title: Changes in physical activity, sedentary time, and risk of falling: The Women's Health Initiative Observational Study.
abstract: Falling significantly affects quality of life, morbidity, and mortality among older adults. We sought to evaluate the prospective association between sedentary time, physical activity, and falling among post-menopausal women aged 50-79years recruited to the Women's Health Initiative Observational Study between 1993 and 1998 from 40 clinical centers across the United States. Baseline (B) and change in each of the following were evaluated at year 3 (Y3) and year 6 (Y6; baseline n=93,676; Y3 n=76,598; Y6 n=75,428): recreational physical activity (MET-h/wk), sitting, sleeping (min/day), and lean body mass by dual energy X-ray absorptiometry (subset N=6475). Falls per year (0, 1, 2, ≥3) were assessed annually by self-report questionnaire and then dichotomized as ≤1 and ≥2falls/year. Logistic regression models were adjusted for demographics, body mass index, fall history, tobacco and alcohol use, medical conditions, and medications. Higher baseline activity was associated with greater risk of falling at Y6 (18%; p for trend <0.0001). Increasing sedentary time minimally decreased falling (1% Y3; 2% Y6; p<0.05). Increasing activity up to ≥9MET-h/wk. (OR: 1.12, 95% CI: 1.03-1.22) or maintaining ≥9MET-h/wk. (OR: 1.20, 95% CI: 1.13-1.29) increased falling at Y3 and Y6 (p for trend <0.001). Adding lean body mass to the models attenuated these relationships. Physically active lifestyles increased falling among post-menopausal women. Additional fall prevention strategies, such as balance and resistance training, should be evaluated to assist post-menopausal women in reaching or maintaining levels of aerobic activity known to prevent and manage several chronic diseases.
authors.affiliation: University of Arizona, Cancer Center, 1515 N. Campbell Ave., Tucson, AZ 85724, United States. Electronic address: jbea@uacc.arizona.edu.
authors.forename: Jennifer W
authors.initials: JW
authors.lastname: Bea
authors.affiliation: University of Arizona, 3950 S Country Club Rd., Suite 330, Tucson, AZ 85714, United States.
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Thomson
authors.affiliation: University of Iowa, 145 N Riverside Dr., Iowa City, IA 52242, United States.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Wallace
authors.affiliation: Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, M3-A410, Seattle, WA 98109, United States.
authors.forename: Chunyuan
authors.initials: C
authors.lastname: Wu
authors.affiliation: Cornell University, Savage Hall, Room 412, Ithaca, NY 14853, United States.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Seguin
authors.affiliation: University of Arizona, 3950 S Country Club Rd., Suite 330, Tucson, AZ 85714, United States.
authors.forename: Scott B
authors.initials: SB
authors.lastname: Going
authors.affiliation: University of California, San Diego, 9500 Gilman Dr., #0725, La Jolla, CA 92093, United States.
authors.forename: Andrea
authors.initials: A
authors.lastname: LaCroix
authors.affiliation: Brown University, 111 Brewster Street, Pawtucket, RI 02860, United States.
authors.forename: Charles
authors.initials: C
authors.lastname: Eaton
authors.affiliation: University of Massachusetts, 55 Lake Ave North, S7-746, Worcester, MA 01655, United States.
authors.forename: Judith K
authors.initials: JK
authors.lastname: Ockene
authors.affiliation: University at Buffalo, State University of New York, 273 Farber Hall, Buffalo, NY 14214, United States.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: LaMonte
authors.affiliation: Ohio State University, 376 W 10th Avenue, Suite 205, Columbus, OH 43210, United States.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Jackson
authors.affiliation: Ohio State University, 2050 Kenny Road, Columbus, OH 43221, United States.
authors.forename: W
authors.initials: W
authors.lastname: Jerry Mysiw
authors.affiliation: University at Buffalo, State University of New York, 410 Kimball Hall, Buffalo, NY 14214, United States.
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control / Q000706:statistics & numerical data*; D000368:Aged; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D011998:Recreation; D012307:Risk Factors; D057185:Sedentary Behavior; D014481:United States; D016387:Women's Health / Q000706:statistics & numerical data*
keywords: Accidental falls; Exercise; Falls; Menopause; Sedentary lifestyle