Using QCT to evaluate bone mineral and abdominal adipose changes in patients with primary hyperparathyroidism and comparing it to DXA for bone status assessment: a retrospective case-control study

Abstract

Background: Patients with primary hyperparathyroidism (PHPT) show changes in bone metabolism and adipose tissue, but the results are inconsistent. Quantitative computed tomography (QCT) was reported useful for detecting bone mineral and adipose tissue change, but information on the role of QCT in PHPT is limited. We aimed to explore the changes of lumbar bone mineral density (BMD) and abdominal adipose tissue in patients with PHPT using QCT based on existed CT images, and to assess the consistency between QCT and dual-energy X-ray absorptiometry (DXA) in assessing bone status.Methods: This retrospective case-control study was conducted on 48 PHPT patients, with healthy controls (HCs) matched by their age (±3 years) and gender, and the case-to-control ratio was approximately 1:3.Volumetric bone mineral density (vBMD), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and total adipose tissue (TAT) were measured by QCT in both PHPT and control groups and compared with the independent samples T-test. In the PHPT group, areal bone mineral density (aBMD) was measured by DXA. Pearson correlation analysis was used to investigate the association between QCT-derived vBMD and DXA-derived aBMD. Weighted kappa consistency analysis was used to clarify the agreement between QCT and DXA.Results: Compared with HCs, the PHPT group had significantly lower vBMD (114.30±41.71 vs. 136.92±42.23 mg/cm 3 ; P=0.002) and higher TAT (261.98±74.65 vs. 236.69±69.00 cm 2 ; P=0.033); however, differences in SAT (120.81±40.19 vs. 109.94±36.83 cm 2 ; P=0.085) and VAT (141.17±48.11 vs. 126.75±50.50 cm 2 ; P=0.085) were not statistically significant. There was a strong correlation between QCT-derived vBMD and

Quantitative CT Evaluation of Bone Mineral Density in the Thoracic Spine on 18F-Fluorocholine PET/CT Imaging in Patients With Primary Hyperparathyroidism

“…Correlation between DXA-derived aBMD and QCTderived vBMD or HU was strongest in femoral neck, total hip and lowest T-score and less strong in the lumbar spine, which may be explained by lower accuracy of DXA for spinal evaluation due to degenerative changes 4 and the superior accuracy of QCT, largely independent of degenerative changes. 6 The correlation in the lumbar spine was also less strong than a previous study showing correlation between lumbar QCT and lumbar DXA in primary hyperparathyroidism (r = 0.690 versus r = 0.494 in our study), 13 but this study evaluated younger patients (mean age 53,8 versus 65.4 years in our study) with possible different prevalence of degenerative lumbar changes. The correlation in the lumbar spine was also less strong than a previous study showing correlation between thoracic HU and lumbar DXA (r = 0.767 versus r = 0.479 in our study), 20 but this study evaluated patients with COPD, limiting comparison.…”

“…Application of the ACR criteria for lumbar QCT 25 on our thoracic QCT results would classify 38 % as having osteopenia and 48 % of patients as having osteoporosis, similar to recent estimates of the prevalence of osteoporosis in primary hyperparathyroidism, ranging from 39 to 62.9 %. 2 Although both methods 13 and postmenopausal women with spinal surgery indications, 8 respectively. Our results are also similar to discordance rates between different measurements sites within single DXA examinations.…”

“…9 According to recent appropriate use criteria from the American College of Radiology (ACR), 10 lumbar QCT is considered superior to DXA in patients with extremes in height, obesity, severe degenerative spine disease and in cases where increased sensitivity to small changes in trabecular bone density is desired (such as parathyroid hormone and glucocorticoid treatment monitoring). Several studies have demonstrated feasibility of osteoporosis screening using QCT or Hounsfield unit (HU) measurements of lumbar vertebrae at routine diagnostic abdominal CT or low-dose CT. 11,12 QCT data of patients with primary hyperparathyroidism is currently limited to a single study of the lumbar spine on diagnostic abdominal CT in 48 patients, 13 which showed a strong correlation between BMD at CT and DXA.…”

Quantitative CT lumbar spine BMD cutpoint value for classifying osteoporosis among older Chinese men can be the same as that of older Chinese women, both much lower than the value for Caucasians

“…This result forms the cornerstone of the analyses of the current article, and it is in agreement with other studies such as the mixed-sex cohort study of Chen et al (Fig. 2B) [20], Lin et al [21], and Uemura et al [22].…”

“…In conclusion, while there have been fewer results available for men than for women, the data analyses in this article For QCT value of 50 mg/ml, the corresponding DXA BMD value is 0.594 g/cm 2 . B: Results of mixed-sex 48 primary hyperparathyroidism patients (age: 53.77 ± 11.04 years) reported by Chen et al [20]. The blue dotted crosses show the relationship between DXA measure and QCT measure in (B) is approximately similar to that in (A) based on DXA LS BMD and QCT LS BMD correlation and supported by the relationship between lower QCT LS BMD and prevalence of fragility fracture consistently suggest that, for older Chinese men (≥ 50 years), the cutpoint for the QCT LS BMD classification of osteoporosis is 45∼50 mg/ml which is the same value as for Chinese women.…”