Walker MD, Liu XS, Zhou B, Agarwal S, Liu G, McMahon DJ, Bilezikian JP, Guo XE
Pre- and postmenopausal differences in bone microstructure and mechanical competence in Chinese-American and white women.
Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. 2013 Jan 08;
INTRODUCTION: Compared to white women, premenopausal Chinese-American women have more plate-like trabecular (Tb) bone. It is unclear whether these findings are relevant to postmenopausal women and if there are racial differences in the deterioration of bone microarchitecture with aging. METHODS: We applied individual trabecula segmentation and finite element analysis to high-resolution peripheral quantitative computed tomography images in pre- and postmenopausal Chinese-American and white women to quantify within-race age-related differences in Tb plate- versus rod-microarchitecture and bone stiffness. Race-menopause interactions were assessed. Comparisons between races within menopause status were adjusted for age, height and weight. Comparisons between pre- and postmenopausal women were adjusted for height and weight. RESULTS: Adjusted analyses at the radius indicated that premenopausal Chinese-Americans had a higher plate bone volume fraction (pBV/TV), Tb plate-to-rod ratio (P-R Ratio), and greater plate-plate junction densities (P-P Junc.D) versus white women (all p<0.01), resulting in 27% higher Tb stiffness (p<0.05). Greater cortical thickness and density (Ct.Th & Dcort) and more Tb plates led to 19% greater whole bone stiffness (p<0.05). Postmenopausal Chinese-Americans had similar pBV/TV and P-P Junc.D, yet higher P-R ratio versus white women. Postmenopausal Chinese-American versus white women had greater Ct.Th, Dcort and relatively intact Tb plates, resulting in similar Tb stiffness but 12% greater whole bone stiffness (p<0.05). In both races, Ct.Th and Dcort were lower in post- versus premenopausal women and there were no differences between races. Tb plate parameters were also lower in post- vs. premenopausal women, but age-related differences in pBV/TV, P-R ratio and P-P Junc D were greater (p<0.05) in Chinese-Americans versus white women. CONCLUSION: There are advantages in cortical and Tb bone in premenopausal Chinese-American women. Within-race cross-sectional differences between pre- and postmenopausal women suggest greater loss of plate-like Tb bone with aging in Chinese-Americans, though thicker cortices and more plate-like Tb bone persists. © 2013 American Society for Bone and Mineral Research.