Wayne Yang, MD, Keith Gersin, MD, Dimitrios Stefanidis, MDPhD, Timothy Kuwada, MD. Carolinas Medical Center
Background: Previous studies have sought to identify early predictors of poor weight loss response that would allow interventions to be pursued sooner following bariatric surgery. Our goal was to identify the earliest interval at which failure to meet a threshold of weight loss would predict inadequate results at 12 months post-operatively for Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG).
Methods: We performed a retrospective review of consecutive patients who underwent bariatric surgery by a single surgeon between January 2012 and September 2014. We included patients who had complete follow-up information at 2 weeks, 3 months, 6 months, and 12 months post-operatively. Weight loss at each interval was expressed as a percentage of excess body weight lost using day of surgery weight as a baseline. Failure to lose adequate weight was defined as less than 45% excess body weight loss at 12 months. Unpaired t-tests were used to compare 3 month weights between those who ultimately lost more than 45% of excess body weight at 12 months and those who did not. Fisher's exact test was then used to assess whether failure to reach a mean 3 month excess body weight loss of 36% would be predictive of failure.
Results: 356 patients were initially identified, 150 of which had complete follow-up information (RYGB=62 and SG=88). A wide range of percent excess weight loss was observed at one year following RYGB (mean 56.2%, range 22.1% to 100.0%) and SG (mean 46.4%, range -1.3% to 113.2%). Mean excess body weight loss at 3 months was significantly higher in those who ultimately achieved weight loss success at 12 months than in those who failed in both RYGB (36.6% vs 23.8%, p<0.0001) and SG (37.1% vs 25.6%, p<0.0001). Of those who did not achieve at least 36% excess body weight loss at 3 months, there were significantly more weight loss failures at 12 months for both RYGB (43.2% vs 16.0%, p=0.0294) and SG (62.3% vs 22.2%, p=0.0010).
Conclusions: Patients at higher risk for eventual weight loss failure can be identified at three months post-operatively. Thus, supplemental weight loss therapy should be considered at this relatively early junction. More studies are required to determine whether earlier post-operative interventions in those at risk individuals will be beneficial.