The impact of physical activity level on SF-36 role-physical and bodily pain indices in midlife women

Background: This study was done to determine whether physical activity at baseline is independently associated with musculoskeletal pain and fulfilling one's physical role over 3 subsequent years. Methods: Our research involved a 3-year longitudinal study of over 2400 community-dwelling, midlife women from the Study of Women's Health Across the Nation (SWAN). Measurements included baseline physical activity using the Kaiser Permanente Health Plan Activity Survey and SF-36 role-physical and bodily pain indices at each of 3 annual follow-up visits. Results: Each 1-point increase on the physical activity score was associated with a 7% greater likelihood of a high role-physical score (95% CI = 1.02-1.13) and a 10% greater likelihood of a low bodily pain score (95% CI = 1.04-1.17) after adjusting for age, race, menopausal status, educational level, body mass index, depressive symptoms, smoking, and chronic medical conditions. The association between physical activity level and role-physical score was eliminated in the fully adjusted model after adjustment for pain level in post hoc analysis [OR = 1.04 (95% CI = 0.98-1.09)]. Conclusion: This study demonstrates that women who are more physically active at midlife experience less bodily pain over time regardless of menopausal status, sociodemographics, and medical conditions. Higher physical activity level positively impacts fulfilling one's physical role; however, this is mediated by pain level.