Trabecular Bone Score in Obese and Nonobese Subjects With Primary Hyperparathyroidism Before and After Parathyroidectomy

Contradictory links between lipid levels and bone health: atherogenic index of plasma and bone microarchitecture

PURPOSE

Lipids increase osteoporosis and fracture risk, yet research on Atherogenic Index of Plasma (AIP), bone mineral density declines (BMD), and trabecular bone score (TBS) is limited. This study examined the relationships between AIP, TBS, and BMD in American adults using the National Health and Nutrition Examination Survey (NHANES) data, including the effect of obesity.

METHODS

Based on data from 3,162 Americans, multivariable logistic regression and a generalized additive model (GAM) were used to analyze AIP, BMD, and TBS. Mediation studies assessed the impact of obesity (BMI) on these relationships. A threshold effect study identified turning points.

RESULTS

The average participant age was 47.5 ± 17 years. AIP showed no correlation with BMD after BMI adjustment but was significantly associated with lumbar spine and femoral neck BMD without BMI adjustment. AIP negatively correlated with TBS even after adjusting for covariates. The relationship between AIP and TBS was L-shaped, with a turning point at -0.17. BMI mediated the AIP-BMD relationship by 122.01-131.49% (P < 0.05).

CONCLUSIONS

This study found AIP levels associated with decreased TBS and increased BMD, influenced by obesity. AIP may be a valuable tool in evaluating bone metabolism, indicating high BMD but poor TBS, warranting further exploration.

Parathyroidectomy Improves Bone Density in Women With Primary Hyperparathyroidism and Preoperative Osteopenia

CONTEXT

Osteoporosis and/or bone fractures are indications of parathyroidectomy in primary hyperparathyroidism (PHPT), especially in women. However, the benefit of surgery in patients with osteopenia remains unclear.

OBJECTIVE

To evaluate bone mineral density (BMD) and bone remodeling biomarkers changes 1 year after parathyroidectomy in women with PHPT.

DESIGN

In the prospective, monocentric, observational prospective cohort with primary hyperparathyroidism patients (CoHPT) cohort, women operated for sporadic PHPT since 2016 with ≥1 year follow-up were included. BMD (dual-X ray absorptiometry) and bone remodeling biomarkers [cross-linked C-telopeptide (CTX), procollagen type 1 N-terminal propeptide (P1NP), and bone-specific alkaline phosphatases] were assessed before and 1 year after parathyroidectomy.

SETTING

Referral center.

PATIENTS

A total of 177 women with PHPT (62.5 ± 13.3 years, 83.1% menopausal, 43.9% osteopenic, and 45.1% osteoporotic) were included.

INTERVENTION

Parathyroidectomy.

MAIN OUTCOME MEASURE

BMD change between before and 1 year after parathyroidectomy.

RESULTS

Parathyroidectomy resulted in significant increase in BMD and decrease in serum bone remodeling biomarker concentrations. In the 72 patients with baseline osteopenia, mean BMD significantly increased at the lumbar spine [+0.05 g/cm2 (95% confidence interval [CI], 0.03-0.07)], the femoral neck [+0.02 g/cm2 (95% CI 0.00-0.04)], the total hip [+0.02 g/cm2 (95% CI 0.01-0.02)], and the forearm [+0.01 (95% CI 0.00-0.02)], comparable to osteoporotic patients. Among osteopenic patients, those with individual BMD gain (>0.03 g/cm2) at ≥1 site had higher preoperative serum CTX, P1NP, and urine calcium concentrations than those without improvement.

CONCLUSION

Parathyroidectomy significantly improved BMD and remodeling biomarkers in women with osteopenia, thereby supporting the benefit of parathyroidectomy in these patients. Preoperative serum CTX and P1NP concentrations could be useful to predict expected BMD gain.

Primary Hyperparathyroidism: Assessment of the Effects of Parathyroidectomy Using Dual X-Ray Absorptiometry, Trabecular Bone Score, and Dual X-Ray Absorptiometry-Based Three-Dimensional Modeling

OBJECTIVE

This study aimed to evaluate the bone microstructure to determine whether curative surgery of primary hyperparathyroidism produces changes in bone mineral density (BMD), trabecular bone score (TBS), and three-dimensional (3D) dual x-ray absorptiometry (DXA) parameters and whether these changes are comparable.

METHODS

We retrospectively studied 85 patients (60 women and 25 men, 60.4 ± 12.5 years) diagnosed with primary hyperparathyroidism and undergoing parathyroidectomy. Mean percent changes in BMD (lumbar spine [LS], femoral neck [FN], total hip [TH], and 1/3 radius), TBS and 3D-DXA parameters (trabecular volumetric BMD (vBMD), cortical vBMD, integral vBMD, cortical surface density (sBMD), and cortical thickness at TH) after surgery (12, 24, and/or 36 months) were calculated and compared, and we sought the determinants of these changes.

RESULTS

After parathyroidectomy, BMD presented statistically significant mean increases in LS, FN, and TH during the first 3 years after surgery (P < .001), accompanied by an improvement in all 3D-DXA parameters, but there were no significant changes in 1/3 radius BMD or TBS. Cortical sBMD, trabecular vBMD, and integral vBMD reached mean increases of similar magnitude to those of FN and TH BMD. Age and preoperative serum levels of parathyroid hormone and carboxy-terminal telopeptide of type 1 collagen were significantly associated with percent changes after surgery.

CONCLUSION

We found a benefit of parathyroidectomy for bone, with significant percent increases in LS, FN, and TH BMD up to the third year after surgery, and a qualitative benefit for the hip in both its trabecular and cortical compartments and bone strength.

Evaluation of Trabecular Bone Microarchitecture and Bone Mineral Density in Young Women, Including Selected Hormonal Parameters

The absence of non-invasive methods for assessing bone material and structural changes is a significant diagnostic challenge. Dual-energy X-ray absorptiometry (DXA) bone mineral density (BMD) testing is the gold standard for osteoporosis diagnosis. BMD and the trabecular bone score (TBS) have facilitated targeted osteoporosis prevention and treatment in clinical settings. The findings from this study indicate that BMD modulation in young women is influenced by various hormones, potentially compromising the diagnostic precision of BMD for subclinical bone demineralization. A total of 205 women aged 19 to 37 underwent anthropometric measurements and hormonal tests. BMD was determined using DXA, and TBS values were computed from the lumbar spine L1-L4 segment. The multivariate analysis findings suggest that BMD might not be determined by hormones. The relationship between TBS and TSH was statistically significant in the univariate analysis, which indicates the efficacy of further studies to determine the link between TBS and specific hormones. Analyzing the strength of the correlation between TBS and hormones in the univariate analysis shows which factors are worth considering in further analyses. This makes it possible to create better techniques that will help identify young women who are at a higher risk of developing osteoporosis.

Reference Value of Dual X-Ray Absorptiometry-Derived Lumbar Spine Trabecular Bone Score in the Thai Population

INTRODUCTION

Little is known about the normative values of trabecular bone score (TBS) in Thailand. We aimed to provide reference values of dual-energy x-ray absorptiometry (DXA)-derived lumbar spine TBS in Thai community-dwelling adults of varying ages.

METHODOLOGY

Bone density studies of participants aged 20-90 years who underwent bone mineral density (BMD) testing at Srinagarind Hospital, Kohn Kaen, Thailand were reviewed. DXA studies were performed using a narrow fan-beam bone densitometer. Lumbar spine TBS for each of the L1-L4 vertebra was obtained using the iNsight software. Mean TBS (L1-L4 TBS) was calculated. This study was approved by the institutional research ethics committee (HE581241).

RESULTS

A total of 1372 participants were included. The mean ± SD age was 57.25 ± 17.35 years and 799 (58.2%) were female. There were 476 (34.7%) and 243 (17.7%) participants with osteopenia (T-score -1.0 to -2.5) and osteoporosis (T-score ≤-2.5) of the lumbar spine. Age and sex stratified analysis of L1-L4 TBS revealed peak TBS among females aged 30-49 years (mean ± SD: 1.42 ± 0.08) and males aged 30-59 years (mean ± SD: 1.42 ± 0.09). The rate of L1-L4 TBS reduction from ages 30 to 90 year is 13.4% (0.27%/year) for females and 5.6% (0.11%/year) for males.

CONCLUSION

This is the first study reporting a normative database for DXA derived TBS in Thai community-dwelling population. We found that TBS decreased with age at the rate of approximately 0.27%/year for females and 0.11%/year for males.

Classical and Nonclassical Manifestations of Primary Hyperparathyroidism

This narrative review summarizes data on classical and nonclassical manifestations of primary hyperparathyroidism (PHPT). It is based on a rigorous literature search, inclusive of a Medline search for systematic reviews from 1940 to December 2020, coupled with a targeted search for original publications, covering four databases, from January 2013-December 2020, and relevant articles from authors' libraries. We present the most recent information, identify knowledge gaps, and suggest a research agenda. The shift in the presentation of PHPT from a predominantly symptomatic to an asymptomatic disease, with its varied manifestations, has presented several challenges. Subclinical nephrolithiasis and vertebral fractures are common in patients with asymptomatic disease. The natural history of asymptomatic PHPT with no end organ damage at diagnosis is unclear. Some observational and cross-sectional studies continue to show associations between PHPT and cardiovascular and neuropsychological abnormalities, among the different disease phenotypes. Their causal relationship is uncertain. Limited new data are available on the natural history of skeletal, renal, cardiovascular, neuropsychological, and neuromuscular manifestations and quality of life. Normocalcemic PHPT (NPHPT) is often diagnosed without the fulfillment of rigorous criteria. Randomized clinical trials have not demonstrated a consistent long-term benefit of parathyroidectomy (PTX) versus observation on nonclassical manifestations. We propose further refining the definition of asymptomatic disease, into two phenotypes: one without and one with evidence of target organ involvement, upon the standard evaluation detailed in our recommendations. Each of these phenotypes can present with or without non-classical manifestations. We propose multiple albumin-adjusted serum calcium determinations (albumin-adjusted and ionized) and exclusion of all secondary causes of high parathyroid hormone (PTH) when establishing the diagnosis of NPHPT. Refining the definition of asymptomatic disease into the phenotypes proposed will afford insights into their natural history and response to interventions. This would also pave the way for the development of evidence-based guidance and recommendations. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Preoperative Thoracic Muscle Mass Predicts Bone Density Change After Parathyroidectomy in Primary Hyperparathyroidism

CONTEXT

Predicting bone mineral density (BMD) gain after parathyroidectomy may influence individualized therapeutic approaches for treating patients with primary hyperparathyroidism (PHPT).

OBJECTIVE

This study aimed to assess whether skeletal muscle mass data could predict BMD change after parathyroidectomy in patients with PHPT.

METHODS

This retrospective study collected data from 2012 to 2021 at Severance Hospital, Seoul, Korea. A total of 130 patients (mean age, 64.7 years; 81.5% women) with PHPT who underwent parathyroidectomy were analyzed. Thoracic muscle volume (T6-T7 level) was estimated using noncontrast parathyroid single photon emission computed tomography/computed tomography (SPECT/CT) scans and an automated deep-learning-based software. The primary outcome assessed was the change in femoral neck BMD (FNBMD, %) 1 year after parathyroidectomy.

RESULTS

The median degree of FNBMD change after parathyroidectomy was + 2.7% (interquartile range: -0.9 to + 7.6%). Elevated preoperative PTH level was associated with lower thoracic muscle mass (adjusted β: -8.51 cm3 per one log-unit PTH increment, P = .045) after adjusting for age, sex, body mass index (BMI), and baseline FNBMD. One SD decrement in thoracic muscle mass was associated with lesser FNBMD (adjusted β: -2.35%, P = .034) gain and lumbar spine BMD gain (adjusted β: -2.51%, P = .044) post surgery after adjusting for covariates.

CONCLUSION

Lower thoracic skeletal muscle mass was associated with elevated preoperative PTH levels in patients with PHPT. Lower skeletal muscle mass was associated with lesser BMD gain after parathyroidectomy, independent of age, sex, BMI, preoperative BMD, and PTH level.

Bone Mineral Density Compared to Trabecular Bone Score in Primary Hyperparathyroidism

Individuals with primary hyperparathyroidism (PHPT) have reduced bone mineral density (BMD) according to dual X-ray absorptiometry at cortical sites, with relative sparing of trabecular BMD. However, fracture risk is increased at all sites. Trabecular bone score (TBS) may more accurately describe their bone quality and fracture risk. This study compared how BMD and TBS describe bone quality in PHPT. We conducted a retrospective cross-sectional study with a longitudinal component, of adults with PHPT, admitted to a tertiary hospital in Australia over ten years. The primary outcome was the TBS at the lumbar spine, compared to BMD, to describe bone quality and predict fractures. Secondary outcomes compared changes in TBS after parathyroidectomy. Of 68 included individuals, the mean age was 65.3 years, and 79% were female. Mean ± SD T-scores were −1.51 ± 1.63 at lumbar spine and mean TBS was 1.19 ± 0.12. Only 20.6% of individuals had lumbar spine BMD indicative of osteoporosis, while 57.4% of TBS were ≤1.20, indicating degraded architecture. There was a trend towards improved fracture prediction using TBS compared to BMD which did not reach statistical significance. Comparison of 15 individuals following parathyroidectomy showed no improvement in TBS.

Skeletal abnormalities in Hypoparathyroidism and in Primary Hyperparathyroidism

Both hypoparathyroidism (HypoPT), as well as its pathological counterpart, primary hyperparathyroidism (PHPT), can lead to skeletal abnormalities. Chronic deficiency of PTH in patients with HypoPT is associated with a profound reduction in bone remodeling, with consequent increases in bone density, and abnormalities in microarchitecture and bone strength. It is still not clear whether there is an increase in fracture risk in HypoPT. While standard therapy with calcium supplements and active vitamin D does not restore bone homeostasis, treatment of HypoPT with PTH appears to correct some of those abnormalities. In PHPT, the continuous exposure to high levels of PTH causes an increase in bone remodeling, in which bone resorption prevails. In the symptomatic form of PHPT, patients can present with fragility fractures, and/or the classical radiological features of osteitis fibrosa cystica. However, even in mild PHPT, catabolic skeletal actions of PTH are evident through reduced BMD, deterioration of bone microarchitecture and increased risk of fragility fractures. Successful parathyroidectomy improves skeletal abnormalities. Medical treatment, such as bisphosphonates and denosumab, can also increase bone density in patients with PHPT who do not undergo surgery. This article reviews skeletal involvement in HypoPT and in PHPT, as assessed by bone remodeling, DXA, trabecular bone score, and quantitative computed tomography, as well as data on bone strength and fracture risk. The effects of PTH replacement on the skeleton in subjects with HypoPT, and the outcome of parathyroidectomy in patients with PHPT, are also reviewed here.

Trabecular Bone Score (TBS) in Primary Hyperparathyroidism (PHPT): A Useful Tool?

Primary Hyperparathyroidism (PHPT) often leads to bone loss, even in its asymptomatic presentations. Trabecular Bone Score (TBS) is a method to assess the trabecular bone structure of the spine. This study aimed to evaluate TBS measurements combined with Dual X-ray Absorptiometry (DXA) values in the search for more accurate bone fragility risk assessment among PHPT patients. From 2017 to 2019, patients diagnosed with PHPT (n = 64), before surgery, were invited to participate in this study. Bone mineral density (BMD) by DXA at the lumbar spine, total hip, femoral neck, distal third radius, and TBS were determined in patients and controls (n = 63). The vertebral fracture was defined using the Genant method in vertebral images by DXA and vertebral fracture assessment (VFA). Patients and controls did not differ in age, sex, menopausal status, or body mass index (BMI). The PHPT patients presented significantly lower BMD values than the controls in all sites evaluated. The TBS measurements were also statistically lower in PHPT patients than controls (mean TBS PHPT = 1.233 vs TBS controls = 1.280, p = 0.044). Osteoporosis was observed in 50% of PHPT patients and 26.6% of controls (p = 0.02). However, lumbar spine T-Score < -2.5 was observed only in 21.8% of PHPT patients. Vertebral fractures were detected in nine individuals (14%) from the PHPT group and four (6.3%) in the controls (p = 0.24). The TBS area under the curve (AUC) was higher than DXA AUC in all sites, for vertebral fracture assessment. The TBS AUC was significant in the PHPT group (0.75, 95% CI 0.62 - 0.88, p = 0.02) and not significant in the DXA analysis. The ROC curve showed that TBS values < 1.187 are associated with a significantly higher risk of vertebral fracture among PHPT patients (p = 0.02). The TBS used as a complement to DXA measurements is a useful tool which may better assess fragility risk among PHPT patients.

Circulating miR-122-5p and miR-375 as Potential Biomarkers for Bone Mass Recovery after Parathyroidectomy in Patients with Primary Hyperparathyroidism: A Proof-of-Concept Study

Primary hyperparathyroidism (PHPT) is the leading cause of secondary osteoporosis. Although bone mineral density (BMD) tends to recover after parathyroidectomy in PHPT patients, the degree of recovery varies. Circulating microRNAs (miRNAs) profiles are known to be correlated with osteoporosis and fracture. We aimed to investigate whether osteoporotic fracture-related miRNAs are associated with postoperative BMD recovery in PHPT. Here, 16 previously identified osteoporotic fracture-related miRNAs were selected. We analyzed the association between the preoperative level of each miRNA and total hip (TH) BMD change. All 12 patients (among the 18 patients enrolled) were cured of PHPT after parathyroidectomy as parathyroid hormone (PTH) and calcium levels were restored to the normal range. Preoperative miR-19b-3p, miR-122-5p, and miR-375 showed a negative association with the percent changes in TH BMD from baseline. The association remained robust for miR-122-5p and miR-375 even after adjusting for sex, age, PTH, and procollagen type 1 N-terminal propeptide levels in a multivariable model. In conclusion, preoperative circulating miR-122-5p and miR-375 levels were negatively associated with TH BMD changes after parathyroidectomy in PHPT patients. miRNAs have the potential to serve as predictive biomarkers of treatment response in PHPT patients, which merits further investigation.

DXA-Based Bone Strain Index: A New Tool to Evaluate Bone Quality in Primary Hyperparathyroidism

CONTEXT

Primary hyperparathyroidism (PHPT) is associated with impaired bone quality and increased fracture risk. Reliable tools for the evaluation of bone quality parameters are not yet clinically available. Bone Strain Index (BSI) is a new metric for bone strength based on Finite Element Analysis from lumbar spine and femoral neck dual-energy x-ray absorptiometry (DXA) images.

OBJECTIVE

To assess the lumbar spine (LS), femoral neck (FN), and total hip (TH) BSI in PHPT patients compared with controls and to investigate the association of BSI with vertebral fractures (VFs) in PHPT.

METHODS

This case-control study enrolled 50 PHPT patients and 100 age- and sex-matched control subjects from an outpatient clinic. The main outcome measures were LS-BSI, FN-BSI, and TH-BSI.

RESULTS

FN bone mineral density (BMD) and one-third distal radius BMD were lower in the PHPT group than in controls (FN 0.633 ± 0.112 vs 0.666 ± 0.081, P = 0.042; radius 0.566 ± 0.07 vs 0.625 ± 0.06, P < 0.001). PHPT group has significant lower TBS score compared with controls (1.24 ± 0.09 vs 1.30 ± 0.10, P < 0.001). BSI was significantly higher at LS (2.28 ± 0.59 vs 2.02 ± 0.43, P = 0.009), FN (1.72 ± 0.41 vs 1.49 ± 0.35, P = 0.001), and TH (1.51 ± 0.33 vs 1.36 ± 0.25, P = 0.002) in PHPT. LS-BSI showed moderate accuracy for discriminating VFs (AUC 0.667; 95% CI, 0.513-0.820). LS-BSI ≥ 2.2 and was a statistically significant independent predictor of VFs, with an adjusted odds ratio ranging from 5.7 to 15.1.

CONCLUSION

BSI, a DXA-derived bone quality index, is impaired in PHPT and may help to identify PHPT subjects at high risk of fractures.

Association between obesity and risk of fracture, bone mineral density and bone quality in adults: A systematic review and meta-analysis

BACKGROUND

The association between obesity and fracture risk may be skeletal site- and sex-specific but results among studies are inconsistent. Whilst several studies reported higher bone mineral density (BMD) in patients with obesity, altered bone quality could be a major determinant of bone fragility in this population.

OBJECTIVES

This systematic review and meta-analysis aimed to compare, in men, premenopausal women and postmenopausal women with obesity vs. individuals without obesity: 1) the incidence of fractures overall and by site; 2) BMD; and 3) bone quality parameters (circulating bone turnover markers and bone microarchitecture and strength by advanced imaging techniques).

DATA SOURCES

PubMed (MEDLINE), EMBASE, Cochrane Library and Web of Science were searched from inception of databases until the 13th of January 2021.

DATA SYNTHESIS

Each outcome was stratified by sex and menopausal status in women. The meta-analysis was performed using a random-effect model with inverse-variance method. The risks of hip and wrist fracture were reduced by 25% (n = 8: RR = 0.75, 95% CI: 0.62, 0.91, P = 0.003, I2 = 95%) and 15% (n = 2 studies: RR = 0.85, 95% CI: 0.81, 0.88), respectively, while ankle fracture risk was increased by 60% (n = 2 studies: RR = 1.60, 95% CI: 1.52, 1.68) in postmenopausal women with obesity compared with those without obesity. In men with obesity, hip fracture risk was decreased by 41% (n = 5 studies: RR = 0.59, 95% CI: 0.44, 0.79). Obesity was associated with increased BMD, better bone microarchitecture and strength, and generally lower or unchanged circulating bone resorption, formation and osteocyte markers. However, heterogeneity among studies was high for most outcomes, and overall quality of evidence was very low to low for all outcomes.

CONCLUSIONS

This meta-analysis highlights areas for future research including the need for site-specific fracture studies, especially in men and premenopausal women, and studies comparing bone microarchitecture between individuals with and without obesity.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42020159189.

Bone Quality as Measured by Trabecular Bone Score in Normocalcemic Primary Hyperparathyroidism

OBJECTIVE

The impact of normocalcemic hyperparathyroidism (NHPT) on bone quality remains largely unexplored. We aimed to investigate the usefulness of trabecular bone score (TBS) assessment in NHPT and the accuracy of TBS in predicting vertebral fractures (VFs) in NHPT.

METHODS

In this multicentric cross-sectional study, we assessed the TBS in 47 subjects with NHPT, 41 with primary hyperparathyroidism (PHPT), and 39 age- and sex-matched control subjects.

RESULTS

TBS values did not differ among the 3 groups. The prevalence of low TBS (TBS < 1.2) was 23.4% in NHPT, 26.8% in PHPT, and 15.4% in controls, without statistically significant differences between groups. However, we found a lower lumbar spine Z-score adjusted for TBS (LS Z-score∗TBS) in PHPT participants when compared with controls (-0.48 ± 1.06 vs 0.07 ± 0.93, P = .017). In NHPT group, LS Z-score∗TBS did not detect patients with overall VFs (threshold, -0.15; area under the curve, 0.45; 95% CI, 0.253-0.648; accuracy, 55.3%). Instead, it was useful for moderate-severe VFs (threshold, 0.55; area under the curve, 0.81; 95% CI, 0.62-0.996; accuracy, 83%). In PHPT subjects also, TBS did not predict VFs.

CONCLUSION

In NHPT, TBS is not reduced. When adjusted for TBS, the LS Z-score might predict moderate-to-severe VFs.

Preoperative imaging predicts change in bone mineral density after parathyroidectomy for primary hyperparathyroidism

BACKGROUND

Bone Mineral Density (BMD) improves after parathyroidectomy (PTX), but data on factors that predict bone recovery are limited. No studies have evaluated if preoperative imaging findings are associated with postoperative change in BMD. We hypothesized that larger, metabolically active glands would be associated with greater increase in BMD after PTX.

METHODS

Patients with primary hyperparathyroidism (PHPT) who underwent combined Tc-99m sestamibi and 4D-CT imaging prior to PTX and had pre- and post-operative dual-energy X-ray absorptiometry (DXA) at our institution were considered for inclusion. Retrospectively, data were collected from imaging studies on each parathyroid gland, including estimated weight (using the ellipsoid formula) and contrast enhancement on 4D-CT as well as sestamibi avidity. Total estimated parathyroid weight was calculated. The main outcome measure was the percent change in BMD at the lumbar spine (LS) from pre- to post-operative DXA. Predictors of change in BMD at the LS were assessed.

RESULTS

Complete DXA data was available in 25 patients. Median total parathyroid weight on 4D-CT was 270 mg, and mean change in BMD at the LS was 2.4 ± 4.3%. The increase in BMD was best predicted by higher preoperative serum calcium (p = 0.01), greater estimated parathyroid weight (p = 0.001), sestamibi avidity (p = 0.03), and increased time between DXA scans (p = 0.03) in the multivariable model (R² = 0.79, p < 0.0001).

CONCLUSION

In PHPT, higher preoperative serum calcium, parathyroid gland weight on imaging, and sestamibi avidity are associated with greater increases in BMD after curative PTX. These findings suggest that larger, metabolically active adenomas may mobilize more calcium from bone.

Does Baseline PTH Influence Recovery of Bone Mineral Density, Trabecular Bone Score and Bone Turnover Markers? A Prospective Study Following Curative PArathyroidectomy in Primary Hyperparathyroidism

OBJECTIVE

This prospective study was carried out to assess trabecular bone score, bone mineral density (BMD), and bone biochemistry in Indian subjects with symptomatic primary hyperparathyroidism (PHPT), and to study the influence of baseline parathyroid hormone (PTH) on recovery of these parameters following curative surgery.

METHODS

This was a 2-year prospective study conducted at a tertiary care centre in southern India. Baseline assessment included demographic details, mode of presentation, bone mineral biochemistry, BMD, trabecular bone score (TBS), and bone turnover markers (BTMs). These parameters were reassessed at the end of the first and second years following curative parathyroid surgery.

RESULTS

Fifty-one subjects (32 men and 19 women) with PHPT who had undergone curative parathyroidectomy were included in this study. The mean (SD) age was 44.6 (13.7) years. The TBS, BTMs, and BMD at lumbar spine and forearm were significantly worse at baseline in subjects with higher baseline PTH (≥250 pg/mL) when compared to the group with lower baseline PTH (<250 pg/mL). At the end of 2 years, the difference between high versus low PTH groups (mean ± SD) persisted only for forearm BMD (0.638±0.093 versus 0.698±0.041 g/cm²; P =.01). However, on follow-up visits in the first and second year after curative parathyroidectomy, there was no significant difference in BTMs, BMD at the femoral neck, lumbar spine, and TBS between the 2 groups stratified by baseline PTH.

CONCLUSION

The BMD at the forearm remained significantly worse in individuals with high baseline PTH even at 2 years after surgery, while other parameters including TBS improved significantly from baseline.

ABBREVIATIONS

25(OH)D = 25-hydroxyvitamin D; BMD = bone mineral density; BMI = body mass index; BTMs = Bone turnover markers; CTX = C-terminal telopeptide of type 1 collagen; DXA = dual energy X-ray absorptiometry; P1NP = N-terminal propeptide of type 1 procollagen; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; TBS = trabecular bone score.

The Potential Role of Preoperative Trabecular Bone Score in Predicting Changes in Bone Mineral Density After Parathyroidectomy

BACKGROUND

The skeletal indication for parathyroidectomy for primary hyperparathyroidism (PHPT) is based on bone mineral density (BMD) T-score <  - 2.5. Whether trabecular bone score (TBS) additionally identifies patients who benefit from parathyroidectomy in terms of bone health is unknown. We aimed to study changes in BMD and TBS among Chinese who underwent curative parathyroidectomy for PHPT, in relation to their preoperative parameters, especially in those with worst site BMD T-score ≥  - 2.5 (non-osteoporotic range).

METHODS

We included consecutive Chinese individuals who underwent curative parathyroidectomy during 2002-2015 for PHPT and completed preoperative and postoperative BMD and TBS measurements in Queen Mary Hospital. Correlations between preoperative parameters and changes in densitometric parameters were studied.

RESULTS

45 Chinese individuals (13 men, 32 women) were included (mean age 62.0 ± 10.0 years and BMI 24.6 ± 4.7 kg/m²). After parathyroidectomy, BMD at lumbar spine (LS) improved by 6.7% (p < 0.001) while TBS did not change. Among women, peak preoperative parathyroid hormone and calcium levels independently predicted LS BMD gain. Among women with BMD in non-osteoporotic range, LS BMD also improved after parathyroidectomy, where preoperative TBS was the only significant variable inversely correlating with percentage change in LS BMD (ρ - 0.775, p = 0.005). Particularly, those with preoperative TBS ≤ 1.25 gained 7.1% LS BMD post-parathyroidectomy (p = 0.003).

CONCLUSIONS

LS BMD, but not TBS, improved after parathyroidectomy. Among non-osteoporotic PHPT women, preoperative TBS inversely correlated with postoperative BMD improvement. Hence, low preoperative TBS may be an additional indication for surgical benefit with parathyroidectomy in non-osteoporotic PHPT women, as those with worse preoperative TBS tend to benefit more from surgery.

Effects of metabolic syndrome on bone health in older adults: the Bushehr Elderly Health (BEH) program

Based on the clinical, BMD, and TBS data of 2380 participants aged ≥ 60 which was gathered during the BEH program, stage II, we showed that MetS was positively associated with BMD, while a negative or no association was observed between MetS and TBS depending on the sex and the adjustment model.

INTRODUCTION

The results of previous reports in regard to the effect of metabolic syndrome (MetS) on bone health are not conclusive. This study aimed to evaluate the association between MetS with bone mineral density (BMD) and trabecular bone score (TBS) as an indicator of bone quantity and quality, respectively.

METHODS

Using a cross-sectional design, this study was carried out based on the data collected during the BEH Program, stage II. MetS was defined according to NCEP-ATP III criteria. BMD (at the lumbar spine and the hip) and lumbar spine TBS were assessed by dual-energy X-ray absorptiometry device.

RESULTS

The data of 2380 participants (women = 1228, men = 1152) aged ≥ 60 were analyzed. In the fully adjusted regression models (including BMI), significant associations between MetS and mean BMD were observed across all locations in men (P values ≤ 0.001) and in the lumbar spine in women (P value = 0.003). In addition, the prevalence of osteoporosis (based on BMD) was significantly lower in those with MetS than those without MetS in both sexes, even after full adjustments (women, OR = 0.707, P value = 0.013; men, OR = 0.563, P value = 0.001). In contrast, in age-adjusted regression analyses, the prevalence of degraded bone microarchitecture (TBS ≤ 1.2) was significantly increased in those with MetS than those without, irrespective of the participants' sex (P values < 0.05). The mean TBS was also negatively associated with MetS in women (β = - 0.075, P value = 0.007) but not in men (β = - 0.052, P value = 0.077), in age-adjusted regression models. However, after including BMI in the adjusted models, all significant associations between TBS values and MetS disappeared.

CONCLUSION

It seems that a positive association exists between MetS and BMD, while MetS is either not associated or negatively correlated with bone quality as measured by TBS.

Effects of denosumab as compared with parathyroidectomy regarding calcium, renal, and bone involvement in osteoporotic patients with primary hyperparathyroidism

PURPOSE

To evaluate the effects of denosumab (Dmb) on calcium, renal, and bone involvement in osteoporotic patients with primary hyperparathyroidism (PHPT) and compare with those who underwent a parathyroidectomy (PTX) procedure.

METHODS

This retrospective, longitudinal study included patients treated with Dmb (60 mg) once every 6 months (n = 19) and those who successfully underwent a PTX procedure (n = 19) corrected calcium (cCa), eGFR, bone mineral density (BMD) in the lumbar spine (LS), total hip (TH), and femoral neck (FN) and LS-trabecular bone score (TBS) changes at 1 year after beginning Dmb or undergoing PTX were measured.

RESULTS

Dmb group had older age, and showed milder disease activity and lower eGFR as compared with PTX group. In PTX group, cCa and eGFR were significantly decreased following surgery, while those were stable in Dmb group. There were significant increases in LS, TH, and FN-BMD in both Dmb (LS: 6.0 ± 0.8%, TH: 3.7 ± 1.0%, FN: 4.3 ± 1.5%) and PTX (LS: 11.2 ± 1.5%, TH: 7.5 ± 1.5%, FN: 7.9 ± 2.1%) groups. In Dmb group, LS-TBS was significantly improved by 3.0 ± 1.0%, while TBS change in PTX group approached significance (2.8 ± 1.5%). Percent change in TH-BMD was significantly correlated with baseline tartrate-resistant acid phosphatase-5b (TRACP-5b) in both groups.

CONCLUSIONS

Dmb treatment not only increased BMD, dependent on bone turnover status, the same as PTX, but also improved LS-TBS. In addition, it did not decrease the level of eGFR, whereas PTX did. These results suggest that Dmb treatment help in the clinical management of osteoporotic patients with PHPT who do not undergo surgery as alternative to PTX.

Beyond the metabolic syndrome: Visceral and marrow adipose tissues impair bone quantity and quality in Cushing's disease

The present study was designed to evaluate the relationship between bone traits [bone mineral density (BMD) and trabecular bone score (TBS)] and the accumulation of fat in adipose tissues [abdominal subcutaneous (SAT), visceral (VAT), marrow (MAT) and intrahepatic lipids (IHL)], as well as insulin resistance, in subjects with Cushing’s disease (CD). The study included control (C = 27), paired (P = 16) and Cushing’s disease (CD = 10) groups, which underwent biochemical assessment, dual X-ray absorptiometry, TBS, and magnetic resonance imaging to determine fat deposits. The CD group showed higher serum levels of glucose and insulin, as well as HOMA-IR values, but lower circulatory levels of osteocalcin, in comparison to C and P. The CD group exhibited lower L1-L4 BMD than P (P = 1.059 ± 0.141 vs CD = 0.935 ± 0.093 g/cm², p < 0.05) (Fig 1A). The lumbar spine BMD from the C group was similar to the other groups. TBS was lower in CD than in P and C (C = 1.512±0.077 vs P = 1.405±0.150 vs CD = 1.135±0.136; p<0.05); there was also significant difference between C and P (p<0.05). MAT, VAT, and IHL were higher in CD than in C and P (p<0.05). Considering all subjects, there was a positive association between TBS with both lumbar spine BMD (R² = 0.45; p<0.0001) and osteocalcin (R² = 0.44; p = 0.05). TBS was negatively associated with MAT (R² = 0.49; p = 0.01), VAT (R² = 0.55; p<0.05), and HOMA-IR (R² = 0.44; p<0.01). MAT was positively related with VAT (R² = 0.44; p<0.01) and IHL (R² = 0.41; p<0.05). In CD, insulin resistance and adipose tissue dysfunction, including high MAT, are active players in bone deterioration, as confirmed by lower lumbar spine BMD and lower TBS. Thus, our findings point to an additional component of the already well-known complex mechanisms of osteoporosis associated with hypercortisolism.

Fat Mass Does Not Increase the Precision Error of Trabecular Bone Score Measurements

INTRODUCTION

Trabecular bone score (TBS) is an indirect index of trabecular microarchitecture derived from lumbar spine dual-energy X-ray absorptiometry. Previous phantom study showed that an increase in soft tissue thickness does not affect TBS reproducibility. We investigated the effect of increasing body mass index (BMI) and waist circumference on TBS precision error on patients, compared to bone mineral density (BMD).

METHODOLOGY

A population of postmenopausal Caucasian women was distributed in 3 different BMI (normal, overweight, and class I obesity), plus 2 further groups based on waist circumference diameter (≤88 cm and >88 cm, respectively). In vivo precision error was calculated on 30 consecutive subjects that were scanned 2 times, with patient repositioning, using the Hologic QDR-Discovery W densitometer. Coefficient of variation, percent least significant change, and reproducibility were calculated according to the International Society for Clinical Densitometry guidelines.

RESULTS

Ninety-five women aged 66 ± 10 (mean ± standard deviation) were included. No significant differences were found both for BMD and TBS precision errors, respectively, when comparing BMI groups and waist circumference groups. BMD reproducibility ranged from 95.9% (BMI > 30 kg/m²) to 97.5% (BMI < 25 kg/m²). TBS reproducibility ranged between 95.8% (BMI = 25-29.9 kg/m², waist circumference > 88 cm) and 96.6% (BMI < 25 kg/m²). With the exception of obese group, a significant difference was found between BMD and TBS reproducibility, being that of TBS slightly lower than BMD. A significant decrease of TBS values was found between normal and obese subjects, as well as between waist circumference groups.

CONCLUSIONS

TBS precision error is not affected by BMI and waist circumference differences. TBS reproducibility showed to be slightly lower than that of BMD, but this difference was mitigated in obese patients. A negative association was found between the amount of fat mass and TBS mean values.

Mild primary hyperparathyroidism-to treat or not to treat?

INTRODUCTION

The presentation of primary hyperparathyroidism (PHPT) has shifted from a disease characterized by renal and skeletal complications to a mild or asymptomatic condition. Modern imaging allows localization of a surgical target in the majority of cases.

SOURCES OF DATA

Data were collected from literature searches of online databases including PUBMED, MEDLINE and Cochrane. A narrative review was performed.

AREAS OF AGREEMENT

Parathyroidectomy is the only therapy with curative potential with good outcomes and low risk of complications in experienced hands. Current guidelines advocate that surgery is offered in all symptomatic cases and in those who meet criteria depending on age, serum calcium concentration, skeletal and renal parameters. A structured monitoring approach should be offered to those who do not undergo surgery.

AREAS OF CONTROVERSY

Thresholds for intervention to improve skeletal and renal outcomes are debatable. In addition, controversy persists over the benefit of surgery for non-skeletal/renal outcomes.

GROWING POINTS

The role of medical management of PHPT using agents such as bisphosphonates, denosumab and cinacalcet are discussed.

AREAS TIMELY FOR DEVELOPING RESEARCH

In summary, further data on the natural history and effects of treatment of mild and asymptomatic PHPT are required to determine thresholds for surgery. In particular, further investigations of non-skeletal and non-renal parameters, such as neurocognitive quality of life and cardiovascular disease are required. Data on normocalcaemic PHPT are lacking. Large-scale randomized controlled trials would be welcome in these areas, however in view of the cost implications a more pragmatic approach may be to develop collaborative multi-centre registries.

Associations between trabecular bone score and biochemistry in surgically vs conservatively treated outpatients with primary hyperparathyroidism: A retrospective cohort study

PURPOSE

Trabecular Bone Score (TBS) is a software-based method for indirect assessment of trabecular bone structure of the spine, based on analysis of pixels in dual energy x-ray absorptiometry (DXA) images. Few studies describe the use of TBS in patients with primary hyperparathyroidism (PHPT). This study aimed at further describing this relationship, investigating possible correlations between biochemistry, body mass index (BMI), fracture incidence and TBS.

METHODS

Cross-sectional study of 195 patients with verified PHPT, surgically (27) or conservatively (168) treated at the Department of Endocrinology, Aalborg University Hospital. TBS was acquired by reanalyzing DXA-images of the included subjects from the outpatient clinic. Biochemical variables were obtained from clinical routine blood samples taken in relation to the DXA-scans. History of fractures and medical history was obtained from radiology reports and medical charts.

RESULTS

Patients with active PHPT had a TBS-score signifying a partly degraded bone structure, whereas surgically treated patients had a normal bone structure as judged by TBS, though the difference in TBS-score was not statistically significant. Use of antiresorptive treatment was negatively associated with BMD but not TBS. No correlations between the biochemical variables and TBS were found. A negative correlation between TBS and BMI in patients with PHPT was present. Patients experiencing a fragility fracture had a significantly lowered TBS, BMD and T-Score.

CONCLUSION

Biochemistry does not seem to predict bone status in terms of TBS in patients with PHPT. TBS is negatively correlated to BMI, which is also seen in patients not suffering from PHPT. The lack of a predictive value for antiresorptive treatment for TBS may raise concern. TBS appears to have a predictive value when assessing risk of fracture in patients with PHPT.

MINI ABSTRACT

This cross-sectional study investigates possible correlations between biochemical variables, body mass index (BMI) and trabecular bone score (TBS) in 195 patients with primary hyperparathyroidism. It finds no correlation between biochemical variables and TBS, but finds a negative correlation between TBS and BMI and a clear association between fracture incidence and low TBS-score.

TRABECULAR BONE SCORE (TBS) HAS A POOR DISCRIMINATIVE POWER FOR VERTEBRAL FRACTURES IN 153 ROMANIAN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM

CONTEXT

Trabecular Bone Score (TBS) has been recently proposed as a good tool to investigate secondary osteoporosis.

OBJECTIVE

The aim of this study was to assess TBS from spine DXA images in patients with primary hyperparathyroidism (PHPT) and look at its correlates.

SUBJECTS AND METHODS

153 patients, mean age 59.1 ± 12.1 yrs, females and males (10%), mean BMI 26.2 ± 4.8 kg/m2, mean serum calcium and PTH of 11.3 ± 1.2 mg/dL and 232 ± 329 pg/mL, respectively; 89% had osteoporosis/osteopenia by LS DXA and 46% had renal involvement. There were 7.6% patients with vertebral fractures, 13.2% patients with nonvertebral fractures. TBS indices were derived from LS-DXA images and cutoff points used were those previously reported.

RESULTS

Mean TBS was in the partially degraded range (1.258 ± 0.115); 32% of patients had degraded microarchitecture (TBS ≤ 1.20), 51% had partially degraded microarchitecture (TBS > 1.20 and < 1.35) and 17% had normal TBS. TBS was significantly correlated with areal BMD both at the LS (r=0.544; p<0.001) and FN (r = 0.315; p < 0.001), and negatively with age (r= - 0.354; p < 0.001) and years since menopause - YSM (r = - 0.257, p = 0.005). Patients with vertebral fractures had mean values of TBS in the degraded range, significantly lower than those without vertebral fractures (1.173 ± 0.076 vs. 1.263 ± 0.115; p = 0.006). The presence of vertebral fracture was independently associated only with YSM (OR = 1.131, 95% CI = 0.032 - 0.214, p = 0.008) but not with TBS.

CONCLUSIONS

In a cohort of symptomatic PHPT patients, including postmenopausal, premenopausal and male patients, we have shown that TBS was in the partially degraded range, but it was not independently associated with fractures.