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PubMed1997

Hormone replacement therapy and prevention of osteoporosis: risk assessment and practical advice.

A review of the Debrecen Regional Osteoporosis Program (DROP) in Hungary is given, with special reference to the detection of postmenopausal osteoporosis (PMOP) and its treatment by hormone replacement therapy (HRT). The new definition of osteoporosis by focusing on bone mineral density (BMD) measurements has the major advantage of practical usefulness. The algorithm of managing osteoporotic patients can be easily constructed from the result of bone densitometry as the primary diagnostic tool. The DROP serves a total population of 550,000, is equipped with a DXA bone densitometer, a bone metabolism laboratory and backed by a multidisciplinary team of clinicians from gynecology, radiology, rheumatology, internal medicine, and orthopedic surgery. In 1995 the total number of patients undergoing densitometry was 3170. In 2045 patients T scores of -1 or below were found. From this total number, 348 patients received HRT for 1 year or longer. The results of the treatment showed a positive response (i.e. no bone loss, or net gain) in 65%, while half of the 'non responders' proved in fact non compliant. The contradiction between risk assessment and early diagnosis is explained and replacing 'risk assessment' by 'selection criteria for bone densitometry' is proposed. 'Prevention of osteoporosis' is also to be replaced by 'prevention of complications', i.e. osteoporotic fractures. One of these measures is HRT. Its rational use in the prevention and treatment of osteoporosis and its relation to other treatment methods in the authors' own experience is discussed.

Bone Density↗
PubMed2001

Evaluation of the simple calculated osteoporosis risk estimation (SCORE) in a sample of white women from Belgium.

Identifying patients at risk of developing an osteoporosis-related fracture will continue to be a challenge. The "gold standard" for osteoporosis diagnosis is bone densitometry. However, economic issues or availability of the technology may prevent its use under a mass screening scenario. A risk assessment instrument, the "simple calculated osteoporosis risk estimation" (SCORE), has been reported to appropriately identify women likely to have low (t score < or = -2 SD) bone mineral density (BMD) and who should be referred for bone densitometry. The aim of our study is to evaluate the discriminatory performance of SCORE in a random sample of postmenopausal white women from Belgium. For this purpose, we gathered medical data on 4035 consecutive patients aged > or = 45 years, either consulting spontaneously or referred for a BMD measurement to an outpatient osteoporosis center located at the University of Liège, Belgium. BMD measurements, using dual-energy X-ray absorptiometry (DXA) technology, were taken at the hip (total and neck) and lumbar spine (L2-4). At the recommended cutoff point of 6, SCORE had a sensitivity of 91.5% to detect low BMD at any of the measured sites, a specificity of 26.5%, a positive predictive value of 52.8%, and a negative predictive value of 77.7%. According to SCORE, 18% of the patients would not be recommended for densitometry. Among these, 10.9% were misclassified as they had osteoporosis (t score < or = -2.5 SD) at one or more of the sites investigated. The negative predictive errors of SCORE, when failing to detect osteoporosis, were only 1% for the total hip, 3.2% for the femoral neck, and 8.8% for the lumbar spine. We conclude that, notwithstanding the high values of sensitivity, SCORE specificity is too low to be useful as a diagnostic tool for screening patients at high risk to later develop osteoporosis. Nevertheless, from a resource allocation perspective, this instrument can be used with relative confidence to exclude patients who do not need a BMD measurement, and would therefore provide an opportunity to realize substantial cost savings in comparison to a mass screening strategy.

Absorptiometry, Photon↗
PubMed1998

Comparison of two methods for radiometric evaluation of resin-based restorative materials.

OBJECTIVES: To compare radiographic densitometry with indirect digital image analysis for evaluating the radiopacity of nine different resin-based restorative materials. METHODS: Discs of amalgam and nine different resin-based restorative material, 10 mm in diameter and 2 mm thick, were radiographed together with 2 mm thick discs of intact and carious human teeth and an aluminium stepwedge. Density was evaluated by digital transmission densitometry and with the histogram function of an image analysis programme (Image Tool 1.27, University of Texas Health Sciences Center, Texas, USA) following the digitization of the radiographs with a drum scanner. RESULTS: The two methods produced essentially similar results. With both methods, Dyract (Dentsply De Trey, Konstanz, Germany) had the highest radiodensity and Estilux Hybrid (Kulzer, Werheim, Germany) the lowest. CONCLUSION: Digital image analysis is a suitable alternative to transmission densitometry for evaluation of the radiopacity of restorative materials.

Absorptiometry, Photon↗
PubMed1992

Four-component model for the assessment of body composition in humans: comparison with alternative methods, and evaluation of the density and hydration of fat-free mass.

1. Body composition was assessed in 28 healthy subjects (body mass index 20-28 kg/m2) by dual-energy X-ray absorptiometry, deuterium dilution, densitometry, 40K counting and four prediction methods (skinfold thickness, bioelectrical impedance, near-i.r. interactance and body mass index). Three- and four-component models of body composition were constructed from combinations of the reference methods. The results of all methods were compared. Precision was evaluated by analysis of propagation of errors. The density and hydration fraction of the fat-free mass were determined. 2. From the precision of the basic measurements, the propagation of errors for the estimation of fat (+/- SD) by the four-component model was found to be +/- 0.54 kg, by the three-component model, +/- 0.49 kg, by deuterium dilution, +/- 0.62 kg, and by densitometry, +/- 0.78 kg. Precision for the measurement of the density and hydration fraction of fat-free mass was +/- 0.0020 kg/l and +/- 0.0066, respectively. 3. The agreement between reference methods was generally better than between reference and alternative methods. Dual-energy X-ray absorptiometry predicted three- and four-component model body composition slightly less well than densitometry or deuterium dilution (both of which greatly influence these multi-component models). 4. The hydration fraction of fat-free mass was calculated to be 0.7382 +/- 0.0213 (range 0.6941-0.7837) and the density of fat-free mass was 1.1015 +/- 0.0073 kg/l (range 1.0795-1.1110 kg/l), with no significant difference between men and women for either. 5. The results suggest that the three- and four-component models are not compromised by errors arising from individual techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1999

Prognostic value of vertebral lesions detected by magnetic resonance imaging in patients with stage I multiple myeloma.

We assessed the role of spinal magnetic resonance imaging (MRI) and bone densitometry as prognostic factors in patients with asymptomatic stage I multiple myeloma (MM) and negative skeletal survey. 55 consecutive patients underwent spinal MRI and 41 of them underwent bone densitometry by dual-energy X-ray absorptiometry (DEXA). Spinal MRI studies showed evidence of bone marrow involvement in 17/55 patients (31%). A diffuse pattern was present in three patients and a focal pattern in 14 patients, nine of them with only one nodular lesion. During a median follow-up of 25 months, 10 patients had disease progression, 8/17 patients with abnormal MRI and 2/38 patients with normal MRI. Median time to disease progression was not reached in both groups but was significantly different for patients with normal and those with abnormal patterns on MRI (P < 0.0001). Lumbar BMD was only slightly decreased compared with normal people (median lumbar Z score -0.43) and was not of prognostic value. Using a multivariate analysis the only two independent significant prognostic parameters were abnormal MRI (P<0.001, HR 30.4, 95% CI 4.3-213) and bone marrow plasmacytosis >20% (P=0.004, HR 16.4, 95% Cl 2.6-104). Thus, spinal MRI but not bone densitometry, appeared to be justified in patients with stage I asymptomatic MM and negative skeletal survey.

Absorptiometry, Photon↗
PubMed2003

Immediate dual energy X-ray absorptiometry reveals a high incidence of osteoporosis in patients with advanced prostate cancer before hormonal manipulation.

OBJECTIVE: To examine the incidence of osteoporosis in patients with advanced prostate cancer (using forearm densitometry) before commencing androgen deprivation therapy (ADT), as osteoporotic fractures are more frequent in patients with prostate cancer who have undergone either medical or surgical castration, because of rapid loss of bone mass. PATIENTS AND METHODS: In all, 174 patients (mean age 74.6 years, range 46-90) with advanced prostate cancer presented over 2 years. Their forearm bone densitometry values were compared with those from 106 age-matched controls (mean age 74.3 years, range 66-90). RESULTS: Of the 174 patients, 73 (42%) were osteoporotic (t score <or=- 2.5) and 65 (37%) were osteopenic (t score - 1 to - 2.4). This compares with a 27% incidence of osteoporosis in the control group (P = 0.022). There were also no significant correlations between prostate specific antigen levels, Gleason score, tumour stage, biochemical markers and the presence or absence of osteoporosis risk factors. CONCLUSION: Patients with advanced prostate cancer requiring ADT have a high incidence of osteoporosis before treatment. In addition, osteoporosis in these men cannot be predicted from clinical or biochemical values. Therefore, bone densitometry should be used in all patients with advanced cancer requiring ADT, as the results have implications for the choice of cancer therapy and the prophylaxis for osteoporosis.

Absorptiometry, Photon↗
PubMed2001

Albumin is the major plasma protein target of oxidant stress in uremia.

BACKGROUND: Patients with uremia are exposed to increased oxidative stress. Examination of the oxidation of individual plasma proteins may be useful in establishing specific pathways of oxidative stress in vivo and in determining functional consequences of oxidant stress exposure. We therefore examined oxidative modification of plasma proteins by carbonyl formation using Western blot immunoassay and enzyme-linked immunosorbent assay (ELISA) techniques in patients with chronic renal failure (CRF) and on chronic hemodialysis therapy (HD). METHODS: Plasma was obtained from 25 HD, 20 CRF, and 20 healthy volunteers, derivatized with 2,4 dinitrophenylhydrazine (DNP) and electrophoresed on duplicate 4 to 12% gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels, transferred to nitrocellulose, and stained for DNP for carbonyls and amido black for protein content. Data are recorded as DNP area/protein area and are reported in densitometry units. Total plasma carbonyls were determined by ELISA. RESULTS: Plasma albumin is substantially more oxidized in HD than in healthy volunteers (1.22 +/- 0.14 densitometry units vs. 0.60 +/- 0.08, P = 0.002). There were no significant differences in oxidation of plasma transferrin, immunoglobulin, and fibrinogen in HD versus healthy volunteers. In CRF patients, plasma albumin is more oxidized compared with normal volunteers (1.36 +/- 0.20 densitometry units vs. 0.94 + 0.08, P = 0.09). There were no differences in oxidation of plasma transferrin, fibrinogen, and immunoglobulin in CRF patients versus healthy volunteers. An increased plasma protein carbonyl concentration in CRF patients compared with healthy volunteers was confirmed by ELISA (0.31 +/- 0.07 vs. 0.04 +/- 0.01 nmol/mg protein (P = 0.001). CONCLUSION: Albumin is the major plasma protein target of oxidant stress in CRF and HD patients.

Aged↗
PubMed2004

[Intravenous contrast medium application in elderly patients -- evaluation of Iopentol (Imagopaque 300)].

PURPOSE: We examined the subjective compatibility of elderly patients who received the intravenous contrast medium Iopentol (Imagopaquetrade mark 300). In addition, objective data were aquired to show possible interactions between contrast media and organ systems in old patients. METHODS AND MATERIALS: A CT scan with intravenous application of contrast media was performed on 132 patients ranging in age from 75 to 96 years. The patients were questioned about their individual sensations. In addition, blood pressure, creatinine and CT-densitometry were acquired as objective data. RESULTS: The patients' individual sensations and clinical data show a very low rate of complications. Mild allergic reactions were noticed in two patients. No severe anaphylactic reactions were encountered. Statistically significant changes in blood pressure before and after administration of the contrast medium were not observed. The serum creatinine concentration was unchanged after application of contrast media. For CT-densitometry, the patients were divided into two groups, one group with patients 75 - 84 years and the other group with patients 85 - 96 years of age. CT-densitometry showed no age-related differences. The protocol of contrast administration resulted in excellent opacification of the examined regions, only the liver did not enhance in some cases before the opacification of the portal vein. CONCLUSION: It is shown that old age alone is no reason to withhold contrast media containing iodine when performing CT. For the evaluation of the liver, however, the peculiarities of old age have to be taken into account and the interval between injection of the contrast medium and beginning of the spiral-CT has to be extended.

Age Factors↗
PubMed1982

[Video-densitometric demonstration of abnormal movement of the left ventricle compared with results of levocardiography (author's transl)].

Video-densitograms of the heart of 46 patients were obtained in three projections; these patients had clinically and angiocardiographically confirmed coronary disease of varying severity, or suffered from cardiomyopathy or were normal. The results were compared with levocardiography. The purpose of the investigation was to determine to what extent abnormalities of movement, seen on levocardiography, can also be demonstrated by video-densitometry. Our results show that video-densitometry, compared with levocardiography, has a sensitivity of 97%, a specificity of 44% and an accuracy of 86%. Video-densitometry provides definite proof of abnormal cardiac movement. The differentiation of hypokinesia from akinesia by the two methods is discussed.

Absorptiometry, Photon↗
PubMedDate not supplied

Practice variation in the diagnosis and treatment of osteoporosis: a case for more effective physician education in primary care.

Bone mineral density (BMD) performed by dual energy x-ray absorptiometry (DEXA) has been used at our institution as a screening test for osteoporosis since 1986. Of 2789 bone densitometry tests done between 1992 and 1996 on women aged 51-75 years, 1743 (62.5%) were ordered by general internists (GIM), endocrinologists (ENDO), rheumatologists (RHEUM), and a metabolic bone disease specialist (MBDS). We compared the percentage of densitometry tests ordered by GIM, ENDO, RHEUM, and MBDS resulting in one of three possible diagnoses (normal, osteopenia, or osteoporosis). Applying the World Health Organization's (WHO) definition of normal (< 1 standard deviation [SD] below the mean for young, adult women), osteopenia (> or = 1 SD-< 2.5 SD below the mean), and osteoporosis (> or = 2.5 SD below the mean), we found that 34% of patients tested between 1992 and 1996 were osteoporotic, 42% were osteopenic, and 24% had normal bone density results. The rate of osteoporosis diagnosis was highest in the MBDS cohort (chi 2 = 9.19, p = 0.002) compared with patients in the other cohorts. To explore trends in management of this condition, a random sample of osteoporotic women aged 51-75 who had densitometry in 1996 (n = 82) was obtained. Review of medical records revealed that 73% were on some form of osteoporosis treatment (bisphosphonate, estrogen, or calcitonin, with or without calcium and vitamin D supplementation). Treatment rates differed significantly, however, by the ordering physician specialty (96% for MBDS, 63% for ENDO, 75% for RHEUM, and 53% for GIM, chi (2)3df = 11.37, p = 0.01). There were no significant differences in selected clinical or demographic characteristics between patients treated by GIM and MBDS. This variation in treatment rates suggests that an opportunity to enhance primary care physicians' recognition and treatment of osteoporosis exists. Making osteoporosis management an educational focus may help narrow differences in practice and improve the effectiveness of a larger number of physicians treating patients with this problem.

Absorptiometry, Photon↗
PubMed1989

Body composition changes assessed by bioelectrical impedance measurements.

Twelve healthy volunteers consumed a very-low-calorie diet for 2 d to achieve a body-weight loss mainly from a loss of fat-free mass, ie, of glycogen plus water. Body weight, body density, and bioelectrical impedance were measured before and after weight loss. Body-weight loss was 1.3 +/- 0.5 kg. Loss of fat-free mass as measured by densitometry was 1.2 +/- 0.8 kg. Changes in body weight and fat-free mass measured by densitometry did not differ significantly and were significantly different from zero. Reduction of fat-free mass as determined by bioelectrical impedance was 0.5 +/- 0.8 kg, which was significantly different from body-weight loss and loss of fat-free mass as measured by densitometry but not significantly different from zero. The results show that after weight loss the bioelectrical impedance method overestimates the fat-free mass by approximately 1 kg.

Adult↗
PubMed1996

Coralline hydroxyapatite bone graft substitutes. Evaluation of bone density with dual energy x-ray absorptiometry.

RATIONALE AND OBJECTIVES: The authors evaluate whether dual-energy x-ray absorptiometry (DXA) is a reliable method to determine the density of natural coralline hydroxyapatite (HA) blocks used as bone graft substitutes. METHODS: To evaluate the basic density of HA blocks from the same coral heads with and without titanium meshes, densitometry of 12 HA-500 blocks (genus Goniopora) and 12 HA-200 blocks (genus Porites) was performed. In addition, density measurements of 30 HA blocks (HA-500, n = 15; HA-200, n = 15) from different coral heads were obtained to assess if the originating coral head influences the basic density of blocks within one coral genera. To assess standard deviation serial measurements on eight coralline HA blocks, four with titanium meshes and four without were performed. In the ex vivo study, densitometry of 12 HA blocks (HA-500, n = 4; HA-200, n = 8) used as bone graft substitutes in the mandibles and craniums of adult mongrel dogs was performed. Densities were measured after bone ingrowth for 2 and 4 months, respectively. All measurements were obtained with a Lunar DPX with scan mode "slow 750" in the spine program with the regions-of-interests selected manually. Bone ingrowth was assessed by computer-assisted histomorphometry, which was considered the gold standard. Statistical analysis was performed to correlate the densities of plain HA blocks with and without meshes to the specific weights of the blocks. RESULTS: Significant positive correlation was found between the density of each HA block (both coral species) with and without meshes and the calculated specific weights. Densitometry values showed no significant differences depending on the originating coral heads. Standard deviation ranged between +/- 3.8% and +/- 4.1% (HA-500) and between +/- 3.0% and +/- 3.8% (HA-200). Hydroxyapatite-500 blocks showed marked increased densities between 15% and 34% after 4 months in three specimens in which bone ingrowth between 16.9% and 21.1% was revealed by histomorphometry; no increase of density was observed in one specimen, which presented only minimal bone ingrowth and signs of infection. Despite bone invasion between 12% and 25.8%, no increased densities were observed for HA-200 implants. CONCLUSIONS: Dual-energy x-ray absorptiometry is an accurate and reproducible modality to assess the densities of plain coralline HA blocks and to monitor bone ingrowth into coralline HA-500 but not into HA-200 block implants.

Absorptiometry, Photon↗
PubMed2002

Noninvasive measurement of cerebral blood flow in adults using near-infrared spectroscopy and indocyanine green: a pilot study.

This pilot study was designed to determine the feasibility of measuring cerebral blood flow noninvasively after an intravenous bolus of indocyanine green using near-infrared spectroscopy and pulse dye-densitometry. Feasibility aside, this study did not attempt to validate the measured values of cerebral blood flow against an established method of measurement. Twelve healthy volunteers were investigated after peripheral intravenous injection of indocyanine green. Arterial and cerebral changes in indocyanine green concentration were measured using pulse dye-densitometry and near-infrared spectroscopy, respectively. Two methods of calculating cerebral blood flow were used, and a blood flow index was also estimated. Absolute cerebral blood flow was calculated using a modification of the Fick principle and a deconvolution algorithm to derive the impulse residue function. Mean (range) estimated cerebral blood flow for the Fick method was 8.2 mL/100 g/min (4.2-16.2 mL/100 g/min) and 8.3 mL/100 g/min (4.7-15.3 mL/100 g/min) for the impulse residue function method. The impulse residue function method provided a more precise intrasubject estimation of cerebral blood flow compared with the modified Fick principle, with a coefficient of variation of 10.1% versus 25.5%. The blood flow index was 8.6 mg/sec (range: 5.6-17.3 mg/sec) with an intrasubject coefficient of variation of 12.0%. Estimation of cerebral blood flow using near-infrared spectroscopy and pulse dye-densitometry can be made at the bedside after intravenous injection of indocyanine green, and the precision can be improved using a deconvolution algorithm. Notwithstanding the low values obtained for absolute cerebral blood flow, further investigation and validation of this bedside technique is warranted.

Adult↗
PubMed2002

Femoral neck trabecular patterns predict osteoporotic fractures.

In this paper we show that texture analysis of femoral neck trabecular patterns can be used to predict osteoporotic fractures. The study is based on a sample of 123 women aged 44-66 years with and without fractures. We analyzed trabecular patterns using the Co-occurrence Matrix texture analysis algorithm and compared the predictive utility of the textural data with densitometry. Logistic regression was used to estimate the predictive utility, exp(B), of clinical and textural data per standard deviation. Reproducibility was also demonstrated using paired films at 1-year intervals (CoV=4.5%). Bone mass estimated by DEXA measurements of the spine and hip were the most predictive of fractures giving a two-fold increase in fractures per s.d. bone mass loss (95% CI: 1.2-3.1, p<0.005). Age was also highly predictive with fracture risk increasing by 1.07-fold per year (95% CI: 1.01-1.14, p<0.02). Trabecular texture was found to give a lower, but significant, prediction of fracture of 1.5-fold per s.d. trabecular pattern loss (95% CI: 0.96-2.31, p<0.05). Combining age, weight, and trabecular texture increased the fracture prediction to 1.78-fold per s.d. (95% CI: 1.19-2.67). Combining trabecular texture with densitometry increased the predictive ability to 2.06-fold per s.d. (95% CI: 1.32-3.22) and combined with age and weight as well increased exp(B) to 2.1-fold per s.d. (95% CI: 1.32-3.35). This shows that osteoporotic trabecular texture changes can be "measured." Moreover, the combination of age, weight, and trabecular texture is more predictive than either alone. We propose therefore that this trabecular texture analysis is both reproducible and clinically meaningful. The application of such methods could be used to improve the estimation of fracture risk in conjunction with other clinical data, or where densitometry data cannot be obtained (e.g., in retrospective studies).

Absorptiometry, Photon↗
PubMed2001

Acid-induced gene expression in Helicobacter pylori: study in genomic scale by microarray.

To understand the RNA expression in response to acid stress of Helicobacter pylori in genomic scale, a microarray membrane containing 1,534 open reading frames (ORFs) from strain 26695 was used. Total RNAs of H. pylori under growth conditions of pH 7.2 and 5.5 were extracted, reverse transcribed into cDNA, and labeled with biotin. Each microarray membrane was hybridized with cDNA probe from the same strain under two different pH conditions and developed by a catalyzed reporter deposition method. Gene expression of all ORFs was measured by densitometry. Among the 1,534 ORFs, 53 ORFs were highly expressed (> or = 30% of rRNA control in densitometry ratios). There were 445 ORFs which were stably expressed (<30% of rRNA in densitometry) under both pH conditions without significant variation. A total of 80 ORFs had significantly increased expression levels at low pH, while expressions of 4 ORFs were suppressed under acidic condition. The remaining 952 ORFs were not detectable under either pH condition. These data were highly reproducible and comparable to those obtained by the RNA slot blot method. Our results suggest that microarray can be used in monitoring prokaryotic gene expression in genomic scale.

Acids↗
PubMed1994

Accurate vessel width measurement from fundus photographs: a new concept.

Accurate determination of retinal vessel width measurement is important in the study of the haemodynamic changes that accompany various physiological and pathological states. Currently the width at the half height of the transmittance and densitometry profiles are used as a measure of retinal vessel width. A consistent phenomenon of two 'kick points' on the slopes of the transmittance and densitometry profiles near the base, has been observed. In this study, mathematical models have been formulated to describe the characteristic curves of the transmittance and the densitometry profiles. They demonstrate the kick points being coincident with the edges of the blood column. The horizontal distance across the kick points would therefore indicate the actual blood column width. To evaluate this hypothesis, blood was infused through two lengths of plastic tubing of known diameters, and photographed. In comparison with the known diameters, the half height underestimated the blood column width by 7.33% and 6.46%, while the kick point method slightly overestimated it by 1.40% and 0.34%. These techniques were applied to monochromatic fundus photographs. In comparison with the kick point method, the half height underestimated the blood column width in veins by 16.67% and in arteries by 15.86%. The characteristics of the kick points and their practicality have been discussed. The kick point method may provide the most accurate measurement of vessel width possible from these profiles.

Fluorescein Angiography↗
PubMed2002

Long-lasting bone damage detected by dual-energy x-ray absorptiometry, phalangeal osteosonogrammetry, and in vitro growth of marrow stromal cells after allogeneic stem cell transplantation.

Bone complications after allogeneic stem cell transplant (allo-SCT) include osteoporosis, fractures, and osteonecrosis. We investigated bone abnormalities in long-term survivors after busulfan cyclophosphamide-conditioning regimen, followed by human leukocyte antigen-identical sibling SCT. Bone density was measured by dual-energy x-ray absorptiometry at lumbar spine (LS) and femoral neck (FN) and phalangeal osteosonogrammetry (OSG) in 41 patients 1-10 yr after allo-SCT. Using colony-forming units-fibroblast (CFU-F) assay, we analyzed the repopulating capacity of clonogenic fibroblast progenitors belonging to the osteogenic stromal lineage. LS and FN bone mineral density (BMD) and phalangeal densitometric values were significantly reduced, compared with 188 healthy controls (P < 0.001). Decrease in T-score less than 1 SD was documented in 29% and 52% of patients at the LS and FN, respectively. OSG detected densitometric values with a T-score less than 1 SD in 68% of transplanted patients. The patients examined within the first 3 yr after transplant showed low BMD, which remained stable at FN and improved at LS. Phalangeal densitometry was low up to 10 yr after transplant. CFU-F was found permanently depressed and unable to give rise to a confluent stroma. Low serum osteocalcin levels were present throughout the whole follow-up period. A significant correlation was found between densitometric values detected by both techniques and CFU-F growth in vitro. Osteonecrosis was associated with lower FN BMD, and phalangeal densitometry correlated inversely with duration of amenorrhea and chronic graft vs. host disease requiring long-lasting steroid therapy. In conclusion, dual-energy x-ray absorptiometry and phalangeal OSG may provide complementary information on bone density after allo-SCT. Prolonged severe impairment of femoral BMD and phalangeal densitometry suggest that bone loss may persist for many years after transplant. Inability to regenerate a normal number of osteoblastic precursors in the stromal stem cell compartment may in part account for severe long-lasting posttransplant decrease in bone mass.

Absorptiometry, Photon↗
PubMed1998

Prevalence of osteoporosis in women referred for bone density testing: utility of multiple skeletal sites.

The objective of this study was to determine retrospectively the prevalence of osteoporosis in a referral population and to compare the effectiveness of measuring multiple skeletal sites for identifying osteoporosis. Although osteoporosis is considered to be a major public health problem in the United States, and there are reliable methods for diagnosis based on bone densitometry, fewer than 25% of cases are currently identified. There is no consensus about which skeletal site(s) should be measured for optimal results. In this study, bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) at the radius (proximal site), lumbar spine, femoral neck, and total proximal femur regions in 537 consecutive white females age 50 and older referred by community physicians for bone densitometry. The prevalence of osteopenia and osteoporosis (based on the World Health Organization definitions) was determined, as well as the incidence of misclassification of patients based on different skeletal sites. Overall, 53.3% had osteoporosis, an additional 37.7% had osteopenia, and only 8.7% had normal BMD at all measurement sites. The prevalence was similar at all measurement sites and the incidence of misclassification was low. Given the magnitude of undetected osteoporosis and the efficacy of bone densitometry at any skeletal site, these data have important implications for the optimal deployment of bone density measurement facilities.

Journal Article↗