title: Greater short-term weight loss in women 20-45 versus 55-65 years of age following bariatric surgery.
abstract: BACKGROUND
  Whether and how sex and age affect bariatric-surgery outcome is poorly understood. Estrogens regulate body composition in women and animals, and increase weight loss in a rodent model of gastric bypass, suggesting that premenopausal women may lose more weight following bariatric surgery.
  
  
  METHODS
  One thousand three hundred fifty-six female gastric-bypass or gastric-banding patients were retrospectively grouped as 20-45 years old (presumptively premenopausal; n = 1,199) and 55-65 years old (presumptively postmenopausal; n = 157). Mixed-model ANCOVA followed by Bonferroni-corrected t tests were used to categorically test the effect of age on percent excess body weight loss (%EBWL) at 1 and 2 years post-surgery, controlling for preoperative EBW and surgery type. Age effects were also tested dimensionally in all women and in 289 male patients.
  
  
  RESULTS
  Twenty- to forty-five-year-old women showed greater %EBWL 1 and 2 years post-surgery than 55-65-year-old women (p's < 0.0005). No age effect was detected in 20-25- vs. 30-35-, 30-35- vs. 40-45-, or 20-25- vs. 40-45-year-old women (p's > 0.2) This age effect was detected only after gastric banding, with 20-45-year-old women losing ∼7 kg more than 55-65-year-old women after 2 years. Dimensional analysis confirmed a significant inverse effect of age on bariatric surgery outcome in women, but did not detect any effect in men.
  
  
  CONCLUSIONS
  Results indicate that 55-65-year-old women lose less weight than 20-45-year-old women in the initial 2 years after bariatric surgery, especially gastric banding; this may be mediated by age- or menopause-associated changes in physical activity, energy expenditure, or energy intake.
authors.affiliation: Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY, USA, cochner@gmail.com.
authors.forename: Christopher N
authors.initials: CN
authors.lastname: Ochner
authors.forename: Julio
authors.initials: J
authors.lastname: Teixeira
authors.forename: Nori
authors.initials: N
authors.lastname: Geary
authors.forename: Lori
authors.initials: L
authors.lastname: Asarian
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D001481:Basal Metabolism; D001823:Body Composition; D004734:Energy Metabolism; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D015391:Gastroplasty; D006801:Humans; D008593:Menopause / Q000378:metabolism*; D008875:Middle Aged; D009518:New York / Q000453:epidemiology; D009767:Obesity, Morbid / Q000453:epidemiology / Q000378:metabolism* / Q000601:surgery; D011184:Postoperative Period; D012189:Retrospective Studies; D016896:Treatment Outcome; D015431:Weight Loss
chemical_list: D004967:Estrogens