Higher Impact Physical Activity is Associated with Maintenance of Bone Mineral Density but Not Reduced Incident Falls or Fractures in Older Men: The Concord Health and Ageing in Men Project.
J Bone Miner Res. 2020 Dec 05;: Authors: Ng CA, Scott D, Seibel MJ, Cumming RG, Naganathan V, Blyth FM, Le Couteur DG, Waite LM, Handelsman DJ, Hirani V
High-impact physical activities with bone strains of high magnitude and frequency may benefit bone health. This study aimed to investigate the longitudinal associations between changes in loading intensities and application rates, estimated from self-reported physical activity, with bone mineral density (BMD) changes over five years, and also with incident falls over two years and long-term incident fractures, in community-dwelling older men. 1,599 men (mean age 76.8±5.4 years) from the Concord Health and Ageing in Men Project (CHAMP) were assessed at baseline (2005-2007), 2-year and 5-year follow-up. At each time point, hip and lumbar spine BMD were measured by dual-energy x-ray absorptiometry, and physical activity energy expenditure over the past week was self-reported via the Physical Activity Scale for the Elderly (PASE) questionnaire. Sum effective load ratings (ELRs) and peak force were estimated from the PASE questionnaire, reflecting the total and highest loading intensity and application rate of physical activities, respectively. Participants were contacted every 4 months over two years to self-report falls, and over 6.0±2.2 years for fractures. Hip fractures were ascertained by data-linkage for 8.9±3.6 years. Compared to sum ELR and PASE scores, peak force demonstrated the greatest standardised effect size for BMD maintenance at the spine (β=9.77mg/cm2 ), total hip (β=14.14mg/cm2 ) and femoral neck (β=13.72mg/cm2 ) after adjustment for covariates, including PASE components (all p<0.01). Only PASE scores were significantly associated with reduced falls risk (standardised incident rate ratio=0.90, 95% confidence interval=0.81-1.00, p=0.04). All physical activity measures were significantly associated with reduced incident fractures in univariate analyses but none remained significant after multivariable adjustments. Older men who engaged in physical activity of high and rapid impact maintained higher BMD, while higher energy expenditure was associated with reduced falls risk. Coupling traditional physical activity data with bone loading estimates may improve understanding of the relationships between physical activity and bone health. This article is protected by copyright. All rights reserved. PMID: 33278306 [PubMed - as supplied by publisher]