The Relationship Between Prospectively Assessed Body Weight and Physical Activity and Prevalence of Radiological Knee Osteoarthritis in Postmenopausal Women
CASSANDRA SZOEKE, LORRAINE DENNERSTEIN, JANET GUTHRIE, MARGARET CLARK, and FLAVIA CICUTTINI
Objective. To determine the effect of weight and physical activity on the prevalence of radiological knee osteoarthritis (OA) in a cohort of middle-aged women.
Methods. The longitudinal phase of the Melbourne Women's Mid-life Health Project is a population-based prospective study of 438 Australian-born women who have been followed annually over 11 years. Of these women, 257 (59%) remained in longitudinal assessment at eleventh year of followup, and 224 of these women agreed to undergo radiographs of their knees. Radiographs were scored for features of OA [osteophytes and joint space narrowing (JSN)] using a validated scale, by 2 investigators who were blinded to questionnaire results. Data were obtained by both self-administered and face-to-face interview questionnaires.
Results. The average weight increase over the study period of 11 years was 4 kg (range –14 to 25 kg). Of the 224 women evaluated, 65 (29%) had knee joint osteophytes and 95 (42%) had evidence of knee JSN. Current weight and weight at baseline were independent factors associated with a higher prevalence of both osteophytes and JSN in all compartments of the knee. The average amount of physical activity over the 11 years of followup was a significant factor independently associated with an increased prevalence of patellofemoral JSN and approached significance for tibiofemoral osteophytes and total knee JSN.
Conclusion. Our study supports a longterm detrimental effect of weight on the knee joint and suggests the importance of longterm weight maintenance programs in preventing knee OA. The average amount of physical activity was associated with an increased prevalence of some features of knee OA. (First Release Aug 1 2006; J Rheumatol 2006;33:1835–40)
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From the Office for Gender and Health, Department of Psychiatry, University of Melbourne; Department of Medicine, The Royal Melbourne Hospital; Department of Epidemiology and Preventive Medicine, Monash University, Melbourne; and the Department of Rheumatology, Alfred Hospital, Prahran, Victoria, Australia.
Radiographs were funded by a grant from the Shepherd Foundation. Dr. Szoeke has received research funding from the Arthritis Foundation of Australia, the University of Melbourne (Viola Edith Scholarship and JA Thompson Prize), and the Royal Australian College of Physicians (Tweedle Fellowship). Data entry and analysis was supported by a grant from the Australian Menopausal Society. The Melbourne Women's Midlife Health Project baseline data collection was funded by the Victorian Health Promotion Foundation.
C.E.I. Szoeke, MBBS, Bsc (Hons), Office for Gender and Health, Department of Psychiatry, University of Melbourne and Department of Medicine, Royal Melbourne Hospital; L. Dennerstein, MBBS, FRANZCP, PhD, Professor; J.R. Guthrie, PhD; M.S. Clark, PhD, Office for Gender and Health, Department of Psychiatry, University of Melbourne; F.M. Cicuttini, MBBS, FRACP, PhD, Associate Professor, Department of Epidemiology and Preventive Medicine, Monash University and Department of Rheumatology, Alfred Hospital.
Address reprint requests to Dr. C.E.I. Szoeke, P.O. Box 2026, The Royal Melbourne Hospital, Parkville, 3050, Victoria, Australia. E-mail: Cassandra.Szoeke@mh.org.au
Accepted for publication May 9, 2006.