A E Litwic1,2, L D Westbury1, K Ward1, C Cooper1,3,4, E M Dennison5,6. 1. MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK. 2. Department of Nephrology, Transplantology and Internal Medicine, Medical University of Gdańsk, Gdańsk, Poland. 3. NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK. 4. NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK. 5. MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK. emd@mrc.soton.ac.uk. 6. Victoria University of Wellington, Wellington, New Zealand. emd@mrc.soton.ac.uk.
Abstract
Low body mass index (BMI) is an established risk factor for fractures in postmenopausal women but the interaction of obesity with bone microarchitecture is not fully understood. In this study, obesity was associated with more favourable bone microarchitecture parameters but not after parameters were normalised for body weight. INTRODUCTION: To examine bone microarchitecture in relation to fat mass and examine both areal bone mineral density (aBMD) and microarchitecture in relation to BMI categories in the UK arm of the Global Longitudinal Study of Osteoporosis in Women. METHODS: Four hundred and ninety-one women completed questionnaires detailing medical history; underwent anthropometric assessment; high-resolution peripheral quantitative computed tomography (HRpQCT) scans of the radius and tibia and DXA scans of whole body, proximal femur and lumbar spine. Fat mass index (FMI) residuals (independent of lean mass index) were derived. Linear regression was used to examine HRpQCT and DXA aBMD parameters according to BMI category (unadjusted) and HRpQCT parameters in relation to FMI residuals (with and without adjustment for anthropometric, demographic and lifestyle covariates). RESULTS: Mean (SD) age was 70.9 (5.4) years; 35.0% were overweight, 14.5% class 1 obese and 7.7% class 2/3 obese. There were significant increasing trends according to BMI category in aBMD of whole body, hip, femoral neck and lumbar spine (p ≤ 0.001); cortical area (p < 0.001), thickness (p < 0.001) and volumetric density (p < 0.03), and trabecular number (p < 0.001), volumetric density (p < 0.04) and separation (p < 0.001 for decreasing trend) at the radius and tibia. When normalised for body weight, all HRpQCT and DXA aBMD parameters decreased as BMI increased (p < 0.001). FMI residuals were associated with bone size and trabecular architecture at the radius and tibia, and tibial cortical microarchitecture. CONCLUSION: Significant trends in HRpQCT parameters suggested favourable bone microarchitecture at the radius and tibia with increasing BMI but these were not proportionate to increased weight.
Low body mass index (BMI) is an established risk factor for fractures in postmenopausal women but the interaction of obesity with bone microarchitecture is not fully understood. In this study, obesity was associated with more favourable bone microarchitecture parameters but not after parameters were normalised for body weight. INTRODUCTION: To examine bone microarchitecture in relation to fat mass and examine both areal bone mineral density (aBMD) and microarchitecture in relation to BMI categories in the UK arm of the Global Longitudinal Study of Osteoporosis in Women. METHODS: Four hundred and ninety-one women completed questionnaires detailing medical history; underwent anthropometric assessment; high-resolution peripheral quantitative computed tomography (HRpQCT) scans of the radius and tibia and DXA scans of whole body, proximal femur and lumbar spine. Fat mass index (FMI) residuals (independent of lean mass index) were derived. Linear regression was used to examine HRpQCT and DXA aBMD parameters according to BMI category (unadjusted) and HRpQCT parameters in relation to FMI residuals (with and without adjustment for anthropometric, demographic and lifestyle covariates). RESULTS: Mean (SD) age was 70.9 (5.4) years; 35.0% were overweight, 14.5% class 1 obese and 7.7% class 2/3 obese. There were significant increasing trends according to BMI category in aBMD of whole body, hip, femoral neck and lumbar spine (p ≤ 0.001); cortical area (p < 0.001), thickness (p < 0.001) and volumetric density (p < 0.03), and trabecular number (p < 0.001), volumetric density (p < 0.04) and separation (p < 0.001 for decreasing trend) at the radius and tibia. When normalised for body weight, all HRpQCT and DXA aBMD parameters decreased as BMI increased (p < 0.001). FMI residuals were associated with bone size and trabecular architecture at the radius and tibia, and tibial cortical microarchitecture. CONCLUSION: Significant trends in HRpQCT parameters suggested favourable bone microarchitecture at the radius and tibia with increasing BMI but these were not proportionate to increased weight.
Authors: Janne Pesonen; Joonas Sirola; Marjo Tuppurainen; Jukka Jurvelin; Esko Alhava; Risto Honkanen; Heikki Kröger Journal: Osteoporos Int Date: 2005-06-16 Impact factor: 4.507
Authors: C De Laet; J A Kanis; A Odén; H Johanson; O Johnell; P Delmas; J A Eisman; H Kroger; S Fujiwara; P Garnero; E V McCloskey; D Mellstrom; L J Melton; P J Meunier; H A P Pols; J Reeve; A Silman; A Tenenhouse Journal: Osteoporos Int Date: 2005-06-01 Impact factor: 4.507
Authors: Carrie M Nielson; Mary L Bouxsein; Sinara S Freitas; Kristine E Ensrud; Eric S Orwoll Journal: J Clin Endocrinol Metab Date: 2008-11-18 Impact factor: 5.958
Authors: Andrew J Burghardt; Galateia J Kazakia; Sweta Ramachandran; Thomas M Link; Sharmila Majumdar Journal: J Bone Miner Res Date: 2010-05 Impact factor: 6.741