The association between hemoglobin level and sarcopenia in Chinese patients with Crohn's disease.

Sarcopenia and anemia are common complications in patients with Crohn's Disease (CD). However, few studies have shown the association between sarcopenia and hemoglobin levels in CD patients. This retrospective study aimed to explore such association in Chinese patients with CD. Two hundred and twelve adult CD inpatients who underwent computed tomography (CT) or magnetic resonance imaging (MRI) examinations from July 2019 to December 2021 were included in the study. Sarcopenia was defined according to the cutoff value of skeletal muscle index of lumbar spine 3 (SMI-L3) (< 44.77cm2/m2 for males and < 32.5cm2/m2 for females). The CD patients were divided into two groups based on the presence or absence of sarcopenia. Clinical data, hemoglobin levels, and other laboratory data were retrospectively collected. The association between hemoglobin levels and sarcopenia was analyzed by univariable and multivariable logistic regression analysis. Sarcopenia occurred in 114 CD patients (53.8%). Compared to patients without sarcopenia, patients with sarcopenia had a lower proportion of L1 (30.7% vs. 45.8%, p = 0.032) and B1 classification (58.8% vs. 72.4%, p = 0.037). Patients with sarcopenia had significantly lower levels of hemoglobin (Hb) (116.5 ± 22.8 vs. 128.1 ± 21.0, p < 0.001). The prevalence of sarcopenia increased with the decrease in hemoglobin level (p for trend < 0.05). Linear regression analysis showed that hemoglobin levels were associated with SMI-L3 (ß = 0.091, p = 0.001). Multivariable logistic regression analysis found that higher hemoglobin levels (OR:0.944; 95% CI: 0.947,0.998; p = 0.036) were independent protective factors for sarcopenia. Lower hemoglobin levels are independently associated factors of sarcopenia in adult Chinese patients with CD.

Bone mineral density in lower thoracic vertebra for osteoporosis diagnosis in older adults during CT lung cancer screening.

BACKGROUND: Quantitative computed tomography (QCT)-based lumbar bone mineral density (LBMD) has been used to diagnose osteoporosis. This study explored the value of lower thoracic BMD (TBMD) in diagnosing osteoporosis in older adults during CT lung cancer screening. METHODS: This study included 751 subjects who underwent QCT scans with both LBMD and TBMD. 141 of them was selected for a validation. Osteoporosis was diagnosed based on LBMD using the ACR criteria (gold standard). TBMD thresholds were obtained using receiver operating characteristic curve. TBMD was also translated into LBMD (TTBMD) and osteoporosis was defined based on TTBMD using ACR criteria. The performance of TBMD and TTBMD in identifying osteoporosis was determined by Kappa test. The associations between TBMD- and TTBMD-based osteoporosis and fracture were tested in 227 subjects with followed up status of spine fracture. RESULTS: The performance of TBMD in identifying osteoporosis was low (kappa = 0.66) if using the ACR criteria. Two thresholds of TBMD for identifying osteopenia (128 mg/cm3) and osteoporosis (91 mg/cm3) were obtained with areas under the curve of 0.97 and 0.99, respectively. The performance of the identification of osteoporosis/osteopenia using the two thresholds or TTBMD both had good agreement with the gold standard (kappa = 0.78, 0.86). Similar results were observed in validation population. Osteoporosis identified using the thresholds (adjusted hazard ratio (HR) = 18.72, 95% confidence interval (CI): 5.13-68.36) or TTBMD (adjusted HR = 10.28, 95% CI: 4.22-25.08) were also associated with fractures. CONCLUSION: Calculating the threshold of TBMD or normalizing TBMD to LBMD are both useful in identifying osteoporosis in older adults during CT lung cancer screening.

The Association Between Environmental Cadmium Exposure and Parathyroid Hormone Levels.

Cadmium exposure is associated with renal dysfunction and bone damage. Chronic kidney disease and bone loss are also related to parathyroid hormone (PTH). However, whether cadmium exposure affect PTH level is not completely understood. In this study, we observed the association between environmental cadmium exposure and PTH levels in a Chinese population. A ChinaCd study was performed in China in 1990s which included 790 subjects living in heavily, moderately and low cadmium polluted area. 354 of them (121 men and 233 women) also had the data of serum PTH. The cadmium levels in blood (BCd) and urine (UCd) were determined by flame atomic absorption spectrometry. Serum PTH was detected by immunoradiometric assay. Renal function was assessed based on urinary N-acetyl-ß-d-glucosaminidase (UNAG), ß2-microglobulin (UBMG) and urinary albumin (UALB). The median BCd and UCd levels were 4.69 µg/L and 5.50 µg/g creatinine. The BCd, UCd, UNAG, UBMG and UALB levels in subjects with low PTH (< 5.0 ng/L) were significantly higher than those with PTH ≥ 5.0 ng/L (p < 0.05 or p < 0.01). Spearman correlation analysis also showed that UCd level was negatively correlated to PTH levels (r = -0.17, p = 0.008) in women. A weak correlation was also observed between PTH level and BCd in women (r = -0.11, p = 0.09) and UBMG in total population (r = -0.114, p = 0.07). Univariable and mutivariable logistic regression analysis both demonstrated that high BCd (> 10 µg/L) (odds ratio (OR) = 2.26, 95% confidence interval (CI):1.10-4.63; OR = 2.36, 95%CI: 1.11-5.05) and UCd level (> 20 µg/g cr) (OR = 2.84, 95% CI:1.32-6.10; OR = 2.97, 95%CI: 1.25-7.05) were associated with high risk of low PTH. Our data showed that environmental cadmium exposure was associated with low PTH level.

Opportunistic Muscle Evaluation During Chest CT Is Associated With Vertebral Compression Fractures in Old Adults: A Longitudinal Study.

BACKGROUND: Sarcopenia and bone loss are both common in older individuals. However, the association between sarcopenia and bone fractures has not been evaluated longitudinally. In this study, we evaluated the association between computed tomography (CT)-based erector spinae muscle area and attenuation and vertebral compression fracture (VCF) in elderly individuals in a longitudinal study. METHODS: This study recruited individuals 50 years of age and older, who did not have VCF and underwent CT imaging for lung cancer screening during January 2016 to December 2019. Participants were followed up annually until January 2021. Muscle CT value and muscle area of the erector spinae were determined for muscle assessment. Genant score was used to define new-onset VCF. Cox proportional hazards models were used to assess the association between muscle area/attenuation and VCF. RESULTS: Of the 7 906 included participants, 72 developed new VCF over a median follow-up of 2 years. Large area of the erector spinae (adjusted hazard ratio [HR] = 0.2, 95% confidence interval [CI]: 0.1-0.7) and high bone attenuation (adjusted HR = 0.2, 95% CI: 0.1-0.5) were independently associated with VCF. High muscle attenuation was associated with severe VCF (adjusted HR = 0.46, 95% CI: 0.24-0.86). The addition of muscle area improved the area under the curve of bone attenuation from 0.79 (95% CI: 0.74-0.86) to 0.86 (95% CI: 0.82-0.91; p = .001). CONCLUSIONS: CT-based muscle area/attenuation of the erector spinae was associated with VCF in elderly individuals, independently of bone attenuation. The addition of muscle area improved the performance of bone attenuation in predicting VCF.

A Computed Tomography-based Radiomics Nomogram for Predicting Osteoporotic Vertebral Fractures: A Longitudinal Study.

CONTEXT: Fractures are a serious consequence of osteoporosis in older adults. However, few longitudinal studies have shown the role of computed tomography (CT)-based radiomics in predicting osteoporotic fractures. OBJECTIVE: We evaluated the performance of a CT radiomics-based model for osteoporotic vertebral fractures (OVFs) in a longitudinal study. METHODS: A total of 7906 individuals without OVF older than 50 years, and who underwent CT scans between 2016 and 2019 were enrolled and followed up until 2021. Seventy-two cases of new OVF were identified. A total of 144 people without OVF during follow-up were selected as controls. Radiomics features were extracted from baseline CT images. CT values of trabecular bone, and area and density of erector spinae were determined. Cox regression analysis was used to identify the independent associated factors. The predictive performance of the nomogram was assessed using the receiver operating characteristic curve, calibration curve, and decision curve. RESULTS: CT value of vertebra (adjusted hazard ratio (aHR) = 2.04; 95% CI, 1.07-3.89), radiomics score (aHR = 6.56; 95% CI, 3.47-12.38), and area of erector spinae (aHR = 1.68; 95% CI, 1.02-2.78) were independently associated with OVF. Radscore was associated with severe OVF (aHR = 6.00; 95% CI, 2.78-12.93). The nomogram showed good discrimination with a C-index of 0.82 (95% CI, 0.77-0.87). The area under the curve of nomogram and radscore were both higher than osteoporosis + muscle area for 3-year and 4-year risk of fractures (P < .05). The decision curve also demonstrated that the radiomics nomogram was useful. CONCLUSION: Bone radiomics is associated with OVF, and the nomogram based on radiomics signature and muscle provides a tool for the prediction of OVF.