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PubMed2004

Noninvasive measurement of bone strontium.

The strontium content of bone has hitherto been impossible to measure noninvasively. A novel dual-photon absorptiometry (DPA) method was developed. 241Am (59.5 keV) and 133Ba (356 keV) were used as radiation sources. The linearity of the DPA method was studied in monkey bones ex vivo after treatment over 52 wk with strontium ranelate. The bone strontium expressed in terms of the percentage molar ratio SrHA/(SrHA + CaHA) x 100%, where HA denotes hydroxyapatite, was measured (1) by the DPA method and (2) by inductively coupled plasma-atomic emission spectrophotometry at the same distal site of the femur. The results correlated significantly: y = 0.33%Sr + 1.086x; r = 0.976; standard error of the estimate (SEE) = 0.57%Sr. In order to measure the accuracy error of Sr%, 30 normal volunteers were measured. Their mean values did not differ significantly from zero and the SD was 0.5%. The radiation dose was small, the equivalent whole-body dose to human subjects being 0.005 micro Sv. This novel DPA method is likely to be successful for bone strontium measurement in humans.

Absorptiometry, Photon↗

PubMed2004

Forearm bone mineral density in 1294 middle-aged women: a strong predictor of fragility fractures.

The aim of this study was to find out whether a single bone mineral density (BMD) measurement performed at middle age in early postmenopausal women could predict future fragility fractures. The Malmo Preventive Project, a population-based cardiovascular prevention study, included a subgroup of 1294 women, mean age 53, on which forearm BMD measurements were made using single-photon absorptiometry (SPA). Risk ratios (RRs) were calculated for an age-adjusted decrease in BMD of one standard deviation. During the 9-yr follow-up, 65 women sustained 86 fractures. The data were analyzed with Cox's proportional hazard analysis. The relative risk for sustaining any fragility fracture were 2.02 (95% confidence interval [CI] = 1.56-2.61) and 1.62 (CI = 1.26-2.08) at the distal and proximal forearm BMD measurement, respectively. The risk increase was significant for forearm fracture at the distal BMD level (RR = 1.94; range = 1.40-2.68) and at the proximal BMD level (RR = 1.77; range = 1.29-2.42). Our study is one of the first to show that a BMD measurement in a population at age 50 can predict fracture over almost 10 yr, indicating that early identification of women with increased fracture risk is possible, and the cost-effectiveness of such an approach needs to be further evaluated.

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PubMed1996

Detecting osteoporosis using dental radiographs: a comparison of four methods.

The authors evaluated dental radiographs for signs of osteoporosis using four methods: fractal dimension, microdensitometry, pixel intensity and panoramic analysis of cortical thickness. The efficacy of these methods also was compared against three standard bone density measurement techniques used to diagnose osteoporosis in bones other than the jaws: quantitative computed tomography and single- and dual-photon absorptiometry. Pixel intensity was significantly more effective than the other dental methods at distinguishing between radiographs from the osteoporotic group and the control group, although fractal dimension and microdensitometry methods also were effective.

Absorptiometry, Photon↗

PubMed1989

[The effect of 1,25(OH)2D3 on bone mineral content in senile osteoporosis--a dose-finding study].

In order to clarify the effect of 1,25(OH)2D3 on the bone mineral content in senile osteoporosis, we examined the radial mineral density in 41 female cases of senile osteoporosis treated with 1,25(OH)2D3. The diagnostic criteria of senile osteoporosis were as follows. 1) Radial mineral density at below 0.5 g/cm2 by SPA 2) Bone dystrophy score in vertebra at over I degree 3) Presence of vertebral fracture 4) Over 60 years of age The subjects were divided into 5 groups: a control group (n = 11), a 0.25 microgram of 1,25(OH)2D3 once-a-day group (n = 5), a 0.5 microgram of 1,25(OH)2D3 once-a-day group (n = 8), a 0.25 microgram of 1,25(OH)2D3 twice-a-day group (n = 8) and a 0.25 microgram of 1,25(OH)2D3 three times-a-day group (n = 9). There was no significant difference in background data among these groups except for serum Al-P activity. The radial mineral density was measured in these 5 groups before and every 3 months after, starting the treatment by single photon absorptiometry in 1/3 distal site of radius for 1 year. No significant difference was detected in the serum levels of Ca, Pi and Al-P activity after starting the treatment among the 5 groups. The area under curve (AUC) of the radial mineral content after the treatment was calculated in each group. There was a significant dose-related increase in the AUC (p less than 0.05). However, the urinary Ca/Cr ratio was increased in the group receiving 0.75 microgram/day of 1,25(OH)2D3 The final AUC in the group receiving 0.5 microgram/day of 1,25(OH)2D3 tended to be very high compared with that in the other groups. From the above, it was suggested that 1,25(OH)2D3 might be effective for the treatment of senile osteoporosis especially at the dose of 0.5 microgram/day.

Absorptiometry, Photon↗

PubMedDate not supplied

Recombinant human growth hormone replacement therapy and bone metabolism in children.

Growth hormone (GH) influences not only skeletal growth and maturation but also bone turnover and mineral deposition. The effect on bone mineral status of 2 different regimens of rhGH therapy was evaluated in 22 children with idiopathic GH deficiency (GHD) - age 5-8 yrs; bone age 3-5 yrs. Ten of them (group 1) were treated 3 times a week with rhGH, administered subcutaneously, for a total weekly dose of 0.5 IU/kg and 12 (group 2) with the same weekly dose 6 times per week. Insulin-like growth factor 1 (IGF-1) and osteocalcin (OC) levels increased in both groups after therapy but they were higher in group 2. In basal conditions bone mineral content (BMC) and BMC/bone width ratio (determined by dual image-assisted photon absorptiometry) were significantly lower in patients than in controls and significantly increased after 6 months of rhGH therapy only in patients of group 2. rhGH administered 3 times a week increased IGF-1 and OC levels, indicating that turnover and remodeling processes of the bone had started, but the same dose had to be given every day to lead to calcium deposition in the bones. Probably a continuous supply of rhGH better optimizes the body utilization of the hormone, as indicated by better height velocity and bone density in patients of group 2. The response to an acute load of 1,25(OH)2D3 (1.5 micrograms/day for 4 days), both before and after a month of rhGH therapy (weekly dose of 0.5 IU/kg 6 times were week), was evaluated in 16 children with GHD - age 6-9 yrs.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1996

Follow-up of bone mineral density in 27 cases of anorexia nervosa.

Cortical and trabecular bone loss can lead to osteoporosis in chronic forms of anorexia nervosa (AN). As there is some debate about the reversibility of this condition, we performed a longitudinal follow-up study of 27 cases in which clinical, biological, X-ray and lumbar and femoral neck dual photon absorptiometry examinations were conducted every 6 months for up to 30 months. Three groups were distinguished: G1, untreated amenorrheic AN (N = 14, total follow-up 126 months); G2, effectively treated AN (N = 11, total follow-up 192 months), with two subgroups: fluoride (N = 5) and estrogen (N = 6); and G3, remitting AN with normalization of the gonadic function (N = 2, total follow-up 36 months). Results were adjusted for each patient to a 6-month variation. Semestrial variations in lumbar bone mineral density (BMD) were -2.1 +/- 1.3%, +2.8 +/- 1.5%, and -0.3 +/- 1.3% (mean +/- SEM), respectively for G1, G2 and G3; those for femoral neck BMD semestrial variations were -5.9 +/- 2.1%, -3.8 +/- 1.2% and -1.0 +/- 0.6%. Femoral neck and lumbar BMD variations for G1 were mainly correlated positively with bone-forming markers (serum osteocalcin, alkaline phosphatase) and negatively with initial lumbar BMD. Estrogen alone increased lumbar BMD by +1.4 +/- 2.3% every 6 months but did not stabilize femoral neck BMD (-3.5 +/- 1.4%). Fluoride increased lumbar BMD by 4.8 +/- 1.8%. Both lumbar and femoral neck BMD were stabilized in the remission group (-0.3 +/- 1.3% and -1.0 +/- 0.6%), despite half of the follow-up time with amenorrhea. In conclusion, untreated AN is associated with a marked trabecular and cortical bone loss (4-10% per year), which can lead to osteoporotic fractures. In prevention of bone loss, the efficacy of estrogen is difficult to investigate in AN, even with a well-controlled trial. Our study could provide argument that, when the observance of this preventive treatment is assessed, lumbar BMD can be stabilized in chronic forms of AN.

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PubMed2006

Peripheral bone densitometry: Clinical applications.

Technologies for the measurement of bone mineral density and other parameters of bone strength at peripheral skeletal sites have been studied since the 1960s. Single-energy Photon Absorptiometry (SPA), Radiographic Absorptiometry (RA), Radiogrametry (RG), Single-energy X-ray Absorptiometry (SXA), Peripheral Dual-energy X-ray Absorptiometry (pDXA), and Quantitative Ultrasonometry (QUS) have been successively evaluated. These technologies and their clinical applications are discussed in this article. The available scientific evidence supports the clinical use of these technologies at peripheral skeletal for assessment of fracture risk. Peripheral measurements other than the 33% (one-third) radius by DXA cannot be used to diagnose osteoporosis according to current standards. Peripheral skeletal sites are not clinically useful for monitoring changes in BMD with natural evolution of the disease and its treatment. Peripheral BMD measurement can theoretically be used to screen patients for selection to central DXA testing, although device-specific cut-points should be developed before this is implemented. When central DXA testing is not available, peripheral BMD testing may be considered to identify individuals who might benefit from pharmacological intervention.

Absorptiometry, Photon↗

PubMed1998

Mineralized bone loss at different sites in dialysis patients: implications for prevention.

To characterize the magnitude and location of mineralized bone loss, 40 patients (20 men, 20 women, 29 white, 11 black) with clinically significant renal osteodystrophy who could be unambiguously classified based on histologic criteria as having osteitis fibrosa (OF; 20 cases) or osteomalacia (OM; 20 cases) were studied; they had been on maintenance hemodialysis for 4.6 +/- 3.0 yr. One hundred forty-two healthy women of similar age and ethnic composition served as control subjects. In all subjects, the proportions of mineralized bone, osteoid, and porosity (nonbone soft tissue) were measured separately in cortical and cancellous bone tissue, from intact full-thickness biopsies of the ilium, representative of the axial skeleton. The results were related to the volumes of cortical and cancellous bone tissue separately and to the volume of the entire biopsy core. Approximately three-quarters of the patients had measurements in the appendicular skeleton by single photon absorptiometry of the radius and morphometry of the metacarpal. Disease effects did not differ significantly between ethnic groups. Mineralized cortical bone volume (per unit of core volume) was reduced by approximately 45% in both patient groups. Mineralized cancellous bone volume was significantly increased by 36% in the patients with OF and nonsignificantly reduced by 9% in the patients with OM; however, the reduction in the latter patients was significant in relation to tissue volume. The combined total deficit for both types of iliac bone was approximately 20% in the patients with OF and approximately 40% in the patients with OM. Significant reductions in appendicular cortical bone were demonstrated in both patient groups at both measurement sites. Regardless of the current histologic classification, the major structural abnormality in the skeleton is generalized thinning of cortical bone due to increased net endocortical resorption, the most characteristic effect on bone of hyperparathyroidism. Protection of the skeleton from the adverse consequences of renal failure will require therapeutic intervention in patients with no symptoms of either renal or bone disease.

Absorptiometry, Photon↗

PubMed1999

The association between osteopenia and periodontal attachment loss in older women.

BACKGROUND: Recent research suggests that osteopenia may be a predisposing factor for periodontal tissue destruction. If so, then a relationship should exist between measures of systemic bone mineral density and periodontal tissue destruction. The purpose of the present cross-sectional study was to evaluate the association between systemic bone mineral density and the clinical signs of periodontal tissue destruction in a large population of elderly dentate women. METHODS: A total of 292 dentate women (average age 75.5 years) were randomly selected for a cross-sectional periodontal substudy from participants at the Pittsburgh Field Center of the Study of Osteoporotic Fractures (SOF), a prospective study of a cohort of elderly women (age > or =65 years at baseline) to determine risk factors for fractures. Bone mineral density (BMD) was measured using single photon absorptiometry (radius, calcaneus) and dual energy x-ray absorptiometry (hip, spine). Oral health examinations, including periodontal probings and an assessment of bleeding on probing, were made using an NIDR probe at 3 buccal sites of all teeth. Multiple regression models were used to assess the association between bone mineral density and measures of periodontal disease status while controlling for potential confounders. Periodontal status variables examined included: average loss of periodontal attachment (LOA); number of sites with at least 4 mm LOA; number of sites with at least 6 mm LOA; number of sites with bleeding on probing; and deepest probing depth per person. RESULTS: This study found no statistically significant association between the 5 indicators of periodontal disease and measures of systemic BMD at 8 anatomic sites after controlling for age, smoking, and number of remaining natural teeth. Some suggestive findings support a weak association between generalized osteopenia and periodontal disease. CONCLUSIONS: Systemic osteopenia is, at best, only a weak risk factor for periodontal disease in older non-black women.

Absorptiometry, Photon↗

PubMed1991

Criteria to evaluate bone mineralization in cattle: II. Noninvasive techniques.

An experiment was conducted to evaluate the capabilities of dual photon absorptiometry (PA), radiographic photometry (RP), and ultrasound (U) to estimate bone mineral content (BMC) and bone strength of a group of bovine third metacarpals (McIII). Metacarpals were chosen for evaluating BMC and bone strength because of their accessibility and susceptibility to biomechanical stress. The right and left McIII of 14 Angus heifers (24 to 32 mo of age) were collected at slaughter and all soft tissues (including periosteum) were removed. The BMC was estimated at both the midpoint and 3 cm proximal to the midpoint on the McIII diaphysis. Metacarpals then were tested by three-point bending to determine breaking load (BL) and breaking strength (BS). Bones were reassembled and two 2-cm sections were removed, one at the midpoint and one 1 cm proximal to the midpoint section. Sections then were ashed and ash content was expressed as grams per 2-cm slice and defined as BMC. Correlation coefficients (r) between BMC vs PA, RP, and U were .908 (P less than .0001), .967 (P less than .0001), and .565 (P less than .0001), respectively; r values between BS vs PA, RP, and U were .406 (P less than .05), .429 (P less than .05), and .499 (P less than .01), respectively, and r values between BL vs PA, RP, and U were .870 (P less than .0001), .865 (P less than .0001), and .588 (P less than .001), respectively. These data indicate that noninvasive techniques are useful in predicting BMC and BL in the bovine.

Absorptiometry, Photon↗

PubMed1992

Longitudinal study of cortical bone loss in patients with inflammatory bowel disease.

Bone mineral density of the radius was measured by single-photon absorptiometry in 50 patients with inflammatory bowel disease. Thirty-three had Crohn's disease and 17 ulcerative colitis; 25 were women. The mean age was 45 years (range, 18-70 years). Measurements were repeated in 39 of them after a mean follow-up period of 7.9 years (range, 7.1-8.2 years). In female patients the mean (95% confidence interval) annual change in radial bone mineral density was -0.74% (-1.34% to -0.14%) (P = 0.022), the greatest bone loss occurring in postmenopausal women (mean, -1.16% (-2.01% to -0.30%)). In male patients the mean annual rate of bone loss was -0.07% (-0.41% to 0.28%) (P = NS). Patients with abnormally low values at the first measurement remained osteopenic at the second measurement, whilst some others with normal values initially showed increased rates of bone loss and had a subnormal bone mineral density after the follow-up period. These results show increased rates of cortical bone loss in some patients with inflammatory bowel disease and emphasize the need to monitor bone mass in these patients so that prophylactic measures can be instituted.

Absorptiometry, Photon↗

PubMed1995

Bone mineral status in end-stage liver disease and the effect of liver transplantation.

BACKGROUND: The aim of this study was to determine bone mass at different skeletal sites in patients with end-stage liver disease and the effect of liver transplantation on bone mineralization. METHODS: Bone mineral density in different skeletal regions was measured by photon absorptiometry in 25 patients with chronic liver disease, and the measurements were repeated in nine patients after orthotopic liver transplantation. RESULTS: In patients with liver failure bone mass values were not significantly different from those of controls. After liver transplantation bone mass decreased significantly during the first 6 posttransplant months at the distal radius, lumbar spine, and femur (p < 0.01) and was still below pretransplant values at the 12th posttransplant month. Serum osteocalcin increased significantly from the 3rd month after transplantation (from 6.9 +/- 4.4 to 12.0 +/- 6.5 micrograms/l; p < 0.0001) and remained increased throughout the first posttransplant year. CONCLUSION: Early and accelerated bone loss occurred after liver transplantation. This bone reduction seems to be mainly the result of increased bone resorption, possibly related to corticosteroid therapy.

Absorptiometry, Photon↗

PubMed1987

Osteoporosis and amenorrhea in young women.

Bone density of the radius was measured using both standard photon absorptiometry and X-ray computed tomography (CT) scanning, and of the femur using CT, in 21 young women with amenorrhea and estrogen deficiency due to hyperprolactinemia, 8 due to ovarian failure or weight loss, 17 postmenopausal women with bone fractures presumed to be due to osteoporosis, and 36 young normal controls. Bone density in the postmenopausal women was reduced by 18-20% in the radius and 11% in the femur (p less than 0.001). In the hyperprolactinemic group bone density was significantly reduced only in the femur (by 4%, p less than 0.01). Bone density appeared to be reduced in the other young amenorrheic women both in the radius (by 2-5%) and the femur (3%) but the difference was not significant, although the group was small. This and other studies of bone density suggest the need for prophylactic treatment to prevent osteoporosis in young women with amenorrhea and estrogen deficiency, whatever the cause.

Absorptiometry, Photon↗

PubMed1999

Association of tibolone and fluoride displays a pronounced effect on bone mineral density in postmenopausal osteoporotic women.

A double-blind, placebo-controlled, randomized, prospective two-center study was carried out to assess the effects of tibolone + fluoride versus placebo + fluoride therapy on trabecular and cortical bone in postmenopausal osteoporotic women. Ninety-four subjects (mean age 61.1 years, postmenopausal 13.5 years on average) with low bone mineral density (BMD) at baseline were randomized to 2.5 mg of tibolone (Org OD 14, Livial) plus 26.4 mg of fluoride (Fluocalcic) or placebo plus 26.4 mg of fluoride daily over 2 years; 55 (58.5%) subjects completed the study, the main reason for discontinuation being untoward gastrointestinal effects. BMD at the lumbar spine was measured by both dual photon absorptiometry (DPA) and dual-energy X-ray absorptiometry (DXA), and at the hip by DXA at 6-month intervals. Baseline values (DXA, g/cm2) for tibolone + fluoride and placebo + fluoride groups were 0.733 and 0.744 for the lumbar spine, and 0.761 and 0.788 for the hip. Change from baseline and percentage change from baseline were calculated for the intent-to-treat and completers groups. An analysis of variance (ANOVA) model or Wilcoxon test was used for statistical evaluation. There was a mean increase in BMD at the lumbar spine measured by DPA of 25.3% and 12.3% in tibolone + fluoride and placebo + fluoride groups, respectively (p = 0.01); with DXA, respective changes were 32.6% and 14.0% (p = 0.013). Data on BMD at the hip showed mean increases of 7.9% and 2.6% for the tibolone + fluoride and placebo + fluoride groups, respectively. We conclude that combined tibolone + fluoride treatment induces a highly significant increase in BMD at the lumbar spine without simultaneous loss of the cortical bone allowing for a meaningful reduction of the fluoride dose when given in combination with tibolone.

Absorptiometry, Photon↗

PubMed1990

Quantification of bone healing. Comparison of QCT, SPA, MRI, and DEXA in dog osteotomies.

Four noninvasive imaging modalities were used to quantitatively evaluate and compare tibial osteotomy healing in dogs. Quantitative computed tomography (QCT), magnetic resonance imaging (MRI), single-photon absorptiometry (SPA), and dual-energy x-ray absorptiometry (DEXA) were the four techniques examined. Bilateral tibial osteotomies were performed in 32 dogs divided into four groups. The osteotomies were stabilized with a 2-mm gap using unilateral external skeletal fixation. Dogs were anesthetized, imaged with the four noninvasive techniques, and killed at 2-12 weeks. Invasive techniques were used to determine: 1) the torsional properties of the bone; and 2) the local stiffness properties and calcium content within the bone. The techniques which had the strongest associations with the torsional properties of the osteotomies were QCT, SPA and DEXA. Generally, QCT and SPA had marginally stronger correlations than DEXA; but, overall, there were no differences between the techniques. MRI had the poorest associations with the torsional properties of the osteotomies. Generally, QCT had the strongest correlations with local material properties, such as indentation stiffness and calcium content. SPA had the second strongest correlations with calcium content and had the third strongest correlations with indentation stiffness behind DEXA. DEXA had the third strongest correlations for calcium content. With the exception of some of the correlations with indentation stiffness, MRI had the poorest associations with the local parameters studied.

Absorptiometry, Photon↗

PubMed1991

Immobilization increases bone prostaglandin E. Effect of acetylsalicylic acid on disuse osteoporosis studied in dogs.

The effect of acetylsalicylic acid (aspirin) on bone mass and bone prostaglandin E (PGE) in immobilization osteoporosis was studied in 12 growing dogs using a unilateral hind limb cast-fixation model. Osteoporosis was induced by fiberglass-cast immobilization of the right hind limb for 4 weeks, with the left hind limb as a control. Six dogs received buffered aspirin at 25 mg/kg body weight per os every 8 hours; 6 dogs received no treatment. All the dogs were killed after 4 weeks, and bone samples were collected. Bone mineral content of the distal tibial metaphysis was measured by single-photon absorptiometry. In vitro release of PGE from the calcaneus, tibial cortical bone, tibial cancellous bone, and ilium were measured using a specific radioimmunoassay for PGE. Compared with the controls, the casted limb of untreated dogs had half the bone mass and a twofold increase in bone PGE. Aspirin treatment was associated with a 65 percent reduction in bone PGE and a 13 percent bone mass sparing effect. These results provide indirect evidence that PGE plays a role in immobilization osteoporosis.

Absorptiometry, Photon↗

PubMed1991

Piroxicam-induced reduction in osteopenia after external fixation of rabbit tibia.

Twelve rabbits were treated with a unilateral external fixator in one tibia for 12 weeks, while the other tibia served as an intact control. Half of the animals were also treated with 10 mg/kg/day of piroxicam, given in two daily oral doses. Changes in bone mineral content were determined using single photon absorptiometry. After 12 weeks, we found a 3 percent decrease in the bone mineral content in the tibia of the animals treated with piroxicam versus 9 percent in the nonpiroxicam group (P = 0.04). In the femurs, there was an insignificant decrease in bone mineral, 2 percent (piroxicam) and 1 percent (nonpiroxicam) respectively. The results indicate that piroxicam may reduce the osteopenia caused by external fixation.

Absorptiometry, Photon↗

PubMed1992

Colles' fracture associated with reduced bone mineral content. Photon densitometry in 74 patients with matched controls.

In a prospective population-based investigation, we measured bone mineral density (BMD) of the forearm using single-photon absorptiometry at both a distal and a more proximal site in 74 Colles'-fracture patients who were compared with controls matched for age, sex, and years after menopause. For both groups there was a marked inverse relationship between age and bone mass. However, over the entire age range, the probands had 11 percent reduced BMD when compared with the controls. Our findings confirm that patients with fracture of the distal forearm have reduced BMD. They constitute an appropriate group for studies aimed at prevention of fracture in the elderly.

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