Association of Physical Activity and Fracture Risk Among Postmenopausal Women
AuthorLaMonte, Michael J
Larson, Joseph C
Robbins, John A
LeBoff, Meryl S
Jackson, Rebecca D
LaCroix, Andrea Z
Ockene, Judith K
Hovey, Kathleen M
Cauley, Jane A
AffiliationUniv Arizona, Mel & Enid Zuckerman Coll Publ Hlth, Div Epidemiol & Biostat
MetadataShow full item record
PublisherAMER MEDICAL ASSOC
CitationLaMonte MJ, Wactawski-Wende J, Larson JC, et al. Association of Physical Activity and Fracture Risk Among Postmenopausal Women. JAMA Netw Open. 2019;2(10):e1914084. doi:https://doi.org/10.1001/jamanetworkopen.2019.14084
JournalJAMA NETWORK OPEN
RightsCopyright © 2019 LaMonte MJ et al. JAMA Network Open. This is an open access article distributed under the terms of the CC-BY License.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractIMPORTANCE Physical activity is inversely associated with hip fracture risk in older women. However, the association of physical activity with fracture at other sites and the role of sedentary behavior remain unclear. OBJECTIVE To assess the associations of physical activity and sedentary behavior with fracture incidence among postmenopausal women. DESIGN, SETTING, AND PARTICIPANTS The Women's Health Initiative prospective cohort study enrolled 77 206 postmenopausal women aged 50 to 79 years between October 1993 and December 1998 at 40 US clinical centers. Participants were observed for outcomes through September 2015, with data analysis conducted from June 2017 to August 2019. EXPOSURES Self-reported physical activity and sedentary time. MAIN OUTCOMES AND MEASURES Hazard ratios (HRs) and 95% CIs for total and site-specific fracture incidence. RESULTS During a mean (SD) follow-up period of 14.0 (5.2) years among 77 206 women (mean [SD] age, 63.4 [7.3] years; 66 072 [85.6%] white), 25 516 (33.1%) reported a first incident fracture. Total physical activity was inversely associated with the multivariable-adjusted risk of hip fracture (>17.7 metabolic equivalent [MET] h/wk vs none: HR, 0.82; 95% CI, 0.72-0.95; P for trend < .001). Inverse associations with hip fracture were also observed for walking (>7.5 MET h/wk vs none: HR, 0.88; 95% CI, 0.78-0.98; P for trend = .01), mild activity (HR, 0.82; 95% CI, 0.73-0.93; P for trend = .003), moderate to vigorous activity (HR, 0.88; 95% CI, 0.81-0.96; P for trend = .002), and yard work (HR, 0.90; 95% CI, 0.82-0.99; P for trend = .04). Total activity was positively associated with knee fracture (>17.7 MET h/wk vs none: HR, 1.26; 95% CI, 1.05-1.50; P for trend = .08). Mild activity was associated with lower risks of clinical vertebral fracture (HR, 0.87; 95% CI, 0.78-0.96; P for trend = .006) and total fractures (HR, 0.91; 95% CI, 0.87-0.94; P for trend < .001). Moderate to vigorous activity was positively associated with wrist or forearm fracture (HR, 1.09; 95% CI, 1.03-1.15; P for trend = .004). After controlling for covariates and total physical activity, sedentary time was positively associated with total fracture risk (>9.5 h/d vs <6.5 h/d: HR, 1.04; 95% CI, 1.01-1.07; P for trend = .01). When analyzed jointly, higher total activity mitigated some of the total fracture risk associated with sedentary behavior. Analysis of time-varying exposures resulted in somewhat stronger associations for total physical activity, whereas those for sedentary time were materially unchanged. CONCLUSIONS AND RELEVANCE In older ambulatory women, higher total physical activity was associated with lower total and hip fracture risk but higher knee fracture risk. Mild activity and walking were associated with lower hip fracture risk, a finding with important public health implications because these activities are common in older adults. The positive association between sedentary time and total fracture risk requires further investigation.
NoteOpen access journal
VersionFinal published version
SponsorsNational Heart, Lung, and Blood Institute, National Institutes of Health, US Department of Health and Human ServicesUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Heart Lung & Blood Institute (NHLBI) [HHSN268201600018C, HHSN268201600001C, HHSN268201600002C, HHSN268201600003C, HHSN268201600004C]
Except where otherwise noted, this item's license is described as Copyright © 2019 LaMonte MJ et al. JAMA Network Open. This is an open access article distributed under the terms of the CC-BY License.