Measurement of hand bone mineral content by dual energy x-ray absorptiometry: development of the method, and its application in normal volunteers and in patients with rheumatoid arthritis.

OBJECTIVES--To develop a method of measuring hand bone mineral content (BMC) by dual energy x ray absorptiometry (DXA); to apply this method of measuring hand BMC to normal volunteers to ascertain causes of variability; and to measure hand BMC in patients with rheumatoid arthritis (RA) of varying duration and severity. METHODS--The x ray beam of the Hologic QDR 1000 dual energy x ray absorptiometer was hardened by introducing a perspex-aluminium plate and the analysis software altered to allow for the small tissue bulk of the hand compared with the torso. Ninety five volunteers (46 men age 24-81 and 49 women age 20-83) had scans of both hands. Eight volunteers were assessed repeatedly to establish reproducibility and effect of hand position. Fifty six patients (22 men, 34 women, age range 25-86 years) with RA of differing duration and severity, had hand BMC measurement by DXA. RESULTS--The precision of BMC measurement was 2.3% with no additional variation due to hand position. Hand dominance had no significant effect on BMC. In men, hand BMC correlated with height (r = 0.57, p < 0.0001), weight (r = 0.58, p < 0.0001), forearm span (r = 0.5, p = 0.0006) and hand volume (r = 0.66, p < 0.0001). In women hand BMC correlated with height (r = 0.66, p < 0.0001), weight (r = 0.4, p = 0.003), forearm span (r = 0.3, p = 0.03) and hand volume (r = 0.49, p = 0.0008). After correcting for all these variables, male volunteers had significantly higher hand BMC than female volunteers (p = 0.01) and patients with RA had lower hand BMC than normal volunteers (total hand BMC in male volunteers 90.9 gms, 95% CI 86.9-95, in male patients 81.7 gms, 95% CI 73.7-89.6, p < 0.004, total hand BMC in female volunteers 62.2 gms 95% CI 59.8-64.5, female patients 52.3 gms, 95% CI 48.1-56.5, p < 0.005). In patients with RA, the hand BMC showed an inverse correlation with age (r = -0.44, p = 0.01), disease duration (r = -0.62, p = 0.0003), Larsen's grades (r = -0.62, p = 0.0002) and modified Sharp's method score (r = -0.69, p < 0.0001) in female patients only. CONCLUSIONS--A new, sensitive and reproducible technique of measurement of hand bone mineral content by DXA, has been developed and this method has been applied to normal volunteers and patients with RA. Hand dominance had no significant effect on hand BMC. After correcting for physical size, men have higher hand BMC than women. Hand BMC inversely correlates in women patients with disease duration and other validated methods of assessing radiological outcome in RA. Longitudinal studies are needed to establish its role in monitoring disease progression.     

Measurement of periarticular bone mineral density in the hands of patients with early inflammatory arthritis using dual energy x-ray absorptiometry

Hand bone densitometry is more sensitive than standard radiology in the measurement of disease-related bone damage in early arthritis. Most studies employing dual energy x-ray absorptiometry (DXA) have evaluated the whole hand. The aim of this study was to evaluate a method that quantified bone density in regions of interest that were confined to the juxta-articular areas of metacarpo-phalangeal (MCP) and proximal interphalangeal (PIP) joints. Patients with inflammatory arthritis affecting the hands were selected for study. Postero-anterior (PA) scans of selected juxta-articular sub-regions were acquired using a Hologic 4500 Elite bone densitometer and forearm software. Each hand was scanned three times in immediate succession with repositioning between scans. The six selected sub-regions included the periarticular regions of the second, third, and fourth MCP and PIP joints. Sub-regions of different dimensions (4 and 5 mm proximal and distal to the joint space) were assessed at each joint. Coefficients of variation (CV) were calculated for bone mineral density (BMD) and bone mineral content (BMC) of each selected sub-region. Eighty four individual hand joints in seven patients were evaluated three times. Precision values ranged between 0.89% and 2.37% for BMD and between 1.38 and 3.26 for BMC measurements. BMD measurements of MCP joints were more precise than PIP joints. BMD measurements of 10-mm sub-regions were more precise than 8-mm sub-regions. The precision value for the net average BMD measurement of the six sub-regions evaluated was 0.78% for 8-mm sub-regions and 0.73% for 10-mm sub-regions. Net average BMC measurements had CV values of 1.11% and 1.08%, respectively. DXA can be used to reliably measure periarticular BMD and BMC of small joints in the hands in patients with early inflammatory arthritis. Precision values for quantifying juxta-articular bone approximated BMD measurements of the spine.     

Measurement of hand bone mineral density in early rheumatoid arthritis using dual energy X‐ray absorptiometry

Aims: The earliest radiological change in rheumatoid arthritis (RA) is periarticular osteopenia, which occurs prior to the appearance of erosions and clinically apparent deformities. The aim of the study was to measure periarticular bone mineral density (BMD) in the hands of patients with early RA, using dual energy X‐ray absorptiomentry (DEXA) and to correlate this with markers of disease activity and radiological progression. Methods: The study population (n = 50) of patients with RA of < 3 years duration underwent measurement of BMD of the non‐dominant hand, femoral neck and lumbar spine and clinical assessment at baseline, 6 and 12 months. Hand radiographs were performed at baseline and 12 months. Thirty age‐ and sex‐matched controls also underwent measurement of BMD of the non‐dominant hand, femoral neck and lumbar spine. Results: Hand BMD correlated strongly with sex, height, weight and lumbar and femoral neck BMD in both RA subjects and controls. Baseline hand BMD in RA subjects correlated with baseline serum C‐reactive protein (r = ?0.36, P = 0.01) and 12‐month radiographic score (r = 0.36, P = 0.02). There were small non‐significant decreases in hand, femoral neck and lumbar spine BMD over the 12‐month period. Conclusion: Hand BMD measurement using DEXA is a reproducible, well‐tolerated procedure that warrants further investigation as a component of routine assessment in early RA.     

Bone mineral density in juvenile dermatomyositis: assessment using dual x-ray absorptiometry

OBJECTIVE: To determine the bone mineral density (BMD) status of our juvenile dermatomyositis (DM) population and to compare the frequency of osteopenia in patients with active disease requiring corticosteroids with that in patients with inactive disease who are not receiving corticosteroids. METHODS: Medical charts of all children diagnosed as having juvenile DM at our institution between 1989 and 1999 were reviewed for demographic and clinical data, including disease activity and duration of corticosteroid therapy. BMD measurements of the lumbar spine (L1-L4) were performed using dual x-ray absorptiometry (DXA). Z scores were calculated from the BMD data for comparison with published normative data. RESULTS: A total of 15 patients were assessed: 10 with active disease, and 5 with inactive disease who had not taken corticosteroids for an average of 6.0 years (range 3.4-8.1 years). Baseline BMD measurements demonstrated osteopenia or frank osteoporosis in the majority of patients, including 6 of the 10 patients with active disease and 4 of the 5 patients whose disease was in remission. Fourteen patients had serial BMD measurements. Persistent or worsening osteopenia was documented in all patients who had ongoing active disease, except for 3 patients who had been treated with bisphosphonates because of vertebral compression fractures. CONCLUSION: Osteopenia is common in patients with juvenile DM, and it usually worsens with ongoing disease. It can persist for many years after the disease enters remission. Bisphosphonates appeared to beneficially affect bone mineralization in our patients. Treatment to prevent the long-term complications of osteoporosis in patients with juvenile DM should be considered and requires further study.     

Bone mineral density in patients with hyperthyroidism measured by dual energy X-ray absorptiometry

OBJECTIVE We assessed the changes of bone mass in patients with hyperthyroidism by measuring bone mineral density using a new method, dual energy X-ray absorptiometry. DESIGN The values of bone mineral density in patients with hyperthyroidism were compared with data obtained from the controls, and we assessed the correlation analysis between bone mineral density and several metabolic parameters. PATIENTS We studied 52 Japanese patients with hyperthyroidism (20 males, 32 females). Healthy normal subjects served to establish the mean bone mineral density In the healthy Japanese population (Shiraki et al. 1991). MEASUREMENT Bone mineral density was assessed by the measurement of lumbar vertebrae and femur by dual energy X-ray absorptiometry. The bone mineral density of vertebrae for each patient was calculated as the percentage of the mean value (% bone mineral density) obtained from an age and sex-matched control group. Blood was drawn to measure the levels of serum calcium, phosphorus, creatinine, alkaline phosphatase, free T3, free T4, TSH, TSH receptor antibody, parathyroid hormone, and serum osteocalcin. RESULTS The percentage bone mineral density of vertebrae in patients was 92.6 as compared with that of normal controls, and was inversely correlated with serum TSH receptor antibody, osteocalcin, and alkaline phosphatase. CONCLUSIONS These findings suggest that bone mineral density is decreased in patients with hyperthyroidism and that TSH receptor antibody, osteocalcin, and alkaline phosphatase are sensitive markers of bone metabolism alterations in hyperthyroidism.     

Quantitative digital radiography versus dual photon absorptiometry of the lumbar spine

Lumbar spine bone mineral density (BMD) was measured by quantitative digital radiography, a new dual energy x-ray technique, and by 153Gd dual photon absorptiometry (DPA) in 85 patients. Each patient was measured twice by the new method and once by DPA on the same day, with repositioning between measurements. Serial measurements were made on an hydroxyapatite spine phantom embedded in tissue-equivalent plastic to evaluate the long term reproducibility of each instrument. The spinal BMD measurements with the 2 techniques were linearly related and highly correlated (r = 0.98) over a range from severely osteopenic to high normal. This correlation was not affected by the age, weight, or BMD of the patient measured. Quantitative digital radiography's long-term reproducibility using the spine phantom was stable for 180 days (coefficient of variation, 0.23%); DPA values were 3 times as variable for 170 days (coefficient of variation 0.73%) and increased 1.0% (P less than 0.0001) after a software change. The short term reproducibility of quantitative digital radiography, estimated from paired patient measurements, was 2-fold better than reported values for DPA and was independent of the patient's age, weight, or BMD. Measurement time by quantitative digital radiography was 5-8 min, with a maximum radiation exposure of 3 mrem, significantly lower than the corresponding DPA values. Quantitative digital radiography's image resolution was superior to that of DPA, enabling it to measure more bones. These advantages along with the elimination of 153Gd source changes and Nuclear Regulatory Commission licensing requirements indicate that quantitative digital radiography is the superior method for spinal BMD measurements.     

Validated measurement of periarticular bone mineral density at the knee joint by dual energy x ray absorptiometry

OBJECTIVE: The association of inflammatory arthritis with loss of periarticular bone mineral density (BMD) has been well established. However, changes in bone density cannot be quantified by conventional radiography. This study aimed at developing a new technique for measurement of periarticular bone density at the knee joint by dual energy x ray absorptiometry (DXA) and assessing the precision of this technique for selected areas around the knee. METHODS: To validate this technique for bone density assessment in both patient and control subjects, knee joints from healthy subjects and patients with inflammatory arthritis were selected for study. Posteroanterior (PA) and lateral scans of both knees were acquired with the Hologic 4500 elite bone densitometer. Each scan was repeated three times, with repositioning between scans. Knee scans were obtained with the forearm software and evaluated by subregion analysis. Seven femoral and seven tibial subregions of interest (ROIs) were selected on PA scans. Six ROIs were selected on lateral scans. Precision was determined for each ROI selected. RESULTS: 14 knee joints were studied in each group. Precision, expressed as percentage coefficient of variation (CV%), varied widely between subregions. PA scans were most appropriate for measurement of femoral bone density (CV% = 1.89-2.64%), whereas the best value obtained for ROIs within the tibia was on the lateral scan, where CV% for measurement of the proximal 5 mm was 2.67% in the patient group. CV% for BMD of the patella was excellent at 0.84% in the patient group. CONCLUSION: This new application of DXA can be used to measure periarticular bone density at the knee joint. Regions within the distal femur and patella have been identified as the optimal areas to study     

Poor correlations between measurements of bone quality by quantitative ultrasound sonography and dual energy X-ray absorptiometry in patients with beta-thalassaemia major

Objectives: Osteopenia/osteoporosis is a major component of morbidity even in young patients with β‐thalassaemia major. Dual energy X‐ray absorptiometry (DXA) is the reference method for determining bone mineral density (BMD). Quantitative ultrasound sonography (QUS) for bone measurement is a relatively new, inexpensive and radiation‐free method that could serve as an alternative to DXA. Our aim was to assess bone status in thalassaemic patients both with QUS and DXA and, consequently, to investigate the degree of correlation between the two methods. Methods: Thirty‐three patients (15 male and 18 female) with β‐thalassaemia major, regularly transfused and systematically iron‐chelated, participated in the study. Mean age was 22.0 ± 8.0 yr (range: 6.5–41.0 yr). All patients were evaluated with QUS at radius and tibia and had DXA scan at lumbar spine vertebrae (L2–L4), whereas 20 patients were additionally assessed with DXA at the left hip (femoral neck, trochanter region and Ward’s triangle). Results: Results were expressed as Z‐scores compared with sex‐ and age‐matched population. Lowest mean Z‐scores measured with DXA were recorded at lumbar spine and Ward’s triangle (?1.1 ± 1.13 and ?0.95 ± 1.07, respectively). Lowest mean QUS‐derived Z‐scores were measured at radius, statistically significant compared with Z‐scores measured at tibia (?0.6 ± 1.1 vs. 0.4 ± 1.1, P < 0.001). QUS measurements at radius were significantly correlated to QUS measurements at tibia (r = 0.51, P = 0.002). The latter were correlated to BMD measured at lumbar spine (r = 0.516, P = 0.002) and at trochanter region (r = 0.646, P = 0.003). All BMD measurements at hip were significantly correlated to each other. Lumbar spine BMD was correlated to BMD at femoral neck (r = 0.607, P = 0.003) and to BMD at Ward’s triangle (r = 0.438, P = 0.027). Finally, no agreement was recorded between the two methods in identifying thalassaemic patients at risk for osteoporosis (κ = 0.203, P = 0.04). Conclusion: Quantitative ultrasound sonography could not serve as an alternate to DXA.     

Effect of aging on bone mineral content. Part VII. The evaluation of osteoporosis treatment by the measurement of total body bone mineral content using dual photon absorptiometry

In order to evaluate the degree of accuracy of measurement of total body bone mineral content (TBBMC) by dual photon absorptiometry (DPA), the TBBMC in four healthy male volunteers were measured serially for 3 to 12 months. In three to six determinations of TBBMC in various stage of radiation source (153-Gd), the coefficients of variation in four subjects were 1.59, 0.74, 1.25 and 1.27%. Thus, the mean CV was 1.22 +/- 0.35% (mean +/- SD). This indicates that the measurement of TBBMC using DPA is an accurate tool for long-term follow up of bone mineral content and up to 1.6% change of TBBMC might be considered to be a significant change in TBBMC. No apparent drift of TBBMC associated with source decay was noticed in the present study. Subsequently, fifteen females with osteoporosis were studied to evaluate the efficacy of certain therapeutic modes. The patients were divided into two groups. Group 1 (n = 10) given 10 to 40 U of elcatonin (eel calcitonin derivative) intramuscularly every week for 3 to 6 months. Group 2 (n = 5) were treated with 0.5 mu/day of oral 1-alpha-OHD3 for 3 to 6 months. The TBBMC of these fifteen patients were followed by DPA (Lunar DP-4). Seven patients out of ten treated with elcatonin (70%) showed significant (up to 1.6% change in TBBMC compared with baseline) increase in TBBMC after 3 to 6 months treatment. The mean percentage change in TBBMC in group 1 was 101.9 +/- 2.7% (mean +/- SD) when the initial TBBMC was taken as 100%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Detection of low bone mineral density by dual energy x ray absorptiometry in unsuspected suboptimally treated coeliac disease.

Patients with coeliac disease may present with calcium malabsorption but it is unclear whether this results in longterm impairment of bone mineralisation. Dual energy x ray absorptiometry (DXA) was used to study bone mineral density in 34 asymptomatic coeliac disease patients, treated with a gluten free diet for at least two years, and also in 10 newly diagnosed or untreated patients. As expected, untreated patients had low bone mineral density in all regions. In the 29 treated female coeliac disease patients, overall mean values for age adjusted bone mineral density expressed as Z scores were normal although there were many patients with low values, particularly of the lumbar spine and total body. Scores in the postmenopausal patients were significantly worse than in the premenopausal patients and low mean Z scores were found in the five treated male patients. The subjects who had reduced bone mineral density could not be predicted clinically but, despite being asymptomatic, were more likely to have subtotal or partial villous atrophy on small intestinal biopsy (p < 0.0275). In conclusion, although many treated coeliac disease patients have normal bone mineral density, suboptimally treated and newly diagnosed or untreated patients have osteopenia. To reduce the risk of osteoporotic fractures, it is recommended that bone mineral density be measured in all treated coeliac disease patients and those with osteopenia have a repeat intestinal biopsy to assess disease activity.     

Estimating lumbar bone mineral density from routine radiographs of the lumbar spine

Summary To evaluate the information content of lateral lumbar films with respect to bone mineral content, we compared reading criteria with values obtained by quantitative computed tomography (CT) of L1 at baseline and after 5 years. The highest correlations with mineral content were found for the criteria overall assessment of the vertebra, vertebral body density versus soft tissue, and amount of trabeculations. These three reading criteria yielded higher correlations with CT scores in subjects with lower body mass index. Changes in mineral content over the 5-year period could not be read adequately, the average difference representing only a loss of about 10% in the study subjects. We conclude that a rough estimate of bone density can be obtained from lateral radiographs which, in the presence of eventual risk factors for osteoporosis, may serve as an additional indication to timely bone densitometry with methods which allow precise short-term follow-up measurements.     

Alendronate increases lumbar spine bone mineral density in patients with Crohn's disease

BACKGROUND & AIMS: Low bone mineral density (BMD) is a common complication of Crohn's disease and may lead to increased morbidity and mortality because of fractures. We investigated the effect of treatment with the bisphosphonate alendronate on bone mass and markers of bone remodeling in patients with Crohn's disease. METHODS: A 12-month double-blind, randomized, placebo-controlled trial examined the effect of a 10-mg daily dose of alendronate. Thirty-two patients with a bone mass T score of -1 of the hip or lumbar spine were studied. The main outcome measure was the difference in the mean percent change in BMD of the lumbar spine measured by dual-energy x-ray absorptiometry. Secondary outcome measures included changes in BMD of the hip and total body and biochemical markers of bone turnover (S-osteocalcin, urine pyridinoline, and urine deoxypyridinoline excretion). RESULTS: Mean (+/-SEM) BMD of the lumbar spine showed an increase of 4.6% +/- 1.2% in the alendronate group compared with a decrease of 0.9% +/- 1.0% in patients receiving placebo (P < 0.01). BMD of the hip increased by 3.3% +/- 1.5% in the alendronate group compared with a smaller increase of 0.7% +/- 1.1% in the placebo group (P = 0.08). Biochemical markers of bone turnover decreased significantly in the alendronate group (P < 0.001). Alendronate was well tolerated, and there was no difference in adverse events among treatment groups. CONCLUSIONS: Treatment with alendronate, 10 mg daily, significantly increased BMD in patients with Crohn's disease and was safe and well tolerated.     

Long-term metreleptin treatment increases bone mineral density and content at the lumbar spine of lean hypoleptinemic women

Strenuously exercising young women with hypothalamic amenorrhea are hypoleptinemic and have low bone mineral density (BMD) and content (BMC), which predispose them to increased fracture risk. Short-term leptin replacement in these women corrects many neuroendocrine abnormalities and increases circulating levels of bone formation markers. Whether treatment with recombinant methionyl human leptin (metreleptin) for a long period improves BMD and BMC remains unknown. We studied 20 strenuously exercising young women with hypoleptinemia (leptin concentration <5 ng/mL) and hypothalamic amenorrhea of at least 6 months' duration. Eleven were randomized to metreleptin (initial dose, 0.08 mg/[kg·d] for 3 months; altered thereafter to 0.12 mg/kg for lack of efficacy or 0.04 mg/[kg d] for more than 5% weight loss) and 9 were randomized to placebo for 9 months. After a 3-month washout period, subjects were reexamined at the 1-year time point. Six subjects elected to continue on open-label metreleptin treatment for another 12 months. Two subjects dropped out after 18 months, and 4 completed the entire 2-year study. The BMD and BMC of the total body, lumbar spine (L1-L4), hip, and radius were assessed by using dual-energy x-ray absorptiometry at baseline and at 3, 6, 9, 12, 18, and 24 months of treatment. Metabolic and hormonal parameters and bone markers were measured in blood and urine. Metreleptin significantly increased BMC (P = .034) and tended to increase BMD (P = .069) at the lumbar spine at 9 months in the entire study group (intention-to-treat analysis). In subjects who completed the entire 2-year study (n = 4), metreleptin significantly increased BMD (P = .024) and BMC (P = .049) at the lumbar spine by 4% to 6%. Changes were not significant at the whole body, hip, and radius. Changes in hormonal and metabolic parameters and bone markers were moderate during the first year of treatment, but metreleptin further increased insulin-like growth factor 1 and decreased cortisol and cross-linked C-terminal telopeptide of type 1 collagen concentrations in serum during the second year of treatment (P < .05). The incremental area under the estradiol concentration curve over the 2-year course of the study correlated positively with the corresponding increase in lumbar spine BMD (ρ = 0.42, P = .039). Long-term metreleptin administration in strenuously exercising young women with hypothalamic amenorrhea and hypoleptinemia increases lumbar spine BMD and BMC and alters bone remodeling milieu to favor bone accretion. Results from this pilot study should be confirmed by future, larger clinical trials and need to be extended by studying bone microarchitecture and fracture risk.     

Comparison of quantitative ultrasound parameters with dual energy X-ray absorptiometry in pre- and postmenopausal women

BACKGROUND: Quantitative ultrasound (QUS) has been claimed as an alternative technique for risk assessment of hip fractures associated with osteoporosis. However, reports concerning modest correlations between QUS parameters and dual energy X-ray absorptiometry (DXA) in women raise questions about the reliability of QUS technology to predict bone mineral density (BMD). Partially, the lack of stronger correlations may be due to heterogeneity in bone architecture deterioration which may be more pronounced in older than in younger women. Therefore, it was thought important to study QUS/DXA interrelationships in subgroups of pre- and postmenopausal women. METHODS: We studied 217 pre- and postmenopausal women between the ages of 25 and 75 years, who were referred for a BMD measurement because of osteoporosis in at least one family member either in the first or in the second degree. All women had a calcaneal QUS and a DXA measurement at the lumbar spine, total hip and femoral neck. RESULTS: The linear regression coefficients between the QUS parameters broadband ultrasound attenuation (BUA) and speed of sound (SOS) and DXA at the various sites in the group as a whole were 0.53 to 0.54 (P<0.0001). Significantly lower regression coefficients between BUA and DXA at the total hip and the femoral neck were found in premenopausal women (r=0.31 and 0.38, P<0.0001) compared to postmenopausal women (r=0.56 and 0.53, P<0.0001). For SOS there was no significant difference between the regression coefficients in the pre- and postmenopausal group. The overall prevalence of osteoporosis as assessed by DXA in the total group was 25% (6% in the pre- and 36% in the postmenopausal group). BUA failed to detect osteoporosis in all five premenopausal women but also in 20 out of 50 postmenopausal women with osteoporosis according to DXA measurements. SOS measurements were even worse in this respect. CONCLUSIONS: Linear regression coefficients between calcaneal QUS parameters and DXA are only modest considering a group of 25--75-year-old Dutch women. In the subgroup of premenopausal women correlations between BUA and BMD at the hip and femoral neck are worse compared to those in postmenopausal women. The predictive value of QUS parameters for BMD is limited, therefore it is not appropriate to use QUS as a surrogate for DXA.     

Bone mineral content and bone mineral density at lumbar spine and forearm in Chinese girls aged 6-18 years

We investigated the age-related bone mineral content (BMC), bone mineral density (BMD) and the tempo of growth in BMC and BMD at lumbar spine and forearm in 455 Chinese girls aged 6-18 yr. BMC and BMD at the anteroposterior lumbar spine (LS), the left forearm (radius+ulna ultradistal, R+UUD) and one-third region (R+U1/3) were measured using a dual-energy X-ray bone densitometer (DXA). BMC and BMD exhibited different change patterns with the age changes. There were significant correlations between age, height, weight and BMC and BMD at LS, R+UUD and R+U1/3 sites. BMC and BMD increased significantly with increments in pubertal stages at LS, R+UUD and R+U1/3 sites. In conclusion, our study showed that Tanner stage had a significant positive association with BMC and BMD of the lumbar spine and forearm. The differences were found in the growth tempo of BMC and BMD within a region and between the spine and forearm. Both BMD and BMC were recommended to evaluate the bone health in children and adolescents.     

Assessment of osteoporosis by quantitative ultrasound versus dual energy X-ray absorptiometry in children with chronic rheumatic diseases

OBJECTIVE: To evaluate the validity of quantitative ultrasound bone sonometry (QUBS) as a screening tool for the diagnosis of osteoporosis in children with chronic rheumatic diseases (CRD), compared to the conventional dual energy x-ray absorptiometry (DEXA). METHODS: Forty children with CRD [32 with juvenile idiopathic arthritis (JIA), 6 with systemic lupus erythematosus, and 2 with dermatomyositis] aged 9.9 +/- 4.3 years, were evaluated by QUBS of radius and tibia and DEXA of the lumbar spine. Twenty-five (62.5%) patients were treated with corticosteroids. Measurements of the velocity of the ultrasound wave, expressed as speed of sound (SOS) in m/s, and the results of the bone mineral density (BMD) assessed by DEXA were compared to reference data from healthy age and sex matched Israeli children. RESULTS: Compared to controls, patients with CRD had significantly lower values by QUBS and DEXA alike. BMD and SOS z scores < -1 SD were found in 45% and 38% of the patients, respectively. Reduced BMD and SOS values correlated with age at disease onset and corticosteroid treatment. BMD alone correlated negatively with disease duration and methotrexate therapy. BMD was significantly lower in patients with polyarticular JIA compared to patients with oligoarticular disease (p < 0.03). SOS values did not differ between subtypes of JIA. A significant positive correlation was found between the lumbar DEXA and radius SOS. CONCLUSION: QUBS evaluation of radius and tibia yielded results comparable to DEXA and may therefore be used for screening patients with CRD for osteoporosis. QUBS might represent a promising means of evaluating bone quality in at-risk children.     

Bone mineral content of the radius: Good correlations with physicochemical determinations in iliac crest trabecular bone of normal and osteoporotic subjects

Specific gravity, porosity index (physical parameters), hydroxyproline, calcium, magnesium, and phosphorus (chemical parameters) were determined in iliac crest trabecular bone of normal and osteoporotic subjects. These physical and chemical parameters were compared to bone mineral content (BMC) measurements by x-ray photodensitometry of the radius. BMC values correlated negatively with porosity index, specific gravity, and degree of mineralization of trabecular bone matrix, which all increase with osteoporosis. There was a negative correlation between calcium and magnesium contents per net bone volume. “Distal” scans of the radius reflected better the axial skeleton mass than “proximal” scans, and physicochemical data correlated better with bone mineral content values than with bone mineral mass (BMM) values.     

Assessment of the effect of oral corticosteroids on bone mineral density in systemic lupus erythematosus: a preliminary study with dual energy x ray absorptiometry.

Dual energy x ray absorptiometry and a wide range of blood and urine tests were used to assess the propensity of patients with systemic lupus erythematosus to develop an impairment of bone mineral density. Surprisingly, in this preliminary study no significant differences in bone mineral density were found when patients taking 10 mg or more of prednisolone for six months or longer were compared with those who had never taken prednisolone.