Discordance in diagnosis of osteoporosis using spine and hip bone densitometry

Bipolar Disorder and Bone Mineral Density Z-Scores in Relation to Clinical Characteristics and Lithium Medication

Bipolar disorder is associated with a long range of medical comorbidities, including migraine, diabetes, and cardiovascular disease. Bipolar disorder has also been associated with an increased risk of bone fractures. Osteoporosis is a reduction in bone mineral density, which leads to an increased risk for fragility fractures. Currently there is limited research on the association between bipolar disorder and osteoporosis. We aimed to study the association between high and low bone mineral density in relation to disease and treatment history in a sample of bipolar patients. We found that bipolar patients with high bone mineral density were more often on lithium medication, had a more active lifestyle and expressed lower current disease burden. Low mineral density was not associated with any of the addressed aspects of disease and treatment history. In conclusion our results support that patients on lithium treatment have higher bone mineral density; further studies are needed to address if lithium medication causes an increase in bone mineral density, and lowers the risk of bone fractures in bipolar disorder.

Assessment of bone health in patients with prostate cancer using cancer staging computed tomography

PURPOSE

To evaluate the utility of vertebral Hounsfield unit (HU) values from computed tomography (CT) in cancer staging as a supplementary screening tool for bone health among prostate cancer (PCa) patients.

METHODS

T-scores of bone mineral density (BMD) in each lumbar vertebra (L1-L4) and hip for newly diagnosed PCa patients (N = 139) were measured using dual-energy X-ray absorptiometry (DXA). The degenerative changes in each lumbar vertebra were assessed, and the HU values of trabecular bone in axial CT images of each vertebral body (vertebral CT-HU value) were measured using staging CT.

RESULTS

556 vertebrae were analyzed. 326 of 556 (59%) lumbar vertebrae had degenerative changes. The vertebral CT-HU value was positively correlated with the lumbar BMD T-score, with higher correlation coefficients observed in vertebrae without degenerative changes (r = 0.655, N = 230) when compared to vertebrae with degenerative changes (r = 0.575, N = 326). The thresholds matching BMD T-scores of - 2.0 and - 1.5 set by cancer treatment-induced bone loss guidelines were 95 HU and 105 HU, respectively. Based on the intervention threshold (lumbar BMD T-score <  - 1.5), 15.1% of PCa patients required osteoporosis treatment; and, this value increased to 30.9% when L1-L4 CT-HU thresholds that corresponded to BMD T-score <  - 1.5 were used.

CONCLUSION

Lumbar BMD values from DXA may not reflect true bone health in PCa patients who often have lumbar degenerative diseases. Thresholds based on the vertebral CT-HU value can be used as a supplementary method to identify PCa patients who need anti-osteoporosis drugs.

Prevalence and Risk Factors of T-Score Spine-Hip Discordance in Patients with Osteoporotic Vertebral Compression Fracture

Background: T-score discordance between the spine and hip is commonly observed when dual energy X-ray absorptiometry (DXA) is used to diagnose osteoporosis. However, information is scarce regarding the prevalence and risk factors for this problem in Korea. This study evaluated the prevalence of major/minor discordance and associated risk factors in elderly Korean patients with osteoporotic vertebral compression fractures (OVCFs).Methods: This study included 200 patients (37 men, 163 women) treated for thoracic or lumbar compression fractures between January 2015 and August 2021. DXA was performed to examine T‐scores and determine the prevalence of discordance, defined as a difference between the T-score categories of the femur and spine in the same individual. The t-tests, χ2 tests, and regression analyses were used to assess the associated risk factors of T-score discordance among the subjects.Results: T-score concordance, minor discordance, and major discordance were observed in 137 (68.5%), 59 (29.5%), and 4 (2%) patients with OVCFs, respectively. The spinal T-score was lower than the femoral T-score in all major discordance and 81.3% (48/59) of minor discordant cases. Overall, the only factor related to T-score discordance was the age at fracture (odds ratio, -0.01; P=0.014).Conclusions: The results of this study showed that a significant number of subjects (31.5%) showed spine-hip discordance, even with a mean age in their 80s. More attention should be paid to the appropriate evaluation and management of elderly patients with OVCFs. Moreover, a longitudinal study is necessary to verify the clinical importance of T-score discordance in this population.

Discordance in Bone Mineral Density between the Lumbar Spine and Femoral Neck Is Associated with Renal Dysfunction

PURPOSE

Bone mineral density (BMD) determined by dual-energy X-ray absorptiometry is considered a gold standard for diagnosing osteoporosis. Some people show discordance in BMD values measured at the femur and that at the lumbar spine (LS). The aim of the present study was to investigate whether differences in BMD T-scores between the LS and femur neck (FN) are associated with renal dysfunction in the general population of Korea.

MATERIALS AND METHODS

We analyzed national data for 17306 adults from the Korean National Health and Nutrition Examination Survey conducted between 2008 and 2011. BMD T-score differences between LS and FN (termed BMD offset) were calculated by subtracting FN T-scores from LS T-scores. Diminished renal function was defined as estimated glomerular filtration rates (eGFR) less than 60 mL/min/1.73 m².

RESULTS

Among those aged ≥50 years, BMD offset was negatively associated with eGFR levels. Additionally, eGFR levels decreased linearly across increasing BMD offset quartiles. Men and women with an offset of >1.5 showed a 4.79-times and 2.51-times higher risk of renal dysfunction, respectively, compared to individuals with an offset of ≤0, after adjusting for age, body mass index, educational level, current smoking, and physical activity. In contrast, there was little evidence of an association between renal dysfunction and BMD offset in subjects aged <50 years.

CONCLUSION

Discordance between LS and FN BMDs was significantly associated with renal dysfunction in subjects aged ≥50 years. When assessing bone health in older chronic kidney disease patients, physicians should consider the possibility of BMD discordance between LS and FN.

Spine-Hip Discordance and FRAX assessment Fracture Risk in Postmenopausal Women with Osteopenia from Concordant Diagnosis Between Lumbar Spine and Femoral Neck

The diagnostic criteria proposed by the World Health Organization did not consider the discrepancy in diagnosis between lumbar spine (LS) and femoral neck (FN) and the clinical implications is unclear. Therefore, this retrospective study evaluated the probability of fracture risk in postmenopausal women with lumbar spine (LS)-femoral neck (FN) bone mineral density (BMD) discordance or not Patients included 1066 healthy postmenopausal women (median age 55.5 years) who visited our hospital for a health check-up between May 2013 and April 2017. Discordance was defined as a difference of one or two degrees between LS BMD and FN BMD. TBS was calculated from dual energy absorptiometry (DXA) images. Fracture risk was assessed using the Fracture Risk Assessment Tool (FRAX), including TBS-adjusted FRAX Seven hundred and two patients (65.9%) showed concordant LS and FN results, whereas 364 patients (34.1%) exhibited discordance. Normal BMD was found in 519 concordant patients (73.9%). Concordant patients showed significantly higher FRAX scores, including TBS-adjusted FRAX results, than discordant patients with low LS or FN. Furthermore, FRAX results in concordant osteopenia patients were similar to that of osteoporosis patients with osteopenia or a normal result at one site. FRAX and TBS-adjusted FRAX results in concordant osteopenia patients were comparable to that of discordant osteoporosis patients We concluded that patients with colncordant osteopenia in both the FN and LS should be managed in a similar way to patients with discordant osteoporosis.

Multidimensional Bone Density Phenotyping Reveals New Insights Into Genetic Regulation of the Pediatric Skeleton

Osteoporosis is a complex disease with developmental origins. It is therefore important to understand the genetic contribution to pediatric areal bone mineral density (aBMD). Individual skeletal site phenotyping has been primarily used to identify pediatric aBMD loci. However, this approach is limited because there is a degree of aBMD discordance across skeletal sites. We therefore applied a novel multidimensional phenotyping approach to further understand the genetic regulation of pediatric aBMD. Our sample comprised a prospective, longitudinal cohort of 1293 children of European ancestry (52% female; up to seven annual measurements). Principal components analysis was applied to dual-energy X-ray absorptiometry-derived aBMD Z-scores for total hip, femoral neck, spine, and distal radius to generate multidimensional aBMD phenotypes (ie, principal component scores). We tested the association between a genetic score (percentage of bone lowering alleles at 63 loci) and each principal component. We also performed a genomewide association study (GWAS) using the multiethnic baseline data (n = 1885) to identify novel loci associated with these principal components. The first component (PC1) reflected a concordant phenotypic model of the skeleton (eg, higher loading score = higher BMD across all sites). In contrast, PC2 was discordant for distal radius versus spine and hip aBMD, and PC3 was discordant for spine versus distal radius and hip aBMD. The genetic score was associated with PC1 (beta = -0.05, p = 3.9 × 10^-10 ), but was not associated with discordant PC2 or PC3. Our GWAS discovered variation near CPED1 that associated with PC2 (rs67991850, p = 2.5 × 10^-11 ) and near RAB11FIP5 (rs58649746, p = 4.8 × 10^-9 ) that associated with PC3. In conclusion, an established bone fragility genetic summary score was associated with a concordant skeletal phenotype, but not discordant skeletal phenotypes. Novel associations were observed for the discordant multidimensional skeletal phenotypes that provide new biological insights into the developing skeleton. © 2017 American Society for Bone and Mineral Research.

Effectiveness of Osteoporosis Self-Assessment Tool for Asians in Screening for Osteoporosis in Healthy Males Over 40 Years Old in China

In this study, we evaluated the effectiveness of the Osteoporosis Self-assessment Tool for Asians (OSTA) in screening for osteoporosis in the elderly male population in the Chengdu area, China. The Lunar Prodigy Advance bone densitometer was used to measure the bone mineral density of 11,039 healthy males over the age of 40 years. Men with OSTA scores of >-1, -4 < OSTA ≤ -1, or ≤-4 were assigned to the low-risk, moderate-risk, or high-risk group, respectively. The T-scores measured with dual-energy X-ray absorptiometry at the different sites were compared across the groups. The bone mineral density of the lumbar spines L1-L4, the left femur, and other sites decreased gradually with age. With increasing age, the screening sensitivity of OSTA for osteoporosis in the lumbar spine and femur gradually increased, whereas its specificity decreased. The areas under the receiver operating characteristic curves for the OSTA index in different age groups and at different sites were 0.644-0.831. Therefore, the OSTA index demonstrated some value in screening for osteoporosis in men over the age of 50 years. Significant differences in its effectiveness were observed among different age groups.

Dietary Patterns and Fractures Risk in the Elderly

PURPOSE

Although the role of dietary factors in the prevention of bone loss and fractures has been investigated in many studies, few studies have examined the association between dietary patterns and total body bone density. Our aim was to determine the relations between dietary patterns and whole-body bone mineral density (WB-BMD) and the association between dietary patterns, fractures, and multiple fractures in the elderly.

METHODS

This cross-sectional study included 177 individuals aged ≥65 years. A dual X-ray absorptiometry scan was performed to measure BMD. Dietary patterns were ascertained by a combination of dietary intake assessment and principal components analysis.

RESULTS

Only three dietary patterns correlated with whole-body bone density. The multivariate-adjusted mean bone density across tertiles of these dietary patterns showed that the highest tertile of both the patterns 1 and 2 had a significantly higher bone density than the lowest tertile (pattern 1: 1.021 ± 0.01 and 1.070 ± 0.01 g/cm² for T1 and T3, respectively; p = 0.043; pattern 2: 1.023 ± 0.01, and 1.081 ± 0.01 g/cm² for T1 and T3, respectively; p = 0.003). We also find significant gender difference in these results. The highest adherence to the dietary pattern 5 was associated with decreased odds of having fractures (OR = 0.20, p = 0.009), and adherence to the pattern 1 was negatively associated with multiple fractures.

CONCLUSION

A high adherence to the dietary pattern 1 (high intake of grains, fish and olive oil) was associated with a high BMD and a low number of fractures. The highest adherence to the dietary pattern 5 (legumes and wine) was associated with decreased odds of having fractures. Our finding would suggest a potential bone-preserving properties of specific dietary patterns in the elderly.

Prevalence of Osteoporosis in Women in Buenos Aires Based on Bone Mineral Density at the Lumbar Spine and Femur

The aim of the study was to report values for osteoporosis (OP) prevalence in Buenos Aires. Bone mineral density (BMD) at different skeletal sites was measured from November 2012 to July 2014. Participants were recruited through a newspaper advertisement inviting women at least 50 yr of age to receive free BMD measurement. After signing an informed consent form, 5448 women living in Buenos Aires and surrounding districts were studied. Lumbar spine (L1-L4), femur neck, and total hip BMDs were measured (Lunar Prodigy, software version 12.3 GE, Madison, WI, USA). OP was defined as a T-score ≤-2.5 at the lumbar spine or the femoral neck. Results showed that 1021 out of 5448 studied subjects (18.7%) had OP at the lumbar spine or the femoral neck. Comparison of age of the population sample with reference data for the general population showed a moderate (+0.6%) increase in prevalence. Prevalence of OP was low, up to the age of 70 yr when based on femoral neck BMD only. Conversely, the prevalence of OP at the lumbar spine, which was reportedly high in women up to the age of 70 yr, tended to level off over that age. The results of the total femur only added a slight (+0.7%) nonsignificant increase to the OP prevalence. A total 346,500 out of 1,853,000 women aged 50+ yr in Buenos Aires had OP at the lumbar spine or femoral neck, whereas only 163,500 had OP at the upper femur, reducing the number by 53%. The present study assessed OP prevalence in the most densely populated urban area in Argentina. The results are similar to those reported for Caucasian populations in the United States and Canada. As measurement of only the BMD of femoral neck overlooks the diagnosis in half of the women, future studies should include measurement of the lumbar spine in combination with the femoral neck for a more accurate estimation of OP prevalence.

Correlating Whole-Body Bone Mineral Densitometry Measurements to Those From Local Anatomical Sites

Background:

Using the same cutoff points for whole-body measurements as for site-specific measurements will result in underestimation of osteoporosis.

Objectives:

We assessed the correlation between densitometry measurements for the whole body with those for the femur, lumbar spine, and forearm to evaluate the possibility of replacing site-specific values with whole-body measurements.

Patients and Methods:

In this cross-sectional study, we evaluated all patients referred to a single rheumatology clinic for bone mineral density measurements from 2009 to 2010. All patients who had bone mineral density measurements taken from the hip, lumbar spine, forearm, and whole body were enrolled in the study. Standard bone mineral density measurements were performed using a dual energy X-ray absorptiometry device (Hologic Delphi A; Hologic, Bedford, MA, USA). Bone mineral density, Z-score, and T-score were measured for all patients and all body regions.

Results:

The mean age of the 152 participating patients was 56.7 ± 12.6 years, and 97.4% were female. Pearson correlation coefficients of the whole-body bone mineral density values compared with site-specific values in patients over age 50 were 0.66 – 0.75. Using T-score cutoff points of -1 and -2.5 for osteopenia and osteoporosis, whole-body measurements underestimated the percentage of abnormal patients compared with the site-specific measurements (all P < 0.001). Using receiver operating characteristic (ROC) analysis, the whole-body bone mineral density showed respective areas under the curve of 0.96 and 0.84 for the diagnosis of abnormal hip bone mineral density and osteoporosis.

Conclusion:

Using the same cutoff points for whole-body measurements as for site-specific measurements will result in overestimation or especially underestimation of osteopenia and osteoporosis diagnosis. Choosing new and appropriate cutoff points for whole-body densitometric measurements when we want to substitutes this assessment instead of site specific measurements seems mandatory and will decrease the rate of false diagnoses of densitometric deficiencies in these anatomical sites.

Prevalence and Risk Factors of Discordance between Left- and Right-Hip Bone Mineral Density Using DXA

To determine the prevalence of significant left-right differences in hip bone mineral density (BMD), and the impact of this difference on osteoporosis diagnosis, we measured bilateral proximal femora using dual energy X-ray absorptiometry (DXA) in 3481 subjects (608 males, 2873 females). The difference between left and right hip was considered significant if it exceeded the smallest detectable difference (SDD) for any of the three hip subregions. Contralateral femoral BMD was highly correlated at all measuring sites (r = 0.92-0.95). However, significant left-right differences in BMD were common: the difference exceeded the SDD for 54% of patients at total hip, 52.1% at femoral neck, and 57.7% at trochanter. The prevalence of left-right differences was greater in participants >65 years. For 1169 participants with normal spines, 22 (1.9%) had discordant left-right hips in which one hip was osteoporotic; for 1349 patients with osteopenic spines, 94 (7%) had osteoporosis in one hip. Participants with BMI < 20 kg/m(2) were more likely to show major T-score discordance (osteoporosis in one hip and normal BMD in the other). Multiple regression analysis showed that the only significant statically parameter that persists after adjusting for all potential confounding parameters were age over 65 years.

The prevalence of significant left-right hip bone mineral density differences among black and white women

SUMMARY

In a cross-sectional retrospective study, we examined the prevalence of significant opposite hip bone mineral density difference among white and black women. Left-right hip bone mineral density difference was a common finding in both races, raising the possibility that osteoporosis can be missed if only one hip is imaged.

INTRODUCTION

We examined the prevalence of significant left-right hip bone mineral density (BMD) difference among black and white female subjects and its implications on the diagnosis of osteoporosis.

METHODS

This was a retrospective review of dual energy X-ray absorptiometry (DXA) data in black and white subjects age 50 years and older. One thousand four hundred seventy-seven scans obtained using a GE Lunar Prodigy scanner in dual hip mode were analyzed (24% black, 76% white). Significant left-right hip BMD difference was considered present when the subregion least significant change (LSC) was exceeded. Its prevalence was determined, along with consequences on the diagnosis of osteoporosis.

RESULTS

Significant differences in BMD were common in both races; the LSC was exceeded in 47% of the patients at the total hip, 37% at the femoral neck, and 53% at the trochanter. Diagnostic agreement was lower when the LSC was exceeded than when it was not. The LSC was exceeded in a statistically significant number of black and white patients with normal or osteopenic spines and unilateral hip osteoporosis.

CONCLUSIONS

Significant left-right hip BMD difference is a common finding among black and white women and can result in osteoporosis being missed if only one hip is imaged.

DXA scanning in clinical practice

Dual-energy X-ray absorptiometry (DXA) is recognized as the reference method to measure bone mineral density (BMD) with acceptable accuracy errors and good precision and reproducibility. The World Health Organization (WHO) has established DXA as the best densitometric technique for assessing BMD in postmenopausal women and based the definitions of osteopenia and osteoporosis on its results. DXA allows accurate diagnosis of osteoporosis, estimation of fracture risk and monitoring of patients undergoing treatment. However, when DXA studies are performed incorrectly, it can lead to major mistakes in diagnosis and therapy. This article reviews the fundamentals of positioning, scan analysis and interpretation of DXA in clinical practice.