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Background Osteoporosis is a prevalent, under-diagnosed, and treatable disease associated with increased fracture risk. Bone mineral density (BMD) derived from cardiac CT may be used to determine fracture rate. Purpose To assess the association between fracture rate and thoracic BMD derived from cardiac CT. Materials and Methods This prospective cohort study included consecutive participants referred for cardiac CT for evaluation of ischemic heart disease between September 2014 and March 2016. End of follow-up was June 30, 2018. In all participants, volumetric BMD of three thoracic vertebrae was measured by using quantitative CT software. The primary and secondary outcomes were any incident fracture and any incident osteoporosis-related fracture registered in the National Patient Registry, respectively. Hazard ratios were assessed by using BMD categorized as very low (<80 mg/cm 3 ), low (80-120 mg/cm 3 ), or normal (>120 mg/cm 3 ). The study is registered at ClinicalTrials.gov (identifier: NCT02264717). Results In total, 1487 participants (mean age, 57 years ± 9; age range, 40-80 years; 52.5% women) were included, of whom 179 (12.0%) had very low BMD. During follow-up (median follow-up, 3.1 years; interquartile range, 2.7-3.4 years; range, 0.2-3.8 years), 80 of 1487 (5.3%) participants were diagnosed with an incident fracture and in 31 of 80 participants, the fracture was osteoporosis related. In unadjusted Cox regressions analyses, very low BMD was association with a greater rate of any fracture (hazard ratio, 2.6; 95% confidence interval [CI]: 1.4, 4.7; P = .002) and any osteoporosis-related fracture (hazard ratio, 8.1; 95% CI: 2.4, 26.7; P = .001) compared with normal BMD. After adjusting for age and sex, very low BMD remained associated with any fracture (hazard ratio, 2.1; 95% CI: 1.1, 4.2) and any osteoporosis-related fracture (hazard ratio, 4.0; 95% CI: 1.1, 14.6). Conclusion Routine cardiac CT can be used to help measure thoracic bone mineral density (BMD) to identify individuals who have low BMD and a greater fracture rate. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Bredella in this issue.

Despite being a frequent and treatable disease, osteoporosis remains under-diagnosed worldwide. Our study aim was to characterize the bone mineral density (BMD) status in a group of patients with symptoms suggestive of coronary artery disease (CAD) with low/intermediate risk profile undergoing routine cardiac computed tomography (CT) to rule out CAD. This cross-sectional study used prospectively acquired data from a large consecutively included cohort. Participants were referred for cardiac CT based on symptoms of CAD. Quantitative CT (QCT) dedicated software was used to obtain BMD measurements in 3 vertebrae starting from the level of the left main coronary artery. We used the American College of Radiology cut-off values for lumbar spine QCT to categorize patients into very low (<80 mg/cm3), low (80-120 mg/cm3), or normal BMD (>120 mg/cm3). Analyses included 1487 patients. Mean age was 57 years (range 40-80), and 52% were women. The number of patients with very low BMD was 105 women (14%, 105/773) and 74 men (10%, 74/714). The majority of patients with very low BMD was not previously diagnosed with osteoporosis (87%) and received no anti-osteoporotic treatment (90%). Opportunistic screening in patients referred for cardiac CT revealed a substantial number of patients with very low BMD. The majority of these patients was not previously diagnosed with osteoporosis and received no anti-osteoporotic treatment. Identification of these patients could facilitate initiation of anti-osteoporotic treatment and reduce the occurrence of osteoporosis-related complications., (Copyright © 2018 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

Background: Sclerostin, a bone-derived protein, has been linked to cardiovascular calcifications in chronic kidney disease (CKD). The aim of this study was to investigate the associations between sclerostin and mineral and bone disorder in CKD, specifically whether sclerostin levels could predict cardiovascular event, fracture, or all-cause mortality., Materials and Methods: Kidney transplantation candidates (n = 157) underwent computed tomography scans of the chest, abdomen, and pelvis. Calcification scores were calculated for coronary arteries, thoracic aorta, and the aortic and mitral valves. Volumetric bone mineral density (BMD) was measured at the spine and hip. Sclerostin and markers of bone turnover were determined from fasting blood samples., Results: Compared to patients with a calcification score of 0, sclerostin levels were higher in patients with calcifications at the coronary arteries (+23%, p &lt; 0.001) and the thoracic aorta (+27%, p = 0.001), but not in patients with calcifications at the aortic (+1%, p = 0.85) or mitral (+8%, p = 0.20) valves. During a median follow-up of 3.7 years, 28 patients had a major cardiovascular event, 19 patients sustained a fragility fracture, and 32 patients died. Sclerostin levels above the median did not predict major cardiovascular event (p = 0.15), fracture (p = 0.58), or mortality (p = 0.65)., Conclusion: Sclerostin was positively associated with the presence of vascular calcifications, but was not predictive of events associated with mineral and bone disorder in a cohort of kidney transplantation candidates.
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Quantitative computed tomography (CT) can be used to quantify bone mineral density (BMD) in the spine from clinical CT scans. We aimed to determine agreement and precision of BMD measurements by 2 different methods: phantom-less internal tissue calibration and asynchronous phantom-based calibration in a cohort of patients with chronic kidney disease (CKD). Patients with CKD were recruited for CT angiography of the chest, abdomen, and pelvis. BMD was analyzed by 2 different software solutions using different calibration techniques; phantom-based by QCT Pro (Mindways Inc.) and phantom-less by Extended Brilliance Workspace (Philips Healthcare). Intraoperator reanalysis was performed on 53 patients (36%) for both methods. An interoperator reanalysis on 30 patients (20%) using the phantom-based method and 29 patients (19%) using the phantom-less method was made. XY- and Bland-Altman plots were used to evaluate method agreement. Phantom-based measured BMD was systematically higher than phantom-less measured BMD. Despite a small absolute difference of 3.3 mg/cm 3 (CI: -0.2-6.9 mg/cm 3 ) and a relative difference of 5.1% (CI: 2.2%-8.1%), interindividual differences were large, as seen by a wide prediction interval (PI: -47-40 mg/cm 3 ). The Bland-Altman plot showed no systematic bias, apart from 5 outliers. Intraoperator variability was high for the phantom-less method (5.8%) compared to the phantom-based (0.8%) and the interoperator variability was also high for the phantom-less method (5.8%) compared to the phantom-based (1.8%). Despite high correlation between methods, the between-method difference on an individual level showed great variability. Our results suggest agreement between these 2 methods is insufficient to allow them to be used interchangeably in patients with CKD., (Copyright © 2018 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

Background: Fracture risk is increased in chronic kidney disease (CKD), but assessment of bone fragility remains controversial in these patients. This study investigated the associations between bone turnover markers, bone mineral density (BMD), and prevalent fragility fracture in a cohort of kidney transplantation candidates., Methods: Volumetric BMD of spine and hip was measured by quantitative computed tomography. Parathyroid hormone (PTH), bone-specific alkaline phosphatase, procollagen type-1 N-terminal propeptide, tartrate resistant alkaline phosphatase, and C- and N-terminal telopeptides of type 1 collagen were analyzed from fasting morning blood samples. Fragility fractures included prevalent vertebral fractures and previous low-trauma clinical fractures., Results: The fracture prevalence was 18% in 157 adult kidney transplant candidates. Fractured patients had reduced BMD and Z-score at both spine and hip. Levels of bone turnover markers were significantly higher in patients on maintenance dialysis than in pre-dialysis patients; but did not differ between patients with and without fracture. There were strong, positive correlations between PTH and all bone turnover markers. PTH was negatively associated with Z-score at lumbar spine and total hip; in contrast, bone turnover markers were only negatively associated with total hip Z-score., Conclusions: Bone turnover markers were negatively associated with bone density, but not associated with prevalent fracture in kidney transplantation candidates. The role of bone turnover markers in assessing bone fragility in CKD will require further investigation., Trial Registration: This study was registered at ClinicalTrials.gov with identifier NCT01344434 .

Volumetric bone mineral density (vBMD) can be measured from clinical computed tomography (CT) scans, facilitating screening for osteoporosis. However, use of X-ray contrast media may influence vBMD analyses, and previous studies reported as much as a 30% increase in lumbar spine (LS) vBMD after contrast administration. At the total hip (TH), an increase of only 4.1% was reported, indicating less sensitivity to contrast enhancement at this site. This study aimed to investigate the changes in vBMD after intravenous contrast media administration at both the LS and proximal femur in patients with chronic kidney disease. Seventy-one patients underwent CT angiography of the chest, abdomen, and pelvis as part of the cardiac workup before kidney transplantation. vBMD of the LS and proximal femur were calculated before and after administration of 95 mL ioversol intravenously. XY- and Bland-Altman plots and paired Student's t-test were used to evaluate changes in vBMD. After contrast media administration vBMD increased both at the LS and proximal femur. Although the absolute difference was comparable, the relative difference was almost twice as high at the LS (10.2% [6.1-14.1]) compared to the TH (5.9% [2.4-9.3], p <0.001) and femoral neck (FN) (5.3% [0.5-9.9], p <0.001). Women had a greater increase in LS-vBMD than men (13.4 ± 8.0 vs 9.8 ± 4.8 mg/cc, p = 0.02). Based on FN T-scores, 11 patients (16%) changed osteoporotic status after contrast enhancement. In conclusion vBMD of the spine and hip increased after contrast media administration in a cohort of patients with chronic kidney disease. FN T-scores from contrast-enhanced clinical CT scans should therefore be interpreted with caution. The proximal femur may be the preferred region for vBMD analysis from clinical CT scans, as sensitivity to contrast enhancement seem less at this site. These results may not be applicable to other patient populations., (Copyright © 2016 International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

Abstract Background Fracture risk is increased in chronic kidney disease (CKD), but assessment of bone fragility remains controversial in these patients. This study investigated the associations between bone turnover markers, bone mineral density (BMD), and prevalent fragility fracture in a cohort of kidney transplantation candidates. Methods Volumetric BMD of spine and hip was measured by quantitative computed tomography. Parathyroid hormone (PTH), bone-specific alkaline phosphatase, procollagen type-1 N-terminal propeptide, tartrate resistant alkaline phosphatase, and C- and N-terminal telopeptides of type 1 collagen were analyzed from fasting morning blood samples. Fragility fractures included prevalent vertebral fractures and previous low-trauma clinical fractures. Results The fracture prevalence was 18% in 157 adult kidney transplant candidates. Fractured patients had reduced BMD and Z-score at both spine and hip. Levels of bone turnover markers were significantly higher in patients on maintenance dialysis than in pre-dialysis patients; but did not differ between patients with and without fracture. There were strong, positive correlations between PTH and all bone turnover markers. PTH was negatively associated with Z-score at lumbar spine and total hip; in contrast, bone turnover markers were only negatively associated with total hip Z-score. Conclusions Bone turnover markers were negatively associated with bone density, but not associated with prevalent fracture in kidney transplantation candidates. The role of bone turnover markers in assessing bone fragility in CKD will require further investigation. Trial registration This study was registered at ClinicalTrials.gov with identifier NCT01344434 .