Predictors of weight status following laparoscopic gastric bypass.

Division of Preventive and Behavioral Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA.
Obesity Surgery (Impact Factor: 3.74). 09/2006; 16(9):1227-31. DOI: 10.1381/096089206778392284
Source: PubMed

ABSTRACT Weight loss after bariatric surgery varies and depends on many factors, such as time elapsed since surgery, baseline weight, and co-morbidities.
We analyzed weight data from 494 patients who underwent laparoscopic Roux-en-Y gastric bypass (RYGBP) by one surgeon at an academic institution between June 1999 and December 2004. Linear regression was used to identify factors in predicting % excess weight loss (%EWL) at 1 year.
Mean patient age at time of surgery was 44 +/- 9.6 (SD), and the majority were female (83.8%). The baseline prevalence of co-morbidities included 24% for diabetes, 42% for hypertension, and 15% for hypercholesterolemia. Baseline BMI was 51.5 +/- 8.5 kg/m(2). Mean length of hospital stay was 3.8 +/- 4.6 days. Mortality rate was 0.6%. Follow-up weight data were available for 90% of patients at 6 months after RYGBP, 90% at 1 year, and 51% at 2 years. Mean %EWL at 1 year was 65 +/- 15.2%. The success rate (> or = 50 %EWL) at 1 year was 85%. Younger age and lower baseline weight predicted greater weight loss. Males lost more weight than females. Diabetes was associated with a lower %EWL. Depression did not significantly predict %EWL.
The study demonstrated a 65 %EWL and 85% success rate at 1 year in our bariatric surgery program. Our finding that most pre-surgery co-morbidities and depression did not predict weight loss may have implications for pre-surgery screening.

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    ABSTRACT: Background. Current patient education and informed consent regarding weight loss expectations for bariatric surgery candidates are largely based on averages from large patient cohorts. The variation in weight loss outcomes illustrates the need for establishing more realistic weight loss goals for individual patients. This study was designed to develop a simple web-based tool which provides patient-specific weight loss expectations. Methods. Postoperative weight measurements after Roux-en-Y gastric bypass (RYGB) were collected and analyzed with patient characteristics known to influence weight loss outcomes. Quantile regression was used to create expected weight loss curves (25th, 50th, and 75th %tile) for the 24 months after RYGB. The resulting equations were validated and used to develop web-based tool for predicting weight loss outcomes. Results. Weight loss data from 2986 patients (2608 in the primary cohort and 378 in the validation cohort) were included. Preoperative body mass index (BMI) and age were found to have a high correlation with weight loss accomplishment (P < 0.0001 for each). An electronic tool was created that provides easy access to patient-specific, 24-month weight loss trajectories based on initial BMI and age. Conclusions. This validated, patient-centered electronic tool will assist patients and providers in patient teaching, informed consent, and postoperative weight loss management.
    Journal of obesity 01/2014; 2014:364941. DOI:10.1155/2014/364941
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    ABSTRACT: Background: Roux-en-Y gastric bypass (RYGBP) and sleeve gastrectomy (SG) are the most common bariatric procedures undertaken globally but there are no evidenced-based criteria that inform the selection of one operation over the other. The purpose of this study was thus to compare weight loss outcomes between RYGBP and SG, and to define patient factors affecting weight loss. Methods: A single-centre two-year follow-up retrospective cohort study of all adults who underwent either RYGBP (n = 422) or SG (n = 432) between 2007 and 2012, at University College London Hospitals National Health Service Foundation Trust, an academic tertiary referral centre, was undertaken. Multilevel linear regression was used to compare weight loss between groups, enabling adjustment for preoperative BMI (body mass index) and evaluation for interaction factors. Results: One- and two-year results showed that unadjusted BMI loss was similar between groups; 13.7 kg/m2 (95% CI: 12.9, 14.6 kg/m2) and 12.8 kg/m2 (95% CI: 11.8, 13.9 kg/m2) for RYGBP patients respectively compared with 13.3 kg/m2 (95% CI: 12.0, 14.6 kg/m2) and 11.5 kg/m2 (95% CI: 10.1, 13.0 kg/m2) for SG patients respectively. Adjusting for preoperative BMI, there was 2.2 kg/m2 (95% CI: 1.5, 2.8) and 2.3 kg/m2 (95% CI: 1.3, 3.3) greater BMI loss in the RYGBP group compared to the SG group at one and two years respectively (P < 0.001 for both). The interaction analyses demonstrated that age and sex had important differential impacts on SG and RYGBP weight outcomes. Men under 40 and women over 50 years obtained on average far less benefit from SG compared to RYGBP, whereas men over 40 years and women under 50 years experienced similar weight loss with either procedure (P = 0.001 and 0.022 for interaction effects at one and two years respectively). Conclusions: Our results show that patient sex and age significantly impact on weight loss in a procedure-dependent manner and should be considered when choosing between RYGBP and SG. Optimizing procedure selection could enhance the effectiveness of bariatric surgery, thus further increasing the benefit-to-risk ratio of this highly effective intervention. Keywords: Obesity, Bariatric surgery, Gastric bypass, Sleeve gastrectomy, Weight loss, Diabetes, BMI
    01/2014; 1(12):1. DOI:10.1186/2052-9538-1-12
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    ABSTRACT: During Roux-en-Y gastric bypasses (RYGB), some surgeons elect to perform a vagotomy to reduce symptoms of gastro-oesophageal reflux (GER). Routine vagotomy during RYGB may independently affect weight loss and metabolic outcomes following bariatric surgery. We aimed to determine whether vagotomy augments percent excess weight loss in obese patients after RYGB. We examined the effect of vagotomy in 1278 patients undergoing RYGB at our institution from 2003 to 2009. Weight and percent excess weight loss (%EWL) were modelled at three months and annually up to five years using a longitudinal linear mixed model controlling for differences in age, gender, initial body mass index (BMI), ideal body weight, and presence of vagotomy. Vagotomy was performed on 40.3% of our cohort. Vagotomy patients had significantly lower initial BMI (46.4±6.2 vs. 48.3±7.7kg/m(2), p<0.001), but there were no other significant differences at baseline. The strongest predictor of %EWL over time was initial BMI, with lower BMI patients exhibiting greater %EWL (p<0.001). Age and gender effects were also significant, with younger patients (p<0.04) and males (p<0.002) attaining greater %EWL. Vagotomy had no effect on %EWL in either simple or multiple regression models. Our series suggest that vagotomy does not augment %EWL when performed with RYGB. Copyright © 2014. Published by Elsevier Ltd.
    Obesity Research & Clinical Practice 10/2014; DOI:10.1016/j.orcp.2014.09.005 · 0.70 Impact Factor