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  • 1
    ISSN: 1432-0827
    Keywords: Key words: COLIA1 — CTR — Genetics — Bone mass — Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract. The variability of bone mass and bone strength is in part genetically determined. The pathophysiology of the disease is complex and its heritability is almost certainly polygenic. In a large group of women from north eastern Italy, homogeneous for calcium intake and other risk factors for osteoporosis, we investigated three different genetic polymorphic markers that have been associated with bone mineral density (BMD). The study includes 663 postmenopausal (aged 48–85 years) and 52 perimenopausal (aged 47–53 years) women. Lumbar spine and hip BMD were measured by dual energy X-ray absorptiometry (DXA). After DNA extraction, the restriction enzymes utilized were MscI for the SP1 site of the collagen type I regulatory region (COLIA1), AluI for the calcitonin receptor (CTR) gene, and BsmI for the Vitamin D receptor (VDR) gene. COLIA1 genotype was significantly associated with age-adjusted hip BMD, with the highest values in the SS group and the lowest in the ss group (p 〈 0.05). The COLIA1 effect was not visible until the sixth decade of life, but it increased thereafter with aging, becoming statistically significant also at the lumbar spine in subjects aged 〉70 years. CTR genotype was also significantly related to bone mass in the CC group, with the lowest age and weight-adjusted BMD values at the spine (p 〈 0.05). The CTR genotype effect was greater in the younger subset of women. This suggests that the CTR genotype might influence the process of acquiring peak bone mass rather than the process of bone loss along aging. No trend association was found between BMD values and VDR genotype. These findings suggest an association between the COLIA1 gene polymorphism more with the age-related rate of bone loss than with peak bone mass, which apparently is somewhat affected by CTR gene polymorphism.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1433-2965
    Keywords: Osteoporosis ; Bisphosphonates ; Alendronate ; Calcitonin ; Postmeno pausal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Alendronate sodium (ALN) is a potent amino bisphosphonate which specifically inhibits osteoclastic bone resorption and has been found to reverse bone loss in several animal models. To determine if daily oral ALN treatment could prevent or reverse bone loss in osteoporotic postmenopausal women, and to compare ALN to intranasal salmon calcitonin (CT), a 2-year, double-masked, randomized, placebo-controlled study was initiated at 9 clinical centers in Italy. Two hundred and eighty six postmenopausal women (age 48–76) with spinal bone mineral density (BMD) ≥2 SD below adult mean peak, with or without vertebral crush fractures, were randomized to one of four treatment arms: ALN 10 mg daily, ALN 20 mg daily or matching placebo (these groups all double-masked), or CT 100 IU daily (open label) for 2 years. All patients received supplemental calcium (as carbonate) 500 mg daily. Bone mass was measured by dual-energy X-ray absorptiometry of the PA lumbar spine (LS) and proximal femur (femoral neck and trochanter) at 6-month intervals. Subject safety was measured through sequential clinical and laboratory evaluation. A planned 1-year interim analysis of this ongoing study was performed cetrally in a manner that maintains the double-mask for all subjects receiving oral study drug. Relative to PBO, ALN at either 10 mg or 20 mg daily increased LS BMD by 4.7% and 6.1%, respectively; each increased femoral neck BMD by 3.1% and increased trochanter BMD by 3.3% and 3.8% respectively. In contrast, CT failed to significantly increase BMD of either the spine, femoral neck or trochanter, either relative to baseline or to PBO. ALN decreased biochemical markers or bone turnover, whereas both PBO and CT were ineffective. No serious adverse experiences attributable to the use of alendronate were detected. In summary, daily oral ALN for one year appears to be effective in decreasing bone turnover and increasing bone mass at the spine and the hip. In contrast, daily CT 100 IU had no significant effects either to reduce bone turnover or to increase bone mass at either site. In conclusion, ALN effectively increased bone mass in osteoporotic menopausal women, and was associated with an excellent safety profile.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Osteoporosis international 4 (1994), S. S59 
    ISSN: 1433-2965
    Keywords: Bone loss ; Elderly ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A large number of cross-sectional studies suggest that rates of bone loss decrease in the elderly, particularly at the spine and radius. For this reason it has been argued that bone mass measurements are unhelpful in assessing fracture risk in the elderly and that drugs affecting bone metabolism are less likely to be of benefit in reducing this risk. This paper reviews the assumptions on which these conclusions are based and argues that in many instances they are flawed. Indeed, studies examining rates of bone loss in the elderly either directly or by biochemical indices of bone turnover suggest that bone loss continues throughout life and may even accelerate after the age of 70 years. This conclusion supports the view that identification of patients at risk and subsequent treatment is of value in all age groups.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Osteoporosis international 4 (1994), S. S27 
    ISSN: 1433-2965
    Keywords: Calcium intake ; Osteoporosis ; Peak bone mass ; Physical exercise
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Bone mass in the elderly depends on the rate of involutional bone loss and on the peak bone mass, i.e. the bone mass present around the third decade of life. Factors relating to the attainment of peak bone mass include congenital factors, diet, hormones, physical activity, lifestyle factors, drags and diseases. A therapeutic intervention aimed at increasing peak bone mass is conceivable only by controlling factors such as estrogen status, dietary calcium intake and physical activity. Calcium intake appears to be relevant up to the so-called threshold intake (1000 mg/day), but higher allowances do not seem to offer additive advantages. Exercise affects only the regions of the skeleton under mechanical stress. Estrogen administration is realistic only in conditions characterized by severe hypoestrogenism.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Osteoporosis international 5 (1995), S. 75-78 
    ISSN: 1433-2965
    Keywords: Bone mass ; Efficacy endpoint ; Fracture risk ; Osteoporosis ; Therapy ; Women
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Evaluation of the efficacy of osteoporosis treatments poses a major challenge for clinical investigators. This paper addresses the question of whether increases in bone mass induced by therapy for osteoporosis are sufficient to determine the efficacy of that therapy, or whether long-term fracture endpoint studies are required. Osteoporosis has been defined as a systematic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. This association between bone mass and fracture risk has been found to be stronger than other well-recognized risk factor associations, such as blood pressure and risk of stroke. Although fracture endpoint studies would provide confirmation of the benefit of osteoporosis therapy, such trials require that several thousand patients be studied for many years, making such studies impractical as a means for providing data for the approval of new therapies. Determination of increased bone mass may provide data that are just as useful in evaluating therapeutic efficacy. The use of bone mass as the primary efficacy endpoint for those therapies that are associated with normal bone quality is justified by the well-documented relationship between bone mass and fracture risk observed in several epidemiological studies.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1433-2965
    Keywords: Estrogen replacement therapy ; Menopause ; Parathyroid hormone ; Serum bicarbonate ; Serum calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Mineral metabolism was studied in 99 premenopausal and 80 postmenopausal women both before and after 9–14 months of treatment with 50 µg/day transdermal estradiol. In estrogen-repleted subjects (premenopausal women and postmenopausal women on estrogen replacement therapy) total serum calcium was significantly lower (0.065 mmol/l;p〈0.001) than in those who were estrogen-depleted (untreated postmenopausal women). This difference was smaller but still significant for calculated ultrafiltrable calcium (UFCa: 0.02–0.03 mmol/l;p〈0.001). However, ionized calcium (both calculated and measured) was not different in the two groups of women. This finding explains why estrogen repletion does not induce changes in the serum level of intact parathyroid hormone (PTH), despite lower total or ultrafiltrable serum calcium. In a parallel study we have shown that intravenous administration of aminobutane bisphosphonate, a powerful inhibitor of bone resorption, produces similar decreases in serum calcium which were associated with significant increases in intact PTH. Estrogen-depleted women had, on the one hand, significantly higher serum levels of bicarbonate, anion gap, complexed calcium, pH, phosphate and alkaline phosphatase, and higher rates of tubular reabsorption of phosphate and urinary excretion of calcium and hydroxyproline. On the other hand they had lower serum chloride levels and lower rates of tubular reabsorption of calcium. Altogether these findings might indicate that estrogen deficiency decreases renal sensitivity to PTH. This is responsible for the higher serum phosphate and bicarbonate levels, the resulting mild metabolic alkalosis leading to higher serum levels of complexed ultrafiltrable calcium and higher rates of urinary excretion of calcium, but unchanged serum levels of ionized calcium and PTH.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1433-2965
    Keywords: Dual-energy X-ray absorptiometry ; Osteoporosis ; Radiogrammetry ; Radiographic absorptiometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The best method for the diagnosis of osteoporosis and assessment of fracture risk is currently considered to be bone densitometry. The most commonly used dual-energy X-ray absorptiometry (DXA) methods may sometimes not predict bone mass accurately in every skeletal site, are expensive and not widely available. The recent development of computed analysis of a plain radiograph of the hand might provide a practical, inexpensive and rapid method for evaluation of bone mineral status. In this study we evaluated 20 healthy premenopausal and 660 postmenopausal women. In 36 of these subjects a second evaluation was carried out after 2 years of therapy with calcium supplements. The internal and external diameters of the second metacarpal and the metacarpal and ultradistal radial bone density were evaluated using a technical device developed in our laboratory and marketed by NIM, Verona, Italy (Osteoradiometer). The radio-graphic images, captured by a video camera, were digitized and studied by computed analysis. In 150 subjects bone density at the level of the lumbar spine, femur, and ultradistal and proximal radius was also measured by DXA techniques. Both external (D) and internal (d) diameters increase significantly with age and years since menopause (YSM), whereas metacarpal index (D−d/D) and metacarpal and ultradistal radial bone density decrease significantly with age and YSM. The ratio between metacarpal bone mineral content and the cortical area (volumetric metacarpal bone density) did not change with age. Significant correlations were found between radiometric findings and DXA measurements. The best correlation coefficients were between bone density measured at the level of the ultradistal radius by DXA and radiographic absorptiometry. In the 2-year follow-up study, a 4.9% and 6.2% decline in radial metacarpal bone density respectively were observed, but the difference was statistically significant only for the latter. In conclusion, computed radiogrammetry is closely correlated with all DXA measurements and may be useful in screening of large populations, providing a simple, inexpensive and sufficiently precise method for evaluation of bone mineral status. Further studies are warranted for assessing the accuracy of radiogrammetry for longitudinal investigations and its capacity to predict fracture risk.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1433-2965
    Keywords: Cortical bone density ; DXA ; Postmenopausal osteoporosis ; Quantitative computed tomography ; Trabecular bone density
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Bone densitometry has become a major tool for osteoporosis risk assessment. The traditional dual-energy X-ray absorptiometry (DXA) methods are able to evaluate the bone mineral content (BMC; mg/cm) and the areal density (BMD; mg/cm2), but only quantitative computed tomography (QCT) has the potential to measure the true volumetric bone density in the sense of mass per unit volume (mg/cm3). Peripheral QCT (pQCT) measurements were carried out at the non-dominant radius using a Stratec XCT 960 (Unitrem, Roma) in 241 postmenopausal and 29 premenopausal women. The sites of evaluation were both the ultradistal and the proximal radius. The technique used has a coefficient of variation of 2% and it allows separation of the bone section into trabecular and cortical bone on the basis of density threshold. Bone mass of radius, hip and spine was also evaluated by DXA procedures. The bone density data obtained by pQCT were significantly correlated with all DXA measurements. The correlation coefficients between their respective BMD values ranged from 0.48 to 0.75, but for the BMC values of the radius the correlation coefficients ranged from 0.82 to 0.93. The BMD values measured by DXA, but not by pQCT, were positively related with patient heights. All pQCT density measurements, including those obtained at the proximal radius and containing exclusively cortical bone, where negatively related with age and years since menopause. A partial volume effect, which is increasingly relevant the thinner are the bone cortices, might explain that. However, by applying increasing density thresholds, cortical bone density seems to decrease with age as a consequence of a gradual density diminution from the inner part of the bone cortex outwards. Trabecular bone density decreases with aging, but its overall mass does not change as a consequence of an age-related enlargement of trabecular area. Thus, the proportion of trabecular bone over total bone rises, and this might be relevant for our understanding of the age-related changes in bone turnover and rate of bone loss.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1433-2965
    Keywords: Ipriflavone ; Postmenopausal bone loss ; Radial bone mineral density
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two hundred and fifty-five postmenopausal women with distal forearm bone mineral density (BMD) 1 SD below the mean value for normal age-matched postmenopausal subjects were randomly allocated to a 2-year treatment with oral ipriflavone (200 mg t.i.d.) or a matched placebo, according to a double-masked, parallel-group design. All patients also received a 1 g/day calcium supplement. Distal radius BMD and bone metabolism markers were measured at baseline, and every 6 months. Blood haematology and chemistry and physical parameters were monitored at the same time. One hundred and ninety-six patients completed 2 years of treatment. BMD changes from baseline were analysed according to valid completers (VC) and intention to treat (ITT) analyses. In both cases radial BMD was maintained in patients treated with ipriflavone while it decreased in those receiving the placebo, the between-treatment difference being significant at year 1 and year 2. Urinary hydroxyproline/creatinine levels were decreased in the ipriflavone-treated group and increased in the placebo group, with a significant between-treatment difference. Adverse reactions, mainly gastrointestinal, occurred to a similar extent in the two treatment groups.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Etidronate ; Gonadotropin-releasing hormone agonist ; Osteoporosis ; Polycystic ovary syndome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Treatment with gonadotropin-releasing hormone (GnRH) agonist leads to enhanced bone turnover and accelerated bone loss in premenopausal women with endometriosis, uterine leiomyomatomas and hirsutism. Sodium etidronate is a powerful inhibitor of bone resorption which has been proven efficacious in the prevention and treatment of postmenopausal osteoporosis. The objective of this study was to evaluate the skeletal effects of 6 months of therapy with the depot preparation of the GnRH agonist triptorelin (decapeptil 3.75 mg intramuscularly every 4 weeks) in 24 hirsute patients, aged 24–33 years, with hyperandrogenic chronic anovulation. Ten patients also received cyclical etidronate in an oral dose of 400 mg/day for 2 weeks, followed by an 11-week period of 500 mg/day elemental oral calcium (one cycle). The remaining 14 patients received 500 mg/day of elemental calcium continuously. After 6 months all treatments were discontinued for at least a further 6 months. Bone mineral density (BMD) at lumbar spine and hip (dual-energy X-ray absorptiometry, Sophos LXRA, France) and biochemical markers (serum alkaline phosphatase, osteocalcin, urinary N-telopeptide and hydroxyproline/creatinine ratio) were evaluated at baseline, 6 months and 12 months. In the group given GnRH agonist alone BMD fell significantly at all measured skeletal sites during the first 6 months. In the patients treated with etidronate a significant decrease in BMD was observed at lumbar spine but not in the femoral neck and trochanter, and the changes at lumbar spine and trochanter were significantly smaller than those in the control group. At 6 months bone turnover was also increased in patients treated with GnRH and calcium. Cyclical etidronate prevented the increase in biochemical markers of bone formation and resorption, with the exception of calcium/creatinine excretion, which was significantly increased in both groups. Six months after treatment withdrawal BMD did not recover in either group. Biochemical markers (N-telopeptide, serum alkaline phosphatase) remained increased in those patients previously treated with calcium alone while they remained close to baseline values in the patients treated with cyclical etidronate. Our study indicates that: (1) GnRH agonist therapy causes remarkable bone loss in young individuals with androgen excess who are expected to have increased bone mass; (2) this bone loss can be partially prevented by intermittent cyclical etidronate therapy.
    Type of Medium: Electronic Resource
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