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  • Osteoporosis  (9)
  • Bone mineral density  (3)
  • Osteocalcin  (2)
  • Stiffness index  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Mean wall thickness of trabecular bone packets in the human iliac crest: Changes with age (1978)
    Springer
    Calcified tissue international 26 (1978), S. 13-17 
    Details
    ISSN: 1432-0827
    Keywords: Bone remodelling ; Bone histomorphometry ; Amount of bone ; Osteoporosis ; Osteopenia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The mean wall thickness (MWT) of packets of trabecular bone was measured in undecalcified iliac crest bone samples of 36 normal subjects (14 female and 22 male) under polarized light. The mean wall thickness was 49.7±8.7 μm at a mean age of 50.9 years. There existed a significant decrease of MWT with advancing age. With an appositional rate of 0.72 μm/day, the mean formation time of iliac trabecular bone packets is 69 days. The decrease of MWT with age corresponds to a decrease in bone formation at the basic multicellular unit (BMU) level with aging and can partly explain the physiological senile osteopenia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013227
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  • 2
    Electronic Resource
    Electronic Resource
    Relationship between bone fluoride content and histological evidence of calcification defects in osteoporotic women treated long term with sodium fluoride (1993)
    Springer
    Osteoporosis international 3 (1993), S. 204-208 
    Details
    ISSN: 1433-2965
    Keywords: Bone ; Bone fluoride content ; Calcification defects ; Osteoporosis ; Sodium fluoride treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Fluoride treatment is used to increase bone formation and cancellous bone mass in patients suffering from postmenopausal osteoporosis with vertebral fractures. Patients submitted to similar therapeutic protocols have shown various histological responses to the treatment, some developing calcification defects and others not. In fact, the bone histological response to fluoride salts depends on the cumulative uptake of fluoride by bone. To clarify the relationship between the presence of calcification defects (identified by the presence of mottled bone and linear formation defects) and the bone fluoride content, a retrospective study was performed on 29 women with type 1 osteoporosis and treated for several months (11–24) with sodium fluoride (50 mg/day), calcium and vitamin D. Bone fluoride content always significantly increased after treatment, but it was significantly higher in patients showing calcification defects than in those having no defects. These differences between the two groups of patients were not due to differences in clinical details (no significant differences concerning age, duration of treatment, total amount of fluoride ingested, renal function) or in their bone remodelling activity. Thus, it may be hypothesized that the high bone fluoride uptake is due to different individual responses from one patient to another concerning the bioavailability of the same dose of fluoride. This is difficult to predict, except by testing the individual bioavailability of the compound to be used in each patient before starting long-term treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623677
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  • 3
    Electronic Resource
    Electronic Resource
    Ultrasound measurements on os calcis: Precision and age-related changes in a normal female population (1993)
    Springer
    Osteoporosis international 3 (1993), S. 249-254 
    Details
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Broadband ultrasound attenuation ; Speed of sound ; Ultrasound References
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We performed ultrasound measurements in the calcaneus of 512 healthy women. Broadband ultrasonic attenuation (BUA) and speed of sound (SOS) were obtained with a Lunar Achilles ultrasonic instrument. Subjects studied were one group of 67 women working in our hospital (group A) and two groups which are part of two large prospective cohort studies (groups B and C). Group B consisted of 244 women aged 31–79 years randomly selected from a large insurance company, and group C consisted of 201 women aged 74–91 years randomly selected from the electoral rolls. Dual-energy X-ray absorptiometry (DXA) measurements of femoral neck and total body were performed with a Hologic QDR 2000 for group B and with a Lunar DPX Plus for group C. The in vitro precision of the Achilles, estimated by measuring a phantom daily for 45 days, was 0.84% for BUA and 0.12% for SOS. We assessed the in vivo short-term precision in 20 healthy volunteers working at the hospital, measured three times each. The coefficients of variation were 0.93% (±0.21) for BUA and 0.15% (±0.03) for SOS. The precision error was compared with the true variation, to obtain a standardized coefficient of variation. We analysed the three groups pooled together (n=512) and found for BUA an average 20% decrease and for SOS a 5% decrease between the ages of 20 and 90 years. We also performed separate analyses of subjects younger than 50 and older than 50 years, and within each 10-year age group we found that BUA was stable or slightly increased from 20 to 50 years and then decreased after 50. In contrast, SOS did not increase but decreased from the age of 20. We compared DXA measurements of the femoral neck and the total body with ultrasound measurements in groups B and C. In both groups the correlations were better with total body DXA than with femoral neck and spine DXA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623828
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  • 4
    Electronic Resource
    Electronic Resource
    Can we stop bone loss and prevent hip fractures in the elderly? (1994)
    Springer
    Osteoporosis international 4 (1994), S. S71 
    Details
    ISSN: 1433-2965
    Keywords: Calcium ; Hip fracture ; Osteoporosis ; Vitamin D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The two main determinants of hip fractures are falls and bone loss leading to an intrinsic femoral fragility. Substantial femoral bone loss continues throughout old age, with a continuous and exponential increase in the risk of hip fracture; thus any reduction or arrest of this loss will induce an important reduction in the incidence of hip fracture. Preventive measures may be achieved during childhood by increasing peak bone mass with calcium and exercise, by using long-term estrogen replacement therapy after menopause, but also by using vitamin D and calcium supplements for late prevention in the elderly. Vitamin D insufficiency and a deficit in calcium intake are very common in the elderly living either in institutions or at home and the cumulative response to these deficits is a negative calcium balance which stimulates parathyroid hormone secretion. This senile secondary hyperparathyroidism is one of the determinants of femoral bone loss and can be reversed by calcium and vitamin D supplements. We have shown in a 3-year controlled prospective study that the daily use of supplements (1.2 g calcium and 800 IU vitamin D3) given in a large population of 3270 elderly ambulatory women living in nursing homes reduced the number of hip fractures by 23% (intention-to-treat analysis). In parallel, serum parathyroid hormone concentrations were reduced by 28% and low baseline serum 25-hydroxy vitamin D concentration returned to normal values. After 18 months of treatment the bone density of the total proximal femoral region had increased by 2.7% in the vitamin D3-calcium group and decreased by 4.6% in the placebo group (p〈0.001). This prevention is safe and can be recommended for people living in institutions. It could also be useful in other elderly subjects at particular risk due to a low calcium intake, an absence of solar exposure, a low femoral bone density, a high serum parathyroid hormone concentration, a low serum 25-hydroxyvitamin D concentration and a previous history of falls. Prospective studies are needed for further evaluation of these risk factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623440
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  • 5
    Electronic Resource
    Electronic Resource
    hPTH 1–34 treatment of osteoporosis with added hormone replacement therapy: Biochemical, kinetic and histological responses (1991)
    Springer
    Osteoporosis international 1 (1991), S. 162-170 
    Details
    ISSN: 1433-2965
    Keywords: Hormone replacement therapy ; hPTH 1–34 treatment ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Twelve patients with vertebral fracture osteoporosis were recruited into a trial of treatment with hPTH 1–34 by daily injection for 1 year combined (from the 5th month) with an anti-resorptive agent (oestrogen, n=9; nandrolone, n=3). Treatment outcomes were monitored by biochemical and radiotracer measurements together with histomorphometry of transiliac biopsies before and at the end of treatment following double in vivo pre-labelling with demethylchlortetracyc-line. Indices of whole body bone formation, obtained from the analysis of85Sr data, showed substantial increases (P〈0.005) for all three indices measured) while biochemical (hydroxyproline) and kinetic measurements of bone resorption showed modest and equivocal changes only. As a result calcium balance improved. Gastrointestinal calcium absorption showed a tendency to improve, while urine calcium decreased; but these changes were statistically not significant except for radiocalcium absorption in the oestrogen treated subgroup. Histomorphometry revealed substantial increases in cancellous bone volume as reported previously with hPTH 1–34 given alone. However, iliac (as distinct from whole body) indices related to bone formation and resorption appeared to have returned towards pre-treatment values by the time of the second biopsy under the influence of the anti-resorptive agent given with the hPTH 1–34. It is confirmed that hPTH 1–34 therapy can increase iliac cancellous bone mass (as well as spinal cancellous bone mass as reported earlier) without a long-term increment in whole body bone resorption, providing the hPTH is combined with an anti-resorptive agent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01625448
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  • 6
    Electronic Resource
    Electronic Resource
    Dual-energy X-ray absorptiometry of the spine in anteroposterior and lateral projections (1994)
    Springer
    Osteoporosis international 4 (1994), S. 110-116 
    Details
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Densitometry ; Dual-energy X-ray absorptiometry ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Dual-energy X-ray absorptiometry (DXA) of the lumbar spine provides an estimation of the bone mineral content (BMC) corrected by the projected area of the spine and expressed in g/cm2. This two-dimensional estimate of the bone mineral density (BMD) is influenced by the skeletal size, assessed by the subject's height. In order to obtain an estimate of the volumetric BMD, we measured BMC with a new DXA device (Sophos L-XRA) equipped with 24 detectors and a rotating arm, thus allowing scanning of the lumbar spine in both an anteroposterior (AP) projection and a lateral (LAT) projection with the patient in a supine position. Comparison between the results obtained on the third (L3) and fourth (L4) lumbar vertebrae with automatic or manual analysis showed that the best precision was obtained with the lateral measurement of L3 alone with an automatic soft tissue baseline determination. Results were expressed in g/cm2 and in g/cm3 (by dividing the g/cm2 value by the width (AP area divided by the height of the vertebra) of L3), and were compared with those obtained by conventional AP scanning of L2–4 (g/cm2). The in vivo precision error evaluated by triplicate measurements on 10 controls was 17 mg/cm2 (1.96%) and 5.2 mg/cm3 (2.31%) for LAT L3 as compared with 13 mg/cm2 (1.15%) for AP L2–4. Volumetric BMD (g/cm3) measurement, assessed in vitro on a calibrated hydroxyapatite phantom, and the absolute values obtained in normal women were similar to those obtained by quantitative computed tomography (QCT). In 39 healthy adults (27±4 years) BMD expressed in g/cm2 was correlated with height (r=0.36 for AP L2–4 andr=0.39 for LAT L3;p〈0.05 for both) but not with LAT L3 BMD expressed in g/cm3 (r=0.02; NS). The age-related bone loss between 30 and 80 years of age, derived from the normal values for 101 healthy women (age range 19–73 years) was 36% for AP L2–4, 52% for LAT L3 (g/cm2) and 60% for LAT L3 (g/cm3). In a group of 22 women with untreated postmenopausal vertebral osteoporosis (one or more non-traumatic vertebral crush fractures) the mean decrease in BMD, expressed as a percentage of the age-adjusted normal value, was more pronounced (p〈0.001) for LAT L3 BMD (−21% in g/cm2,Z-score −1.08; −22% in g/cm3,Z-score −0.94) than for AP L2–4 BMD (−9%,Z-score −0.66). We conclude that: 1) BMD measurement restricted to the vertebral body of L3 can be achieved with a low precision error with this new DXA device; 2) it allows an estimate of the volumetric density (g/cm3) which does not seem to be influenced by skeletal size; 3) lateral BMD appears to be more sensitive than conventional AP scanning for assessing age-related bone loss and should be useful in the investigation of trabecular osteoporosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623234
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  • 7
    Electronic Resource
    Electronic Resource
    Gastrointestinal calcium absorption and dietary calcium load: Relationships with bone remodelling in vertebral osteoporosis (1995)
    Springer
    Osteoporosis international 5 (1995), S. 14-22 
    Details
    ISSN: 1433-2965
    Keywords: Bone histomorphometry ; Calcium-47 ; Calcium absorption ; Osteoporosis ; Vitamin D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Patients with vertebral osteoporosis have a wide range of bone loss rates, bone remodelling rates and capacities for gastrointestinal (GI) calcium absorption. To test the hypothesis that variations in GI absorptive capacity determine rates of bone loss or remodelling, we have sought relationships betwen calcium absorption or vitamin D metabolite levels on the one hand and rates of cancellous and cortical bone loss (measured by serial quantiative computed tomography in the radius;n=25) or indices of bone remodelling in tetracycline-prelabelled transiliac biopsies (n=41) on the other, in a sequential untreated group. Calcium absorption (net and true) was measured in 18-day balances and by a two-isotope deconvolution method (fractional absorption and maximum absorption rate, MAR). There was no significant seasonal effect on any of these four measures of calcium absorption (variance ratio,F=0.52–1.61,p〉0.1) or on 1,25-dihydroxyvitamin D levels (F=0.13,p〉0.1; range 11–69 pg/ml), notwithstanding the expected seasonal effect on 25-hydroxyvitamin D levels (mean 18.7 ng/ml, zenith mid July, semi-amplitude 7.5 ng/ml;F=6.82,p〈0.01). Neither this metabolite nor 1,25-dihydroxyvitamin D correlated with any index of calcium absorption (p〉0.1). No measure of calcium absorption (or intake) had a significant relationship with radial cortical or cancellous bone loss (p all 〉0.1) but cancellous bone loss was associated with the rate of endogenous calcium excretion (r=0.50,p〈0.05). A positive relationship between 25-hydroxyvitamin D and unlabelled osteoid surface (a marker of reduced blast vigour) persisted after adjustment for season (Student'st=2.70,p〈0.01) but did not reflect 1,25-dihydroxyvitamin D levels. This study did not address the question of whether reduced GI calcium absorption has a uniform effect on bone remodelling in osteoporosis. However, variations in capacity for calcium absorption are unlikely to be responsible for the heterogeneity in bone loss and remodelling rates seen in vertebral osteoporosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623653
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  • 8
    Electronic Resource
    Electronic Resource
    Age-related changes in os calcis ultrasonic indices: A 2-year prospective study (1995)
    Springer
    Osteoporosis international 5 (1995), S. 478-483 
    Details
    ISSN: 1433-2965
    Keywords: Aging ; Bone loss ; Bone mineral density ; Broadband ultrasound attenuation ; Speed of sound ; Stiffness index ; Ultrasound
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We performed repeated ultrasound measurements approximately 2 years apart (average 23 months ±3 months) on the os calcis of 113 healthy postmeno-pausal women recruited from two large prospective cohort studies named OFELY and EPIDOS. Group A (from OFELY) consisted of 88 women aged 52–72 (63±5) years, randomly selected from a large insurance company, and group B (from EPIDOS) consisted of 25 women aged 75–88 (80±4) years, randomly selected from the voting lists. We obtained broadband ultrasonic attenuation (BUA) and speed of sound (SOS) measurements, as well as the Stiffness index, with a Lunar Achilles ultrasound machine. We performed dual energy X-ray absorptiometry (DXA) measurements of femoral neck bone mineral density (neck BMD) with a Hologic QDR 2000 for group A and with a Lunar DPX Plus for group B. The decrease that we observed over 2 years was on average ±1 SD: −1.01±4.6 dB/MHz (p=0.02) for BUA (which is approximately equal to the long-term precision error in vitro), −11.3±9.2 m/s (p=0.0001) for SOS (approximately 5 times the precision error), −3.8±4.2 %YA (p=0.0001) for Stiffness (2.5 times the precision error) and −0.01±0.03 g/cm2 (p=0.0001) for neck BMD (approximately equal to the precision error). In terms of percentage change this represents: −1.0%±4.3% for BUA, −0.8%±0.6% for SOS and −1.85%±4.4% for neck BMD. At the individual level, most SOS and Stiffness values were consistent with a decrease, whereas BUA and neck BMD values were spread out above and below the zero line of no change. The decreases in SOS and Stiffness were significantly larger in the early postmenopause (⩽20 years since menopause [YSM]) than in the late postmenopause (〉20 YSM). We observed a similar trend for BUA and BMD but this did not reach statistical significance. We found a weak but significant correlation between changes in ultrasound variables and changes in neck BMD. However, the 2-year changes observed in SOS were not significantly correlated with changes in BUA. This study suggests that the heel ultrasound measurements of SOS and Stiffness are valuable indices of postmenopausal bone loss, and could be used for follow-up in therapeutic trials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01626612
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  • 9
    Electronic Resource
    Electronic Resource
    Trabecular and endocortical bone remodeling in postmenopausal osteoporosis: Comparison with normal postmenopausal women (1990)
    Springer
    Osteoporosis international 1 (1990), S. 41-49 
    Details
    ISSN: 1433-2965
    Keywords: Bone ; Histomorphometry ; Osteoporosis ; Osteoblasts ; Osteocalcin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To assess the bone turnover abnormalities which characterize postmenopausal osteoporosis with vertebral fractures (PMOp), a transiliac bone biopsy was performed after double labeling of the mineralizing front with tetracycline in 50 untreated PMOp patients who were compared with 13 healthy age-matched volunteer females. The analysis of bone remodeling and structure parameters demonstrated that PMOp is a disease affecting both the cancellous and the endocortical envelopes and characterized by increased resorption and by a marked decrease in the osteoblastic apposition rate due to a reduced duration of bone formation. This induces a decrease in the width of both individual osteons and trabeculae. In PMOp, the wide spectrum of bone turnover as compared with the controls, associated with the typical bimodal distribution of cancellous osteoid perimeter, allowed us to identify two subsets, one with normal turnover (NT) and one with high turnover (HT) representing 30% of the cases. When compared to NT, HT was characterized by increased osteoclast number, lower bone volume, thinner osteons, increased formation at the tissue-level and markedly decreased duration of formation. In HT the marked decrease in the duration of activity of osteoblasts and the markedly increased number of osteoclasts induced a greater decrease in bone volume, despite the increase of bone formation at the tissue level. These subsets could not be distinguished by any clinical or biochemical parameter except for serum bone gla protein (osteocalcin) which was significantly higher (as a group) in HT than in NT. The underlying cause for these two subsets is unknown. We conclude that PMOp affects the cancellous and the endocortical bone. Bone loss results from a wide spectrum of bone turnover abnormalities, with two distinct subsets, one with normal turnover and one with high turnover.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01880415
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  • 10
    Electronic Resource
    Electronic Resource
    Glucocorticoid-induced inhibition of osteoblastic bone formation in ewes: A biochemical and histomorphometric study (1993)
    Springer
    Osteoporosis international 3 (1993), S. 97-102 
    Details
    ISSN: 1433-2965
    Keywords: Bone formation ; Ewes ; Glucocorticoids ; Histomorphometry ; Osteocalcin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The mechanisms underlying glucocorticoid-induced osteoporosis in humans are a defect in bone formation associated with increased bone resorption. The latter may be due to elevated parathyroid hormone (PTH) levels induced by the impairment of intestinal calcium absorption caused by corticosteroids. In this study we analysed the effects of corticosteroids in old ewes, a potential model for the study of human bone turnover. Two groups of seven 9-year-old female sheep were selected. The first group was injected intramuscularly with a daily dose of 30 mg methylprednisone (MP) during the first 2 months and 15 mg during the last month. After 2 and 3 months of treatment, blood samples were taken. At the end of the experiment the animals were slaughtered and the iliac crest kept for bone histomorphometry. Serum osteocalcin (sOC) rapidly and markedly decreased in the MP-treated group compared with controls (−77%;p〈0.01). In contrast, at the end of the experiment serum calcium and PTH levels were similar in both groups. Histomorphometric analysis showed a significant reduction in the wall width of trabecular packets. Dynamic parameters reflecting bone formation at the tissue and cell levels were significantly lower in the MP-treated group than in controls, with a highly significant decrease in the mineralization rate (MAR: −63%,p〈0.05) and double-labeled perimeter (dLPm/B.Pm: −92%p〈0.05). The bone formation rate (BFR/B.Pm) also decreased by 84% and the adjusted apposition rate (Aj.AR) by 80%. The increase in the total formation period was mainly due to an increase in the inactive period. Significant correlations were found between sOC and MAR, dLPm/B.Pm and BFR/B.Pm (withr′ respectively 0.67, 0.76 and 0.51). In conclusion, the effects of corticosteroid on ewe bone remodeling are essentially characterized by a major bone formation defect without evidence of secondary hyperparathyroidism, although this cannot be totally excluded by our results. Ewes treated with glucocorticoids could represent a good model for evaluating the effects of drugs candidates for all bone conditions characterized by reduced bone formation resulting from osteoblastic depression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623380
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