Association of body mass index and community mobility among older adults with osteoarthritis knee

Abstract

Background:Obesity is common among physically inactive older adults with osteoarthritis (OA) knee. Obesity has been shown to affect the joint mechanics as increased body mass can increase the mechanical stress on joints, causing disarrangements or abnormalities. In addition, obesity may increase disability in OAdue to a decrease in lower-extremity performance. Adequate mobility and balance are needed in order to ambulate independently in the community. Mobility limitations (reduced ability to ambulate in indoors and community) in older adults with knee OA found to increase risk for falls. Studies investigating the relationship between BMI andmobility have focused on individuals with severe obesity, and few studies have examined the relationship between BMI and community mobility among older adults with OA knee. Purpose: To examine the association between BMI and community mobility among older adults with OA knee. Methods: Participants were a sample of convenience of 75 older adults diagnosed with OA knee who were receiving out-patient physiotherapy from a tertiary care hospital. Before enrolment, written informed consent was obtained from all the participants. Participants diagnosed according to the American College of Rheumatology Clinical ClassificationCriteria forOsteoarthritis of the kneewere included in the study (N= 75,mean age 57.8± 5.4, 61 females).Wecollected demographic information and baseline measures including disease severity using includingKellegren and Lawrence system for classification of osteoarthritis of knee by radiographic examination (grade I (N= 28), grade II (N= 33), grade III (N= 14)), pain intensity at rest (mean score 2.2± 1.1) and duringwalking using numerical pain rating scale (mean score 4.8± 1.8), and fall history in past one year using self report. BMI was calculated using standardized height and weight measurements. Communitymobility was examined using the community balance and mobility scale, a performance measure composed of 13 challenging tasks used to detect ‘high level’ balance and mobility deficits based on tasks that are commonly encountered in community environments. Community balance and mobility scale is a standardized and validatedmeasure of communitymobility andbalance among elderly adults with OA knee. We compared the mean scores of community balance and mobility scale scores across BMI classifications using oneway ANOVA. Results:Communitymobility and balance is significantly different across various BMI classifications (p= 0.000). Participants with severe obesity (n= 6, mean18.3± 4.93), moderately obese (n= 24, mean21.7± 6.64), and overweight (n= 31, mean34.9± 12.29), had the lowest levels of balance and mobility score when compared to participants with normal weight (n= 14, mean68.5± 7.26). In addition we also found that participants who had a history of fall in the past year had lower scores (21.1± 8.2) than those with no history of fall (41.5± 19.3). Conclusion(s): In older adults with OA knee, obesity is associated with increased balance and mobility deficits related to community environment.We believe that clinicians should consider incorporating education program that communicates patients about the likelihood of increased risk of fall associated with obesity in older adults with OA knee. Implications: Results of this research could lead to more efforts directed towardsmeasuring risk of fall and developing fall prevention interventions among obese elderly adults with OA knee.