Evaluation of calcaneus bone densitometry against hip and spine for diagnosis of osteoporosis

Relationship between the mandibular cortical index and calcaneal bone mineral density in postmenopausal women

BACKGROUND AND OBJECTIVE

In clinical practice, a comparative analysis of bone mineral density (BMD) is carried out by examining different skeletal bones. This is useful for screening of postmenopausal osteoporosis (OP). The objective of this study was to determine the relation between the mandibular cortical index (MCI) and calcaneal BMD among postmenopausal women.

MATERIALS AND METHODS

The study sample included 129 randomly selected postmenopausal women aged 50-77 years. The participants were examined using panoramic radiography for the analysis of the cortical layer in the mandibular base for MCI determination and using DXL for the examination of calcaneal BMD. According to T scores, the subjects were divided into three groups (Groups 1, 2, and 3). The panoramic radiographic examination of the mandible was performed; the MCI was determined and distributed into groups (C1; C2; C3). The MCI validity in determining the calcaneus BMD status was analyzed.

RESULTS

The differences in BMD were statistically significant between Groups C1 and C3 (P<0.01), Groups C2 and C3 (P=0.01), and between the calcaneal BMD groups (P<0.001). There was a statistically significant inverse correlation between the MCI and calcaneal BMD (r=-0.3; P<0.001). The changes characteristic of Group C2 were documented more frequently than those of other morphological groups. The analysis of the MCI validity in BMD status showed low sensitivity (69.4%) and specificity (53.9%).

CONCLUSIONS

The relation between MCI and calcaneal BMD was determined. The diagnostic discrimination of the MCI was found to be not sufficient in screening the women with postmenopausal osteoporosis and its application in clinical practice might be limited.

Do premenopausal hypothyroid women on levothyroxine therapy need bone status monitoring?

BACKGROUND

Suppressive doses of levothyroxine therapy are reported to reduce bone mineral density (BMD) in women. Data on bone changes in premenopausal hypothyroid women with replacement therapy are limited. Hence, this study was undertaken to evaluate bone changes in this group using bone markers and BMD.

MATERIALS AND METHODS

A hospital-based case-control study including 75 premenopausal women aged 30-45 years was conducted. The subjects were categorized based on their thyroid function and history into three groups of 25 euthyroid, 25 newly diagnosed hypothyroid, and 25 hypothyroid women on 100-200 μg of levothyroxine for a minimum of 5 years. The bone changes were evaluated and compared among the groups biochemically by estimating their plasma osteocalcin and serum calcium and phosphorus and radiologically by measuring their BMD by quantitative ultrasonography. Statistical analysis was conducted by using analysis of variance, Tukey's test, and Pearson's correlation using IBM SPSS Statistics 20.

RESULTS

Levels of plasma osteocalcin, serum calcium, and serum phosphorus in patients on long-term levothyroxine therapy were significantly higher than those in newly diagnosed hypothyroid women and in the euthyroid group. BMD showed definite features of osteopenia (T-score: -2.26 ± 0.5) among the women in the treatment group, while it was well within the normal range in the newly diagnosed and euthyroid women. A significant correlation was found between the osteocalcin levels and T-score.

CONCLUSION

Hypothyroid women on long-term levothyroxine therapy showed signs of increased bone turnover and increased resorptive changes, though not frank osteoporosis. Hence, it may be important to evaluate the bone status of patients on levothyroxine for >5 years.

Reducing the need for central dual-energy X-ray absorptiometry in postmenopausal women: efficacy of a clinical algorithm including peripheral densitometry

We evaluated the efficacy of a triage approach based on a combination of osteoporosis risk-assessment tools plus peripheral densitometry to identify low bone density accurately enough to be useful for clinical decision making in postmenopausal women. We conducted a cross-sectional diagnostic study in postmenopausal Caucasian women from primary and tertiary care. All women underwent dual-energy X-ray absorptiometric (DXA) measurement at the hip and lumbar spine and were categorized as osteoporotic or not. Additionally, patients had a nondominant heel densitometry performed with a PIXI densitometer. Four osteoporosis risk scores were tested: SCORE, ORAI, OST, and OSIRIS. All measurements were cross-blinded. We estimated the area under the curve (AUC) to predict the DXA results of 16 combinations of PIXI plus risk scores. A formula including the best combination was derived from a regression model and its predictability estimated. We included 505 women, in whom the prevalence of osteoporosis was 20 %, similar in both settings. The best algorithm was a combination of PIXI + OST + SCORE with an AUC of 0.826 (95 % CI 0.782-0.869). The proposed formula is Risk = (-12) × [PIXI + (-5)] × [OST + (-2)] × SCORE and showed little bias in the estimation (0.0016). If the formula had been implemented and the intermediate risk cutoff set at -5 to 20, the system would have saved <euro>4,606.34 in the study year. The formula proposed, derived from previously validated risk scores plus a peripheral bone density measurement, can be used reliably in primary care to avoid unnecessary central DXA measurements in postmenopausal women.

The relation between bone mineral density in the heel and pixel intensity in the mandibular jaw bone among elderly women

OBJECTIVES

The purpose of this study was to investigate the correlation between pixel intensity (PI) in digital radiographs of the lower jaw and bone mineral density (BMD) in the heels of post-menopausal women (as measured with DXL, a combination of dual energy X-ray absorptiometry and lasers).

METHODS

Two intraoral periapical digital radiographs were taken in the right and left mandible premolar region, and the digital images were analysed by a computer program (Dimaxis) regarding PI. As the radiographs were taken, the BMD of the patient's left heel was measured via a portable Calscan device. The patient answered a questionnaire concerning risk factors. The correlation between variables was analysed using statistical tests.

RESULTS

A significant correlation was found between the PI in the left (P = 0.001) and right (P = 0.004) mandible and the BMD of the left heel for the whole group. A pronounced correlation was found to exist for women > 70 years old. Based on a cut-off value of the PI, to differentiate between healthy individuals and those who required further analysis for osteoporosis, the following values were obtained: sensitivity 0.74, specificity 0.50, positive predictive value 0.77 and negative predictive value 0.46.

CONCLUSION

A positive correlation was found between PI in digital radiographs of the mandible and the BMD of the heel. The low predictive value does not allow any definite conclusions to be drawn from the present study. A reasonable recommendation could be for future studies to employ a larger study population to explore the effect on this value.

Quantitative ultrasound and densitometric measurements and laboratory variables in patients on long-term acenocoumarol therapy

The aim of the study was to establish whether chronic use of acenocomarol affects bone metabolism. Eighty-two males [41 treated with acenocumarol (mean therapy duration of 6.0+/-6.4 years) and 41 age-matched controls] were studied. Skeletal assessment included densitometric measurements at ultradistal forearm and calcaneus and ultrasound examination of hand phalanges and laboratory measurements included serum total calcium, phosphates, bone alkaline phosphatase (bAlp) and C-terminal telo peptide of type I collagen (ICTP). Densitometric and ultrasound variables did not differ significantly between patients and controls. Mean dose and duration of acenocumarol treatment did not affect skeletal and laboratory variables. Bone turnover was depressed, and bAlp and telopeptide were significantly lower in patients than in controls (10.0+/-7 vs. 23.0+/14 U/l, p<0.05, and 1.6+/-1.3 vs. 3.1+/-1.3 microg/l, respectively). In conclusion, despite of the lack of changes in skeletal status, male subjects on long-term acenocumarol therapy may be at high risk for fracture due to disturbances in bone turnover.

Comparisons of bone mass measurements on various skeletal sites including quantitative ultrasonography of the calcaneus for assessing age-related losses, their correlations, and diagnostic agreement using the Japanese and WHO criteria for osteoporosis

PURPOSE

The aim of this study was to compare age-related bone losses and correlations among several bone mass measurements and to evaluate diagnostic agreement among them using the Japanese and WHO criteria for osteoporosis.

MATERIALS AND METHODS

A total of 846 women (mean +/- SD: age 54 +/- 9 years) were evaluated. Bone mineral densities of the lumbar spine, femoral neck, and calcaneus were measured by dual X-ray absorptiometry and distal radius by peripheral computed tomography. Quantitative ultrasonography (QUS) parameters of the calcaneus were also measured. The age-related bone losses after 50 years of age and correlations among bone mass results were evaluated using linear regression analysis. Diagnostic agreement was evaluated by kappa statistics.

RESULTS

The annual losses ranged from 1.0% to 1.6%. The correlation coefficients ranged from 0.54 to 0.78. The kappa scores ranged from 0.52 to 0.30 for all subjects using the Japanese criteria and from 0.38 to 0.15 using the WHO criteria.

CONCLUSION

Bone mass measurements including QUS on various skeletal sites documented age-related changes similarly, and their bone masses correlated moderately. The diagnostic agreements among them were fair to poor. To screen out women with a risk of osteoporosis, it is important to choose which technique to use and which skeletal site to measure.

Heel bone densitometry: device specific thresholds for the assessment of osteoporosis

A diagnosis of osteoporosis is facilitated by bone mineral density (BMD) measurement of the lumbar spine and hip using dual energy X-ray absorptiometry (DXA), interpreted in accordance with criteria published by the World Health Organization (WHO). The use of peripheral DXA is growing in primary care and guidance on its use has recently been published by the National Osteoporosis Society (NOS), recommending a triage approach using thresholds specific to each type of peripheral device. However, no data currently exist for the Norland Apollo heel densitometer (Cooper Surgical, Trumbull, USA). 215 women between 50 years and 75 years of age (mean age 64.6 years) referred for hip and spine BMD measurements also had a heel BMD measurement. Device specific upper and lower thresholds were calculated for the Norland Apollo heel densitometer to give a 90% sensitivity and 90% specificity for osteoporosis at the hip or spine. Patients with a heel T-score of above -1.2 are very likely to have normal bone density on axial densitometry, whilst patients with heel T-score of below -2.2 are very likely to have osteoporosis at the hip or spine. Patients whose measurements lie between the thresholds should be referred for axial DXA.

Low bone mineral density measurements in care home residents--a treatable cause of fractures

PURPOSE

to assess predictors of fracture risk and treatment for osteoporosis among elderly care home residents.

SUBJECTS AND METHODS

DESIGN

cross-sectional survey;

SETTING

residents of care homes in Newcastle upon Tyne, UK;

PARTICIPANTS

representative sample from residential care (87), nursing homes (105) and specialist homes for elderly people with dementia [elderly mentally infirm (EMI)]: residential (124) and nursing (76);

MAIN OUTCOME MEASURES

dual-energy X-ray absorptiometry bone mineral density (BMD) at calcaneum; functional assessments, including cognition, using Mini-Mental State Examination (MMSE), Clifton Assessment Procedure for the Elderly-Behaviour Rating Score (CAPE-BRS) and Functional Assessment Staging Test (FAST) scores; current drug prescription.

RESULTS

MMSE, CAPE, FAST (all ANOVA P < 0.001) and weight (ANOVA P < 0.02) were lower in EMI homes. Drugs with sedative effects (chi-square, P < 0.0001) were more likely and calcium and vitamin D (CaD) supplementation (chi-square, P < 0.02) less likely in EMI care. For residential care, the odds ratio (OR) for sedative drugs in EMI was 2.13 (95% CI 1.11-4.06) with no significant difference between nursing homes. For CaD supplementation, the OR for EMI nursing homes was 0.19 (95% CI 0.05-0.72) and for EMI residential homes 0.38 (NS to 95% CI 0.12-1.27). BMD was low: mean T-score was -2.29 (95% CI -2-48 to -2.09) and Z-score -0.96 (95% CI -1.16 to -0.76) with a prevalence of osteoporosis (T-score < -1.6) of 69.2%. MMSE and FAST scores did not predict BMD. In EMI residential care, a decrease of CAPE score by 5 points was associated with a decrease in T-score by 0.6 (95% CI 0.15-1.1).

CONCLUSIONS

of the tools used to assess function, only CAPE predicted low BMD in EMI residential care. Rates of CaD supplementation are particularly low in EMI care, where risk factors for fracture were the greatest. We conclude that fracture risk is neglected in these homes, and targeted education and treatment are warranted.

Dual-Energy X-Ray Absorptiometry Analysis of Implants in Rat Tibiae

Dual energy x-ray absorptiometry (DXA) was evaluated for its ability to measure changes in bone mineral density in isolated rat tibiae. This technique is available for in vivo use to potentially augment or replace some aspects of conventional histomorphometric techniques used for the evaluation of metallic implant-to-bone interfaces. Known quantities of hydroxyapatite powder, representing various bone densities, were measured using DXA in a series of 3 experiments: (1) the hydroxyapatite powder was placed within a plastic tube, (2) the hydroxyapatite was placed within an excised rat tibia, and (3) hydroxyapatite powder was placed within a rat tibia with soft tissue overlying it. Statistical analysis (analysis of variance) showed significant differences in bone mineral density among groups that varied by only 5% hydroxyapatite density within the plastic tubes. The system detected hydroxyapatite changes of 20% within the tibiae with and without overlying soft tissue (P < 0.05). These data were consistent and linear (R > 0.90). Although DXA analysis has been widely used in clinical and research applications for detection of osteoporosis, its use for documenting bone growth around implants has not been widely reported. The use of such a technique could have substantial benefits for both the clinical and research arenas. These data show that DXA analysis to identify bone density changes adjacent to implants has significant applications in small animal research models.

Bone mineral density measurement in the calcaneus with DXL: comparison with hip and spine measurements in a cross-sectional study of an elderly female population

We investigated the relationship between calcaneal and axial bone mineral density in an elderly female population. We also investigated the influence of changing the reference populations on T-score values. Bone mineral density (BMD) was determined in 388 women (mean age 73 years) participating in a cross-sectional study. BMD values were determined at the left hip and the lumbar spine, L1-L4, using Hologic QDR 4500 equipment for dual X-ray absorptiometry (DXA). The calcaneal measurements were made with DEXA-T, a device using a dual X-ray and laser (DXL) technique that combines DXA measurement with measurement of the heel thickness using a laser reflection technique. DEXA-T is an older version of the Calscan DXL device now commercially available. T-score values were calculated for hip measurements with both the original reference population of the Hologic device and the NHANES III reference population. T scores for heel measurements were calculated with the original reference population of the peripheral device and the Calscan database, a new calcaneal reference population. Changing the reference populations had a great influence on both the heel and the hip T scores, especially those of the femoral neck where the percentage of subjects identified as osteoporotic decreased from 53% to 23%. We conclude that, with the NHANES III and the larger Calscan database, using the cut-off point of -2.5 SD, the heel measurements had optimal accuracy for detecting osteoporosis at either the combination of the lumbar spine and the femoral neck or the combination of the lumbar spine, the femoral neck, the total hip and the trochanter. BMD measurements of the calcaneus with DXL correlated fairly well with measurements at axial sites at the group level, while in individual subjects large deviations were observed between all the measured sites. We also conclude that the influence of the reference populations on the T scores is substantial when different DXA methods are being compared; the total number of subjects classified as osteoporotic varied from 7% to 53% between the sites and with different reference populations.

Dual X-ray and laser absorptiometry of the calcaneus: comparison with quantitative ultrasound and dual-energy X-ray absorptiometry

The aim of our study was to evaluate the reproducibility and the diagnostic accuracy of a new device for the assessment of bone mineral density (BMD) of the heel, called dual X-ray and laser (DXL Calscan). This technique associates X-ray absorptiometry to the measure of heel thickness with a laser beam. The calcaneus BMD, calcaneus quantitative sonography (QUS), and lumbar spine and total-body BMD, were evaluated in 40 postmenopausal women. On the basis of the BMD T-score measured by dual-energy X-ray absorptiometry (DXA) of L2-L4, 20 women were classified as osteoporotic and 20 women were considered nonosteoporotic according to the WHO classification. The short-term coefficient of variation of the DXL was 2.4% and 1.7% in osteoporotic and nonosteoporotic women, respectively. The calcaneus BMD was lower in osteoporotic than in nonosteoporotic women. Among osteoporotic patients, 14 patients had a T-score lower than -2.5 at Calscan, whereas only 4 patients classified as nonosteoporotic based on the lumbar spine BMD were misclassified by Calscan. In these patients, the sensitivity and specificity of heel ultrasound measurements were 70% and 85%, respectively. The DXL BMD was highly correlated with the total-body BMD, Stiffness at the calcaneus, and the L2-L4 BMD. In conclusion, the new measuring device the Calscan DXL appeared easy to use, the time of examination was relatively short, and the reproducibility was sufficiently good; the diagnostic accuracy and relationships with other devices were good.