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Objective:To investigate the normal reference values of spinal bone mineral density measured by quantitative computed tomography (QCT) and the differences of bone mineral density (BMD) in different regions of in Chinese adult males.Methods:Men who underwent low-dose CT lung scan for cancer screening in regions of Northeast, North, East, South, Central and Southwest of China from January 2018 to December 2019 were selected. And the lumbar vertebrae BMD values in the male subjects were measured by the QCT system (Mindways Software, Inc.). The mean BMD values and their decline rates were calculated at an age interval of 10 years, and the prevalence of osteoporosis was calculated according to the American College of Radiology spine QCT osteoporosis diagnostic criteria.Results:A total of 50 682 males with a mean age of (50.22±12.79) years (ranged 20 to 98 years) were included in this study. The peak BMD of (173.11±28.56) mg/cm 3 in the healthy Chinese adult male population appeared in the age group of 20 to 29 years and then declined with age. Before the age of 70 years, the BMD was relatively higher in males in South China, and it was lower in Central China and Southwest China, and it was intermediate in Northeast, North and East of China, with statistically significant differences. There was no significant differences in BMD in the males in the two age groups of 70 to 79 years and 80 and older among the regions in China. The overall decline rate of spinal BMD in Chinese males under QCT was about 46.92% over the lifetime, and it declined obviouslyin the 40-49 age group. The overall prevalence of osteoporosis in Chinese male population aged 50 years and above was approximately 11.42%, with the highest prevalence in Southwest China and Central China (14.72% and 13.87%, respectively) and the lowest in North China and South China (8.53% and 7.71%, respectively). Conclusions:A reference of lumbar spine BMD values for healthy males in China based on QCT is established. BMD values were highest in South China and Lowest in Central China.
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Objective:To explore the association between body composition and blood pressure by quantitative CT (QCT) in a Shanghai population.Methods:A total of 1 307 participants undergoing low-dose CT lung cancer screening and body composition measurem ents using QCT in our hospital from May to December 2018 were retrospectively enrolled. Body composition, including the abdominal soft tissue area (ASTA), visceral adipose area (VAA), and subcutaneous adipose area (SAA) at the central slice of L2, was measured using QCT. To explore the correlations among body composition and systolic blood pressure, diastolic blood pressure, and hypertension, Pearson’s correlation, multivariate linear regression, and multivariate logistic regression analysis were used. The cut-off value for predicting hypertension was analyzed using the ROC curve.Results:Pearson’s correlation analysis showed that ASTA was negatively correlated with systolic blood pressure and diastolic blood pressure ( r=-0.237- -0.102, P<0.05), while VAA and SAA were positively correlated with systolic blood pressure and diastolic blood pressure (VAA: r=0.359-0.486, SAA: r= 0.088-0.365, P<0.05 ). After adjusting for age, sex, body mass index, and waist circumference, multivariate regression analysis showed that VAA was significantly associated with systolic blood pressure (β= 0.142, P= 0.002), diastolic blood pressure (β= 0.245, P<0.001), and hypertension ( OR=1.005, 95% CI: 1.001-1.008, P=0.01), while ASTA or SAA was not significantly associated with systolic blood pressure, diastolic blood pressure, and hypertension. ROC curve analysis indicated that the cut-off values of VAA at the central slice of L2 for predicting hypertension in males and females were 201.89 cm 2 and 136.01 cm 2, respectively. Conclusion:Visceral adiposity was found to be closely related to hypertension. For hypertension management, early screening and strengthening of prevention and management methods are needed for people with abnormally increased visceral adiposity.
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Objective: To explore the feasibility of bone mineral density (BMD) of T12 for replacing abnormal L1 or L2 for diagnosis of osteoporosis during lung cancer screening with low-dose CT and bone mineral density examination with quantitative CT. Methods: Totally 1 298 healthy individuals who underwent lung cancer screening with low-dose CT and BMD examination with quantitative CT were enrolled. BMD of T12 to L2 vertebrae were measured, and the calibrated BMD of T12 was calculated and recorded as T12*. Taking L1+L2 as diagnostic criteria, the consistencies in bone mass assessment and the differences in diagnosis of osteoporosis among vertebral combinations of T12+L1, T12+L2, T12*+L1, T12*+L2 and L1+L2 were analyzed, respectively. Results: There were good consistencies between vertebral combinations and L1+L2 in bone mass assessment (all Kappa>0.75, all P98%. The sensitivities of T12+L1 and T12+L2 in osteoporosis diagnosis were 73.33% (143/195) and 77.95% (152/195), respectively, whereas of T12*+L1 and T12*+L2 in osteoporosis diagnosis were 83.08% (162/195) and 90.26% (176/195), respectively. Conclusion: BMD of T12 for replacing abnormal L1 or L2 during quantitative CT can reduce the sensitivity in diagnosis of osteoporosis, therefore BMD of T12 should be calibrated in measurement.