-17betaE(2) contributes to bone loss in elderly men by increasing bone turnover. Low 17betaE(2) levels may be an important risk factor for osteoporosis in men.

Aging↗

PubMed2001

Effects of a new selective estrogen receptor modulator (MDL 103,323) on cancellous and cortical bone in ovariectomized ewes: a biochemical, histomorphometric, and densitometric study.

The aims of this study performed in ewes were: (1) to confirm in this animal model the effects on bone of ovariectomy (OVX) alone or associated with Lentaron (L), a potent peripheral aromatase inhibitor, used to amplify the effects of OVX and (2) to evaluate the effects of a new selective estrogen receptor modulator (SERM; MDL 103,323) on bone remodeling. Thirty-nine old ewes were divided into five groups: sham (n = 7); OVX (n = 8); OVX + L (n = 8); OVX + L + MDL; 0.1 mg/kg per day (n = 8); and OVX + L + MDL 1 mg/kg per day (n = 8). The animals were treated for 6 months. Biochemical markers of bone turnover (urinary excretion of type 1 collagen C-telopeptide [CTX], serum osteocalcin [OC], and bone alkaline phosphatase [BAP]) were measured each month. Bone biopsy specimens were taken at the beginning and after death at the end of the experiment. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA) on the lumbar spine and femur. OVX induced a significant increase in biochemical markers. This effect was the highest after 3 months for CTX (+156% vs. sham) and after 4 months for OC and BAP (+74% and +53% vs. sham, respectively). L tended to amplify the effect of OVX on OC and BAP. OVX induced significant increases in the porosity, eroded, and osteoid surfaces in cortical bone but no effect was observed in cancellous bone. MDL treatment reduced the bone turnover as assessed by bone markers, which returned to sham levels as well as histomorphometry both in cortical and in cancellous bone. Cancellous osteoid thickness decreased by 27% (p < 0.05), mineralizing perimeter by 81% (p < 0.05), and activation frequency by 84% (p < 0.02) versus OVX + L. Femoral and spinal BMD were increased by MDL and tended to return to the sham values. The effects of OVX on bone turnover were different on cortical and cancellous bone. These effects on cortical bone were reflected by changes in biochemical markers. MDL markedly reduces bone turnover and increases BMD suggesting that this new agent may prevent postmenopausal bone loss.

Alkaline Phosphatase↗

PubMed2000

Cross-sectional assessment of age-related bone loss in men: the MINOS study.

There are few data on osteoporosis in men, but cross-sectional studies have shown that age-related bone loss in men is of lower magnitude than in women. To elucidate some controversies related partially to methodological aspects, we measured bone mineral density (BMD) by dual-energy X-ray absorptiometry (DEXA) at various skeletal sites (spine, hip, and whole body using a Hologic QDR-1500 device; forearm using an Osteometer DTX 100 device) in a large cohort of 1040 men, aged 19-85 years. The final investigation was performed on 934 men, aged 19-85 years, after exclusion of 106 men with disease or treatment known to affect bone metabolism. Peak BMD was achieved at 25 and 29 years at the lumbar spine and hip, respectively, but only at 40 and 37 years at the distal forearm and whole body, respectively. The magnitude of bone loss between peak bone mass and 80 years of age was linear at most sites and averaged 13%-18%; that is, SD of 1.1-1.8 from peak BMD, except for Ward's triangle, which showed a marked bone loss of 43% (i.e., 2.5 SD), and for the lumbar spine. In the entire cohort, increase of the average lumbar spine BMD after the age of 55 years was related to the development of osteoarthritis, because, in men without severe arthritis, lumbar spine BMD continued to decrease. Height-adjusted partial correlations indicate that both the mineral content and the area of long bones of the limbs increased with age up to 50 years, followed by a significant decrease of BMD without change of bone surface. SD of mean BMD increased significantly with age at most skeletal sites. In summary, age-related change of BMD varied according to skeletal site in men with peak bone mass achieved earlier at sites rich in trabecular bone than at those rich in cortical bone. Bone loss varied according to skeletal site from 14% to 43%. The variability of BMD increased with age, which may reflect interindividual variability of age-related bone loss.

Absorptiometry, Photon↗

PubMed2000

Cross-sectional and longitudinal assessment of pre- and postmenopausal bone loss with a portable forearm X-ray device: the Ofely study.

The aim of our study was to describe cross-sectional and longitudinal bone mineral decrease in pre-, peri-, and postmenopausal healthy women using a monoenergy X-ray densitometer specifically designed for forearm assessement. Measurements were performed on the most distal part of the radius (ultradistal, 55% of trabecular bone and 45% of trabecular bone), and on the distal part (distal, 13% of trabecular bone and 87% of cortical bone). A specific trabecular-rich region of interest (nROI) comprising two trapezoids regions of interest located proximally to the endplates of the radius and ulna was also investigated. From a large prospective study (OFELY study), 455 women were measured once a year for 2 years (three measurements). The proportion of postmenopausal women classified as having osteoporosis (i.e., a T score <-2.5) was 33% for the distal region, 44% for the ultradistal region, and 45% for the nROI. No significant bone mineral decrease was found over the 2-year period in premenopausal women (n = 138). In perimenopausal (n = 48) women, a bone loss of 1% was found at the distal site. In the 269 postmenopausal women, a significant decrease was observed at all sites, ranging from 2.14% for the nROI to 2.68% for the ultradistal part. Bone loss was greater in the first 5 years after menopause in trabecular sites and decreased thereafter. For the distal site, bone loss remained stable during the postmenopausal period. We conclude that this small and portable forearm densitometer is suitable for the diagnosis of osteoporosis, and provides information on the rate of bone loss in peri- and postmenopausal women in trabecular and cortical compartments of bone.

Absorptiometry, Photon↗

PubMed2000

Phalangeal osteosonogrammetry study: age-related changes, diagnostic sensitivity, and discrimination power. The Phalangeal Osteosonogrammetry Study Group.

Phalangeal osteosonogrammetry was introduced as a method for bone tissue investigation in 1992. It is based on the measure of the velocity of ultrasound (amplitude-dependent speed of sound [AD-SoS]) and on the interpretation of the characteristics of the ultrasound signal. In this study we have collected a database of 10,115 subjects to evaluate the performance of AD-SoS and to develop a parameter that is able to quantify the signal characteristics: ultrasound bone profile index (UBPI). The database only includes females of which 4.5% had documented vertebral osteoporotic fractures, 16% lumbar spine dual X-ray absorptiometry (DXA), and 6% hip DXA. The analysis of the ultrasound signal has shown that with aging the UBPI, first wave amplitude (FWA), and signal dynamics (SDy) follow a trend that is different from the one observed for AD-SoS; that is, there is no increase during childhood. In the whole population, the risk of fracture per SD decrease for AD-SOS was odds ratio (OR) 1.71 (CI, 1.58-1.84). The AD-SoS in fractured subjects was significantly lower than in a group of age-matched nonfractured subjects (p < 0.0001). In a small cohort of hip-fractured patients UBPI proved to be lower than in a control age-matched group (p < 0.0001). When the World Health Organization (WHO) working group criteria were applied to this population to identify the T score value for osteoporosis, for AD-SoS we found a T score of -3.2 and for UBPI we found a T score of -3.14. Sixty-six percent of vertebral fractures were below the AD-SoS -3.2 T score and 62% were below UBPI -3.14. We observed the highest incidence of fractures (63.6%) among subjects with AD-SoS who had both DXA T score values below the threshold. We conclude from this study that ultrasound investigation at the hand phalanges is a valid methodology for osteoporosis assessment. It has been possible to quantify signal changes by means of UBPI, a parameter that will improve the possibility of investigating bone structure.

Adult↗