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PubMed1993

Radiologic diagnosis of osteoporosis. Current methods and perspectives.

Osteoporosis is defined as a decrease in bone mass accompanied by structural changes, leading to an increase in fracture propensity. Early diagnosis of osteoporosis, fracture risk prediction, and assessment of efficacy of therapy therefore are of great interest. A number of noninvasive techniques are available for measuring bone mass at multiple sites of the skeleton. This article reviews basic methodology and developments in radiology such as x-ray and photon absorptiometry and quantitative computed tomography, which are routinely used in clinical practice. Recent techniques for assessment of bone mineral density and structure, such as ultrasound measurements, and their possible clinical applications also are discussed.

Absorptiometry, Photon↗

PubMed1993

Treatment of postmenopausal osteoporosis with salmon calcitonin nasal spray: evaluation by bone mineral content and biochemical patterns.

We studied 21 women with postmenopausal osteoporosis, treated with salmon calcitonin nasal spray (100 IU/daily) and calcium (1 g/daily) for six months. Bone mineral content (BMC), measured before and at the end of therapy with lumbar dual photon absorptiometry, showed a significant increase (p < 0.01). At the end of the study, there was also a clear improvement of osteoporotic pain. Among biochemical markers of bone turnover, there was a significant (p < 0.01) reduction of urinary excretion of hydroxyproline. No side effect was registered and all patients had a good compliance to therapy.

Absorptiometry, Photon↗

PubMed1993

Effect of exercise on the bone mineral density and bone remodelling indices in women with rheumatoid arthritis: 2 case studies.

Two premenopausal women with rheumatoid arthritis of 16 years' duration were enrolled in a one year conditioning exercise program consisting of walking and low impact aerobics. The effect of exercise on the markers of bone formation (serum bone specific alkaline phosphatase and osteocalcin), bone resorption (urinary calcium/creatine and serum tartrate resistant acid phosphatase), and vertebral bone mineral density as determined by dual photon absorptiometry are discussed.

Absorptiometry, Photon↗

PubMed1993

Effect of "standing" on spasticity, contracture, and osteoporosis in paralyzed males.

The effect of "standing" in a frame on spasticity (clinical assessment and H-reflex), contracture (lower extremity joint range of motion), and osteoporosis (dual photon absorptiometry) was studied in six paralyzed males (mean age 49 yr) who had been confined to wheelchairs for an average of 19 years. Standing time averaged 144 hours over a mean of 135 days. Clinical Assessment measured reflexes, tone, and clonus in the legs. Results revealed no important differences between initial and final scores for clinical assessment and joint range of motion. In three subjects for whom H-reflexes were found, latency and amplitude were not altered by "standing." Bone density was normal in the lumbar spine but significantly reduced in the femoral neck. "Standing" did not modify the bone density in any site. A follow-up interview revealed that 67% of subjects continued to "stand" and felt healthier because of it. In summary, "standing" had no ill effects, did not alter measured variables, and had a positive psychological impact.

Absorptiometry, Photon↗

PubMed1993

Body composition and bone mineral distribution during growth in females.

The total mass of lean tissue, fat and bone mineral was measured in a cross-sectional study by dual-photon absorptiometry in 76 normal, ambulatory females aged 8 to 26 years. These measurements allowed quantification of average total-body bone mineral density and assessment of the mass and the average density of bone mineral in different regions of the body, specifically the head and the legs. Both total-body and regional results are presented as logistic functions of age; the functions were derived by nonlinear regression analysis. Normal ranges, defined as twice the root mean square deviation about the fitted equation, are also expressed as functions of age. As well as providing normal reference values, these data suggest that muscle mass is an important determinant of total-body bone mineral mass and that peak bone mass is achieved at different ages in different regions of the skeleton.

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PubMed1993

Bone density is compromised in amenorrheic women despite return of menses: a 2-year study.

OBJECTIVE: To determine the effects of estrogen deprivation on bone mass in young women in whom large bone mass increases are known to occur. METHODS: Over 2 years, nine amenorrheic and 21 normal women were studied, classified into exercising (dancers) and sedentary subjects. An integrated estrogen exposure score was used to determine estrogen response during the 2 years of study. Bone mineral density was measured by single and dual photon absorptiometry in the spine, wrist, and foot (metatarsus). RESULTS: Hypoestrogenism was present in all amenorrheic women in the first year, and mean estrogen exposure scores were lower in these subjects during the 2 years. Mean spine, wrist, and metatarsal bone mineral density measurements were lower in the amenorrheic women and remained below the levels in controls, despite changing clinical indices and return of menses in some of the subjects. Amenorrheic dancers showed the greatest increase in spine bone mineral density, gaining 9.65% in the first year, 4.49% in the second, and an increase of 14.43% (P < .05) over the total period. Their bone mineral density values, however, remained significantly below those of normal controls during the duration of the study. The most significant gains were seen in two subjects with weight gain and return of irregular periods (three periods in 12 months). CONCLUSION: Young amenorrheic exercising women appear to increase bone mass before the return of normal menses; however, bone mass remained below control values during 2 years of study, possibly because of long-term adolescent hypoestrogenism.

Absorptiometry, Photon↗

PubMed1993

Influence of recreational activity and muscle strength on ulnar bending stiffness in men.

Bone bending stiffness (modulus of elasticity [E] x moment of inertia [I]), a measure of bone strength, is related to its mineral content (BMC) and geometry and may be influenced by exercise. We evaluated the relationship of habitual recreational exercise and muscle strength to ulnar EI, width, and BMC in 51 healthy men, 28-61 yr of age. BMC and width were measured by single photon absorptiometry and EI by mechanical resistance tissue analysis. Maximum biceps strength was determined dynamically (1-RM) and grip strength isometrically. Subjects were classified as sedentary (S) (N = 13), moderately (M) (N = 18), or highly active (H) (N = 20) and exercised 0.2 +/- 0.2; 2.2 +/- 1.3; and 6.8 +/- 2.3 h.wk-1 (P < 0.001). H had greater biceps (P < 0.0005) and grip strength (P < 0.05), ulnar BMC (P < 0.05), and ulnar EI (P = 0.01) than M or S, who were similar. Amount of activity correlated with grip and biceps strength (r = 0.47 and 0.49; P < 0.001), but not with bone measurements, whereas muscle strength correlated with both EI and BMC (r = 0.40-0.52, P < 0.005). EI also correlated significantly with both BMC and ulnar width (P < 0.0001). Ulnar width and biceps strength were the only independent predictors of EI (r2 = 0.67, P < 0.0001). We conclude that levels of physical activity sufficient to increase arm strength influence ulnar bending stiffness.

Absorptiometry, Photon↗

PubMed1993

Deflazacort in juvenile chronic arthritis.

Vertebral crush fracture associated with glucocorticoid therapy causes major morbidity in juvenile chronic arthritis (JCA). Deflazacort (DFZ) may have an advantage over prednisone (PRED) because of its alleged bone sparing properties. Of 34 children with JCA receiving more than 5 mg PRED/day, 31 completed a 1-year, double blind, randomized, comparative trial of DFZ and PRED. Patient characteristics at trial entry were well matched. DFZ and PRED were prescribed in equivalent amounts. DFZ achieved similar disease control to PRED, and was not associated with untoward effects. Joint counts, hematological indices and biochemical values did not differ between treatment groups initially or during the trial. Bone density trends (velocities) in the lumbar spine were measured using dual photon absorptiometry at 3-monthly intervals and trends in bone and soft tissue growth calculated. Lumbar spine bone growth correlated with indices of somatic growth, with wide ranges in each group. Co-variance analysis showed a significant advantage (p < 0.007) of DFZ over PRED when spinal bone density was compared to body surface area and weight. Children taking DFZ showed less weight gain but similar height gain to children taking PRED. Children with poor or no somatic growth showed significant lumbar bone loss only in the PRED group. Of the children originally treated with PRED; 11 were switched to DFZ after completing the double blind study. Data for 26 children treated with DFZ for 1 year were thus available and confirmed a significantly greater rate of spinal bone growth relative to somatic growth, p < 0.002.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1995

Prevention of bone mineral loss in patients with Crohn's disease by long-term oral vitamin D supplementation.

OBJECTIVE: To determine whether long-term dietary supplementation with low doses of vitamin D helps to prevent bone loss and the development of osteoporosis or osteomalacia in out-patients with Crohn's disease. DESIGN: A randomized controlled study. SETTING: The out-patient clinic of a tertiary centre (university hospital). PATIENTS: Seventy-five out-patients (31 men and 44 women, aged 16-77 years) with Crohn's disease. INTERVENTIONS: All patients were randomly assigned to receive either an oral supplement of 1000 IU/day vitamin D for 1 year or no supplement. Bone mineral density, assessed in the distal part of the nondominant forearm using single photon absorptiometry, and serum levels of 25-hydroxyvitamin D, assessed using a competitive protein binding assay, were measured before and after the period of dietary supplementation. MAIN OUTCOME MEASURE: Relative change of bone mineral density. RESULTS: Serum levels of 25-hydroxyvitamin D increased in 57% of patients who received a supplement (compared with 37% of control patients). Bone mineral density decreased significantly in control patients [median -7%, interquartile range -12.6-(+0.4%)] but not in patients who received a supplement [median -0.2%, interquartile range -3.8-(+14%); P < 0.005]. Increases in bone mineral density were especially prevalent among patients who received the supplement and had normal serum levels of 25-hydroxyvitamin D (68%), whereas increases occurred in only 18% of patients with low serum levels of 25-hydroxyvitamin D (P = 0.008). Patients without an intestinal resection and receiving the vitamin D supplement had a marginally greater increase in bone mineral content than patients who had undergone a resection (P = 0.05). CONCLUSION: Long-term oral vitamin D supplementation seems to be an efficient means of preventing bone loss in patients with Crohn's disease and could be recommended, especially for patients at high risk of osteoporosis.

Absorptiometry, Photon↗

PubMed1995

Time-relationship between bone growth and increment of bone mineral content in growing rats.

The aim of the study was to describe the time-relationship between the growth rate of the rat tibia and the increase rate of its mineral content. Appositional and endochondral bone growth rates were derived from sequential X-rays measurements of tibial widening and lengthening, respectively; the increase rate of bone mineral content was derived from sequential photon absorptiometry measurements of the proximal tibio-fibular site. The time-relationship of appositional growth rate and endochondral growth rate versus bone mineral content increase rate was mathematically described. The results allow a better understanding of the time-course of two distinct features of bone growth: increase in size and increase in mineral content.

Absorptiometry, Photon↗

PubMed1996

The effects of long-term heparin therapy during pregnancy on bone density. A prospective matched cohort study.

We performed a prospective matched cohort study to investigate the effects of long-term (> 1 month) heparin therapy on lumbar spine bone density. Twenty-five women who received heparin during pregnancy, and 25 matched controls underwent dual photon absorptiometry of the lumbar spine in the post-partum period. Zero of 25 heparin-treated patients developed fractures. Heparin-treated patients had a 0.082 g/cm2 lower bone density compared to untreated controls, which is clinically and statistically significant (p = 0.0077). There were 6 matched pairs in which only the heparin-treated patient had a bone density below 1.0 g/cm2, compared to only one pair in which only the control patient had a bone density below this level (p = 0.089). The correlation coefficients of the difference in bone density in each matched pair, and the duration of heparin therapy, the mean daily dose, and the total dose of heparin were 0.042, - 0.015, and 0.021, respectively; none of these values is statistically significant. We conclude: 1) long-term heparin therapy was associated with a significant reduction in bone density, although fractures are uncommon, 2) there was no significant correlation between lumbar bone density and the dose or duration of heparin.

Absorptiometry, Photon↗

PubMed1996

Bone mineral density and risk of breast cancer in older women: the study of osteoporotic fractures. Study of Osteoporotic Fractures Research Group.

OBJECTIVE: To test the hypothesis that bone mineral density (BMD) is associated with the risk of developing breast cancer in older women. DESIGN: Prospective cohort study with mean (SD) follow-up of 3.2 (1.6) years. SETTING: Four clinical centers, one each located in the following areas: Baltimore, Md; Minneapolis, Minn; Portland, Ore; and the Monongahela Valley in Pennsylvania. PARTICIPANTS: A total of 6854 nonblack women who were 65 years of age or older and enrolled in the Study of Osteoporotic Fractures. MEASUREMENTS: Radius and calcaneus BMD by single photon absorptiometry at baseline; hip and spine BMD by dual-energy x-ray absorptiometry 2 years later. MAIN OUTCOME MEASURE: Breast cancer confirmed by medical record review. RESULTS: A total of 97 women developed breast cancer. In the multivariate model, adjusting for age, the degree of obesity, and other important covariates, the risk of breast cancer was about 30% to 50% higher per 1 SD increase in BMD (relative risk, distal radius BMD=1.50; 95% confidence interval, 1.16-1.95). The age-adjusted incidence rate of breast cancer per 1000 person-years among women in the lowest quartile of distal radius BMD was 2.46, compared with 5.99 among women with the highest BMD. Women with BMD above the 25th percentile were at 2.0 to 2.5 times increased risk of breast cancer compared with women below the 25th percentile. Results were consistent across all BMD sites. CONCLUSIONS: Bone mineral density predicts the risk of breast cancer in older women. The magnitude of the association is similar to that observed between BMD and all fractures. Our findings suggest a link between 2 of the most common conditions affecting a woman's health. Identifying a common denominator for these conditions should substantially improve our understanding of their etiology and prevention.

Absorptiometry, Photon↗

PubMedDate not supplied

[The effect of lactation during the reproductive age on bone mass in postmenopause].

One of the factors of the reproductive status which affects bone mass of women in the generative period is duration of lactation. The aim of this study was to establish if duration of lactation affects bone mass of postmenopausal women. 81 women up to 5 years of menopause were examined. They were divided into two groups in regard to lactation duration. The first group consisted of those who breast-fed for up to 12 months, while the second group consisted of those who had breast-fed longer than 12 months. In all examined women lumbar bone mineral density was measured using photon absorptiometry. No statistically significant difference was established in the lumbar bone mineral density in the examined groups (0.902 +/- 0.104 g/cm2 to 0.915 +/- 0.127 g/cm2; p < 0.30). In order to eliminate the protective effects of obesity on bone mass all examinees were divided into 4 subgroups: a) nonobese women with up to 12 months of lactation; b) nonobese women with lactation longer than 12 months. c) obese women with up to 12 months of lactation and d) obese women with lactation longer than 12 months. Lumbar bone mineral density of nonobese women, no matter the duration of lactation, did not statistically significantly differ (0.892 +/- 0.107 g/cm2 to 0.900 +/- 0.116 g/cm2; p < 0.40). No statistically significant difference in regard to lumbar bone mineral density was established in the group of obese women, no matter the duration of lactation (0.912 +/- 0.103 g/cm2 to 0.930 +/- 0.139 g/cm2; p < 0.30). The obtained results reveal that bone mass reduction is reversible in the postpartal period and that duration of lactation does not affect bone mass in the postmenopausal period.

Absorptiometry, Photon↗

PubMed1997

[Biological test for menopausal osteoporosis].

Osteoporosis has become a major public health problem in many western countries in which about 25% of women by the age of 65 will have had osteopenic fractures. The most important contributing factor to this condition is loss of gonadal function. This progressive disease, characterized by reduction in bone mass, may be prevented by estrogen replacement therapy. While there are several methods of diagnosing the disease when already established, there is no method that can identify women at high risk of developing osteoporosis. We have developed a biological test in which the serum of postmenopausal women is added to rat osteoprogenitor cell culture and its influence on proliferation, differentiation and mineralization of bone cells is determined. The serum of 20 menopausal women was examined by the biological test and the results compared to the findings of dual photon absorptiometry. This showed that rapid bone-losers had a significantly lower mineralization index as compared to nonosteopenic women (p < 0.0001). The proliferation index (cell count) and alkaline phosphatase activity did not show significant differences between osteopenic and nonosteopenic groups. This preliminary study showed that a test based on serum reacting with a culture of bone cells to induce mineralization may be of value in the diagnosis of osteoporosis.

Absorptiometry, Photon↗

PubMed1998

Bone mineral density of the lumbar spine and proximal femur is decreased in children with sickle cell anemia.

Bone mineral density (BMD) was evaluated in the proximal femora (femoral neck, Ward's triangle, and greater trochanter) and lumbar spines of 25 black children and young adults with sickle cell anemia using dual-photon absorptiometry. Compared with normal subjects from the general population, the patients with sickle cell anemia exhibited lower bone mineral density values in all scan regions (approximately 6% to 21% lower than expected). These differences in the lumbar spine were significant for both girls and boys. When compared with normal black subjects from the general population, the girls with sickle cell anemia exhibited significantly lower lumbar spine bone mineral density, and the boys with sickle cell anemia exhibited significantly lower bone mineral density in the femoral neck and Ward's triangle. No consistent or significant correlations were found between the bone mineral density data and the patients' hematologic indices.

Absorptiometry, Photon↗

PubMed1997

[Comparative analysis of body composition assessment methods in healthy adult men].

BACKGROUND: The degree of agreement between different methods to assess total body composition is not well known. AIM: To determine the level of agreement for total body fat mass measurement by dual-photon absorptiometry (DEXA), bioelectrical impedance (BIA) and anthropometry using the deuterium dilution method as the gold-standard technique, in normal male volunteers. SUBJECTS AND METHODS: Total body fat mass was measured by DEXA, BIA, anthropometry and deuterium dilution in thirty one healthy men, aged 41.9 +/- 8.6 years old. RESULTS: Mean differences in percentage of total body fat compared with deuterium dilution were 0.3% +/- 2.2, 1.3% +/- 3.4 and 1.8 +/- 2.3% for DEXA1 BIA and anthropometry respectively. DEXA had the lower difference with deuterium dilution and the confidence intervals for this difference (+/- DS) showed that, at the individual level, the maximum difference was 4.4%. CONCLUSIONS: All the methods evaluated gave similar average measurements for total body fat mass, but with different individual variability. In this group of healthy male subjects, DEXA was the best method in terms of agreement with the gold-standard.

Absorptiometry, Photon↗

PubMed1998

Injuries in adolescent spine exposed to compressive loads: an experimental cadaveric study.

In a cadaveric experiment, 16 functional spinal units (FSUs) obtained from 7 subjects with a mean age of 16.3 years were tested in compression to failure. The deformation rate was 5 mm/min. The bone mineral content (BMC) in the vertebrae was determined by using dual-photon absorptiometry (DPA). In 15 of the FSUs, traumatic changes were registered. Three different types of changes were seen. In nine vertebrae, there was a rupture in the cartilaginous end plate, in 12, a separation of the end plate from the vertebral body, and in three vertebrae, a compression fracture was registered. A close relation was found between BMC and the ultimate force (r2 = 0.63), the ultimate displacement (r2 = 0.73), and the energy absorption (r2 = 0.74). The weakest part of a spinal segment in this experimental situation is the growth plate.

Absorptiometry, Photon↗

PubMed1991

Body composition and calcium metabolism in adult treated coeliac disease.

Twenty two treated adult patients with coeliac disease (aged 20-70 years) were examined. Body composition was assessed from anthropometry and directly measured by dual photon absorptiometry. Bone mineral content was measured in the spine (dual photon absorptiometry) and at two forearm sites (single photon absorptiometry). Compared with age matched healthy subjects, treated coeliac patients had lower body mass index (-5%, p less than 0.05) and lower directly measured total body fat mass (-30%, p less than 0.001). They also had decreased bone mineral content (-9 to -13%, p less than 0.01) in the spine and in the forearms. The serum concentrations of albumin, D vitamin binding protein, and iron were reduced (-6 to -22%, p less than 0.01), but otherwise blood and urine analyses were normal. We conclude that this group of treated adult coeliac patients had a reduced fat mass and bone mineral content compared with the general population.

Adult↗