title: Predictors of weight status following laparoscopic gastric bypass.
abstract: BACKGROUND
  Weight loss after bariatric surgery varies and depends on many factors, such as time elapsed since surgery, baseline weight, and co-morbidities.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Preventive and Behavioral Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA. Yunsheng.Ma@umassmed.edu
authors.forename: Yunsheng
authors.initials: Y
authors.lastname: Ma
authors.forename: Sherry L
authors.initials: SL
authors.lastname: Pagoto
authors.forename: Barbara C
authors.initials: BC
authors.lastname: Olendzki
authors.forename: Andrea R
authors.initials: AR
authors.lastname: Hafner
authors.forename: Richard A
authors.initials: RA
authors.lastname: Perugini
authors.forename: Robin
authors.initials: R
authors.lastname: Mason
authors.forename: John J
authors.initials: JJ
authors.lastname: Kelly
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass; D006801:Humans; D010535:Laparoscopy; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications / Q000601:surgery*; D011237:Predictive Value of Tests; D012737:Sex Factors; D016896:Treatment Outcome; D015431:Weight Loss