Summary: Peripheral quantitative computed tomography (pQCT) provides biomechanical estimates of bone strength. Rural South Indian men have reduced biomechanical indices of bone strength compared to US Caucasian and Afro-Caribbean men. This suggests an underlying higher risk of osteoporotic fractures and greater future fracture burden among the rural South Indian men. Introduction: Geographical and racial comparisons of bone mineral density (BMD) have largely focused on DXA measures of areal BMD. In contrast, peripheral quantitative computed tomography (pQCT) measures volumetric BMD (vBMD), bone structural geometry and provides estimates of biomechanical strength. To further understand potential geographical and racial differences in skeletal health, we compared pQCT measures among US Caucasian, Afro-Caribbean, and rural South Indian men. Methods: We studied men aged ≥ 60 years enrolled in the Mobility and Independent Living among Elders Study (MILES) in rural south India (N = 245), Osteoporotic Fractures in Men Study (MrOS) in the US (N = 1148), and the Tobago Bone Health Study (N = 828). Results: The BMI (kg/m2) of rural South Indian men (21.6) was significantly lower compared to the US Caucasians (28) and Afro-Caribbean men (26.9). Adjusting for age, height, body weight, and grip strength; rural South Indian men compared to US Caucasians had significantly lower trabecular vBMD [− 1.3 to − 1.5 standard deviation (SD)], cortical thickness [− 0.8 to − 1.2 SD]; significantly higher endosteal circumference [0.5 to 0.8 SD]; but similar cortical vBMD. Afro-Caribbean men compared to US Caucasians had similar trabecular vBMD but significantly higher cortical vBMD [0.9 to 1.2 SD], SSIp [0.2 to 1.4 SD], and tibial endosteal circumference [1 SD], Conclusions: In comparison to US Caucasians, rural South Indian men have reduced bone strength (lower trabecular vBMD) and Afro-Caribbean men have greater bone strength (higher cortical vBMD). These results suggest an underlying higher risk of osteoporotic fractures and greater future fracture burden among rural South Indian men.
Bibliographical noteFunding Information:
Acknowledgements The Osteoporotic Fractures in Men (MrOS) Study is supported by the National Institutes of Health funding. The following institutes provide support: the National Institute on Aging (NIA), the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), the National Center for Advancing Translational Sciences (NCATS), and NIH Roadmap for Medical Research under the following grant numbers: U01 AG027810, U01 AG042124, U01 AG042139, U01 AG042140, U01 AG042143, U01 AG042145, U01 AG042168, U01 AR066160, and UL1 TR000128. The Tobago Bone Health Study is supported in part by National Institutes of Health Grants R01-AR049747 from the National Institute of Arthritis and Musculoskeletal and Skin Diseases and R01-CA84950 from the National Cancer Institute. The Mobility and Independent Living in Elders Study (MILES) was carried out with institutional support from the University of Pittsburgh Graduate School of Public Health and SHARE INDIA. This study was approved by Health Screening Committee of Indian Council of Medical Research. This study did not receive any grant funding from foundations or commercial or not-for-profit agencies. Authors GRJ and PKS were trainees of the Fogarty International Center grant D43-TW009078.
© 2018, The Author(s).
- Volumetric BMD