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PubMed2000

Contributions of bone density and geometry to the strength of the human second metatarsal.

We investigated, at the whole bone level, the contribution of bone density and geometry to the fracture load of the second metatarsal, a bone that is prone to stress fracture. Dual-energy X-ray absorptiometry (DXA) was used to determine the areal bone mineral density (BMD), projected area of bone, and bone mineral content. Peripheral quantitative computed tomography (pQCT) was used to determine the volumetric cortical bone mineral density (vCtBMD) and cross-sectional moment of interia. Various metatarsal linear dimensions were also measured. The load at failure in cantilever bending was determined. The only linear dimension that had a significant correlation with load at failure was the height of the metatarsal base (r(2) = 0.30, p = 0.008). Utilizing all of the information provided by DXA gave no greater indication of whole bone strength than just BMD alone (adjusted r(2) = 0.40, p = 0.001). Using all of the information provided by pQCT gave no greater indication of whole bone strength than just vCtBMD alone (r(2) = 0. 46, p < 0.001). Volumetric cortical density and BMD were strongly correlated (r(2) = 0.81, p < 0.001). Our data suggest that, in the human second metatarsal, a variable such as material strength (as inferred from cortical density), and not geometry, may be the major factor in determining cantilever load to failure.

Absorptiometry, Photon↗

PubMed2003

Radiographic bone density around immediately loaded oral implants.

OBJECTIVES: The aim of this study was to analyze the bone density around immediately loaded oral implants by a new volumetric CT scan (Maxiscan) and to compare it with that of unloaded implants. MATERIAL AND METHODS: Four patients with an age range from 44 to 65 years old were selected for this study. All the patients needed a prosthetic rehabilitation in partially edentulous posterior maxillas or mandibles. A total of 12 oral implants were placed in the four patients. Six of these implants were immediately loaded while six were left unloaded. Six months after placement, immediately loaded and unloaded oral implants were analyzed by a volumetric CT scan. RESULTS: The overall success rate in this study with immediately loaded oral implants was 100%. The radiological assessments showed that the mean densitometric profile, which is a measure of bone mineralization, was higher in the immediately loaded group than in the unloaded group. The differences observed between the two groups of oral implants (immediately loaded and unloaded) were statistically significant (P<0.05). The bone was significantly more dense around immediately loaded than unloaded oral implants on the basis of a radiological assessment. CONCLUSION: The innovative aspect of this clinical study is to propose a new method to analyze the bone density, reducing the need for histological analysis from human biopsy.

Absorptiometry, Photon↗

PubMed2006

Vertebral marrow fat content and diffusion and perfusion indexes in women with varying bone density: MR evaluation.

PURPOSE: To prospectively study the relationship among vertebral marrow fat content, marrow diffusion indexes, and marrow and erector spinae muscle perfusion indexes in female subjects with varying bone mineral density. MATERIALS AND METHODS: Institutional study approval and informed consent were obtained. Dual x-ray absorptiometry, proton magnetic resonance (MR) spectroscopy, diffusion-weighted MR imaging, and dynamic contrast material-enhanced MR imaging of the lumbar spine and erector spinae muscle were performed in 110 women (mean age, 73 years; range, 67-84 years). Marrow fat content, marrow apparent diffusion coefficient (ADC), and perfusion indexes (maximum enhancement and enhancement slope) of marrow and erector spinae muscle were compared among three bone density groups (normal, osteopenic, and osteoporotic). The t test comparisons and Pearson correlations were applied. RESULTS: Seven subjects were excluded, which yielded a final cohort of 103 subjects: 18 with normal bone density, 30 with osteopenia, and 55 with osteoporosis. Vertebral marrow fat content was significantly increased in the osteoporotic group (67.8% +/- 8.5 [standard deviation]) when compared with that of the normal bone density group (59.2% +/- 10.0, P = .002). Vertebral marrow perfusion indexes were significantly decreased in the osteoporotic group (enhancement slope, 1.10%/sec +/- 0.51) compared with those of the osteopenic group (1.45%/sec +/- 0.51, P = .01) and normal bone density group (1.70%/sec +/- 0.52, P < .001). Erector spinae muscle perfusion indexes did not decrease as bone density decreased. The ADC of vertebral marrow did not change with bone density. CONCLUSION: The subjects experienced a decrease in vertebral marrow maximum enhancement and enhancement slope and an increase in marrow fat content as bone density decreased. The reduction in perfusion indexes occurred only within the vertebral body and not in the paravertebral tissues supplied by the same artery.

Absorptiometry, Photon↗

PubMed1992

Reduced bone density and major hormones regulating calcium metabolism in anorexia nervosa.

Bone density of lumbar vertebrae (L2 to L4) and the whole body in 29 patients with anorexia nervosa were measured by dual photon absorptiometry, and the results were compared with those of 10 age-matched normal controls. The patients had significantly lower bone mineral density (BMD) in L3 and L2-4 than controls. However, there was no difference in whole-body BMD. L3 and L2-4 BMD was positively correlated with body weight and was negatively correlated with duration of illness and amenorrhea. Patients who had been more active 6 months before the time of the study had significantly higher L3 BMD than the less active patients. Most patients had an abnormally low serum estrogen level, whereas the mean serum levels of thyroid hormone (T3, T4), cortisol, calcitonin, parathyroid hormone and vitamin D were within the normal range. No correlation was found between L3 or L2-4 BMD and the levels of these hormones. These results suggest that severe weight loss, low physical activity, longer duration of amenorrhea and deficiency of estrogen contribute to bone loss in patients with anorexia nervosa, whereas calcium-regulating hormones such as parathyroid hormone, calcitonin and vitamin D are unlikely to be a primary contributor to bone loss.

Adolescent↗

PubMed1998

Clinical report on long-term bone density after short-term EMF application.

A 1984 study determined the effect of a 72 Hz pulsating electromagnetic field (PEMF) on bone density of the radii of post-menopausal (osteoporosis-prone) women, during and after treatment of 10 h daily for 12 weeks. Bone mineral densities of the treated radii increased significantly in the immediate area of the field during the exposure period and decreased during the following 36 weeks. Bone density determination of the radii of these women, remeasured after eight years, suggests no long-term changes. The bone density-enhancing effect of PEMFs should be further studied, alone and in combination with exercise and pharmacologic agents such as the bisphosphonates and hormones, as prophylaxis in the osteoporosis-prone postmenopausal woman and as a possible block to the demineralization effect of microgravity.

Absorptiometry, Photon↗

PubMed2000

High sodium chloride intake is associated with low bone density in calcium stone-forming patients.

BACKGROUND: Although renal stone disease has been associated with reduced bone mass, the impact of nutrient intake on bone loss is unknown. SUBJECTS AND METHODS: The present study was undertaken to investigate the influence of nutrient intake on bone density of 85 calcium stone-forming (CSF) patients (47 male and 38 premenopausal females) aged 41+/-11 years (X+/-SD). Bone mineral density (BMD) was measured using dual energy X-ray absorptiometry at the lumbar spine (L2-L4) and femoral neck sites, and low BMD was defined as a T score < -1 (WHO criteria). A 4-day dietary record and a 24-hour urine sample were obtained from each patient for the assessment of nutrient intake and urinary calcium (U(Ca)), sodium (U(Na)), phosphate and creatinine excretion. RESULTS: Forty-eight patients (56%) presented normal BMD and 37 (44%) low BMD. There were no statistical differences regarding age, weight, height, body mass index, protein, calcium and phosphorus intakes between both groups. The mean U(Ca), phosphorus and nitrogen appearance also did not differ between groups. However, there was a higher percentage of hypercalciuria among low vs normal BMD patients (62 vs 33%, p < 0.05). Low BMD patients presented a higher mean sodium chloride (NaCl) intake and excretion (UNa) than normal BMD (14+/-5 vs 12+/-4 g/day and 246+/-85 vs 204+/-68 mEq/day, respectively p < 0.05). The percentage of patients presenting NaCl intake > or = 16 g/day was also higher among low vs normal BMD patients (35 vs 12%, p < 0.05). After adjustment for calcium and protein intakes, age, weight, body mass index, urinary calcium, citrate and uric acid excretion, and duration of stone disease, multiple-regression analysis showed that a high NaCl intake (> or = 16 g/day) was the single variable that was predictive of risk of low bone density in CSF patients (odds ratio = 3.8). CONCLUSION: These data suggest that reducing salt intake should be recommended for CSF patients presenting hypercalciuria and osteopenia.

Absorptiometry, Photon↗

PubMedDate not supplied

Evaluation and treatment of low bone density in anorexia nervosa.

The prevalence of anorexia nervosa has increased in recent years, and a large proportion of adults as well as adolescents with this disorder have low bone density and, therefore, an increased risk of fractures. Anorexia nervosa often begins during adolescence, when peak bone mass is accumulated, resulting in significant deficits in bone mass accrual. Therefore, it is important to determine bone mineral density in adolescent and adult women who have this disorder, and to improve or at least stabilize bone metabolism in those with low bone mass. To do this, it is necessary to understand the mechanisms underlying low bone density in anorexia nervosa. This article discusses current concepts related to bone loss associated with anorexia nervosa, including how to prevent it.

Adolescent↗

PubMed1995

Evaluation of bone density using cutting resistance measurements and microradiography: an in vitro study in pig ribs.

A method using cutting resistance measurements during low-speed threading for identification of various bone densities has been evaluated with regard to its precision and potential. Pig ribs were used as test samples. Differing hand pressure, minor deviation (5 degrees) from a vertical tapping direction and individual threading did not reveal any significant differences in cutting resistance values. After implants were inserted into the threaded canals, the total bone as well as trabecular and compact bone areas surrounding the implants were calculated via a computer program and using microradiographs of the bone test samples. The outcome of the cutting resistance measurements was compared with that of the microradiographic technique, and good agreement was observed between the two procedures in the ability to identify bone density. Therefore, cutting resistance measurements may in the future also be used to clinically identify bone qualities in jaws.

Animals↗

PubMed1998

[A clinical study of decreased bone density in the patients treated with long-term luteinizing hormone releasing hormone analogue (LHRH-a)--the risk of iatrogenic osteoporosis due to treatment of carcinoma of prostate].

BACKGROUND: It is well known that androgens play an important role in bone metabolism and male hypogonadism induce osteoporosis. Luteinizing hormone-releasing hormone analogue (LHRH-a) which is essential for conservative therapy of prostatic carcinoma (CaP) ultimately reduces circulating testosterone to castration levels. The purpose of this study was to determine the risk of decrease of bone mineral density in men receiving LHRH-a for CaP. PATIENTS AND METHODS: Fifty-three man with CaP aged 63 to 95 years (mean 75.5 years) were included in this study. Seven patients received LHRH-a with estrogen drug, forty-six patients received LHRH-a with or without anti androgen drug. To estimate patient's bone density we use the second metacarpal bone density using a microdensitometry method. RESULTS: Blood level of sex hormone of the forty-six patients who were received LHRH-a without estrogen, was the same as that of castration. Patients who were treated more than twelve months had less bone density than patients who were treated less than eleven months. As the duration of medical castration period was prolonged, patients bone density were reduced. Whereas seven patients who received estrogen drug did not find a decrease of bone density regardless of duration of treatment period. CONCLUSIONS: Hypogonadism induced LHRH-a also reduce bone density, so there is a risk of iatrogenic osteoporosis caused by therapy for CaP with LHRH-a. Patients with osteoporosis easily suffer from a much complicated and pernicious bone fracture, so we should measure bone density of male patients same as female treated with LHRH-a for a long-term.

Aged↗

PubMed1995

Dose-related decrease in bone density among asthmatic patients treated with inhaled corticosteroids.

BACKGROUND: Inhaled corticosteroids are being prescribed more commonly and in higher doses than previously in the management of asthma. Although these topically active compounds have less potential for systemic impact than oral steroids, biochemical markers suggest that they are not devoid of systemic side effects. We conducted this study to investigate the effect of commonly prescribed doses of inhaled steroids on bone density. METHODS: We studied 36 patients with asthma. Those in group A (n = 18) had been taking inhaled beclomethasone dipropionate or budesonide in a dosage of 800 micrograms or more per day for at least 1 year. Those in group B (n = 18) had used only bronchodilator therapy. Adrenal function was assessed by morning serum cortisol level and by short adrenocorticotropic hormone stimulation test. Bone turnover was assessed by measurement of serum osteocalcin, alkaline phosphatase, and urinary pyridinium cross-links. Bone mineral density was measured by dual-energy x-ray absorptiometry with a Hologic QDR-1000 densitometer (Hologic Inc., Waltham, Mass.). RESULTS: Group A, mean age (SD) = 36.6 (8.4) years, had used inhaled corticosteroids at a mean dose of 1323 micrograms/day (range, 800 to 2000 micrograms/day) for a median duration of 24 months. Group B, mean age (SD) = 33.4 (8.1) years, had not been taking any form of steroid. Four patients from group A had suppressed morning serum cortisol; three of these had abnormal adrenocorticotropic hormone stimulation test results. All patients in group B had normal baseline adrenal function and an appropriate response to adrenocorticotropic hormone. Mean serum osteocalcin level in group A was significantly lower than that in group B (8.8 vs 14.2 ng/ml, p = 0.0003). Bone density measurements showed parallel changes: in group A the mean Z score (SD) of the femoral neck was -0.78 (1.02), significantly below predicted normal values (p = 0.0025). Mean Z scores of the lumbar spine and of femoral Ward's triangle were not significantly reduced. In group B the mean Z scores of the lumbar spine, femoral neck, and femoral Ward's triangle were all within normal limits. In group A the dose duration of inhaled corticosteroid therapy corrected for body mass index correlated negatively with bone density and adrenal function measurements. CONCLUSION: We conclude that the regular use of conventional doses of inhaled corticosteroids by patients with asthma can suppress adrenal function and decrease bone density in a dose-related fashion.

Administration, Inhalation↗

PubMed1979

Bone densitometry using computed tomography. Part II: increased trabecular bone density in children with chronic renal failure.

The method of gamma-ray computed tomography (gamma-ray CT) bone densitometry described in the preceding article provides selective determination of trabecular bone density (TBD), the relative amount of compact bone (bone density, BD), and the total absorption (TA) within a bone cross section. Seven of nine children with chronic renal failure (CRF), and selected only on the basis of their serum creatinine value (greater than 5 mg/100 ml), had increased TBD values above the normal range, whereas the other bone mineral parameters were normal. Radiographic signs of secondary hyperparathyroidism (subperiosteal erosions, cysts) were reported in the five patients with the highest TBD values, whereas the subjective diagnosis of osteosclerosis reported in three of these five and in one other patient correlated less well with the TBD increases. However, this is the first report of an objective, non-invasive documentation of the radiological finding of osteosclerosis in CRF. It also explains why methods for bone mineral measurements used previously, such as a photon absorptiometry which provides only a parameter equivalent to TA, failed to reveal increases in bone mineral content in renal osteodystrophy even when signs of osteosclerosis were present. Thus, gamma-ray CT helps to document objectively the degree of osteosclerosis and its location.

Adolescent↗

PubMed2004

Reduced bone density among children with severe hemophilia.

OBJECTIVE: Children with severe hemophilia are at risk for reduced bone mineral density (BMD) because of reduced weight-bearing exercise and hepatitis C infection. Reduced bone density in childhood is a risk factor for osteoporosis in later life. STUDY DESIGN: We performed a cross-sectional survey of bone density among 19 children with severe hemophilia, at the Royal Children's Hospital. Results were correlated with findings of blinded objective evaluations of the joints of the lower limb and with hepatitis C status. RESULTS: The mean lumbar bone mineral apparent density for patients was reduced (0.102 g/cm3), compared with that for control subjects (0.113 g/cm3). The mean areal BMD z score was -0.92, which was significantly reduced, compared with that for control subjects. The difference in bone density was independent of body size. There was a statistically significant relationship between the lumbar BMD z scores and the maximal single joint evaluation scores, but there was no difference based on hepatitis C status. CONCLUSIONS: Our results suggest that children with severe hemophilia have reduced BMD. Patients at risk are those with signs of hemophilic arthropathy. Because osteoporosis may complicate the future treatment of patients with hemophilia, screening of young patients for reduced bone density is recommended.

Adolescent↗

PubMed1992

A comparison of nutrition knowledge and attitudes, dietary practices, and bone densities of postmenopausal women, female college athletes, and nonathletic college women.

This study evaluated the nutrition knowledge and attitudes, dietary practices, and bone densities of four groups of women: 18 postmenopausal women, 14 college-aged dancers, 13 members of a college track team, and 14 nonathletic college women. Subjects completed a personal information questionnaire, a 24-hour food recall, a food frequency questionnaire, a nutrition knowledge test, and an attitude survey; measurements of the subjects' spinal bone density were also taken. The mean (+/- 0.5 standard error [SEM]) nutrition knowledge score of the dancers (22.5) was significantly lower than the mean scores of the postmenopausal women (28.5), the nonathletes (29.7), and the track team members (26.5). Dancers also reported eating fewer mean (+/- 4.0 SEM) servings of high-calcium foods per month (43) than did postmenopausal women (77), nonathletes (66), or track team members (73). Track team members had a significantly higher mean (+/- 0.2 SEM) anorexia/bulimia score (3.7) than did postmenopausal women (2.5), nonathletes (2.1), or dancers (2.2). There were no significant differences in bone mineral density among the four groups. The number of servings of high-calcium foods eaten was significantly correlated with nutrition knowledge scores (r = .38) and attitude scores (R = .32), but nutrition knowledge and attitude scores were not significantly correlated with each other. The track team members exercised significantly more than women in all other groups--mean (+/- 40 SEM) minutes exercise time was 700 minutes/week for track team members, 79 minutes/week for postmenopausal women, 92 minutes/week for nonathletes, and 500 minutes/week for dancers--and also experienced the most amenorrhea.

Adolescent↗

PubMed2003

Longitudinal changes in bone density in relation to oral contraceptive use.

The primary aim of this 36-month prospective cohort study was to evaluate the association between use of oral contraceptives (OCs) and bone mineral density in reproductive-age women. The 36-month bone density (g/cm2) at the spine, hip and whole body and percent change from baseline (measured at 6-month intervals) were evaluated among 245 women 18-39 years of age; 89 were using OCs (median duration: 3.7 years at study entry) and 156 were not using any hormonal contraception. Before and after adjustment for covariates (baseline bone density, age, race, ever pregnant, exercise, body mass and calcium intake), women using OCs did not differ significantly from comparison women in percent change in bone density over 36 months or in absolute bone density at 36 months. All p-values for between-group differences were >0.55. In conclusion, within the limitations of this study, OCs did not appear to impact bone density over time in this cohort of reproductive-age women.

Adolescent↗

PubMed1990

Bone density changes in osteoporosis-prone women exposed to pulsed electromagnetic fields (PEMFs).

To determine the effect of a 72 Hz pulsating electromagnetic field (PEMF) on bone density of the radii of osteoporosis-prone women, the nondominant forearms of 20 subjects were exposed to PEMF 10 h daily for a period of 12 weeks. Bone density before, during, and after the exposure period was determined by use of a Norland-Cameron bone mineral analyzer. Bone mineral densities of the treated radii measured by single-photon densitometry increased significantly in the immediate area of the field during the exposure period and decreased during the following 36 weeks. A similar but weaker response occurred in the opposite arm, suggesting a "cross-talk" effect on the nontreated radii, from either possible arm proximity during sleep or very weak general field effects. The data suggest that properly applied PEMFs, if scaled for whole-body use, may have clinical application in the prevention and treatment of osteoporosis.

Aged↗

PubMed2003

Influence of environmental cadmium exposure on forearm bone density.

Cadmium may have both direct and indirect effects on bone turnover. It is nephrotoxic and can interfere with vitamin D metabolism. Such perturbation may result in osteoporosis and osteomalacia. In this study, a total of 790 persons (302 males and 488 females) participated; they were all over 35 years old and resided in an area near a cadmium smelter in southeast China. All participants completed a questionnaire, and bone mineral density was measured by SPA-4 single-photon absorptiometry at the radius and ulna. Cadmium content of urine was determined by graphite-furnace atomic absorption spectrophotometry as a measure of dose. The decline in bone mineral density with age in a heavily polluted area was greater than that in a control area for subjects over 60 years of age of both sexes (p < 0.05). In single regression, forearm bone densities were negatively correlated with urinary cadmium excretion in both males and females (p < 0.001), whereas stepwise regression showed that forearm bone density decreased linearly with age (p < 0.001) and urinary cadmium (p < 0.01) in both sexes, suggesting a dose-effect relationship between cadmium dose and bone mineral density. Based on the World Health Organization criteria, (bone mineral density < -2.5 SDs below the normal young adult), the prevalence of osteoporosis in women increased from 34.0% in the control area to 51.9% in the heavily polluted area (p < 0.01) among subjects over 50 years old, and the odds ratio value was 2.09 (95% CI: 1.08-4.03) for the highly polluted area compared with the control area. A striking observation in the study was the marked increase of the prevalence of fracture in the cadmium-polluted area in both sexes. It was concluded that environmental exposure to cadmium is associated with an increased loss of bone mineral density in both males and females, leading to osteoporosis and increased risk of fractures, especially in the elderly and in females.

Adult↗

PubMed1992

Growth hormone deficiency during puberty reduces adult bone mineral density.

Bone mineral density (BMD) was evaluated by dual energy x ray absorptiometry in 60 adults (33 males, 27 females; aged 50, range 23-76 years) who were growth hormone deficient from various causes for 10.4 (1-31) years. Adult patients who had acquired growth hormone deficiency before completion of puberty had significantly reduced mean (SEM) BMD compared with age matched healthy controls at the lumbar spine: 0.87 (0.09) v 1.20 (0.03) g/cm2, femoral neck: 0.81 (0.06) v 1.08 (0.04) g/cm2, and Ward's triangle: 0.68 (0.07) v 1.04 (0.05) g/cm2. These values were also reduced compared with those of patients who had received human growth hormone during puberty. Untreated growth hormone deficiency when present during puberty results in reduced adult bone density.

Absorptiometry, Photon↗

PubMedDate not supplied

Influence of cyclic intravenous pamidronate on proinflammatory monocytic cytokine profiles and bone density in rheumatoid arthritis treated with low dose prednisolone and methotrexate.

OBJECTIVES: The aim of this work was to evaluate in a randomised double-blind prospective study the effect of pamidronate on intracellular monocytic cytokine profiles (IL-1, IL-6, TNF-alpha) and bone density in rheumatoid arthritis patients. METHODS: Twenty rheumatoid arthritis patients were treated for one year with methotrexate and a low dose of prednisolone. Double blind randomisation was performed for either i.v. pamidronate (at 3-month intervals) or placebo. The effect of pamidronate was evaluated on intracellular cytokine profiles (IL-1, IL-6, TNF-alpha), disease activity and bone mass measurements. The human monocytic cell line THP-1 was used to evaluate in vitro apoptosis by pamidronate. RESULTS: Spontaneous production of interleukin-1 beta by patient blood monocytes was lower in the pamidronate group and was associated with an increase in bone density of the spine after 12 months of therapy. In vitro a dose-related increase in pamidronate induced apoptosis was found in THP-1 cells. CONCLUSIONS: This prospective double-blind randomised study demonstrated that pamidronate therapy resulted in an increase of bone density despite treatment with steroids. This rise is associated with a suppression of interleukin-1 beta production in monocytes of patients treated with pamidronate. Our in vitro experiments suggest that this anti-inflammatory effect could be due to an increase in the apoptosis of monocytic cells.

Adult↗