Bone and muscle properties associated with fracture risk among persons living with HIV infection

About This Grant

Project Summary/Abstract People with human immunodeficiency virus (HIV) infection (PWH) experience rates of bone loss and subsequent fractures exceeding those of similarly aged people without HIV infection (PWoH). Bone mineral density (BMD) is known to decline substantially and quickly in PWH, and measurements of BMD are the most common method used to identify people in need of osteoporosis treatment. Yet evidence exists suggesting that other bone, muscle, and body composition characteristics differ for PWH compared to PWoH. We have little understanding of how, or if, variations in these other characteristics may affect an individual's fracture risk, and how identification of those PWH at highest risk of fracture could be improved with the consideration of other measures beyond BMD. The overall objective of this project is to improve identification of PWH at highest risk of fracture to enable targeted osteoporosis treatment and to reduce the burden of fractures among this vulnerable population. We will accomplish this by leveraging the Kaiser Permanente Southern California (KPSC) HIV Registry and rich electronic health records to study the association of HIV status with bone, muscle, and body composition characteristics, and then to use those measures, singly and in combinations, to improve prediction of fractures. All included cohort members will have qualifying CT scans available, and we will employ novel, non-invasive methods of biomechanical analyses of existing computed tomography scans (BCT+) to make these bone, muscle, and body composition measurements for sub-groups of the cohort with CTs taken during the 2 years prior to HIV diagnosis date and/or taken 2-5 years after HIV diagnosis date. The resulting group of PWH aged ≥40 with CT scans will be matched 1:1 on sex, race/ethnicity, and age at CT scan to PWoH. We then aim to 1) compare each BCT+ bone, muscle, and body composition measure (including BMD) by HIV status; and 2) evaluate whether the BCT+ measures, singly or in combinations, improve prediction of PWH at highest risk of fracture. Successful completion of this project will illuminate the contributions of bone and muscle parameters, independently and in combination, to the increased fracture risk observed among PWH, and provide critical information for refining the guidance on the screening for and treatment of bone health issues among PWH.