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Biomedical subjects

C L Benhamou

Publications and source records attributed to C L Benhamou.

At least 19 recordsLinked to original sources
PubMed2007

Preserved bone health in adolescent elite rhythmic gymnasts despite hypoleptinemia.

BACKGROUND/AIMS: Leptin is linked to hormonal disturbances occurring in anorexia and positively linked with bone mineral density. The aim of this study was to determine whether hypoleptinemia occurring in rhythmic gymnasts may affect bone health. METHOD: Leptin, insulin, cortisol, IGF1 levels and bone markers were determined in 36 rhythmic gymnasts (EG) and 20 controls (C). Body composition, BMD at the whole body (WBBMD), lumbar spine (LSBMD) and bone ultrasound properties (SOS, BUA) were measured. RESULTS: The rhythmic gymnasts had lower fat mass and leptin level than the controls. There was no difference for IGF1, cortisol and insulin levels. Bone turnover rate was higher in elite gymnasts. The uncoupling index showed that remodeling favored the bone formation. LSBMD, WBBMD, SOS and BUA were higher in elite gymnasts after adjustment for fat mass. Leptin correlated positively with fat mass and negatively with physical activity. CONCLUSION: High impact training is able to counterbalance bone effects usually encountered in hormonally disturbed subjects. Our results suggest that hypoleptinaemia might be related to direct osteogenic effects and indirect hormonal mechanisms including preservation of IGF and cortisol levels.

Adolescent↗
PubMed2006

Doping dose of salbutamol and exercise: deleterious effect on cancellous and cortical bones in adult rats.

Animal studies suggest that bone remodeling is under beta-adrenergic control via the sympathetic nervous system. To our knowledge, the impact of beta-agonist substances, at doping doses, has not been studied in adult rats. The purpose of this study was to examine the effects of salbutamol injections with or without treadmill exercise on trabecular and cortical bone in adult rats. Adult (36 wk of age) female Wistar rats (n = 56) were treated with salbutamol (3 mg.kg(-1).day(-1) sc, 5 days/wk) or vehicle (sham) with or without subsequent treadmill exercise (13 m/min, 60 min/day, 5 days/wk) for 10 wk. Tibial and femoral bone mineral density was analyzed by dual-energy X-ray absorptiometry. Metaphysic trabecular bone structure was analyzed by micro-CT at the time of the animals' death. Bone cell activities were assessed histomorphometrically. After 10 wk, the increase in bone mineral density was less in salbutamol-treated than in sham rats (+3.3% vs. +12.4%, P < 0.05), and trabecular parameters were altered and bone resorption was increased in salbutamol-treated rats compared with controls. The negative effect on bone architecture in salbutamol-treated rats persisted, even with treadmill exercise. These results confirm the deleterious effect of beta(2)-agonists on bone mass during chronic treatment and describe its effects on bone mechanical properties in adult rats. Bone loss occurred independently of a salbutamol-induced anabolic effect on muscle mass and was equally severe in sedentary and exercising rats, despite a beneficial effect of exercise on the extrinsic and intrinsic energy to ultimate strain. These bone effects may have important consequences in athletes who use salbutamol as a doping substance.

Adrenergic beta-Agonists↗
PubMed2006

Effect of specimen conditioning on the microarchitectural parameters of trabecular bone assessed by micro-computed tomography.

The best way to preserve the mechanical properties of bone specimens is hydration in NaCl, whereas the reference process in microCT analysis is defatting. However, for finite element modelling (FEM) it is necessary to use the same bone specimens for biomechanical testing and 3D imaging. This study aimed to evaluate the effect of sample conditioning on trabecular bone microarchitectural parameters. Trabecular bones were analysed by microCT under three successive conditions: first, the fatted samples were analysed immersed in NaCl (process N); second, they were hydrated for 24 h then imaged without immersion (process H); third, the samples were defatted before analysis (process D). The microarchitectural parameters bone volume/tissue volume (BV/TV), trabecular spacing (Tb.Sp), number (Tb.N) and thickness (Tb.Th) were calculated. Except for BV/TV, there was no significant difference between the processes N and D. In process H, BV/TV, Tb.Th and Tb.N were higher and BS/BV and Tb.Sp were lower than in process D. Results showed that the process D may be replaced by the process N. The process H induced significant differences in microarchitectural parameters when compared to process D. Nevertheless, this sample conditioning should be used to develop FEM when microCT images are to be acquired during compressive testing.

Biomechanical Phenomena↗
PubMed2006

Dose effects of propranolol on cancellous and cortical bone in ovariectomized adult rats.

Animal studies suggest that bone remodeling is under beta-adrenergic control via the sympathetic nervous system. The purpose of this study was to examine the preventive effect of different doses of nonspecific beta-blockers (propranolol) on trabecular and cortical bone envelopes in ovariectomized rats. Six-month-old female Wistar rats were ovariectomized (OVX, n = 60) or sham-operated (n = 15). Then, OVX rats were subcutaneously injected with 0.1 (n = 15), 5 (n = 15), or 20 (n = 15) mg/kg propranolol or vehicle (n = 15) for 10 weeks. Tibial and femoral bone mineral density (BMD) were analyzed longitudinally by dual-energy X-ray absorptiometry. At death, the left tibial metaphysis and L(4) vertebrae were removed, and microcomputed tomography (Skyscan 1072; Skyscan, Aartselaar, Belgium) was performed for trabecular bone structure investigation. Histomorphometry analysis was performed on the right proximal tibia to assess bone cell activities. After 10 weeks, OVX rats had decreased BMD and trabecular parameters and increased bone turnover, as well as cortical porosity compared with the sham group (p < 0.001). Bone architecture alteration was preserved by 0.1 mg/kg propranolol due to higher trabecular number and thickness (+50.35 and +6.81%, respectively, than OVX; p < 0.001) and lower cortical pore number (-52.38% than OVX; p < 0.001). Animals treated by 0.1 mg/kg propranolol had a lower osteoclast surface and a higher osteoblast activity compared with OVX. Animals treated by 20 mg of propranolol did not significantly differ from OVX rats. Animals treated by 5 mg of propranolol have been partially preserved from the ovariectomy. These results showed a dose effect of beta-blockers. The lower the dose of propranolol breeding, the better the preventive effect against ovariectomy.

Animals↗
PubMed2005

Severe bone alterations under beta2 agonist treatments: bone mass, microarchitecture and strength analyses in female rats.

AIMS: Beta2 adrenergic agonists are widely used in therapeutics and as doping agents by athletes. However, their effects on bone tissue, especially bone microarchitecture, remain poorly understood. Using three-dimensional (3D) microtomography, dual-energy X-ray absorptiometry, biomechanical testing and enzyme-linked immunosorbent assay, we evaluated the effects of two beta2 agonists, clenbuterol and salbutamol, on bone in growing rats. METHODS: Twelve-week-old Wistar female rats (N = 39), divided in 3 groups, received during 6 weeks either salbutamol (4 mg/kg/day), clenbuterol (2 mg/kg/day) or normal saline (0.5 ml/kg/day) by subcutaneous injections. RESULTS: After 6 weeks, the salbutamol and clenbuterol groups displayed lower bone mineral content (BMC), femoral length and cortical width than controls. Clenbuterol treatment further reduced bone mineral density. Bone microarchitecture was clearly altered by clenbuterol, as evidenced by lower trabecular number (-40.40%; P < 0.001), connectivity and trabecular bone volume (-42.85%; P < 0.001), leading to lower ultimate force. Clenbuterol significantly increased muscle mass (P < 0.01) and reduced fat mass when compared to controls. Salbutamol did not seem to have any effect on bone microarchitecture or body composition. Both beta2 agonists increased the bone resorption marker (C-terminal collagen crosslinks) without any change of a bone formation marker. At the end of the treatment, a drop in leptin was seen in the clenbuterol group only. Leptin levels were correlated with BMC (r = 0.69, P = 0.003). CONCLUSION: These results confirm the deleterious effect of beta2 agonists on bone mass and show the negative effects of clenbuterol on trabecular bone microarchitecture. Bone loss occurred independently from muscle mass but was related to fat mass. A leptin-mediated effect on bone tissue seems likely. These pathophysiological effects may have important consequences in human therapeutics and doping.

Adrenergic beta-Agonists↗
PubMed2005

Bone geometry in response to long-term tennis playing and its relationship with muscle volume: a quantitative magnetic resonance imaging study in tennis players.

The benefit of impact-loading activity for bone strength depends on whether the additional bone mineral content (BMC) accrued at loaded sites is due to an increased bone size, volumetric bone mineral density (vBMD) or both. Using magnetic resonance imaging (MRI) and dual energy X-ray absorptiometry (DXA), the aim of this study was to characterize the geometric changes of the dominant radius in response to long-term tennis playing and to assess the influence of muscle forces on bone tissue by investigating the muscle-bone relationship. Twenty tennis players (10 men and 10 women, mean age: 23.1+/-4.7 years, with 14.3+/-3.4 years of playing) were recruited. The total bone volume, cortical volume, sub-cortical volume and muscle volume were measured at both distal radii by MRI. BMC was assessed by DXA and was divided by the total bone volume to derive vBMD. Grip strength was evaluated with a dynamometer. Significant side-to-side differences (P<0.0001) were found in muscle volume (+9.7%), grip strength (+13.3%), BMC (+13.5%), total bone volume (+10.3%) and sub-cortical volume (+20.6%), but not in cortical volume (+2.6%, ns). The asymmetry in total bone volume explained 75% of the variance in BMC asymmetry (P<0.0001). vBMD was slightly higher on the dominant side (+3.3%, P<0.05). Grip strength and muscle volume correlated with all bone variables (except vBMD) on both sides (r=0.48-0.86, P<0.05-0.0001) but the asymmetries in muscle parameters did not correlate with those in bone parameters. After adjustment for muscle volume or grip strength, BMC was still greater on the dominant side. This study showed that the greater BMC induced by long-term tennis playing at the dominant radius was associated to a marked increase in bone size and a slight improvement in volumetric BMD, thereby improving bone strength. In addition to the muscle contractions, other mechanical stimuli seemed to exert a direct effect on bone tissue, contributing to the specific bone response to tennis playing.

Absorptiometry, Photon↗
PubMed2003

Changes in body composition during post-menopausal hormone therapy: a 2 year prospective study.

BACKGROUND: Post-menopausal hormone therapy (pHT) induces changes in both body composition and bone mineral density (BMD). METHODS: In 109 post-menopausal women beginning either tibolone 2.5 mg (n=29), tibolone 1.25 mg (n=42) or estradiol 2 mg plus norethisterone acetate 1 mg (E2 + NETA) (n=38), we assessed body composition, total and regional BMD by dual energy X-ray absorptiometry, and the serum bone alkaline phosphatase (BAP), osteocalcin and the urinary excretion to type I collagen C-telopeptide (CTX) at baseline and after 2 years. RESULTS: At baseline, BMD at all sites correlated negatively with age and years since menopause, and positively with lean mass and fat mass (r=0.42, P<0.001 and r=0.26, P=0.006 at the total femur). During treatment, BMD increased at all sites (P<0.001), and serum BAP, osteocalcin, and urinary CTX decreased in all groups (P<0.001). Lean mass increased whereas android fat and android obesity index decreased. The increase in BMD at all sites correlated positively with changes of lean mass at 2 years. CONCLUSIONS: Both fat mass and lean mass are related to BMD in post-menopausal women, the relationship being strongest with lean mass; an increase in lean mass and a change in distribution of body fat are observed during treatment with E2 + NETA and tibolone.

Adipose Tissue↗
PubMed2002

Randomized, double-masked, 2-year comparison of tibolone with 17beta-estradiol and norethindrone acetate in preventing postmenopausal bone loss.

In this 2-year, randomized study, we compared the efficacy and tolerability of tibolone 2.5 mg (n = 75), tibolone 1.25 mg (n = 76) and estradiol 2 mg plus norethindrone acetate 1 mg (E2/NETA: n = 74) for preventing bone loss in postmenopausal women. Bone mineral density (BMD), measured by dual-energy X-ray absorptiometry, and bone remodeling markers were assessed every 6 months. Side-effects were assessed quarterly. After 24 months, the mean increase (+/- SD) in lumbar spine BMD from baseline was 3.6% +/- 2.9%, 1.9% +/- 3.5% and 6.8% +/- 4.5% in the tibolone 2.5 mg, tibolone 1.25 mg and E2/NETA groups, respectively. All pairwise differences were significant. The proportion of responders (women with a change from baseline in lumbar spine BMD of > or = -2% after 2 years) was 95.7%, 89.0% and 98.5% with tibolone 2.5 mg, tibolone 1.25 mg and E2/NETA, respectively. Similar results were obtained for femoral BMD, although the difference between tibolone 2.5 mg and E2/NETA was not significant at 24 months. Decreases in bone remodeling markers were similar in the three groups. Vaginal bleeding was more common in the E2/ NETA group (33.8%) than with tibolone 2.5 mg (12.0%) or tibolone 1.25 mg (9.2%), as was breast pain (23.0%, 2.7% and 2.6%, respectively). Each treatment effectively prevented bone loss. Overall, tolerability of tibolone was better than with E2/NETA, because of less frequent vaginal bleeding and breast pain. This may promote long-term adherence.

Androgen Antagonists↗
PubMed2002

Fractal analysis of trabecular bone texture on calcaneus radiographs: effects of age, time since menopause and hormone replacement therapy.

An analysis of trabecular bone texture based on fractal mathematics, when applied to trabecular bone images on plain radiographs, can be considered as a reflection of trabecular bone microarchitecture. It has been shown to be able to distinguish postmenopausal osteoporosis cases from controls. This cross-sectional study was carried out to investigate the influence of age, time since menopause and hormone replacement therapy (HRT) on the fractal dimension of trabecular bone texture at the calcaneus in a sample of 537 healthy women. Fractal analysis of texture was performed on calcaneus radiographs and the result expressed as the Hmean parameter (H = 2-fractal dimension). Total hip, femoral neck and lumbar spine bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. There was a statistically significant Hmean parameter decrease with age (p<0.0001) but the degree of correlation was low (r = -0.2) compared with the correlation between age and BMD (r = -0.36 to -0.61 according to the BMD site). We found a weak but statistically significant correlation between time since menopause and Hmean (r = -0.14, p = 0.03) in the 241 postmenopausal women included in the study. Hmean was significantly lower in a group of postmenopausal women without HRT (n = 110) compared with a group of age-matched postmenopausal women with HRT (n = 110): respectively 0.683 +/- 0.043 and 0.695 +/- 0.038 (p = 0.03). In conclusion, this study suggests that there is a menopause- and age-related decrease in the Hmean parameter and that HRT interferes with the results of the fractal analysis of trabecular bone texture on calcaneus radiographs.

Absorptiometry, Photon↗
PubMed2002

Osteopenia in patients infected by the human immunodeficiency virus. A case control study.

Summary - In the last few years, the use of highly active antiretroviral therapy has radically modified the prognosis of human immunodeficiency virus (HIV) infection. Osteonecrosis and osteoporosis are among the bone complications recently described in HIV-infected patients. We report a preliminary study comparing 47 HIV-infected patients (31 men and 16 women) to 47 age- and sex-matched controls. Bone mineral density was lower in patients than in controls: in men, 0.919 +/- 0.120 g/cm2 vs. 1.010 +/- 0.139 g/cm2 (P = 0.01) at the total hip and 0.948 +/- 0.100 g/cm2 vs. 1.043 +/- 0.117 g/cm2 (P = 0.0008) at the lumbar spine; in women, 0.912 +/- 0.149 g/cm2 vs. 0.968 +/- 0.090 g/cm2 at the total hip (P = 0.17) and 0.989 +/- 0.152 g/cm2 vs. 1.080 +/- 0.097 g/cm2 (P = 0.01) at the lumbar spine. HIV-infected males were more likely to have osteopenia and osteoporosis, as compared to the male controls (19 vs. 14 and 4 vs. 1, respectively, P = 0.02). None of the women had osteoporosis; nine HIV-infected women and one female control had osteopenia (P = 0.003). No fractures were recorded. In this preliminary study, no evidence supporting a relationship between bone loss and protease inhibitor treatment was found.

Absorptiometry, Photon↗
PubMed2002

[Bone evaluation in ten adults with cutaneous mastocytosis].

BACKGROUND: To systematically evaluate the bone status, searching for osteoporosis in patients with cutaneous mastocytosis. PATIENTS AND METHODS: In a prospective study from March 1997 to June 2000, we included all new patients examined for cutaneous signs of mastocytosis. Past history, physical examination, skin biopsy, laboratory tests, bone densitometry, cytology and histopathology of bone marrow and other complementary investigations were performed in all these patients. RESULTS: Ten patients were included. Two patients had osteoporosis. Five others had osteopenia. Four patients had bone marrow involvement due to mastocytosis. One of these four patients had myelodysplasia. DISCUSSION: This study suggests better investigation of bone density and bone marrow in patients who have cutaneous mastocytosis. Systematic histopathology of bone marrow and osteodensitometry help to detect patients with systemic involvement. Bone densitometry is particularly effective for early detection of patients at risk for fracture and is of practical interest since patients with osteoporosis can now be treated with Pamidronate.

Adult↗
PubMed2001

Fractal analysis of radiographic trabecular bone texture and bone mineral density: two complementary parameters related to osteoporotic fractures.

Trabecular bone microarchitecture and bone mineral density (BMD) are two main factors related to osteoporotic fractures. Currently, however, microarchitecture is not evaluated. We have developed and validated a trabecular bone texture analysis from radiographic images. The objective was to determine if the fractal analysis of texture was able to distinguish osteoporotic fracture groups from control groups, either in vertebrae, hip, or wrist fractures, and to determine if this indicator and BMD were independent and complementary. In this cross-sectional unicenter case-control population study in postmenopausal women, 107 fracture cases were enrolled and age-matched with 197 control cases. This population comprised 40 vertebral fractures (with 70 controls), 30 hip fractures (55 controls), and 37 wrist fractures (62 controls). Hip and lumbar spine BMD were measured by double-energy X-ray absorptiometry. Fractal analysis of texture was performed on calcaneus radiographs and the result was expressed as the H parameter (H = 2-fractal dimension). The H parameter showed a lower value (0.679 +/- 0.053 SD) in fracture cases versus control cases (0.696 +/- 0.030; p = 0.007), the statistical significance persisting after adjustment for age and for lumbar spine (LS) or hip BMD. This result was confirmed in vertebral fractures (p = 0.0001) and hip fractures (p = 0.003) but not wrist fractures (p = 0.07). We determined the threshold between high and low H values and then the odds ratios (OR) of fracture for low H for BMD < or = -2.5 SD in T score and for the combinations of both parameters. The OR of fracture for low H was 1.6 (95% CI, 1.1-2.6). For LS BMD < or = -2.5 SD the OR of 6.1 (3.4-10.8) shifted to 9.0 (4.0-20.4) when we added low H and for hip BMD it shifted from 5.6 (3.3-9.4) to 8.1 (4.0-16.8). In vertebral, hip, and wrist fracture cases the results were also significant. These data have shown that the fractal analysis of texture on calcaneus radiographs can distinguish osteoporotic fracture groups from control groups. This analysis and BMD provide independent and complementary information. These data suggest that we can improve the fracture risk evaluation by adding information related to microarchitecture, derived from analysis of conventional radiographic images.

Absorptiometry, Photon↗
PubMed2000

A new method for three-dimensional skeleton graph analysis of porous media: application to trabecular bone microarchitecture.

This paper introduces a new three-dimensional analysis of complex disordered porous media. Skeleton graph analysis is described and applied to trabecular bone images obtained by high resolution magnetic resonance imaging. This technique was developed bearing in mind topological considerations. The correspondence between vertices and branches of the skeleton graph and trabeculae is used in order to get local information on trabecular bone microarchitecture. In addition to real topological parameters, local structural information about trabeculae, such as length and volume distributions, are obtained. This method is applied to two sets of samples: six osteoporosis and six osteoarthritis bone samples. We demonstrate that skeleton graph analysis is a powerful technique to describe trabecular bone microarchitecture.

Femur Head↗
PubMed2000

Fractal dimension of trabecular bone projection texture is related to three-dimensional microarchitecture.

The purpose of this work was to understand how fractal dimension of two-dimensional (2D) trabecular bone projection images could be related to three-dimensional (3D) trabecular bone properties such as porosity or connectivity. Two alteration processes were applied to trabecular bone images obtained by magnetic resonance imaging: a trabeculae dilation process and a trabeculae removal process. The trabeculae dilation process was applied from the 3D skeleton graph to the 3D initial structure with constant connectivity. The trabeculae removal process was applied from the initial structure to an altered structure having 99% of porosity, in which both porosity and connectivity were modified during this second process. Gray-level projection images of each of the altered structures were simply obtained by summation of voxels, and fractal dimension (Df) was calculated. Porosity (phi) and connectivity per unit volume (Cv) were calculated from the 3D structure. Significant relationships were found between Df, phi, and Cv. Df values increased when porosity increased (dilation and removal processes) and when connectivity decreased (only removal process). These variations were in accordance with all previous clinical studies, suggesting that fractal evaluation of trabecular bone projection has real meaning in terms of porosity and connectivity of the 3D architecture. Furthermore, there was a statistically significant linear dependence between Df and Cv when phi remained constant. Porosity is directly related to bone mineral density and fractal dimension can be easily evaluated in clinical routine. These two parameters could be associated to evaluate the connectivity of the structure.

Femur Head↗
PubMed2000

Long-term corticosteroid therapy induces mild changes in trabecular bone texture.

The relative roles of bone mineral density (BMD) decrease and of microarchitectural changes in corticosteroid-induced osteoporosis (CIOP) are debated. Our objective has been to evaluate both bone microarchitecture (by a fractal analysis of texture on radiographs) and BMD in corticosteroid (CS)-treated patients. In this study, 60 patients from a rheumatology unit with a mean age of 60.6+/-14.8 years taking CS therapy for more than 6 months and a cumulative dose of prednisone over 1 g and 57 controls among age-matched patients and hospital staff were recruited. Bone diseases and bone-modifying drugs (except calcium, vitamin D, and hormonal replacement therapy [HRT]) were considered as exclusion criteria. A fractal analysis of trabecular bone texture was performed on calcaneus radiographs after an oriented analysis in 18 directions. The fractal analysis was based on the fractional Brownian motion model. Results were expressed by H parameter (H = 2 - fractal dimension) in each direction, Hmean being the average of 18 directions, Hmini the minimum, and Hmaxi the maximum. BMD was measured by double-energy X-ray absorptiometry (DEXA) at the femoral neck (FN) and lumbar spine (LS). The odds ratios (OR) were calculated for a variation of 1 SD. The mean duration and dose of CS therapy was 5.6+/-6.6 years and 16.9+/-19.7 g. CS therapy was significantly correlated to a decrease in FN or LSBMD: OR = 1.95, 95% confidence interval (CI, 1.29-2.97) and OR = 3.19 (CI, 1.80-5.66), respectively. The Hmean and Hmaxi were significantly lower in the cases than in the controls: P = 0.03 and P = 0.02; OR = 1.67 (CI, 1.10-2.54) and OR = 1.75 (CI, 1.05-2.37). A similar trend was observed with Hmini but the difference did not reach the level of statistical significance: P = 0.06, OR = 1.57 (CI, 1.05-2.37). This study was repeated among cases and controls who had never taken HRT (respectively, n = 40 and n = 39). The results were similar. Among patients taking CS therapy, the presence of nontraumatic fractures was inversely related to BMD values but not to texture parameters. These data have shown that long-term CS therapy induces both BMD decrease and trabecular bone texture changes. The effect of CS therapy was much stronger on BMD than on the fractal H parameter. These results are in accordance with previous studies showing a lower effect of CS therapy on bone microarchitecture than on bone mass. These results can be contrasted with those observed in women with postmenopausal osteoporosis and vertebral crush fractures in which the variations in the fractal parameters are more significant than the BMD variations.

Adrenal Cortex Hormones↗
PubMed2000

Glucocorticoid-induced osteoporosis: is the bone density decrease the only explanation?

BACKGROUND: Glucocorticoids may increase bone fragility via mechanisms independent from their bone mass reducing effect. OBJECTIVE: To study relationships between osteoporotic fractures and bone mineral density in patients on long-term glucocorticoid therapy. PATIENTS AND METHODS: We studied 121 women with a mean age of 60.4 +/- 14.3 years on long-term glucocorticoid therapy (cumulative dose > or = 1 g of prednisone equivalent, duration > or = 6 months) for rheumatoid arthritis (n = 38), polymyalgia rheumatica or giant cell arteritis (n = 26), connective tissue disease (n = 15), asthma (n = 14), another inflammatory joint disease (n = 14), or another condition (n = 14). The control group was composed of 125 subjects who had the same mean age and met the same exclusion criteria as the case group. Bone mineral density was measured at the lumbar spine and femoral neck using a Hologic QDR 4500 unit. In subjects with back pain, radiographs of the thoracic and lumbar spine were obtained to look for fractures. RESULTS: The odds ratio for a bone mineral density decrease of one standard deviation at the femoral neck was 1.68 (1.20-2.35) in patients with a cumulative glucocorticoid dose of 10 g of prednisone equivalent and 1.67 (1.22-2.29) in those with a glucocorticoid therapy duration of 2 years. Sixty-eight fractures were recorded in 56 patients (46% of the overall patient group). Even after adjustment on age, glucocorticoid therapy duration, and dose, mean bone mineral density values at the lumbar spine and femoral neck were significantly lower in the subgroup of patients with fractures than in the subgroup without fractures. Sensitivity and specificity of bone mineral density at the femoral neck and/or lumbar spine for the diagnosis of vertebral fracture and/or peripheral fracture were 73% and 51%, respectively. In the stepwise logistic regression model, factors explaining the presence of fractures were as follows, in hierarchical order: age; absence of calcium/vitamin D supplementation, femoral neck T-score, and glucocorticoid dose. CONCLUSION: Our data are compelling evidence that bone mineral density is a major determinant of the fracture risk in patients with glucocorticoid-induced osteoporosis.

Bone Density↗