Discordance between changes in bone mineral density measured at different skeletal sites in perimenopausal women--implications for assessment of bone loss and response to therapy: The Danish Osteoporosis Prevention Study

Development and internal validation of a clinical prediction model for osteopenia in Chinese middle-aged and elderly men: a prospective cohort study

BACKGROUND

Early identification of patients at risk of osteopenia is an essential step in reducing the population at risk for fractures. We aimed to develop and validate a prediction model for osteopenia in Chinese middle-aged and elderly men that provides individualized risk estimates.

METHODS

In this prospective cohort study, 1109 patients who attend regular physical examinations in the Second Medical Centre of Chinese PLA General Hospital were enrolled from 2015.03 to 2015.09. The baseline risk factors included dietary habits, exercise habits, medical histories and medication records. Osteopenia during follow-up were collected from Electronic Health Records (EHRs) and telephone interviews. Internal validation was conducted using bootstrapping to correct the optimism. The independent sample T-test analysis, Mann_Whitney U test, Chi-Square Test and multivariable Cox regression analysis were utilized to identify predictive factors for osteopenia in Chinese middle-aged and elderly men. A nomogram based on the seven variables was built for clinical use. Concordance index (C-index), receiver operating characteristic curve (ROC), decision curve analysis (DCA) and calibration curve were used to evaluate the efficiency of the nomogram.

RESULTS

The risk factors included in the prediction model were bone mineral density at left femoral neck (LNBMD), hemoglobin (Hb), serum albumin (ALB), postprandial blood glucose (PBG), fatty liver disease (FLD), smoking and tea consumption. The C-index for the risk nomogram was 0.773 in the prediction model, which presented good refinement. The AUC of the risk nomogram at different time points ranged from 0.785 to 0.817, exhibiting good predictive ability and performance. In addition, the DCA showed that the nomogram had a good clinical application value. The nomogram calibration curve indicated that the prediction model was consistent.

CONCLUSIONS

Our study provides a novel nomogram and a web calculator that can effectively predict the 7-year incidence risk of osteopenia in Chinese middle-aged and elderly men. It is convenient for clinicians to prevent fragility fractures in the male population.

Assessing Change in Spine Bone Density from Different Numbers and Combinations of Lumbar Vertebrae: The Manitoba BMD Registry

INTRODUCTION

Change in bone mineral density (BMD) is considered significant when it exceeds the 95 % least significant change (LSC) derived from that facility's precision study. The lumbar spine is often affected by structural artifact such that not all four lumbar vertebrae are evaluable. Guidelines suggest using a site-matched LSC when omitting vertebrae from the BMD measurement. The current study describes significant BMD change related to intervening anti-osteoporosis treatment for different numbers and combinations of lumbar vertebrae using site-matched LSC values.

METHODOLOGY

We identified 10,526 untreated adult women mean age 59.6 years with baseline and repeat spine BMD testing (mean interval 4.7 years) where all 4 lumbar vertebrae were evaluable. Change in spine BMD for different combinations of lumbar vertebrae was assessed in relation to intervening anti-resorptive treatment, contrasting women with high treatment exposure (medication possession ratio, MPR ≥ 0.8) versus women who remained untreated. Site-matched LSC values were derived from 879 test-retest precision measurements.

RESULTS

There was consistent linear trend between increasing MPR and BMD change exceeding the LSC for all lumbar vertebral combinations, positive with BMD increase and negative with BMD decrease (all p-trend <0.001). In the high treatment exposure group, mean percent increases in spine BMD were similar for all vertebral combinations, from L1-4 to a single vertebra. In untreated women, mean percent decreases in spine BMD were also similar for all vertebral combinations. The net treatment response (proportion of women with treatment-concordant changes minus proportion with treatment-discordant changes exceeding the LSC) was 29.7 % for 4 vertebrae, 27.5-30.0 % for 3 vertebrae, 22.4-28.5 % for 2 vertebrae, and 18.1-21.9 % for a single vertebra.

CONCLUSIONS

All numbers and combinations of lumbar vertebrae, when used in conjunction with site-matched LSC values, can provide clinically meaningful follow-up in treated and untreated patients, even when spine BMD is based on a single vertebral body.

Outdoor air pollution exposure, bone mineral density, osteoporosis, and osteoporotic fractures: A systematic review and meta-analysis

BACKGROUND

The prevalence of osteoporosis and osteoporotic fractures is expected to increase with the aging of the population in the coming decades. In this study, we systematically reviewed the evidence on the association between exposure to air pollution and osteoporosis-related outcomes.

METHODS

We systematically searched evidence according to the PRISMA on PubMed, Scopus, and Web of Science (until August 2022). The risk of bias (RoB) was assessed using the Risk of Bias in the Non-randomized Studies of Exposures (ROBINS-E) tool. Random effects meta-analysis was applied to calculate combined estimates. We evaluated the heterogeneity using Cochran's Q test and quantified it by I² and tau² statistics. The overall body of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation system (GRADE) tool.

RESULTS

Out of 5254 retrieved articles, 19 studies (11 cross-sectional, seven cohorts, and one case-control) met our inclusion criteria. Most of the studies had a high probability of RoB (n = 17), and only two had a moderate RoB. Different outcomes including bone mineral density, bone mineral content, osteoporotic fracture, osteoporosis, and osteopenia were reported across the studies. The associations were reported for different air pollutants including PM2.5, PM10, nitrogen oxides, nitrogen dioxide, ozone, black carbon, carbon monoxide, sulfur dioxide, nitrogen oxide, and coarse particulate matter. Evidence was suggestive of the negative role of PM10, PM2.5, and nitrogen dioxide (e.g. bone mineral density pooled estimate: -0.02, 95%CI: -0.03: -0.01). The overall body of evidence for most of the exposure-outcome pairs was low and very low.

CONCLUSIONS

The evidence on the association between air pollution exposure and osteoporosis-related outcomes is heterogenic. However, the evidence suggests an increased risk of osteoporotic fracture and osteoporosis in outdoor air pollutants. Due to the small number of studies in each group, also observed heterogeneity, and publication bias, the results should be interpreted with caution.

Unravelling hip-spine bone mineral density discordance in people living with HIV

INTRODUCTION

In people living with HIV (PLWH), bone mineral density (BMD) discordance between the lumbar spine (LS) and femoral neck (FN) could be frequent given the high frequency of secondary osteoporosis, including HIV-related factors for bone disease.

MATERIALS AND METHODS

Retrospective cohort of PLWH with a dual X-ray absorptiometry scan. Hip-spine BMD discordance was defined as different T-score or Z-scores categories at LS and FN.

RESULTS

Overall, 865 individuals (mean 49.5 years, female 27%) were included. Osteoporosis diagnosis was four-to-seven times lower when both skeletal sites were affected than when considering the lowest T-score at any site (overall, 21% vs 4%). Hip-spine BMD discordance was observed in 381 (44%) individuals, it increased with age (from 43 to 52%, P = 0.032), and it was mainly due to lower LS-BMD. A lower FN-BMD was associated with older age, lower BMI (P < 0.01), and HIV-related factors, such as low CD4 + T-cell counts, duration of HIV infection, and time on antiretroviral therapy (ART). In a multivariate regression analysis, sex male (Odds Ratio, OR 4.901), hyperparathyroidism (OR, 2.364), and time on ART (OR 1.005 per month) were independently associated with discordance. A higher estimated fracture risk by FRAX equation was observed in individuals with BMD discordance due to lower FN-BMD compared to those with lower LS-BMD (+ 36% for major osteoporotic fracture, P = 0.04; + 135% for hip fracture, P < 0.01).

CONCLUSION

Hip-spine BMD discordance is highly prevalent in PLWH and it is associated with classical and HIV-related risk factors, modifying the rate of osteoporosis and fracture risk estimation.

Novel nomogram for predicting the 3-year incidence risk of osteoporosis in a Chinese male population

OBJECTIVE

To establish a rapid, cost-effective, accurate, and acceptable osteoporosis (OP) screening model for the Chinese male population (age ≥ 40 years) based on data mining technology.

MATERIALS AND METHODS

This was a 3-year retrospective cohort study, which belonged to the sub-cohort of the Chinese Reaction Study. The research period was from March 2011 to December 2014. A total of 1834 subjects who did not have OP at the baseline and completed a 3-year follow-up were included in this study. All subjects underwent quantitative ultrasound examinations for calcaneus at the baseline and follow-ups that lasted for 3 years. We utilized the least absolute shrinkage and selection operator (LASSO) regression model to select feature variables. The characteristic variables selected in the LASSO regression were analyzed by multivariable logistic regression (MLR) to construct the predictive model. This predictive model was displayed through a nomogram. We used the receiver operating characteristic (ROC) curve, C-index, calibration curve, and clinical decision curve analysis (DCA) to evaluate model performance and the bootstrapping validation to internally validate the model.

RESULTS

The predictive factors included in the prediction model were age, neck circumference, waist-to-height ratio, BMI, triglyceride, impaired fasting glucose, dyslipidemia, osteopenia, smoking history, and strenuous exercise. The area under the ROC (AUC) curve of the risk nomogram was 0.882 (95% CI, 0.858-0.907), exhibiting good predictive ability and performance. The C-index for the risk nomogram was 0.882 in the prediction model, which presented good refinement. In addition, the nomogram calibration curve indicated that the prediction model was consistent. The DCA showed that when the threshold probability was between 1 and 100%, the nomogram had a good clinical application value. More importantly, the internally verified C-index of the nomogram was still very high, at 0.870.

CONCLUSIONS

This novel nomogram can effectively predict the 3-year incidence risk of OP in the male population. It also helps clinicians to identify groups at high risk of OP early and formulate personalized intervention measures.

Metabolic characteristics of subjects with spine-femur bone mineral density discordances: the Korean National Health and Nutrition Examination Survey (KNHANES 2008-2011)

The diagnosis of osteoporosis is determined based on the lowest bone mineral density (BMD) T-score at the lumbar spine (LS) and hip. However, there are occasional marked discordances between the T-score of LS and femur neck (FN). We aimed to examine the prevalence and characteristics of individuals with spine-femur BMD discordance using a nationwide survey. A total of 3233 men aged ≥ 50 years and 2915 postmenopausal women were included from the Korean National Health and Nutrition Examination Surveys (2008-2011). The spine-femur discordance was defined as a difference of ≥ 1.5 SD between LS and FN BMD. Subjects were divided into three groups: low LS (LS < FN), low FN (LS > FN), and no discordance. Four-hundred and seventeen men (12.9%) and two hundred and ninety women (10%) exhibited spine-femur BMD discordance. The prevalence of hypertension and diabetes was higher in men and women with low FN BMD than in any other group. Fasting plasma glucose and homeostasis model assessment of insulin resistance was the highest in subjects with low FN BMD among the three groups. Low FN BMD revealed higher serum parathyroid hormone and lower 25-hydroxyvitamin D3 levels compared to any other group in women, but this was not observed in men. Osteoporosis was prevalent in subjects with discordance in both genders, particularly, in those with low LS BMD (31.6% in men and 63.5% in women). Given the high prevalence of spine-femur BMD discordance, low FN BMD may be associated with vitamin D deficiency and insulin resistance, but low LS BMD may present severe osteoporosis.

Which is the preferred site for bone mineral density monitoring as an indicator of treatment-related anti-fracture effect in routine clinical practice? A registry-based cohort study

Change in total hip bone mineral density (BMD) provides a robust indication of anti-fracture effect during treatment monitoring in routine clinical practice, whereas spine BMD change is not independently associated with fracture risk.

PURPOSE

The role of monitoring bone mineral density (BMD) as an indicator of an anti-fracture effect is controversial. Discordance between the spine and hip BMD is common and creates uncertainty in clinical practice.

METHODS

Using a population-based BMD Registry for the Province of Manitoba, Canada, we compared change in the spine and hip BMD as an indicator of treatment-related fracture risk reduction. The study cohort included 6093 women age > 40 years initiating osteoporosis treatment with two consecutive dual-energy X-ray absorptiometry (DXA) scans (mean interval 4.7 years). We computed change in the spine, total hip, and femur neck BMD between the first and second DXA scans as categorical (categorized as stable, detectable decrease, or detectable increase) and continuous measures. We modeled time to first incident fracture, ascertained from health services data, using Cox regression adjusted for baseline fracture probability.

RESULTS

During a mean follow-up of 12.1 years, 995 women developed incident major osteoporotic fractures (MOF) including 246 with hip fractures and 301 with clinical vertebral fractures. Women with a detectable decrease in total hip BMD compared with stable BMD experienced an increase in MOF (adjusted hazard ratio [aHR] 1.46, 95% confidence interval [CI] 1.25-1.70) while those with a detectable increase in total hip BMD experienced a decrease in MOF (aHR 0.71, 95% CI 0.61-0.83), and these results were not attenuated when adjusted for change in spine BMD. Similar results were seen for hip and clinical vertebral fracture outcomes, when BMD change was assessed as a continuous measure, and when femur neck BMD monitoring was used instead of total hip BMD monitoring.

CONCLUSIONS

Treatment-related increases in total hip BMD are associated with lower MOF, hip, and clinical vertebral fracture risk compared with stable BMD, while BMD decreases are associated with higher fracture risk. In contrast, spine BMD change is not independently associated with fracture risk.

Comparison of Bone Mineral Densitometry at 2 Sites Versus 3 Sites in Patients Suspicious for Osteoporosis

Objectives:

In this study, we aim to evaluate the bone mineral density (BMD) results of 2 standard sites with 3 sites including wrist in diagnosing osteoporosis.

Methods:

We evaluated the BMD results of 1272 individuals referred for suspected osteoporosis between 2012 and 2015. Those individuals were included with BMD at lumbar spine, femur neck, and wrist. Bone mineral density was measured using a dual-energy X-ray absorptiometry (DXA) device. Bone mineral density and T score were measured for all 3 sites.

Results:

There was significant correlation between wrist T score with hip T score (r = 0.606, P < .001) and lumbar T score (r = 0.527, P < .001). With BMD of 2 sites, patients had osteopenia in 46.3% and osteoporosis in 23.7%, while by adding wrist T-BMD, subjects had osteopenia in 46.6% and osteoporosis in 33%. Between BMD at 2 sites and 3 sites, there was concordance in 81.9%, minor discordance in 17.6%, and major discordance in 0.5%.

Conclusions:

We observed discordance between BMD measurements of 2 sites and 3 sites, with latter detecting more cases with osteoporosis. In fact, measurement of T scores of wrist along with lumbar and femur neck improves the diagnosis.

Positive association between serum uric acid and bone mineral density in Chinese type 2 diabetes mellitus stratified by gender and BMI

Accumulating evidence has demonstrated that serum uric acid (UA), a natural powerful antioxidant, plays a beneficial role in bone health in the general population. However, few reports are available on the association between serum UA and bone in patients with type 2 diabetes mellitus (T2DM). We therefore investigated whether the benefit of serum UA for bone health was still present in those patients. 626 males and 609 postmenopausal females with T2DM were enrolled in this cross-sectional study. Serum UA concentrations and bone mineral density (BMD) measured at lumbar spine, femoral neck and total hip by dual-energy X-ray absorptiometry were obtained from all subjects. Meanwhile, data on osteoporosis prevalence, glucose metabolism, bone turnover markers and other serum biochemical indexes were collected. After adjustment for potential confounders, the results suggested that serum UA was positively associated with BMD in patients with normal weight, but this positive association varied by gender and skeletal sites in overweight T2DM patients [body mass index (BMI) ≥ 25 kg/m²]. Moreover, significantly lower odds ratios (ORs) for osteoporosis were found in postmenopausal patients with the highest UA tertile and male patients with medium UA tertile [adjusted OR 0.315, 95% confidence interval (CI) 0.170-0.581 for postmenopausal patients; adjusted OR 0.464, 95% CI 0.225-0.955 for male patients]. The positive association between serum UA and BMD found in Chinese T2DM patients may imply that relatively high UA is a protective factor for bone in these patients. Large intervention studies are needed to further confirm the outcomes and provide possible explanations.

Thiazide diuretic usage and risk of fracture: a meta-analysis of cohort studies

Inconsistent findings in regard to association between thiazide diuretic use and the risk of fracture have been reported during the past decade. This updated meta-analysis, which pooled data from 11 qualified prospective designed studies, found that thiazides have a significant protective effect on fracture risk.

INTRODUCTION

An updated comprehensive meta-analysis examine the association between thiazide diuretic use and therisk of fracture is needed.

METHODS

Cohort studies regarding thiazide diuretic exposure and the risk of fracture, published from inception to May 1 2017, were identified through MEDLINE, EMBASE, SCOPUS, and the Cochrane Database of Systematic Reviews. The literature search, study selection, study appraisal, and data extraction were pre-defined in the protocol and were independently conducted by two investigators. Due to the heterogeneity of the original studies, a random effects model was used to pool the confounder-adjusted relative risk (RR).

RESULTS

Eleven eligible cohort studies involving 2,193,160 participants were included for analysis. Overall, thiazide diuretic users, as compared with non-users, had a significant 14% reduction in the risk of all fractures (relative risk [RR], 0.86; 95% confidence interval [CI], 0.80-0.93; p = 0.009) and an 18% reduction in the risk of hip fracture (RR, 0.82; 95%CI, 0.80-0.93; p = 0.009). However, the effect size associated with thiazide use became slightly weaker when the analysis was limited to only high-quality original studies (quality score > 8) (RR, 0.89; 95%CI, 0.80-0.99; p = 0.005), studies with a larger sample size (> 10,000) (RR, 0.90; 95%CI, 0.80-1.00; p = 0.002), and studies published after 2007 (RR, 0.92; 95%CI, 0.82-1.02; p = 0.001).

CONCLUSION

Our findings indicate that thiazide diuretic use may convey a decreased risk of fracture and as such, the protective effect of this class of medicine should be considered when prescribing thiazide diuretics in clinical practice.

Does bone mineral density improve the predictive accuracy of fracture risk assessment? A prospective cohort study in Northern Denmark

OBJECTIVE

To evaluate the added predictive accuracy of bone mineral density (BMD) to fracture risk assessment.

DESIGN

Prospective cohort study using data between 01 January 2010 and 31 December 2012.

SETTING

North Denmark Osteoporosis Clinic of referred patients presenting with at least one fracture risk factor to the referring doctor.

PARTICIPANTS

Patients aged 40-90 years; had BMD T-score recorded at the hip and not taking osteoporotic preventing drugs for more than 1 year prior to baseline.

MAIN OUTCOME MEASURES

Incident diagnoses of osteoporotic fractures (hip, spine, forearm, humerus and pelvis) were identified using the National Patient Registry of Denmark during 01 January 2012-01 January 2014. Cox regression was used to develop a fracture model based on predictors in the Fracture Risk Assessment Tool (FRAX®), with and without, binary and continuous BMD. Change in Harrell's C-Index and Reclassification tables were used to describe the added statistical value of BMD.

RESULTS

Adjusting for predictors included in FRAX®, patients with osteoporosis (T-score ≤-2.5) had 75% higher hazard of a fracture compared with patients with higher BMD (HR: 1.75 (95% CI 1.28 to 2.38)). Forty per cent lower hazard was found per unit increase in continuous BMD T-score (HR: 0.60 (95% CI 0.52 to 0.69)).Accuracy improved marginally, and Harrell's C-Index increased by 1.2% when adding continuous BMD (0.76 to 0.77). Reclassification tables showed continuous BMD shifted 529 patients into different risk categories; 292 of these were reclassified correctly (57%; 95% CI 55% to 64%). Adding binary BMD however no improvement: Harrell's C-Index decreased by 0.6%.

CONCLUSIONS

Continuous BMD marginally improves fracture risk assessment. Importantly, this was only found when using continuous BMD measurement for osteoporosis. It is suggested that future focus should be on evaluation of this risk factor using routinely collected data and on the development of more clinically relevant methodology to assess the added value of a new risk factor.

Bone mineral density in midlife long-term users of hormonal contraception in South Africa: relationship with obesity and menopausal status

BACKGROUND

In South Africa, hormonal contraception is widely used in women over the age of 40 years. One of these methods and the most commonly used is depot-medroxyprogesterone acetate (DMPA) which has been found to have a negative effect on bone mass. Limited information is available on the effect of norethisterone enanthate (NET-EN) on bone mass, and combined oral contraceptives (COCs) have not been found to be associated with loss of bone mass. The aim of this study was to investigate bone mineral density (BMD) in pre and perimenopausal women (40-49 years) in relation to use of DMPA, NET-EN and COCs for at least 12 months preceding recruitment into the study and review associations with body mass index (BMI) and menopausal status.

METHODS

One hundred and twenty seven users of DMPA, 102 NET-EN users and 106 COC users were compared to 161 nonuser controls. Menopausal status was assessed, BMI and forearm BMD was measured at the distal radius using dual X-ray absorptiometry. Comparison analysis was conducted at baseline and 2.5 years.

RESULTS

There was no significant difference in BMD between the four contraceptive user groups (p = 0.26) with and without adjustment for age at baseline or at 2.5 years (p = 0.52). The BMD was found to be significantly associated with BMI (p = < 0.0001) with an increase of one unit of BMI translating to an increase of 0.0044 g/cm2 in radius BMD. Follicle stimulating hormone (FSH) level ≥ 25.8 mIU/mL was associated with a decrease of 0.017 g/cm2 in radius BMD relative to women with FSH < 25.8 mIU/mL. Significant interaction between FSH and BMI in their effect on BMD was observed (p = .006).

CONCLUSION

This study found no evidence that long-term use of DMPA, NET-EN and COCs affects forearm BMD in this population at baseline or after 2.5 years of follow-up. This study also reports the complex relationship and significant interaction between FSH and BMI in their effect on BMD. BMD research in older women needs to ensure that women are assessed for menopausal status and BMI.

Dienogest 2 mg Daily in the Treatment of Adolescents with Clinically Suspected Endometriosis: The VISanne Study to Assess Safety in ADOlescents

STUDY OBJECTIVE

To study the safety and efficacy of dienogest 2 mg in adolescents with suspected endometriosis.

DESIGN

A 52-week, open-label, single-arm study.

SETTING

In 21 study centers, in 6 European countries.

PARTICIPANTS

Adolescents aged 12 to younger than 18 years with clinically suspected or laparoscopically confirmed endometriosis.

INTERVENTIONS

Dienogest 2 mg once daily.

MAIN OUTCOME MEASURES

The primary end point was relative change in lumbar spine (L2-L4) bone mineral density (BMD) measured using dual-energy x-ray absorptiometry. A key secondary end point was change in endometriosis-associated pain assessed using a visual analogue scale.

RESULTS

Of 120 patients screened, 111 comprised the full-analysis set (ie, patients who took ≥1 dose of study drug and had ≥1 post-treatment observation) and 97 (87.4%) completed the study. Mean lumbar BMD at baseline was 1.1046 (SD, 0.1550) g/cm². At the end of dienogest treatment (EOT; defined as at 52 weeks or premature study discontinuation), mean relative change in BMD from baseline was -1.2% (SD, 2.3%; n = 103). Follow-up measurement 6 months after EOT in the subgroup with decreased BMD at EOT (n = 60) showed partial recovery in lumbar BMD (mean change from baseline: -2.3% at EOT, -0.6% 6 months after EOT). Mean endometriosis-associated pain score was 64.3 (SD, 19.1) mm at baseline and decreased to 9.0 (SD, 13.9) mm by week 48.

CONCLUSION

In adolescents with suspected endometriosis, dienogest 2 mg for 52 weeks was associated with a decrease in lumbar BMD, followed by partial recovery after treatment discontinuation. Endometriosis-associated pain was substantially reduced during treatment. Because bone accretion is critical during adolescence, results of the VISanne study to assess safety in ADOlescents (VISADO) study highlights the need for tailored treatment in this population, taking into account the expected efficacy on endometriosis-associated pain and an individual's risk factors for osteoporosis.

Z-score discordance and contributing factors in healthy premenopausal women with low bone mineral density: the Korean National Health and Nutrition Examination Survey 2008-9

The premenopausal period is important for bone health and prevention of future fractures, but measuring bone mineral density (BMD) at only one site may not be sufficient to determine therapeutic strategies for low BMD in premenopausal women due to the presence of Z-score discordance. In this study, we investigated Z-score discordance in addition to contributing factors of idiopathic low BMD in healthy premenopausal Korean women. We studied 3003 premenopausal women aged 18-50 years, without secondary causes for low BMD and history of fragility fracture, who had participated in the Fourth Korean National Health and Nutrition Examination Surveys (2008-2009). Low body mass index (BMI), low vitamin D level, and low body muscle mass were associated with low BMD even in premenopausal women. Risk factors differed depending on the anatomic site. Low BMI and low vitamin D level were risk factors for low femoral neck BMD (FN-BMD), but not for low lumbar spine BMD (LS-BMD). Only total muscle mass had a slight effect on low LS-BMD. Z-score discordance was much higher than expected, in 75 and 73.8 % of the low LS-BMD and low FN-BMD groups, respectively. Our findings suggest the need to consider BMD discordance in premenopausal women and also to provide information on correctable factors affecting low BMD in younger populations. Long-term follow-up is needed to evaluate the possible effect of Z-score discordance on the prognosis of osteoporosis and subsequent fracture risk.

Contribution of Lumbar Spine BMD to Fracture Risk in Individuals With T-Score Discordance

Fracture risk estimates are usually based on femoral neck (FN) BMD. It is unclear how to address T-score discordance, where lumbar spine (LS) T-score is lower than FN T-score. The objective of this work was to examine the impact of LS BMD on fracture risk, in individuals with lower LS T-score than FN T-score. Participants aged 60+ years from the Dubbo Osteoporosis Epidemiology Study with LS and FN BMD measured at first visit, and were followed from 1989 to 2014. Five-hundred and seventy-three (573) of 2270 women and 131 of 1373 men had lower LS than FN T-score by ≥ 0.6 standard deviation (SD) (low-LS group based on least significant change). In low-LS women, each 1 SD lower LS T-score than FN was associated with a 30% increase in fracture risk (hazard ratio [HR] 1.30; 95% CI, 1.11 to 1.45). For low-LS men there was a 20% nonsignificant increase in fracture risk for each 1 SD lower LS than FN T-score (HR 1.20; 95% CI, 0.10 to 1.67). Low-LS women had greater absolute fracture risks than the rest of the women. This increased risk was more apparent for lower levels of FN T-score and in older age groups. At an FN T-score of -2, low-LS women had a 3%, 10%, and 23% higher 5-year absolute fracture risk than non-low LS women in the 60 to 69 year, 70 to 79 year, and 80+ years age-groups, respectively. Furthermore, an osteoporotic LS T-score increased 5-year absolute fracture risk for women with normal or osteopenic FN T-score by 10% to 13%. Men in the low-LS group had very few fractures; therefore, a meaningful analyses of fracture risk could not be conducted. This study shows the significant contribution of lower LS BMD to fracture risk over and above FN BMD in women. A LS BMD lower than FN BMD should be incorporated into fracture risk calculators at least for women in older age-groups.

Clinical and molecular studies related to bone metabolism in patients with congenital adrenal hyperplasia

Patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency need glucocorticoid (GC) therapy, which alters bone mineral metabolism. We analyze clinical and biochemical parameters and different polymorphisms of candidate genes associated with bone mineral density (BMD) in CAH patients. The CAH patients treated with GC and healthy controls were studied. Anthropometric parameters, biochemical markers of bone turnover, and BMD were evaluated. Polymerase chain reaction technique was used to genotype different candidate genes. The 192-192 genotype frequency (IGF-I) was lower in poorly controlled patients than that from controls. In CAH patients, FF genotype (vitamin D receptor, VDR) correlated with lower lumbar spine BMD and there was a significant association between the 0-0 genotype (IGF-I) and high values of β-CrossLaps and a low total BMD. This study contributes to understanding of the association of genetic determinants of BMD with the variable response to GC treatment in CAH patients and demonstrates the usefulness of these genetic polymorphisms.

Major and minor discordance in the diagnosis of postmenopausal osteoporosis among Indian women using hip and spine dual-energy X-ray absorptiometry

Objective:

To determine discordance in the diagnosis of osteoporosis among postmenopausal Indian women using hip and spine Dual-energy X-ray Absorptiometry.

Materials and Methods:

The study included postmenopausal women who underwent bone mineral densitometry (BMD) for suspected osteoporosis at a referral hospital at Hyderabad, India. The BMD measures at the hip and spine were used to derive T-scores and to determine the prevalence of discordance. Factors potentially associated with discordance were explored in univariate and a multivariate regression model.

Results:

The mean age of the 348 postmenopausal women in the study was 53.62 ± 8.94 years (median 53.00 years, range 27.00 to 84.00 years). Major discordance was seen in 16.67% (95% confidence intervals [CI]: 12.73, 20.60) of the study population and minor discordance in 34.48% (95% CI: 29.46, 39.50%) of the study population. Age >50 years (adjusted odds ratios [OR]: 2.60, 95% CI: 1.24, 5.46, P value = 0.01), premature menopause (adjusted OR: 2.94, 95% CI: 1.27, 6.81, P value = 0.03), and multiple pregnancies (adjusted OR: 2.64, 95% CI: 1.28, 5.41, P value = 0.008) were found to be significantly associated with major discordance.

Conclusions:

The large prevalence of discordance may reflect the differences in osteoporosis in different populations and suggests the need to redefine ranges and risk factors used for the diagnosis of osteoporosis in India.

Serum uric acid plays a protective role for bone loss in peri- and postmenopausal women: a longitudinal study

OBJECTIVE

Oxidative stress has been linked to osteoporosis. Serum uric acid (UA), a strong endogenous antioxidant, has been associated with higher bone mineral density (BMD), lower bone turnover and lower prevalence of fractures in a large cross-sectional study of men. Whether this relationship is present in women and how UA relates to changes in BMD longitudinally has not been examined.

METHODS

A sample of 356 peri- and postmenopausal women, mean age 60.5 years was studied. Each individual had baseline BMD and body composition measurements by dual energy x-ray absorptiometry (DXA) and at least one repeat measure, on average 9.7 years later. Annual rate of change in BMD (A%ΔBMD) was calculated. UA was measured at each DXA visit. Calciotropic hormones and bone turnover markers were measured at the final visit only.

RESULTS

Cross-sectional data analyses revealed that women with higher UA levels had significantly higher absolute BMD measures at all skeletal sites. These women also had higher measures of body weight and its components such as lean mass (LM) and fat mass (FM). Results of multiple regression analyses showed a positive association between UA and BMD that remained significant even after accounting for possible confounders including LM and FM. Regression analyses of the longitudinal BMD data demonstrated significant associations between serum UA levels and annual rates of change in BMD at all skeletal sites. After adjustment associations remained significant for lumbar spine, forearm and whole body BMD but not for hip BMD.

CONCLUSION

Higher serum UA levels appear to be protective for bone loss in peri- and postmenopausal women and this relationship is not affected by changes in body composition measures.

Site specificity of bone architecture between the distal radius and distal tibia in children and adolescents: An HR-pQCT study

High-resolution quantitative computerized tomography permits evaluation of site specific differences in bone architecture. The purpose of this study was to compare bone architecture between distal radius and distal tibia. We present bone architecture at the distal radius and distal tibia in 151 male and 172 female participants, as follows: total bone area (mm(2)), total bone density (mg HA/cm(3)), trabecular bone density (mg HA/cm(3)), cortical bone density (mg HA/cm(3)), cortical thickness (μm), trabecular number (1/mm), trabecular thickness (μm), and trabecular separation (μm). We evaluated differences in and correlations between bone variables (absolute values) across sites. We calculated individual z scores and used regression to assess discordance between sites. In pubertal and postpubertal male and female participants, absolute values of total bone area, cortical bone density, cortical thickness, and trabecular thickness were significantly lower at the radius compared with the tibia (P < 0.01). Absolute values for trabecular bone density were significantly lower at the radius compared with the tibia in postpubertal male and female participants (P < 0.01). Absolute values for trabecular separation was significantly lower at the radius compared with the tibia in pubertal female participants (P < 0.01). Bone architecture was moderately to highly correlated between sites (r = 0.34-0.85). There was discordance between z scores at the radius and tibia within male participants (pubertal R (2) between 36 and 64%; postpubertal R (2) between 22 and 77%) and female participants (pubertal R (2) between 10 and 44%; postpubertal R (2) between 25 and 62%). In conclusion, it is vital to evaluate bone architecture at the specific skeletal site of interest.

Utility of biochemical markers of bone turnover and bone mineral density in management of osteoporosis

Biochemical markers of bone turnover (bone-turnover markers) are released during bone formation or resorption and can be measured in blood and/or urine. The concentration of bone-turnover markers in serum or urine reflect bone remodeling activity and can potentially be used as surrogate markers of the rate of bone formation or bone resorption. While the diagnosis of osteoporosis is based on bone mineral density (BMD), the absolute fracture risk for a particular BMD measurement varies several fold depending on age and is also influenced by other clinical risk factors. The measurement of bone-turnover markers may be of additional value to BMD and clinical risk factors in fracture risk assessment by improving the sensitivity and specificity of prediction of future fractures. In clinical practice, bone-turnover markers may help make cost-effective treatment decisions in patients with borderline absolute risk. BMD changes following treatment cannot be detected with confidence for 12-24 months due to measurement imprecision. Bone-turnover markers, which show an early response following treatment, may be useful for monitoring therapy, identifying non-compliance and non-responders, and predicting early response to therapy. This review concludes by identifying the need for internationally agreed-upon standards for bone resorption and formation.

Bone mineral density changes during the menopause transition in a multiethnic cohort of women

CONTEXT

Rates of bone loss across the menopause transition and factors associated with variation in menopausal bone loss are poorly understood.

OBJECTIVE

Our objective was to assess rates of bone loss at each stage of the transition and examine major factors that modify those rates.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a longitudinal cohort study of 1902 African-American, Caucasian, Chinese, or Japanese women participating in The Study of Women's Health Across the Nation. Women were pre- or early perimenopausal at baseline.

OUTCOME MEASURE

We assessed bone mineral density (BMD) of the lumbar spine and total hip across a maximum of six annual visits.

RESULTS

There was little change in BMD during the pre- or early perimenopause. BMD declined substantially in the late perimenopause, with an average loss of 0.018 and 0.010 g/cm2.yr from the spine and hip, respectively (P<0.001 for both). In the postmenopause, rates of loss from the spine and hip were 0.022 and 0.013 g/cm2.yr, respectively (P<0.001 for both). During the late peri- and postmenopause, bone loss was approximately 35-55% slower in women in the top vs. the bottom tertile of body weight. Apparent ethnic differences in rates of spine bone loss were largely explained by differences in body weight.

CONCLUSIONS

Bone loss accelerates substantially in the late perimenopause and continues at a similar pace in the first postmenopausal years. Body weight is a major determinant of the rate of menopausal BMD loss, whereas ethnicity, per se, is not. Healthcare providers should consider this information when deciding when to screen women for osteoporosis.

Discordance in diagnosis of osteoporosis using spine and hip bone densitometry

Diagnostic discordance for osteoporosis is the observation that the T-score of a patient varies between skeletal sites, falling into 2 different diagnostic categories identified by the World Health Organization classification system. Densitometrists and clinicians should expect that at least 4 of every 10 patients tested by dual-energy X-ray absorptiometry (DXA) to demonstrate T-score discordance between spine and total hip measurement sites. T-score discordance can occur for a variety of reasons related to physiologic and pathologic patient factors and the performance or analysis of DXA itself.

Growth hormone therapy improves bone mineral density in children with cerebral palsy: a preliminary pilot study

CONTEXT

Cerebral palsy is associated with osteopenia, increased fracture risk, short stature, and decreased muscle mass, whereas GH therapy is associated with increased bone mineral density (BMD) and linear growth and improvement in body composition.

OBJECTIVE

We conducted a pilot study to evaluate the effect of 18 months of GH therapy on spinal BMD, linear growth, biochemical markers, and functional measures in children with cerebral palsy.

DESIGN AND SETTING

The study was a randomized control trial, conducted from 2002-2005 at the University of California, Los Angeles, Orthopedic Hospital's Center for Cerebral Palsy.

PATIENTS

Patients included 12 males with cerebral palsy, ages 4.5-15.4 yr.

INTERVENTION

We compared 18 months of GH (50 microg daily) vs. no treatment.

PRIMARY OUTCOME MEASURES

Spinal BMD (dual-energy x-ray absorptiometry scan), height, growth factors, and bone markers were assessed.

RESULTS

Ten subjects (five in each group) completed the study. Pre- and post-average height z-scores were -1.47 +/- 0.23 and 0.8 +/- 0.2 (GH-treated group) vs. -1.35 +/- 1.26 and -1.36 +/- 1.27 (control group) (Delta SD score, 0.67 vs. -0.01; P = 0.01). Average change in spinal BMD z-score (Delta SD score corrected for height) was 1.169 +/- 0.614 vs. 0.24 +/- 0.25 in the treated and control groups, respectively (P = 0.03). Osteocalcin, IGF-I, and IGF-binding protein 3 levels increased during GH therapy. There was no change in quality of life scores as measured by the Pediatric Orthopedic Disability Inventory.

CONCLUSIONS

This small pilot study suggests that 18 months of GH therapy is associated with statistically significant improvement in spinal BMD and linear growth.

Number of osteoporotic sites and fracture risk assessment: a cohort study from the Manitoba Bone Density Program

Site-discordance in BMD assessment is common and significantly affects patient categorization. Greater number of osteoporotic sites correlates with lower T scores at each index site. This largely explains the positive association between number of osteoporotic sites and fracture risk.

INTRODUCTION

Site-discordance in BMD is common when used to classify patients based on a cut-off T score of -2.5. It is unclear whether fracture risk assessment is improved by considering BMD information from multiple sites. Our objective was to assess the contribution of number of osteoporotic sites to overall fracture risk.

MATERIALS AND METHODS

The study population was drawn from the regionally based clinical database of the Manitoba Bone Density Program that includes all clinical DXA test results for the Province of Manitoba, Canada. Analyses were limited to 16,505 women>or=50 years of age at the time of baseline DXA of the spine (L1-L4) and hip (three sites). During follow-up (3.2+/-1.5 years), longitudinal health service records showed 765 women with at least one osteoporotic fracture code (hip, forearm, spine, or humerus).

RESULTS

Of 5012 women classified as osteoporotic by at least one site (T score -2.5 or lower), almost one half (2370; 47%) were abnormal at only a single site. Among the 1856 women with an osteoporotic total hip measurement, mean total hip T scores decreased as the number of additional osteoporotic sites increased (-2.58, no other osteoporotic sites; -2.69, one other site; -2.87, two other sites; -3.17, three other sites; Spearman r=-0.44, p<0.0001). Age-adjusted fracture risk from a Cox proportional hazards model increased as the number of osteoporotic sites increased (p<0.0001), but number of osteoporotic sites was no longer an independent predictor after total hip BMD was included as a covariate (p=0.19). Covariate adjustment for other sites of BMD measurement attenuated, but did not eliminate, the effect of number of osteoporotic sites.

CONCLUSIONS

Site-discordance is common and significantly affects patient categorization when different skeletal sites are used for diagnosis. Greater number of osteoporotic sites correlates with lower T scores at each index site. This largely explains the positive association between number of osteoporotic sites and fracture risk.

Which screening strategy using BMD measurements would be most cost effective for hip fracture prevention in elderly women? A decision analysis based on a Markov model

INTRODUCTION

Hip fractures are responsible for excessive mortality, decreasing the 5-year survival rate by about 20%. From an economic perspective, they represent a major source of expense, with direct costs in hospitalization, rehabilitation, and institutionalization. The incidence rate sharply increases after the age of 70, but it can be reduced in women aged 70-80 years by therapeutic interventions. Recent analyses suggest that the most efficient strategy is to implement such interventions in women at the age of 70 years. As several guidelines recommend bone mineral density (BMD) screening of postmenopausal women with clinical risk factors, our objective was to assess the cost-effectiveness of two screening strategies applied to elderly women aged 70 years and older.

METHODS

A cost-effectiveness analysis was performed using decision-tree analysis and a Markov model. Two alternative strategies, one measuring BMD of all women, and one measuring BMD only of those having at least one risk factor, were compared with the reference strategy "no screening". Cost-effectiveness ratios were measured as cost per year gained without hip fracture. Most probabilities were based on data observed in EPIDOS, SEMOF and OFELY cohorts.

RESULTS

In this model, which is mostly based on observed data, the strategy "screen all" was more cost effective than "screen women at risk." For one woman screened at the age of 70 and followed for 10 years, the incremental (additional) cost-effectiveness ratio of these two strategies compared with the reference was 4,235 euros and 8,290 euros, respectively.

CONCLUSION

The results of this model, under the assumptions described in the paper, suggest that in women aged 70-80 years, screening all women with dual-energy X-ray absorptiometry (DXA) would be more effective than no screening or screening only women with at least one risk factor. Cost-effectiveness studies based on decision-analysis trees maybe useful tools for helping decision makers, and further models based on different assumptions should be performed to improve the level of evidence on cost-effectiveness ratios of the usual screening strategies for osteoporosis.

Correlation of transmenopausal bone mass in healthy white women: a long-term longitudinal study

INTRODUCTION

It is well established that menopause is associated with accelerated bone loss. However, no study has tested whether bone mass after the menopause transition is correlated with the premenopausal bone mass; that is, whether a high premenopausal bone mass will be predicatively high after menopause in an individual.

MATERIALS AND METHODS

We examined the association of transmenopausal bone mass in 54 healthy premenopausal white women age 46 years or older at the initiation. These subjects experienced normal menopause and stayed in the study at least 1 year after their last menses without hormone replacement therapy. Bone mass of the lumbar spine (L2-L4) and total body were measured semiannually for 9.5 years.

RESULTS AND DISCUSSION

In the 6-year period for which the data were analyzed, we found statistically significant correlations (p<0.05) over the 5.5-year and 5-year periods around menopause for pairwise transmenopausal lumbar spine Z-score and total body bone mineral content, respectively. The correlation declined with increase of the time interval across menopause. We conclude that for a limited time interval, bone mass after menopause is correlated with that before menopause.

Preferred skeletal site for osteoporosis screening in high-risk populations

OBJECTIVES

The current World Health Organization (WHO) definition of osteoporosis, which is based on densitometry of lumbar and femoral regions, is extensively used for decision-making in clinical practice. Discordance in diagnosis of osteoporosis using this definition is a known phenomenon. The aim of this study was to evaluate the impact of such discordance and to assess the diagnostic value of using one skeletal site for screening purposes as opposed to the two sites required in the WHO criteria.

STUDY DESIGN

Data was collected from 4188 individuals (3848 female); mean age=53.4 years (standard deviation 11.8) referred to a community-based outpatient osteoporosis testing centre in Tehran, Iran.

METHODS

Dual-energy X-ray absorptiometry (DXA) was performed on L1-L4 lumbar spine and total hip for all cases. The DXA results were categorized according to WHO criteria. Sensitivity for each site was calculated as number of cases with T-score < -2.5 at that site divided by the total number of cases with T-score < -2.5 at any site.

RESULTS

Prevalence of osteoporosis diagnosis using lumbar DXA, femoral DXA, and WHO criteria (either of the sites) were 24.7%, 12.4%, and 27.8%, respectively. Sensitivity of lumbar DXA for diagnosis of osteoporosis (88.9%) was significantly higher than femoral DXA (44.6%, P<0.001); but this difference became non-significant for men > or = 60 and women > or = 70 (P=0.615 and P=0.077, respectively). Agreement of the procedures in different sites (kappa) was 0.40 (0.37 to 0.43). When proximal femur was considered as the reference, positive likelihood ratios of lumbar DXA to detect cases were 4.7 and 2.0 in younger and older groups, respectively.

CONCLUSIONS

Concerning the high rate of discordance and low agreement between DXA results, the data obtained from each anatomical site cannot predict the condition of the other site. However, if use of a single assessment is intended for screening programs, public health authorities can develop different strategies for different age groups of their population. We propose lumbar DXA for the younger group (men < 60 and women < 70) and femoral densitometry for the older.

The effect of measurement of the contralateral hip if the spine is not included in the bone mineral density analysis

The aim of this study was to determine if measurement of the contralateral femora has an effect on osteoporosis diagnosis and treatment classification if the spine is not included in the bone mineral density (BMD) scan. The method used was the T-score discordance from the dual femur BMD scans of 537 women (mean age: 61.2 yr; standard deviation: 10.5; age range: 32-90 yr) who were evaluated to determine if inclusion of the contralateral hip in the BMD study made a difference in clinical diagnosis and treatment classification when the spine was not included in the BMD scan. Clinical diagnosis and treatment classification was based on the lowest T-score at each hip of three femur sites: the neck, the trochanter, and the total femur. The results of the diagnosis classification (i.e., normal, osteopenia, and osteoporosis) differed in the right versus the left femora in 28% of subjects at one or more sites, and in 14%, 15%, and 10% of subjects at the neck, trochanter, and total femur, respectively. Diagnosis discordance increased in subjects who were aged 65 yr and older. Treatment classification (T>or=-1.5; T<-1.5; T<-2.0) differed in the right versus the left femora in 33% of subjects at one or more sites, and in 18%, 14%, and 12% of subjects at the neck, trochanter, and total femur, respectively. Treatment discordance increased in subjects age 65 yr and older. Using the lowest T-score for clinical diagnosis classification, when the contralateral hip was considered, a clinical difference in diagnosis from normal-->osteopenia occurred in 3.9% of subjects, and from osteopenia-->osteoporosis in 1.3% of subjects. A clinical difference in treatment category from T>or=-1.5-->T<-1.5 occurred in 2.7% of subjects, and from T>or=-2-->T<-2 in 2.7% of subjects. In conclusion, inclusion of the bilateral hip in the BMD study made a clinical difference in diagnosis classification in 5.2% of subjects and in treatment classification in 5.4% of subjects. T-score differences between the contralateral hips increased with age. In the subgroup of subjects age 65 yr and older, a clinical difference in classification to a more severe diagnosis or treatment category occurred in 5.35% and 7.25% of subjects, respectively.

Ten-year prediction of osteoporosis from baseline bone mineral density: development of prognostic thresholds in healthy postmenopausal women. The Danish Osteoporosis Prevention Study

Osteopenia is common in healthy women examined in the first year or two following menopause. Short-term fracture risk is low, but we lack algorithms to assess long-term risk of osteoporosis. Because bone loss proceeds at only a few percent per year, we speculated that baseline bone mineral density (BMD) would predict a large proportion of 10-year BMD and be useful for deriving predictive thresholds. We aimed to identify prognostic thresholds associated with less than 10% risk of osteoporosis by 10 years in the individual participant, in order to allow rational osteodensitometry and intervention. We analyzed dual energy X-ray absorptometry (DXA) of the lumbar spine (LS) and femoral neck (FN) from 872 women, who participated in the non-HRT arms of the Danish Osteoporosis Prevention Study and had remained on no HRT, bisphosphonates or raloxifene since inclusion 10 years ago. We defined development of a T -score below -2.5 at the LS and/or FN or incident fracture as end-point, and we derived prognostic thresholds for baseline BMD, defining 90% NPV (negative predictive value) and 90% sensitivity, respectively. Seventy-six percent of the variation in BMD of the LS at 10 years was predicted by baseline BMD. In an individual participant, a baseline BMD T -score above -1.4 (FN or LS, whichever was lower) was associated with a 10-year risk of less than 10% of developing osteoporotic BMD or fracture. This covered 69% of the population. By contrast, participants with T -scores below -1.4 had a 56% risk of fracture or low BMD within 10 years. At the population level, baseline T -score cutoffs below 0 at the LS (68% of the population), 0 at the FN (72%) or -0.6 (62%) at the lower of the two sites capture 90% of the population that developed osteoporosis during the following 10 years. A BMD measurement, performed in the first two years following menopause, is a strong long-term predictor of BMD in healthy women. The association is strong enough to provide robust prognostic thresholds, which can be used to divide the population into two prognostic classes at menopause.

Discordance in diagnosis of osteoporosis using spine and hip bone densitometry

BACKGROUND: Diagnostic discordance for osteoporosis is the observation that the T-score of an individual patient varies from one key measurement site to another, falling into two different diagnostic categories identified by the World Health Organization (WHO) classification system. This study was conducted to evaluate the presence and risk factors for this phenomenon in a large sample of Iranian population. METHODS: Demographic data, anthropometric measurements, and risk factors for osteoporosis were derived from a database on 4229 patients referred to a community-based outpatient osteoporosis testing center from 2000 to 2003. Dual-energy X-ray absorptiometry (DXA) was performed on L1-L4 lumbar spine and total hip for all cases. Minor discordance was defined as present when the difference between two sites was no more than one WHO diagnostic class. Major discordance was present when one site is osteoporotic and the other is normal. Subjects with incomplete data were excluded. RESULTS: In 4188 participants (3848 female, mean age 53.4 +/- 11.8 years), major discordance, minor discordance, and concordance of T-scores were seen in 2.7%, 38.9% and 58.3%, respectively. In multivariate logistic regression analysis, older age, menopause, obesity, and belated menopause were recognized as risk factors and hormone replacement therapy as a protective factor against T-score discordance. CONCLUSION: The high prevalence of T-score discordance may lead to problems in interpretation of the densitometry results for some patients. This phenomenon should be regarded as a real and prevalent finding and physicians should develop a particular strategy approaching to these patients.

Density of organic matrix of native mineralized bone measured by water- and fat-suppressed proton projection MRI

Water- and fat-suppressed projection MR imaging (WASPI) utilizes the large difference between the proton T(2) (*)s of the solid organic matrix and the fluid constituents of bone to suppress the fluid signals while preserving solid matrix signals. The solid constituents include collagen and some molecularly immobile water and exhibit very short T(2) (*). The fluid constituents include mobile water and fat, with long T(2) (*). In WASPI, chemical shift selective low-power pi/2 pulses excite mobile water and fat magnetization which is subsequently dephased by gradient pulses, while the magnetization of collagen and immobile water remains mostly in the z-direction. Additional selective pi pulses in alternate scans further cancel the residual water and fat magnetization. Following water and fat suppression, the matrix signal is excited by a short hard pulse and the free induction decay acquired in the presence of a gradient in a 3D projection method. WASPI was implemented on a 4.7 T MR imaging system and tested on phantoms and bone specimens, enabling excellent visualization of bone matrix. The bone matrix signal per unit volume of bovine trabecular specimens was measured by this MR technique and compared with that determined by chemical analysis. This method could be used in combination with bone mineral density measurement by solid state (31)P projection MRI to determine the degree of bone mineralization.

A 2-year prospective study on the effects of depot medroxyprogesterone acetate on bone mass-response to estrogen and calcium therapy in individual users

The primary aim of this prospective 2-year follow-up study was to investigate the effect of depot medroxyprogesterone acetate (DMPA) on the maintenance of bone mass in women aged 30-45 years. The effects of estrogen or calcium substitution during the second year of follow-up was investigated in seven DMPA users with a high annual bone loss during the first year. The bone mass of 35 users of DMPA and 10 women without hormonal contraception was investigated using peripheral quantitative computed tomography. The baseline cortical and trabecular bone mass (TBM) and the annual change was not different in DMPA users and controls. Over 24 months we measured an increase in TBM of 0.6% and a decrease in cortical bone mass of 0.1% in exposed women. Some but not all of the DMPA users with a bone loss during the first year could be successfully treated with estradiol or calcium. In conclusion, we did not observe an accelerated bone loss in DMPA users aged 30-45 years.

Standardization of BMD T-Scores in the first five years after the menopause: do femoral neck-equivalent and older normative range T-Scores improve diagnostic agreement?

Calculating T-scores using an older reference population reduces inconsistency between measurement sites when osteoporosis is diagnosed in the elderly. The present analysis in a younger, early postmenopausal cohort examined 5-yr consistency of normalization by local and femoral neck-equivalent T-scores. NHANES (femur) and Hologic (spine and forearm) references were applied to baseline, 1-, 2-, 3-, and 5-yr scans in 925 untreated women in a national cohort study, and alternative local and neck-equivalent scores calculated. The baseline prevalence of osteopenia/osteoporosis was 35.5%/4.1% (spine), 31.0%/1.2% (neck), 31.3%/1.2% (total hip), and 37.2%/2.5% (forearm). It increased to 54.6%/7% by combining sites. The prevalences at 5-yr were 57.2%/12.4% (spine), 51.9%/5.0% (neck), 46.6%/3.7% (total hip), 52.5%/7.4% (forearm), and 77.3%/17.8% (any). A T-score cut-off at the lowest of four sites of -1.65 for osteopenia and -3.37 for osteoporosis was equivalent in patient numbers to T<-1 and T<-2.5 at the femoral neck. The proportion of inconsistently classified subjects decreased from 48% to 42% (p<0.05) with neck-equivalent scores. No improvement remained after 5 yr. Kappa scores did not improve by the use of local or femoral neck scores. In conclusion, adjusted thresholds cannot remove the anatomic discrepancy between T-scores. To overcome this problem, risk-based diagnostic cut-offs must therefore be calculated separately for each measurement site and fracture localization.

When should densitometry be repeated in healthy peri- and postmenopausal women: the Danish osteoporosis prevention study

Intervention should be considered in postmenopausal women with bone mineral density (BMD) > or = 1 SD below the reference (T or Z score < -1). However, it is unclear when densitometry should be repeated. This study aimed at determining the need for repeat DXA within 5 years in untreated peri-/postmenopausal women to detect declines of T or Z score to below -1 with 85% confidence. A cohort of 925 healthy women (aged 51.2 +/- 2.9 years) were followed within the Danish Osteoporosis Prevention Study (DOPS) for 5 years without hormone-replacement therapy (HRT). DXA of spine, hip, and forearm was done at 0,1, 2, 3, and 5 years (Hologic QDR-1000/2000). The annual loss in SD units was 0.12 +/- 0.10 at the spine (1.3%), 0.10 +/- 0.09 at the femoral neck (1.2%), and 0.07 +/- 0.09 at the ultradistal (UD) forearm (1.0%). Accordingly, T scores below -1 developed earlier at the spine. The need for a future DXA scan to predict declines of T and Z scores below -1 depended strongly on baseline BMD. In subjects with a positive T score, the risk of developing T < -1 remained at <15% for 5 years at all measured sites. A new scan was needed after 1 year if the T score was below -0.5, and after 3 years if the T score was between 0 and -0.5. Slightly longer intervals apply if Z scores are used. Follow-up densitometry in untreated women should be individually targeted from baseline BMD rather than scheduled at fixed time intervals. An algorithm for planning repeat densitometry in perimenopausal women is provided.