Which preoperative clinical factors are associated with long-term postoperative weight loss after Roux-en-Y gastric bypass (RYGB)?
This retrospective analysis of 726 RYGB patients 7 or more years after surgery found that preoperative insulin use, history of smoking, and use of 12 or more medications were significantly associated with greater long-term postoperative weight loss. Preoperative hyperlipidemia, older age, and higher body mass index were significantly associated with poorer long-term postoperative weight loss.
Preoperative identification of patients at higher risk for long-term suboptimal outcomes can help to guide clinical care, and identification of potentially modifiable risk factors has the potential to improve surgical outcomes.
Weight loss after bariatric surgery varies, yet preoperative clinical factors associated with long-term suboptimal outcomes are not well understood.
To evaluate the association between preoperative clinical factors and long-term weight loss after Roux-en-Y gastric bypass (RYGB).
Design, Setting, and Participants
From June 2001 to September 2007, this retrospective cohort study followed up RYGB patients before surgery to 7 to 12 years after surgery. The setting was a large rural integrated health system. Of 1033 eligible RYGB patients who consented to participate in longitudinal research and completed surgery before October 2007, a total of 726 (70.3%) had a weight entered in the electronic medical record 7 or more years after surgery and were included in the analyses after exclusions for pregnancy and mortality. Date of the long-term weight measurement was recorded between August 2010 and January 2016.
Main Outcomes and Measures
The primary outcome was percentage weight loss (%WL) at 7 to 12 years after surgery. Preoperative clinical factors (>200) extracted from the electronic medical record included medications, comorbidities, laboratory test results, and demographics, among others.
Among the 726 study participants, 83.1% (n = 603) were female and 97.4% (n = 707) were of white race, with a mean (SD) preoperative body mass index (calculated as weight in kilograms divided by height in meters squared) of 47.5 (7.4). From the time of surgery to long-term follow-up (median, 9.3 postoperative years), the mean (SD) %WL was 22.5% (13.1%). Preoperative insulin use, history of smoking, and use of 12 or more medications before surgery were associated with greater long-term postoperative %WL (6.8%, 2.8%, and 3.1%, respectively). Preoperative hyperlipidemia, older age, and higher body mass index were associated with poorer long-term postoperative %WL (−2.8%, −8.8%, and −4.1%, respectively).
Conclusions and Relevance
Few preoperative clinical factors associated with long-term weight loss after RYGB were identified. Preoperative insulin use was strongly associated with better long-term %WL, while preoperative hyperlipidemia, higher body mass index, and older age were associated with poorer %WL. Our findings provide additional insight into preoperative identification of RYGB patients at higher risk for long-term suboptimal outcomes.
Wood GC, Benotti PN, Lee CJ, Mirshahi T, Still CD, Gerhard GS, Lent MR. Evaluation of the Association Between Preoperative Clinical Factors and Long-term Weight Loss After Roux-en-Y Gastric Bypass. JAMA Surg. 2016;151(11):1056-1062. doi:10.1001/jamasurg.2016.2334