Physical activity and physical function changes in obese individuals after gastric bypass surgery.

Background: Little is known about the effects of gastric bypass surgery (GBS) on physical activity and physical function. We examined the physical activity, physical function, psychosocial correlates to physical activity participation, and health-related quality of life of patients before and after GBS.

Methods: A total of 20 patients were assessed before and 3 months after GBS. Physical activity was assessed using the 7-day physical activity recall questionnaire and a pedometer worn for 7 days. Physical function was assessed using the 6-minute walk test, Short Physical Performance Battery, and the physical function subscale of the Medical Outcomes Short Form-36 (SF-36). The Physical Activity Self-Efficacy questionnaire, the Physical Activity Barriers and Outcome Expectations questionnaire, the SF-36, and the Numeric Pain Rating Scale were also administered.

Results: Physical activity did not significantly increase from before (191.1 +/- 228.23 min/wk) to after (231.7 +/- 230.04 min/wk) GBS (n = 18); however, the average daily steps did significantly increase (from 4621 +/- 3701 to 7370 +/- 4240 steps/d; n = 11). The scores for the 6-minute walk test (393 +/- 62.08 m to 446 +/- 41.39 m; n = 17), Short Physical Performance Battery (11.2 +/- 1.22 to 11.7 +/- .57; n = 18), physical function subscale of the SF-36 (65 +/- 18.5 to 84.1 +/- 19.9), and the total SF-36 (38.2 +/- 23.58 to 89.7 +/- 15.5; n = 17) increased significantly. The Numeric Pain Rating Scale score decreased significantly for low back (3.5 +/- 1.8 to 1.7 +/- 2.63), knee (2.4 +/- 2.51 to 1.0 +/- 1.43), and foot/ankle (2.3 +/- 2.8 to 0.9 +/- 2.05) pain. No significant changes were found in the Physical Activity Self-Efficacy questionnaire or the Physical Activity Barriers and Outcome Expectations questionnaire.

Conclusion: GBS improves physical function, health-related quality of life, and self-reported pain and results in a modest improvement in physical activity. These are important clinical benefits of surgical weight loss. Long-term follow-up is needed to quantify the ability to sustain or further improve these important clinical outcomes.