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PubMed1993

Changes in cortical and trabecular bone in algodystrophy.

We studied the pattern of bone loss in the hand of 77 patients with Colles' fracture using metacarpal morphometry, single photon absorptiometry and a radiographic scoring system. Forty-four patients had post-traumatic algodystrophy and the remainder served as controls. Both groups were immobilized in the same manner and for the same period of time and both showed loss of bone during immobilization. The loss of bone 7 weeks after fracture was significantly greater in algodystrophy than in controls both at cortical (P < 0.05) and at trabecular sites (P < 0.001). Recovery of bone occurred in the control patients by 19 weeks after fracture at cortical sites and by 31 weeks in trabecular bone. In contrast, the bone loss seen in patients with algodystrophy persisted for the 6-month duration of the follow-up, and up to 1 year in all nine patients studied for longer. These findings indicate that post-traumatic algodystrophy is associated with regional skeletal losses greater than those following uncomplicated fracture and may result in irreversible changes in the structure and thus the strength of the bony architecture.

Absorptiometry, Photon↗

PubMed1996

The influence of body size, smoking, and diet on bone density in pre- and postmenopausal women.

We studied the determinants of low bone mineral density, using data from a population-based screening program of osteoporosis carried out among 1,373 women (age 40-64 years) in the province of Pordenone, Italy, by means of dual photon absorptiometry of the lumbar spine. Menopause had a major effect on bone mineral density. Age had little influence before menopause. In multivariate linear regression analyses, weight was the strongest predictor of bone mineral density in pre- as well as postmenopausal women. After the inclusion in a single model of a term for current weight, weight at ages 12 and 30 years explained some additional variance, whereas high waist-to-hip ratio (an indicator of central adiposity) had no influence. Smoking 15 or more cigarettes per day entailed a small increased risk of osteoporosis, but this effect, independent of weight, appeared to be restricted to premenopausal women. No food or micronutrient that we examined was predictive of bone mineral density, nor was coffee or alcoholic beverage intake.

Absorptiometry, Photon↗

PubMedDate not supplied

The impact of a senior dancing program on spinal and peripheral bone mass.

Because activity and regular exercise are important factors to maintain general good health in senior citizens, we investigated whether senior dancing has any effect on peripheral or lumbar bone density. We performed a prospective study over a12-mo period on bone density at a spinal and peripheral measuring site in 28 female senior members (mean age: 67 +/- 2 yr) of a dancing group in Vienna. Lumbar bone mineral density was assessed by quantitative computed tomography (qCT) and radial bone density by single photon absorptiometry of the distal forearm. The mean training time per week was 3.2 +/- 0.8 h. In the entire group of female dancers, no significant effects of dancing on radial or lumbar bone density could be observed. Linear regression analysis showed that the lower the qCT at the beginning of the observation period, the higher was the percentage increase of spinal qCT in the entire group during 12 mo of dancing (r = 0.52, P < 0.0001). For additional evaluation, females were divided into two subgroups, osteoporotic or nonosteoporotic, based on x-rays and lumbar bone mineral density (BMD) as measured by qCT. The group classified as dancers with osteoporosis (group I) showed a significant increase in lumbar bone density, whereas in the group of dancers without signs of osteoporosis (group II), BMD remained unchanged. Additionally, radial bone density did not show any changes in either group. Group I showed a significant correlation between basal spinal BMD and the percentage change of BMD during the observation period (r = 0.7, P < 0.001). Changes of the biochemical parameters were observed in the bone-specific isoenzyme of alkaline phosphatase, a marker of osteoblastic activity, in group I giving additional evidence of increased bone formation.

Absorptiometry, Photon↗

PubMed1991

Factors affecting bone mineral density in elderly men receiving chronic in-center hemodialysis.

Twenty-five elderly men receiving chronic hemodialysis had measurements of their bone mineral density (BMD) by dual-photon absorptiometry (DPA). Loss of BMD was much more pronounced in femoral necks than in lumbar vertebrae. Stepwise multiple liner-regression analysis showed that low BMD was associated with 1) hypoalbuminemia, hypermagnesemia, hyperaluminemia, and high serum alkaline phosphatase for femoral necks and 2) hypercalcemia and hypermagnesemia for lumbar vertebrae. These observations suggest that the femoral neck is the preferred site for measurement of BMD in dialysis patients. Along with factors directly affecting bone metabolism, nutritional factors may affect BMD in such patients.

Absorptiometry, Photon↗

PubMed1989

A DPA technique for simultaneously measuring bone, soft tissue, and fat content.

Although conventional dual photon absorptiometry (DPA) techniques can be used to estimate fat and soft tissue content, such estimates are not possible where bone is present. We propose a method that can make these estimates in the presence of bone in the extremities of the body. The combination of this method with the conventional method should yield fat and soft tissue composition from most points within the body. The proposed technique simultaneously measures thicknesses of bone, soft tissue, and fat. These thicknesses are determined of bone, soft tissue, and fat. These thicknesses are determined from a combination of gamma-ray transmission data at two energies and a measurement of total tissue thickness. To test the technique, a feasibility study was performed with known thicknesses of aluminum (simulating bone), lucite (simulating tissue), and polyethylene (simulating fat). A variety of thicknesses of each material were employed (Al: 0-1.3 cm, lucite: 0-5 cm, polyethylene: 0-5 cm). The accuracies (standard errors of the estimates) of the calculated versus true thicknesses of aluminum, lucite, and polyethylene were 0.6%, 2.6%, and 2.5%, respectively. The estimates of "bone" thickness were insensitive to the presence of varying thicknesses of "fat." (In contrast, application of the conventional DPA method to the same gamma-ray transmission data yielded underestimates in "bone" thickness due to "fat" by as much as 11%.) For a 60 minute (whole body) scan time, the reproducibility of the measurements of the thicknesses of aluminum, lucite, and polyethylene were 0.4%, 1.0%, and 1.3%, respectively. All of these values are in a clinically useful range.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1994

Bone mineral status after renal transplantation. Assessment by noninvasive techniques.

RATIONALE AND OBJECTIVES: Bone mineral status in recipients of renal grafts is related to preexisting renal osteodystrophy and immunosuppressive treatment. The authors assessed bone mineral status after renal transplantation. METHODS: Bone mineral status of 20 male graft recipients was evaluated using the following noninvasive techniques: 1) neutron activation analysis, to measure hand bone phosphorus (HBP); 2) single photon absorptiometry, to measure forearm bone mineral content (BMC); and 3) single energy spectrum quantitative computed tomography, to measure spinal trabecular bone equivalent density (TBED). RESULTS: The mean (+/- SD, P) HBP, BMC, and TBED were found to be respectively, 4.8% (+/- 8.3%, P = .02), 6.6% (+/- 14.6%, P = .07) and 52% (+/- 8.5%, P < .001) lower than that measured in matched normal controls. Renal graft recipients demonstrated mean HBP and BMC decrements that were similar to those observed in matched patients on extrarenal dialysis, although the decrement in TBED was significantly greater in the graft recipients (P < .001). Repeated measurements performed during a 3-year period showed no statistically significant changes. CONCLUSIONS: Renal transplantation was associated with minor degree of osteopenia in the primarily cortical bone tissue. We speculate that the remarkably low TBED values in graft recipients does not reflect a mean 52% decrement of spinal bone minerals, but rather may be attributed in part to the deposition of adipose tissue in the spine as a result of corticosteroid treatment.

Absorptiometry, Photon↗

PubMed1999

The long-term effect of early mineral, vitamin D, and breast milk intake on bone mineral status in 9- to 11-year-old children born prematurely.

BACKGROUND: Although the short-term benefits of mineral supplementation in preterm infants has been established, the long-term benefits are less clear. The purpose of the study was to evaluate effects of early-life mineral, vitamin D, and breast milk intake on bone mineral status in children 9 to 11 years of age who were born prematurely. METHODS: Seventy preterm infants born 1985 through 1987 were randomized into four groups: to receive a vitamin D dose of 500 or 1000 IU/day and calcium- and phosphorus-supplemented or unsupplemented breast milk. At 3 months of age, radial bone mineral content was determined by single-photon absorptiometry and vitamin D metabolites were assessed. At 9 to 11 years of age, the bone mineral status of the radius and lumbar spine was assessed using dual energy x-ray absorptiometry. RESULTS: At the age of 3 months, the preterm infants with diets supplemented with minerals had 36% higher bone mineral content than the preterm infants whose diet was not supplemented with minerals. At the age of 9 to 11 years, in contrast, bone mineral status was comparable among the groups, irrespective of different mineral supplementation during the neonatal period. Interestingly, the lumbar bone mineral apparent density was positively related to lactation in mineral-supplemented children. There was neither short-term nor long-term benefit to bone mineral status of a vitamin D dose of 1000 IU/day compared with 500 IU/day. CONCLUSIONS: The short-term benefit to bone mineral density in preterm infants of mineral supplementation of the early diet is obvious, but, in the long term, the effects seem to disappear. The results also imply that a relatively long period of breast-feeding may be needed to optimize long-term bone mineral acquisition in the lumbar spine.

Absorptiometry, Photon↗

PubMed1992

Assessment of renal osteodystrophy in hemodialysis patients.

We performed a prospective study of 30 patients undergoing chronic hemodialysis to determine which of 6 generally available diagnostic procedures provided the most useful information for the assessment of bone disease in hemodialysis patients. The 6 procedures were: routine biochemical measurements, N-terminal parathyroid hormone (N-PTH), radiographic analysis of hands and clavicles, bone density determination by dual photon absorptiometry (DPA), deferoxamine stimulation test, and iliac crest bone biopsy. Serum N-PTH was elevated in 83% of patients but was not significantly associated with abnormalities of other biochemical parameters. No significant relationship was demonstrated between biochemical data and radiographic findings or between biochemical data and bone density by DPA. All patients with abnormal DPA had an elevation of N-PTH; therefore, DPA did not reveal any unsuspected disease. Bone biopsies were done in 20 patients and findings in each were consistent with uremic osteodystrophy, including osteitis fibrosa cystica in 11 patients and aluminum-associated bone disease in 2 patients. Six patients had mixed disease, and 1 patient had osteoporosis. Despite 11 positive deferoxamine tests, bone biopsy revealed aluminum deposition in only 7 of these patients, suggesting extraosseous aluminum accumulation in the remaining 4. Evaluation of the positive and negative predictive accuracies of DPA, x-ray analysis, N-PTH levels, and aluminum bone deposition revealed that normal DPA or x-ray findings do not exclude bone disease, that N-PTH level is a good marker for secondary hyperparathyroidism, and that a negative deferoxamine test excludes aluminum-associated bone disease. Discriminant analysis also reinforced these conclusions.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1994

A study of bone mineral density versus age in Omani women and a comparison with normal British women.

Dual photon absorptiometry (DPA) of the lumbar spine (2nd, 3rd and 4th lumbar vertebrae) was carried out using a Norland 2600 bone densitometer on 194 Omani women (OW). The exclusion criteria were (1) any medical treatment known to affect calcium metabolism or bone mass, (2) osteomalacia or secondary osteoporosis, (3) the presence of osteophytes or compression fractures of the lumbar vertebrae and (4) the presence of aortic calcifications. The bone mineral density (BMD) results showed a peak value occurring in the 30-35 year old age range (mean 1.1 g cm-2, standard deviation 0.1). The data were compared with a group of 165 normal British women (BW) with a similar age distribution whose peak BMD (obtained with dual X-ray absorptiometry) occurred in the 40-45 year old age range. The two groups were compared in each 10 year age range and the BMD of the OW group was found to be significantly lower in the 40-49 year old age range (P < 0.01) as well as the 50-59 and 60-69 year old age ranges (P < 0.001).

Absorptiometry, Photon↗

PubMed1996

Bone mineral density in patients with spinal cord injuries.

The bone mineral density (BMD) of 157 patients with a spinal cord injury (SCI) was measured using dual-photon absorptiometry (Lunar DP-4). The BMD of the second to fourth lumbar vertebrae (L2-L4) and the right femoral neck was measured and the mean density registered in grams per square centimetre. The likelihood of a fracture was based on the percentage of BMD in young normals and the degree of risk of fracture. The following criteria were used to separate the patients: (1) complete or incomplete immobility due to the SCI; (2) the time between the SCI and measurement of BMD was short ( 3 years); (3) the level at which the SCI occurred was considered to be high (i.e. from the first cervical vertebra to the tenth thoracic vertebra) or low (i.e. from the eleventh thoracic vertebra to the first lumbar vertebra). The rate of abnormal BMD (i.e. a greater risk of fracture) in each of the groups and at each site was measured and differences evaluated using the chi-square test. Fifty-four of the 157 (34%) scans revealed an abnormal BMD at the level of L2-L4 and 126 (80%) in the right femoral neck. The difference between these two incidences was significant (P < 0.001). However, there were no significant differences in abnormal BMD with regard to severity of the SCI, time elapsing since the SCI and level at which the SCI occurred. We conclude that hip demineralization is a common complication in SCI, but that lumbar BMD is better preserved.

Absorptiometry, Photon↗

PubMed1996

Symmetry of bone mineral density in the hips is not affected by age.

To assess the symmetry of bone mineral density (BMD) of the hips, we used dual photon absorptiometry (DPA) to asses BMD in 266 normal Chinese women in the bilateral femoral neck, trochanter and Ward's triangle regions. Linear regression analysis of the results showed excellent correlation between the hips. The correlation coefficients for the femoral neck, trochanter and Ward's triangle regions were 0.899, 0.892 and 0.935 respectively, and the standard errors of the estimate (S.E.E.) were 0.029, 0.027 and 0.022 g cm-2 respectively. Pooling the BMD data of corresponding regions (n = 532), the correlation coefficient was 0.813 for femoral neck versus trochanter, 0.889 for femoral neck versus Ward's triangle, and 0.833 for trochanter versus Ward's triangle. Further analysis showed mean correlation coefficients of 0.854 for elderly subjects (age > or = 65 years, n = 51) and 0.887 for younger subjects (age < 65 years, n = 215). In conclusion, assessment of left or right hip BMD may be used to represent the BMD of the contralateral hip and can reduce both the cost and radiation exposure during mass screening for osteoporosis.

Absorptiometry, Photon↗

PubMed1993

Bone mineral density of the radius in patients with ossification of the cervical posterior longitudinal ligament. A longitudinal study.

Radial bone mineral density (BMD) in the distal one sixth and distal one third of the left radius was measured by single-photon absorptiometry (SPA) in patients with ossification of the cervical posterior longitudinal ligament (OPLL). Twenty-three OPLL patients (15 men and 8 women) with mean initial age of 60.1 years were studied longitudinally for mean follow-up period of 3.9 years. Based on roentgenologic findings, the patients were divided into two groups, those with advancing OPLL and those with non-advancing OPLL. The final value of distal 1/6th BMD in the advancing group was significantly lower than its initial value, but no change of the value of the distal 1/3rd BMD was observed in either group. The final value of distal 1/6th BMD/distal 1/3rd BMD ratio in the advancing group was significantly decreased compared with its initial value. These results suggest that, in the advancing OPLL group, trabecular bone mass decreased while cortical bone mass remained unchanged.

Absorptiometry, Photon↗

PubMedDate not supplied

The effect of hormone replacement therapy on appendicular lean tissue mass in early postmenopausal women.

OBJECTIVE: The impact of hormone replacement therapy (HRT) on skeletal muscle mass is still a controversial issue in women's health. Some authors hypothesize anabolic effects, others catabolic. These hypotheses, however, await confirmation by longitudinal observations based on more direct measurements of muscle mass. The aim of the present preliminary study was to evaluate the effect of a 3-year HRT program on appendicular lean tissue mass (LTM(A)) in early postmenopausal women aged 45-54 years. DESIGN: This was a randomized, double-blind and placebo-controlled trial. Women received HRT with 2 mg estradiol valerate combined either continuously with 1 mg cyproterone acetate (days 1-28; n = 15) or sequentially with 75 mug levonorgestrel (days 17-28; n = 15), or placebo (n = 18). Serum estradiol was measured by radioimmunoassay. LTM(A) was measured by dual photon absorptiometry (baseline) and dual energy X-ray absorptiometry (years 2 and 3). RESULTS: Baseline serum estradiol did not show significant correlation with the respective LTM(A) (r = 0.018, p = 0.88, n = 75). Cross-sectional analysis found no significant differences between the intervention groups at any time points. The longitudinal changes between years 2 and 3 showed a trend toward decreasing LTM(A) in those receiving HRT (-0.08 +/- 0.12 kg, n = 30) compared to those receiving placebo (0.12 +/- 0.25 kg, n = 18, p = 0.44). CONCLUSIONS: The present preliminary study did not find significant effects on LTM(A) caused by HRT. The trends toward decreasing LTM(A) in the HRT groups might suggest catabolic rather than anabolic effects. These trends, however, await confirmation by larger clinical trials.

Absorptiometry, Photon↗

PubMed2001

Bone mineral content and density in asymptomatic children with coeliac disease on a gluten-free diet.

OBJECTIVES: Osteoporosis is a complication of coeliac disease. A gluten-free diet improves but does not normalize bone mineral density in adult patients. Only limited data are available regarding the influence of the disease and diet on bone mineralization in children. The aim of this study was to evaluate the radial bone mineral content and density in children and adolescents who are asymptomatic on a gluten-free diet. SUBJECTS AND METHODS: The bone mineral content (BMC) and density (BMD) values of the non-dominant radius midshaft in 91 children (53 girls, 38 boys, mean age 11.7 years, mean duration of disease 8.7 years) were determined by single-photon absorptiometry. At the diagnosis and at least three years after commencement of a gluten-free diet, serum calcium, phosphorus, albumin concentrations and alkaline phosphatase activities were measured in all patients, and intact parathormone concentrations in 16 patients. RESULTS: The mean BMC Z-score value in the female adolescent group only was significantly lower than normal (mean Z-score -1.04, P < 0.01). In contrast, the mean BMD Z-score was significantly higher compared to a healthy population both in girls (mean Z-score +1.36, P < 0.001) and in boys (mean Z-score +0.53, P < 0.02), as well as in the total patient group (mean Z-score +1.01, P < 0.001). The radial diameter was significantly smaller than normal in both pre-pubertal and adolescent groups. Serum laboratory parameters of asymptomatic patients were in the normal range. The parathormone mean value was significantly lower after at least three years of gluten-free diet than at diagnosis (mean +/- SD 3.77 +/- 1.07 versus 7.89 +/- 2.54 pmol/l, P < 0.01), but significantly higher compared to controls (2.89 +/- 0.90 pmol/l, P < 0.05). CONCLUSIONS: These data indicate that treated, asymptomatic coeliac children and adolescents have normal or even higher radius mineral density values than controls, but the bone size remains reduced. Although there is no direct evidence of calcium malabsorption in this cohort of coeliac patients, the slightly higher parathormone levels, together with some other factors, particularly delayed puberty, may result in reduced bone size.

Absorptiometry, Photon↗

PubMedDate not supplied

Femoral neck and lumbar spine bone mineral densities in a normal population 3-20 years of age.

Dual-photon absorptiometry (DPA) with a 153gadolinium radionuclide source was used to measure bone mineral in the lumbar spine of 109 subjects and the femoral neck of 100 subjects 3-20 years of age. From the scan data collected, multiple linear regression models were developed to predict the measured bone mineral density values as a function of age, height, and weight; male and female data were evaluated separately. From the table of predicted values, a particular subject's bone mineral measurements can be readily compared with that of normal subjects in the same way "growth charts" are commonly used to assess development.

Absorptiometry, Photon↗

PubMedDate not supplied

Lumbar spine and femoral neck bone mineral density in idiopathic scoliosis: a follow-up study.

A follow-up study of the bone mineral densities (BMD) of 22 female subjects with idiopathic scoliosis was performed using dual-photon absorptiometry at an average follow-up period of 30.8 months. Compared to the initial scans, statistically significant increases in lumbar spine and femoral neck BMD were observed. When compared to normal subjects, approximately half of the scoliotic subjects were markedly osteoporotic, having BMD measurements at least two standard deviations below the expected value. Scoliotic curvature data could not be correlated with the BMD data. The observed osteoporosis is not transient and appears characteristic of idiopathic scoliosis.

Absorptiometry, Photon↗

PubMed1989

Nasal calcitonin for treatment of established osteoporosis.

Thirty-seven women with established osteoporosis completed a one-year double-blind, placebo-controlled study with the primary aim of examining the effect of nasal salmon calcitonin (200 IU daily) on bone and calcium metabolism. All the women received a daily calcium supplement of 500 mg. For comparison we also report data from an age-matched group of healthy women who did not receive calcium supplementation. The bone mineral measured in the forearm (single photon absorptiometry) and spine (dual photon absorptiometry) showed a similar pattern during treatment. The calcitonin group (n = 17) did not lose bone mineral in comparison with the placebo (n = 20) and the control groups (n = 19) (P less than 0.01). The biochemical estimates of both bone resorption and bone formation decreased highly significantly in the calcitonin group (P less than 0.001) and were unchanged in the control group, whereas the placebo (calcium) group showed intermediate values. Neither subjective nor objective side-effects occurred in any of the groups. We conclude that nasal calcitonin is a realistic treatment of established osteoporosis.

Administration, Intranasal↗

PubMed1989

Bone mass in hirsute women with androgen excess.

The spinal and femoral bone mass of 32 hirsute women with oligomenorrhoea and androgen excess was measured using dual photon absorptiometry and compared with the bone mass of 32 control women with regular menstrual cycles. Despite significantly lower oestradiol levels in the hirsute population there was no significant difference in the bone mass. Furthermore there was no significant difference in bone mass in five hirsute women with undetectable levels of oestradiol. It is concluded that androgen excess can maintain normal bone mass in the face of low or undetectable oestradiol levels.

Absorptiometry, Photon↗