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PubMed1991

The effects of muscle-building exercise on forearm bone mineral content and osteoblast activity in drug-free and anabolic steroids self-administering young men.

We measured bone mineral content (BMC) and bone density (BD) at appendicular sites by single photon absorptiometry in 18 men engaged in body-building exercises for at least 2 years, and in 14 age- and weight-matched controls. Eight exercises were using anabolic steroids by self-administration. Serum levels of bone Gla-protein (BGP), a reliable index of bone formation were also measured in all subjects. It was observed that muscle-building exercise was associated with increased BMC and BD at the distal radius, which contains both cortical and trabecular (more than 50%) bone. Previous authors have failed to detect any increase in BMC at mid radius, a site consisting almost entirely of cortical bone. Serum BGP levels were significantly higher in exercisers than in controls. If compared to drug-free exercisers, subjects taking steroids showed no significant increase of BMC, BD and serum levels of BGP. This study shows that muscle-building exercise is associated with increase in BMC and BD also at non-weight bearing sites, and that anabolic steroids did not provide, at the time of the observation, any further stimulus for osteoblast activity and bone formation.

Absorptiometry, Photon↗

PubMed1991

Long-term anabolic effects of prostaglandin-E2 on tibial diaphyseal bone in male rats.

The effects of long-term prostaglandin E2 (PGE2) on tibial diaphyseal bone were studied in 7-month-old male Sprague-Dawley rats given daily subcutaneous injections of 0, 1, 3 and 6 mg PGE2/kg/day for 60, 120 and 180 days. The tibial shaft was measured by single photon absorptiometry and dynamic histomorphometric analyses were performed on double-fluorescent labeled undecalcified tibial diaphyseal bone samples. Exogenous PGE2 administration produced the following transient changes in a dose-response manner between zero and 60 days: 1) increased bone width and mineral density; 2) increased total tissue and total bone areas; 3) decreased marrow area; 4) increased periosteal and corticoendosteal lamellar bone formation; 5) activated corticoendosteal lamellar and woven trabecular bone formation and 6) activated intracortical bone remodeling. A new steady-state of increased tibial diaphyseal bone mass and elevated bone activities were observed from day 60 onward. The elevated bone mass level attained after 60 days of PGE2 treatment was maintained at 120 and 180 days. These observations indicate that the powerful anabolic effects of PGE2 will increase both periosteal and corticoendosteal bone mass and sustain the transient increase in bone mass with continuous daily administration of PGE2.

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PubMed1992

Preferential osteopenia in women with osteoporotic fractures.

One-hundred thirty-six women with spontaneous vertebral crush fractures had bone density measurements by photon absorptiometry. Their absolute and relative extent of osteopenia were expressed as Z scores with respect to values from normal white women. Absolute Z scores were used to express the mean bone mass of women with crush fractures vis-a-vis normal women at peak bone mass; relative Z scores were used to express the same means vis-a-vis age-matched controls. The skeletal sites measured included the distal radius, lumbar spine, and three sites on the femur (neck, Ward's triangle, and trochanter). The absolute deficit for the five sites ranged from -1.66 to -2.60. The relative deficit was close to 1 SD for all sites. A discriminant analysis revealed that the spine and femur were predictive for vertebral crush fractures but the radius was not. Comparison with a previously reported hip-fracture population (n = 31) showed that the low bone density of the spine separated the two fracture groups best. We propose the following: (a) vertebral-fracture patients have extensive generalized osteoporosis including the hip with a preferential deficit in the spine and (b) hip-fracture patients have generalized osteoporosis with preferential osteopenia of the hip and do not have a greater mineral deficit in the spine or radius than age-matched normal women. It may be that if a single site is to be selected for screening for spine and hip fractures, the greatest value would be in measurement of the femur, although ideally the skeletal site of interest would be measured. Prospective studies are needed to confirm the utility of measurements at the spine and hip in prediction of future fractures.

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PubMed1992

Ipriflavone and low doses of estrogens in the prevention of bone mineral loss in climacterium.

Estrogen replacement therapy can counteract all postmenopausal symptoms. While low estrogen doses (0.15-0.30 mg of conjugated estrogens/day) can counteract neurovegetative and psychological symptoms, higher estrogen doses (at least 0.625 mg of conjugated estrogens/day) are required to prevent bone mineral loss in postmenopausal women. However, if contra-indications to high estrogen doses exist, drugs other than estrogens can represent a suitable treatment for postmenopausal osteoporosis both alone or in combination with low estrogen doses. Experimental and clinical data have shown that ipriflavone is effective in the treatment of established postmenopausal osteoporosis. With the purpose of evaluating whether ipriflavone is able to enhance estrogen activity on bone metabolism, 133 postmenopausal women were randomly submitted to the treatment with: (1) placebo; (2) 0.15 mg/day of conjugated estrogens; (3) 0.30 mg/day of conjugated estrogens; (4) 0.15 mg/day of conjugated estrogens plus 600 mg/day of ipriflavone; (5) 0.30 mg/day of conjugated estrogens plus 600 mg/day of ipriflavone. One g/day of calcium supplementation was given to all women. In all subjects bone mineral density was measured before and after 6 and 12 months of treatment at the distal radius by dual-photon absorptiometry. A moderate decrease of bone mineral density was evidenced in women submitted to placebo or to estrogen therapy alone. By contrast, an increase of BMD was measured after 12 months of treatment in the women treated with 0.15 (not significant) or 0.30 mg/day (P < 0.01) of conjugated estrogens associated with ipriflavone. Both dosages of conjugated estrogens were able to induce a significant reduction of neurovegetative symptoms. The increase of bone density obtained with the combination of conjugated estrogens with ipriflavone demonstrates that this combination improves the effects of low estrogen doses on bone mass representing a satisfactory approach in the prevention and treatment of all symptoms related to the climacteric syndrome.

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PubMed1994

Determinants of forearm mineral density and its correlation with fracture history in women.

In order to evaluate the role of single photon absorptiometry (SPA) in the prediction of osteoporotic fracture risk, 1935 women, referred for measurement of forearm mineral density (FMD) at the distal radial site, were studied by questionnaire in a cross-sectional design. There was no significant decline in FMD until the age of 47, after which there was a linear decline with age of about 1.2% per year. There was no relationship between age and FMD, or forearm mineral content (FMC), in premenopausal women. There was a fall in FMD with the number of years since menopause, after correcting for the effects of age, of approximately 0.5% per year. Body weight was positively correlated with FMC in postmenopausal women. The duration of exposure to hormone replacement therapy (HRT) was positively correlated with FMD, and the magnitude of this effect was reduced the longer the delay between the onset of the menopause and the commencement of HRT. There was no significant association of FMD with calcium intake, weight-bearing exercise, tobacco or alcohol consumption, or family history of osteoporosis. FMD was significantly lower in postmenopausal women who reported fractures after the age of 25, after correcting for age and years postmenopause. In conclusion, a low FMD is predictive of a past history of fractures and may therefore be capable of predicting future fracture risk.

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PubMed1996

Salmon calcitonin plus intravaginal estriol: an effective treatment for the menopause.

OBJECTIVE: Intravaginal estriol (E3) effectively improves postmenopausal genito-urinary disturbances, without stimulating endometrial proliferation. The aim of the present study was to evaluate the effect of intravaginal estriol (E3) plus nasal spray salmon calcitonin (sCT), to improve neurovegetative symptoms and to prevent the decline of bone mineral density (BMD) of postmenopausal women. METHODS: Two hundred and fourteen (214) healthy postmenopausal women were treated for 12 months with: (1) E3 (0.5 mg every other day) + Ca (0.5 g/day); (2) E3 + Ca + sCT (50 IU x 2/day); (3) sCT + Ca; (4) Ca. Climacteric complaints, such as hot flushes and sweating, BMD at the distal 1/10 of the radius, analyzed by dual photon absorptiometry, urinary excretion of hydroxyproline and serum alkaline phosphatase were evaluated at baseline and every 6 months. At the same time, patient compliance and drug tolerability were evaluated. RESULTS: E3 but not sCT, improved hot flushes and sweating. E3 blunted but not completely counteracted the BMD decline observed in women treated with only Ca, and reduced urinary hydroxyproline excretion. sCT markedly increased BMD values and reduced both urinary hydroxyproline excretion and serum alkaline phosphatase. These effects were not potentiated by E3 coadministration. All treatments were well tolerated. CONCLUSIONS: Present data indicate that the combined administration of intravaginal E3 and sCT may represent an alternative therapeutic regimen for those postmenopausal women who do not accept or have contraindications to classical hormone replacement therapy.

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PubMed1995

Creatinine clearance at menopause is not related to bone mass in later life.

OBJECTIVE: To investigate whether creatinine clearance (Ccr) at menopause is related to bone mass later in life. METHODS: Ccr was measured within 5 years after natural menopause in two groups of normal women. Bone mineral content (BMC) of the distal forearm, lumbar spine, and proximal femur were measured by photon absorptiometry and dual energy X-ray absorptiometry in these women 6 years (n = 47) and 14 years later (n = 98). RESULTS: Ccr corrected for body surface area just after the menopause did not correlate with BMC, 6.5 years and 14.5 years later. CONCLUSION: Low Ccr within the normal range at menopause is not an independent risk factor for osteopenia in later life.

Absorptiometry, Photon↗

PubMedDate not supplied

Effects of anti-epileptic drug therapy on bone mineral density in ambulatory epileptic children.

In order to assess the bone changes in the subjects receiving anti-epileptic drugs (AEDs), bone mineral densities (BMDs) of the arms, legs, ribs, pelvis, spine, and the whole body were scanned in 78 epileptic children and in 78 controls using dual photon absorptiometry. The study subjects were classified according to the duration of the monotherapy with phenobarbital (PB) or phenytoin (PHT); those who received AEDs for less than 12 months as Group I, for 13-23 months as Group II, and for 24 months as Group III. Group III was subclassified according to the kind of AEDs administered, into those receiving PB as Group IIIp, and those receiving PHT as Group IIId. There was no significant differences in the BMDs of each area, when compared to each control in Groups I and II. In Group III, there were significant differences in ribs and spine, according to the duration of administration. In Group IIIp, there was a significant difference in ribs and spine, and, in Group IIId, there was a significant difference in most of the areas. These results show that the measurement of BMDs in the ribs and spine is necessary for the early detection of subtle bone loss, and it is recommended that vitamin D be administered to children with epilepsy receiving AEDs over 24 months.

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PubMed1993

An epidemiologic study of osteoporosis in Taiwan.

In 1989, a cross-sectional study was carried out in Taiwan to understand the distribution of bone mineral density (BMD) in the lumbar spine of Chinese people and to identify the risk factors associated with osteoporosis. BMD of the lumbar spine was measured by dual-photon absorptiometry in 404 healthy volunteers (266 women and 138 men, aged 15 to 83 years) living in Lin-Kou Township. The age-specific mean values of lumbar spine BMD were higher for men than for women after age 60. Furthermore, the BMD of women declined significantly after age 40. However, the BMD of men did not show a downward trend with age. In a multiple logistic regression analysis of fracture risk expressed as a categorical level of BMD, age, diabetes, and years since menopause were associated with lower BMD, while body mass index was associated with higher BMD. In a multiple linear regression analysis of BMD, significant variables were years since menopause, age, body mass index, and seaweed diet. Variables that were significant in bivariate analysis, but not multiple variable analysis were education, milk consumption, breast-feeding, frequency of pregnancy, and age at first menstruation. However, cigarette habits, alcohol consumption, and physical activity were not associated with the BMD level in any of these analyses.

Absorptiometry, Photon↗

PubMed1989

Physical and histomorphological characteristics of iliac crest bone differ according to the grade of osteoarthritis at the hand.

The amount of cortical and trabecular bone was studied in 32 iliac crest necropsy specimens from women 60-75 years of age and examined according to the grade of osteoarthritis. Three different methods to evaluate bone mass were used: dual photon absorptiometry, physical assessment according to Archimedes' principle, and histomorphometry. Patients were divided into groups--with or without osteoarthritis--according to the presence of osteoarthritis on hand x rays. A significantly increased amount of cortical and trabecular bone mass was found in those who had osteoarthritis at the hands. Percent pure/crude bone volume and trabecular width were found to be increased with osteoarthritic grade, indicating that primary osteoarthritis is probably part of a generalized bone disease.

Absorptiometry, Photon↗

PubMed1989

The effect of ovariectomy on spine bone mineral density in rhesus monkeys.

As part of a study on the effects of hormones on uterine biology and estrogen metabolism, 12 normal female rhesus (Macaca mulatta) monkeys were ovariectomized, and treated intermittently with estradiol and progesterone. In order to determine whether there were changes in bone density as a result of ovariectomy despite the hormone therapy, spine bone mineral density (BMD) was measured by dual-photon absorptiometry. The mean +/- SE time from ovariectomy was 26 +/- 3 months, the mean estrogen treatment time was 3.5 +/- 0.4 months and the mean time from last hormonal treatment was 4.1 +/- 0.6 months. In these 12 monkeys aged 7.7 +/- 0.2 years, the mean spine BMD, 0.825 +/- 0.008 g/cm2, was significantly less, p = 0.0011, than the spine BMD, 0.863 +/- 0.007 g/cm2, in 12 intact female rhesus of similar age, 7.6 +/- 0.1 years and weight. Ovariectomy in female rhesus monkeys results in a relatively rapid diminution of spine BMD which is not prevented by intermittent hormonal replacement. This species may be an excellent model for studies of human osteoporosis.

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PubMed1990

Premenopausal bone loss in the lumbar spine and neck of femur: a study of 225 Caucasian women.

Two hundred and twenty-five premenopausal women were studied to evaluate age-related changes in trabecular bone mass. Measurements were made at the lumbar spine and femoral neck by dual photon absorptiometry. It was found that spinal bone density increased significantly from the 20s to reach a peak in the mid-30s. Identical trends were observed in total bone mass and bone mass normalized by length. Bone loss then proceeded at a rate of 1% per year, and by the early 50s, 10% of peak spinal density was lost. There was no peak in femoral neck density; loss commenced in the late 20s and continued at a rate of 0.4% per year. The cumulative premenopausal loss from the femur at 9% was comparable to that in the spine. It is concluded that significant amounts of trabecular bone are lost from both the spine and femoral neck before the menopause. The implications of these findings for the prevention of osteoporosis are discussed.

Absorptiometry, Photon↗

PubMed1990

Perimenopausal appendicular bone loss: a 10-year prospective study.

The rate of bone loss before and after the menopause were studied prospectively in 73 healthy women, who were all aged 47 and premenopausal at the start of the study. Bone mass was measured annually by radiogrammetry of 6 metacarpals and by dual photon absorptiometry of the distal and proximal forearm. The rate of bone loss was nearly linear the first 6 years both before and after the menopause. At the menopause, the mean rate increased more than 3-fold. The postmenopausal rate of bone loss in the forearm demonstrated an inter-individual normal distribution with a range from 1% to 6% per year. This prospective study suggests that the menopause, and not age per se determines the start of a period with increased rate of bone loss from the appendicular skeleton. As this rate varies considerably between women, estimation of early postmenopausal rate of bone loss will be of importance when advising women concerning prophylactic treatment against osteoporosis.

Absorptiometry, Photon↗

PubMed1991

Calcium absorption and osseous organ-, tissue-, and envelope-specific changes following ovariectomy in rats.

Because cancellous bone loss occurs following ovariectomy (OVX) in rats, this has become a popular model to explore therapeutic modalities for postmenopausal bone loss in humans. The purpose of this study was to determine intestinal calcium absorption in situ and organ-, tissue-, envelope-, and site-specific changes in osseous tissues at six weeks after OVX in rats using chemical, biochemical, absorptiometric, microradiographic, and morphometric methods. There were no changes in intestinal absorption of calcium, but duodenal weight per length was significantly increased in the OVX animals compared with age-matched, sham-operated controls. There was an increase in wet bone weight, but decreases in ash/dry bone weight, total bone Ca, and Ca per ash weight in the OVX animals. There were significant decreases in the OVX animals in metaphyseal bone mineral content, as determined by photon absorptiometry and metaphyseal cancellous bone volume. The perimeter to area ratio of the metaphyseal cancellous bone in the OVX animals was increased compared with controls. Endochondral growth rates were increased in the OVX animals, attributable to an increased growth plate hypertrophic cell size and rate of chondrocyte proliferation. In the OVX animals there was an increase in modeling in the formation mode of the periosteal surface at the tibio-fibular junction. Increased periosteal modeling in the formation mode was also observed in the body of the mandible, suggesting that the changes in periosteal bone formation are not strictly coupled with changes in endochondral growth. There was an increase in modeling in the resorption mode of the endocortical surface at the tibio-fibular junction in the OVX animals.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMedDate not supplied

Differences in axial bone mineral density, serum levels of sex steroids, and bone metabolism between postmenopausal and age- and body size-matched premenopausal subjects.

The present study was designed to investigate the differences in serum levels of sex steroids, bone metabolism, and bone mineral density (BMD) between 22 premenopausal subjects and 21 age- and body size-matched postmenopausal subjects. Dual photon absorptiometry (DPA) demonstrated total body BMD significantly decreased in postmenopausal subjects. It was also found that not only spinal BMD as assessed by DPA, but also total third lumbar BMD and third lumbar trabecular BMD as measured by quantitative computed tomography (QCT) significantly decreased in these subjects. In postmenopausal subjects, the urinary-hydroxyproline/creatinine ratio increased significantly, which suggested that bone resorption had been stimulated, and serum levels of alkaline phosphatase (ALPase) and osteocalcin also significantly increased, which suggested a stimulation of bone formation. Consequently, the reduction in BMD was thought to result from a negative balance of bone resorption versus bone formation, or a high turnover of bone metabolism. Androgens were not confirmed to participate in these changes in bone metabolism, but the reduction in serum levels of estradiol, as a major factor, and the reduction in serum levels of estrone, as a participating factor, were assumed to result in an increase in bone resorption in excess of bone formation.

Absorptiometry, Photon↗

PubMed1995

Bone remodelling in human immunodeficiency virus-1-infected patients. A histomorphometric study.

The aim of this study was to identify and describe possible alterations of bone histomorphometry in patients with human immunodeficiency virus (HIV-1) infection and to assess the relation between these alterations and disease severity. Forty-four HIV-1-infected patients seen successively at our hospital were evaluated for the study. In an attempt to avoid confounding factors as far as possible, we excluded patients who fulfilled any of the following criteria: age less than 18 or greater than 40 years; recent history of extended bed rest; previous diagnosis of metabolic bone disease, renal insufficiency, or hepatic failure; clinical or echographic signs of liver cirrhosis; diabetes mellitus or previous diagnosis of other endocrine diseases; drug therapy that could act on bone metabolism; and/or moderate to severe nutritional alteration. Twenty-two patients (13 men, 9 women; age: 27.9 +/- 4.1 years, mean +/- standard deviation) were included in the study. Plasma and urine biochemistry and calcium-regulating hormones were determined. Bone mineral content was measured on vertebrae L2 to L4 and on the neck and intertrochanteric areas of the femur by dual-photon absorptiometry. A transiliac bone biopsy was performed after double-tetracycline labelling, with histomorphometric study of undecalcified bone. Serum osteocalcin was found to be lower in patients who, according to the Centers for Disease Control (CDC) classification, had greater disease severity, and showed a positive correlation with the number of CD4+ T lymphocytes. No alterations in bone densitometry were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1995

Bone minerals in beta-thalassemia minor.

Homozygous beta-thalassemia is a severe hereditary disorder associated with osteopenia. Recently it was suggested that thalassemia minor may be a risk factor for osteoporosis. The purpose of the present study was to investigate this suggestion. Bone mineral status was assessed in 22 premenopausal women and 21 men with beta-thalassemia minor. In vivo neutron activation analysis was applied to measure hand-bone phosphorus (HBP), single-photon absorptiometry to measure forearm bone mineral content (BMC), and dual-energy X-ray absorptiometry to measure spinal bone mineral density (BMD). Comparison of the HBP, BMC, and BMD values with those of sex- and age-matched healthy subjects without the beta-thalassemia trait failed to indicate a statistically significant difference for either sex group. Concerning the biochemical markers of bone metabolism that were studied (serum calcium, phosphate, alkaline phosphatase, osteocalcin, and parathyroid hormone, and 3-h fasting urine calcium-to-urine creatinine ratio) no difference was observed between the study subjects and matched controls. In conclusion, the present study showed that subjects with beta-thalassemia minor are not at risk for osteoporosis.

Absorptiometry, Photon↗

PubMed1996

Influence of pattern of clinical presentation and of gluten-free diet on bone mass and metabolism in adult coeliac disease.

Since no information is available on bone derangements in subclinical coeliac disease (CD), we evaluated bone mineral density (BMD, expressed as z score) at lumbar spine, by X-ray dual-photon absorptiometry, and serum indices of bone metabolism and remodeling in 14 subclinical or silent patients, 10 classical patients, and 15 healthy volunteers all on a gluten-containing diet. In the subclinical group, BMD at lumbar spine was significantly higher than in the classical group (-1.3 +/- 0.8, 73% vs. -2.6 +/- 0.6, 88%, respectively; p < 0.001), but significantly lower than in volunteers (+0.4 +/- 1.1, 104%; p < 0.001). Similar changes were observed in serum calcium, whereas, as regards parathyroid hormone, no significant difference was found between subclinical and classical patients. 25-vitamin D was significantly lower, and 1,25-vitamin D was significantly higher in subclinical and classical patients than in healthy volunteers. Indices of bone remodeling were higher in the subclinical and classical groups than in the volunteers, but lower in the subclinical than in classical patients. Eight subclinical and 8 classical patients were reexamined after a period of gluten-free diet (GFD), and in both groups BMD had significantly improved. Our results show that osteopenia is a frequent feature also in subclinical CD, although the extent of bone and mineral metabolism derangements is lower than in classical CD. GFD is able to normalize BMD in subclinical and to significantly improve it in classical patients.

Absorptiometry, Photon↗