Factors associated with different patterns of weight change after bariatric surgery: A longitudinal study

Abstract

Background Bariatric surgery is the most effective treatment for obesity. During long-term follow-up, weight loss (WL) is variable between subjects. The aim of this study is to assess the change in percentage of total weight loss (%TWL) and excess weight loss (%EWL) and to describe the factors associated with greater or lesser WL over time. Methods Longitudinal study including patients treated with laparoscopic Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (LSG) and followed at Hospital Universitario San Ignacio, Bogotá (Colombia). Baseline data was recorded before surgery. Follow-up was performed at 3 (n=192), 6 (n=190), 9 (n=188), 12 (n=186), 24 (n=99) and 36 (n=30) months. Generalized Estimating Equation (GEE) analysis was used to assess the change in %TWL and %EWL over time. Results 196 patients were included (82.4% female, BMI 41.3±5.2 kg/m2). The tendency to increase on %TWL (31.6±6.6) and %EWL (80.2 RIQ 70.7-97.3) was evident in the first year, stabilizing after that. Nutritionist follow-up, baseline BMI>40 kg/m2 and WL≥10kg before surgery were associated with an average higher increase of %TWL (2.39% p=0.014, 0.41% p<0.001 and 0.37% p=0.003, respectively). Subjects who performed physical activity >30 minutes/day after surgery reduced %TWL in 0.74% (p=0.009). Similar findings were described on %EWL. Conclusion Follow-up during the first year after bariatric surgery is critical to achieving %TWL and %EWL goals. This study suggests that modifiable factors such as nutritional follow-up, WL before surgery and time of physical activity are associated with a significant change in %TWL and %EWL during follow-up by a multidisciplinary team.