Approximately 23% of Roux-en-Y gastric bypass (RYGB) patients met at least one definition of surgical treatment failure five years after surgery, according to a retrospective analysis of prospectively collected data from the Scandinavian Obesity Surgery Registry (SOReg). The authors reported that initial weight loss and early weight regain were strong predictive markers and could be used at an early stage to identify patients with a high risk of long-term failure. The findings, ‘Prevalence of insufficient weight loss 5 years after Roux-en-Y gastric bypass: metabolic consequences and prediction estimates: a prospective registry study’, were published in The BMJ Open.
The study investigators sought to examine the heterogeneity of weight loss five years after RYGB and the association with cardiometabolic health, and to model prediction estimates of surgical treatment failure. The definitions of surgical treatment failure five years after surgery were: (1)<50% excess BMI loss (%EBMIL); (2) <20% total weight loss (%TWL), and; (3) BMI >35 kg/m2 where baseline was <50 kg/m2, or >40 kg/m2 if baseline BMI was >50 kg/m2.
The analysis included 5,936 participants (79.1% females) from 29 surgical units in Sweden, who underwent (RYGB) from 2007 to 2011. At baseline, the mean age was 39.4±9.0 years and BMI was 42.9±5.1 kg/m2 and a t five years, the overall mean BMI was 30.4±5.2, mean weight loss 35.8±13.8 kg, BMIL 12.6±4.7 kg/m2, %EBMIL 72.2±25.2% and %TWL 29.1±9.8%.
Inadequate weight loss (ie, <25% TWL from baseline to year one) was identified in 17.1% of 5,596 participants with available data. Early weight regain (between year one and two) was identified in over a third (38.7%) of 5,010 participants with available data, with a mean increase of 4.5±3.9 kg (range 1–38 kg), compared with a mean decrease of 4.4±5.1 kg (range 66–0 kg) in the no regain group. Long-term weight change from baseline to year five was:>15% regain (+17.7±7.2 kg, range 7–101 kg) in 19.9%, 0.1%–15% regain (+5.7±3.5 kg, range 0 to 19 kg) in 59.3% and no weight regain (−5.0±5.2 kg, range −36 to 0 kg) in 20.8%.
The prevalence of meeting at least one of the three definitions of surgical treatment failure five years after RYGB was 23.1% (n=1,371) and the distribution between the three definitions was 19.2% (n=1,138) for <50%EBMIL, 17.0% (n=1,010) for <20% TWL and 14.1% (n=835) for BMI>35 or >40 kg/m2. The authors noted a substantial overlap, 39.8% (n=545) meeting all three definitions and 38.1% (n=522) meeting two of the three definitions.
They also found that surgical treatment failure was more common among patients with inadequate weight loss (60% vs 15.4%, p<.001) and early weight regain (33.8% vs 15.6%, p<.001). The criteria for failure were higher in participants with >15% regain (46.7%), followed by 0.1%–15% (21.1%) and no regain (5.1%), (p<.001). Patients with no long-term weight regain but surgical treatment failure (n=59) had higher baseline BMI (48.5 vs 43.1, p<.001) and lower %TWL at one-year and two-year follow-up (−18.0% vs −30.5% and −18.1% vs −32.3%, respectively, both p<.001).
The prevalence of cardiometabolic disease decreased from baseline to five years: T2D from 15.1% (n=896) to 6.4% (n=380), dyslipidaemia from 60.7% (n=3603) to 16.4% (n=974) and hypertension from 28.4% (n=1683) to 18.9% (n=1124). Adjusted for sex, age, BMI and corresponding cardiometabolic disease at baseline confirmed an association between surgical treatment failure and cardiometabolic disease at five years.
Interestingly, the authors reported that missing data analysis revealed rates of surgical treatment failure at years one and two higher in the 28.6% that were lost to follow-up year five, suggesting that the actual proportion of surgical treatment failure may be higher than the results indicate.
“RYGB is associated with improvement of obesity-related comorbidity. However, 23% of the patients developed surgical treatment failure five years after surgery, which was associated with a markedly increased risk of cardiometabolic disease. Initial weight loss and early weight regain were strong predictive markers that can be used for the early identification of patients with a high risk of long-term failure,” the authors concluded. “This study underlines the need for long-term follow-up of patients undergoing bariatric surgery by a multidisciplinary team and improved additional behavioural and pharmacological treatment post-surgery are warranted.”
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