Age-related changes in lumbar bone mineral density measured using quantitative computed tomography in healthy female cynomolgus monkeys

Chunyuan Zeng; Bin Guo; Shaojuan Zhang; Ziqing Zhou; Qijun Cai; Lu Hou; Zhiqiang Tan; Jiefeng Gan; Jinci Mai; Ying Li; Yuefeng Li; Lu Wang; Jian Gong; Hao Xu

doi:10.21037/qims-22-763

Age-related changes in lumbar bone mineral density measured using quantitative computed tomography in healthy female cynomolgus monkeys

Quant Imaging Med Surg. 2023 Apr 1;13(4):2038-2052. doi: 10.21037/qims-22-763. Epub 2023 Feb 7.

Authors

Chunyuan Zeng^#¹, Bin Guo^#¹, Shaojuan Zhang¹, Ziqing Zhou¹, Qijun Cai¹, Lu Hou¹, Zhiqiang Tan¹, Jiefeng Gan¹, Jinci Mai¹, Ying Li¹, Yuefeng Li², Lu Wang¹, Jian Gong¹, Hao Xu¹

Affiliations

¹ Department of Nuclear Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, China.
² Guangdong Landau Biotechnology Co., Ltd., Guangzhou, China.

^# Contributed equally.

Abstract

Background: Cynomolgus monkeys are widely used in studies related to osteoporosis, and there is no evidence of age-related changes in volumetric bone mineral density (vBMD) measured using quantitative computed tomography (QCT) in nonhuman primates. This study aimed to describe changes in the characteristics of lumbar vBMD with age, to analyze the relationship between lumbar vBMD and body composition, and to investigate the precision of QCT measurements in healthy female cynomolgus monkeys.

Methods: Age-related changes in lumbar vBMD were described using cubic regression models, and the accumulated bone loss rates (ABLR) of the lumbar spine were calculated. Spearman rank correlation and ridge regression analysis were used to investigate the relationship of the average lumbar vBMD and body components. Thirty animals were selected to analyze the short-term in vivo precision of the QCT measurements. The precision was expressed as the root-mean-square coefficient of variation (RMS-CV%) or root-mean-square standard deviation (RMS-SD).

Results: A total of 72 healthy female cynomolgus monkeys, aged 1-25 years, were included in this study. The average lumbar vBMD of female cynomolgus monkeys increased with age until the age of 10 years, around which it reached peak bone mass, with a relatively marked decline after the age of 13 years. The ABLRs of female cynomolgus monkeys in the premenopausal (13-19 years) and postmenopausal age groups (20-25 years) were -4.9% and -21.2%, respectively. Ridge regression analysis showed that age and subcutaneous adipose tissue (SAT) contributed positively to the average lumbar vBMD in animals aged ≤10 years, whereas in animals aged >10 years, age contributed negatively to lumbar vBMD. The RMS-CV% (RMS-SD) of the lumbar vBMD measured using QCT ranged from 0.47% to 1.60% (1.91-6.31 mg/cm³).

Conclusions: Age-related changes in lumbar vBMD measured using QCT in healthy female monkeys showed similar trends to those in humans. Age and SAT may affect the lumbar vBMD in female cynomolgus monkeys. QCT revealed good precision in measuring the lumbar vBMD in female cynomolgus monkeys.

Keywords: Cynomolgus monkeys; precision; quantitative computed tomography (QCT); volumetric bone mineral density (vBMD).