Factors Associated with Weight Loss After Metabolic Surgery in a Multiethnic Sample of 1012 Patients.

Background: Metabolic surgery is the most effective method for weight loss in the long-term treatment of morbid obesity and its comorbidities. The primary aim of this study was to examine factors associated with percent total weight loss (%TWL) after metabolic surgery among an ethnically diverse sample of patients.

Methods: A retrospective review was performed on 1012 patients who underwent either a sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) at our institution between January 2008 and June 2015.

Results: African Americans had a lower %TWL than non-Hispanic/Latino Whites at 6, 9, 12, 18, and 48 months. At all timeframes, there was a negative association between pre-surgery TWL and %TWL after surgery. Female sex was negatively associated with %TWL at 3 months only. Higher initial BMI was also associated with greater post-operative %TWL at 18, 24 and 36 months. Older patients had lower %TWL at 6, 9, 12 and 24 months post-surgery. Patients who received RYGB had greater %TWL than those who received SG at 3, 6, 9, 12, 24 and 36 months.

Conclusions: African Americans had a lower %TWL than non-Hispanic/Latino Whites at most time points; there were no other significant race/ethnicity or sex differences. BMI (greater initial BMI), age (lower) and RYGB were associated with a greater post-operative %TWL at certain post-surgery follow-up time points. A limitation of this study is that there was missing data at a number of time points due to lack of attendance at certain follow-up visits.