title: Effect of sleeve gastrectomy on thyroid hormone levels.
abstract: BACKGROUND
  Weight loss in morbidly obese patients is associated with changes in thyroid function. Studies have demonstrated equivalent changes following bariatric surgery. Changes in thyroid function were reported following laparoscopic Roux-en-Y gastric bypass (LRYGB), biliopancreatic diversion (BPD), and laparoscopic adjustable gastric banding (LAGB). No data exists on changes in thyroid function following laparoscopic sleeve gastrectomy (LSG). The aim of the current study is to evaluate changes in thyroid function following LSG in patients with normal thyroid function.
  
  
  METHODS
  Data were retrieved from a prospectively collected database of patients who underwent LSG for morbid obesity. Euthyroid patients were evaluated for changes in TSH and free thyroxine (FT4), 6-12 months after surgery. Correlation between changes in thyroid hormone levels, excess weight loss (EWL), and baseline TSH were evaluated.
  
  
  RESULTS
  Thirty-eight patients were included in the study. Mean BMI decreased from 42.4 to 32.5 kg/m(2) (P < 0.0001). Mean TSH levels decreased from 2.45 ± 0.17 mU/L at baseline to 1.82 ± 0.18 mU/L (P < 0.0001), whereas mean FT4 levels remained the same after surgery (13.27 ± 0.45 pmol/L compared to 12.96 ± 0.42 pmol/L, P = NS). TSH decrease was directly related to baseline TSH but did not correlate with EWL.
  
  
  CONCLUSIONS
  This is the first study to evaluate changes in thyroid hormone levels following LSG for morbid obesity. TSH decrease and steady levels of FT4 are expected following LSG. These findings are comparable to reported changes following LRYGB. TSH decrease was not associated with EWL. Further studies are required to elucidate the exact mechanism of this effect.
authors.affiliation: Department of Surgery B, Meir Medical Center, Kfar Saba, Israel.
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Abu-Ghanem
authors.forename: Roy
authors.initials: R
authors.lastname: Inbar
authors.forename: Vitaly
authors.initials: V
authors.lastname: Tyomkin
authors.forename: Ilan
authors.initials: I
authors.lastname: Kent
authors.forename: Liron
authors.initials: L
authors.lastname: Berkovich
authors.forename: Ronen
authors.initials: R
authors.lastname: Ghinea
authors.forename: Shmuel
authors.initials: S
authors.lastname: Avital
mesh_terms: D000328:Adult; D015904:Biliopancreatic Diversion; D005260:Female; D005743:Gastrectomy / Q000379:methods; D015390:Gastric Bypass; D006801:Humans; D010535:Laparoscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood* / Q000601:surgery*; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D015431:Weight Loss / Q000502:physiology; D055815:Young Adult
chemical_list: D013963:Thyroid Hormones; D013972:Thyrotropin