UC San Diego

OBJECTIVE:To examine the association between leisure-time physical activity (PA) and survival to age 85 with mobility limitation or death before age 85 after total knee (TKR) or total hip replacement (THR) for osteoarthritis (OA). METHODS:This was a prospective study among participants from the Women's Health Initiative (WHI), recruited 1993-1998 (baseline age 65-79 yrs) and followed through 2012. Medicare claims data were linked to WHI data to determine TKR (n = 1986) and THR (n = 1034). Self-reported PA was collected before total joint replacement (TJR). RESULTS:Women who were physically inactive before THR had the highest risk of mobility limitation at age 85 (OR 2.36, 95% CI 1.30-4.26) compared with women who had the highest amount of PA [> 17.42 metabolic equivalent of task (MET)-hrs/week]. Women who reported no moderate to vigorous PA (MVPA) before THR had the strongest risk of mobility limitation (OR 2.00, 95% CI 1.24-3.22) compared with women with the highest level of MPVA (≥ 15 MET-hrs/week). Women who were physically inactive before TKR had the highest risk of mobility limitation (OR 1.68, 95% CI 1.15-2.45) compared with women who had the highest PA level. Women who reported no MVPA before TKR had the strongest risk of mobility limitation (OR 1.60, 95% CI 1.16-2.19) compared with women with the highest level of MPVA. There were significant dose-response associations of lower PA levels with increased risk of late-life mobility limitation and death. CONCLUSION:Women with lower PA levels before TJR were more likely to experience mobility limitation in late life following TJR for hip or knee OA.