Change in Pain and Physical Function Following Bariatric Surgery for Severe Obesity
Authors: Wendy C. King, Jia-Yuh Chen, Steven H. Belle, Anita P. Courcoulas, Gregory F. Dakin, Katherine A. Elder, David R. Flum, Marcelo W. Hinojosa, James E. Mitchell, Walter J. Pories, Bruce M. Wolfe, Susan Z. Yanovski
Journal: JAMA (2016)

<h3>Importance</h3> The variability and durability of improvements in pain and physical function following Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB) are not well described. <h3>Objectives</h3> To report changes in pain and physical function in the first 3 years following bariatric surgery, and to identify factors associated with improvement. <h3>Design, Setting, and Participants</h3> The Longitudinal Assessment of Bariatric Surgery-2 is an observational cohort study at 10 US hospitals. Adults with severe obesity undergoing bariatric surgery were recruited between February 2005 and February 2009. Research assessments were conducted prior to surgery and annually thereafter. Three-year follow-up through October 2012 is reported. <h3>Exposures</h3> Bariatric surgery as clinical care. <h3>Main Outcomes and Measures</h3> Primary outcomes were clinically meaningful presurgery to postsurgery improvements in pain and function using scores from the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) (ie, improvement of ≥5 points on the norm-based score [range, 0-100]) and 400-meter walk time (ie, improvement of ≥24 seconds) using established thresholds. The secondary outcome was clinically meaningful improvement using the Western Ontario McMaster Osteoarthritis Index (ie, improvement of ≥9.7 pain points and ≥9.3 function points on the transformed score [range, 0-100]). <h3>Results</h3> Of 2458 participants, 2221 completed baseline and follow-up assessments (1743 [78.5%] were women; median age was 47 years; median body mass index [BMI] was 45.9; 70.4% underwent RYGB; 25.0% underwent LAGB). At year 1, clinically meaningful improvements were shown in 57.6% (95% CI, 55.3%-59.9%) of participants for bodily pain, 76.5% (95% CI, 74.6%-78.5%) for physical function, and 59.5% (95% CI, 56.4%-62.7%) for walk time. Additionally, among participants with severe knee or disability (633), or hip pain or disability (500) at baseline, approximately three-fourths experienced joint-specific improvements in knee pain (77.1% [95% CI, 73.5%-80.7%]) and in hip function (79.2% [95% CI, 75.3%-83.1%]). Between year 1 and year 3, rates of improvement significantly decreased to 48.6% (95% CI, 46.0%-51.1%) for bodily pain and to 70.2% (95% CI, 67.8%-72.5%) for physical function, but improvement rates for walk time, knee and hip pain, and knee and hip function did not (<i>P</i>for all ≥.05). Younger age, male sex, higher income, lower BMI, and fewer depressive symptoms presurgery; no diabetes and no venous edema with ulcerations postsurgery (either no history or remission); and presurgery-to-postsurgery reductions in weight and depressive symptoms were associated with presurgery-to-postsurgery improvements in multiple outcomes at years 1, 2, and 3. <h3>Conclusions and Relevance</h3> Among a cohort of participants with severe obesity undergoing bariatric surgery, a large percentage experienced improvement, compared with baseline, in pain, physical function, and walk time over 3 years, but the percentage with improvement in pain and physical function decreased between year 1 and year 3. <h3>Trial Registration</h3> clinicaltrials.gov Identifier:NCT00465829