Predictors of Weight Loss and Effectiveness of Roux-en-Y Gastric Bypass in the Morbidly Obese Hispano-American Population

Abstract

Co-morbidities and the metabolic response to intervention in morbid obesity have been reported to vary among different ethnic groups. We compared the rate of weight loss, effectiveness of gastric bypass surgery, and variables influencing success after gastric bypass in Hispanics compared to Caucasians. Morbidly obese adult (>18 years old) patients (body mass index [BMI] 40 or above) evaluated by our bariatric group from 2005 to 2006 who underwent Roux-en-Y gastric bypass (RYGBP) were studied. Every patient was evaluated for height, weight, BMI, percent body fat, fat mass, serum metabolic analysis (SMA) 12, lipid profile, complete blood count (CBC), iron, ferritin, Vitamins A, D, and B1, complete urinalysis and Fibrospect score II. Weight loss was evaluated at 1, 3, 6, and 12 months. Seventy-five patients underwent successful open RYGBP with no mortality. Regardless of the significant difference in age and co-morbidities, the mean percentage of total weight loss after 1 year of follow-up was 32% for Hispanics and 30% for Caucasians with no significant difference (p > .5). When comparing the percentage of excess weight lost (% EWL) at 1, 3, 6, and 12 months, there was no significant difference between both groups. Using multiple regression analysis, we found that high-density lipoprotein (HDL) and systolic blood pressure (SBP) significantly predicted EWL at 12 months in Caucasians and Fibrospect predicted significantly EWL at 1 year. At 1 year after RYGBP, both ethnic groups lost approximately 77-80% of their EWL and BMI. All Caucasians and 95.7% of Hispanics achieved successful weight loss (>50% EWL).