William D Leslie1, Lisa M Lix1, Sumit R Majumdar2, Suzanne N Morin3, Helena Johansson4,5, Anders Odén4, Eugene V McCloskey4, John A Kanis4,5. 1. Department of Medicine, University of Manitoba, Winnipeg, Manitoba R3E 3P5, Canada. 2. Department of Medicine, University of Alberta, Edmonton, Alberta T6G 2G3, Canada. 3. Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada. 4. Centre for Metabolic Bone Diseases, University of Sheffield Medical School, Sheffield S10 2RX, United Kingdom. 5. Institute for Health and Aging, Catholic University of Australia, Melbourne, Victoria 3000, Australia.
Abstract
Context: Areal bone mineral density (BMD) measurements are confounded by skeletal size. Hip BMD is an input to the FRAX® tool (Centre for Metabolic Bone Diseases, University of Sheffield, United Kingdom), but it is unknown whether performance is affected by hip area. Objective: To examine whether fracture prediction by FRAX® is affected by hip area. Design and Setting: Cohort study using a population-based BMD registry. Patients: A total of 58,108 white women aged ≥40 years. Main Outcome Measures: Incident major osteoporotic fracture (MOF; n = 4913) and hip fracture (n = 1369), stratified by total hip area quintile, before and after adjustment for hip axis length (HAL). Results: Smaller hip area was associated with younger age and lower FRAX® scores, whereas incident fractures were greater in those with larger hip area (P for trend < 0.001). Larger hip area quintile increased risk for MOF and hip fracture when adjusted for FRAX® score with BMD (P for trend < 0.001). Each standard deviation increase in hip area was associated with greater risk for incident MOF [adjusted hazard ratio (HR), 1.08; 95% confidence interval (CI), 1.05 to 1.11] and hip fracture (HR, 1.16; 95% CI, 1.11 to 1.21), but not after adjustment for HAL. FRAX® with BMD underestimated MOF risk in the largest hip area quintile and underestimated hip fracture risk in the three largest hip area quintiles. Conclusions: In Canadian white women, skeletal size based on hip area affects fracture risk assessment based on FRAX® score with BMD, with risk underestimated in those with larger hip areas. Including HAL in the risk assessment compensates for this confounding by skeletal size and provides for more accurate assessment of fracture risk.
Context: Areal bone mineral density (BMD) measurements are confounded by skeletal size. Hip BMD is an input to the FRAX® tool (Centre for Metabolic Bone Diseases, University of Sheffield, United Kingdom), but it is unknown whether performance is affected by hip area. Objective: To examine whether fracture prediction by FRAX® is affected by hip area. Design and Setting: Cohort study using a population-based BMD registry. Patients: A total of 58,108 white women aged ≥40 years. Main Outcome Measures: Incident major osteoporotic fracture (MOF; n = 4913) and hip fracture (n = 1369), stratified by total hip area quintile, before and after adjustment for hip axis length (HAL). Results: Smaller hip area was associated with younger age and lower FRAX® scores, whereas incident fractures were greater in those with larger hip area (P for trend < 0.001). Larger hip area quintile increased risk for MOF and hip fracture when adjusted for FRAX® score with BMD (P for trend < 0.001). Each standard deviation increase in hip area was associated with greater risk for incident MOF [adjusted hazard ratio (HR), 1.08; 95% confidence interval (CI), 1.05 to 1.11] and hip fracture (HR, 1.16; 95% CI, 1.11 to 1.21), but not after adjustment for HAL. FRAX® with BMD underestimated MOF risk in the largest hip area quintile and underestimated hip fracture risk in the three largest hip area quintiles. Conclusions: In Canadian white women, skeletal size based on hip area affects fracture risk assessment based on FRAX® score with BMD, with risk underestimated in those with larger hip areas. Including HAL in the risk assessment compensates for this confounding by skeletal size and provides for more accurate assessment of fracture risk.
Authors: Erin Mr Bigelow; Daniella M Patton; Ferrous S Ward; Antonio Ciarelli; Michael Casden; Andrea Clark; Robert W Goulet; Michael D Morris; Stephen H Schlecht; Gurjit S Mandair; Todd L Bredbenner; David H Kohn; Karl J Jepsen Journal: J Bone Miner Res Date: 2019-02-04 Impact factor: 6.741
Authors: A Shieh; S Ishii; G A Greendale; J A Cauley; C Karvonen-Gutierrez; A S Karlamangla Journal: Osteoporos Int Date: 2019-08-31 Impact factor: 4.507