title: Body composition changes after laparoscopic adjustable gastric banding: what is the role of -174G>C interleukin-6 promoter gene polymorphism in the therapeutic strategy?
abstract: BACKGROUND
  There is growing evidence that interleukin-6 (IL-6) is linked to the regulation of fat mass (FM). Our previous data define the common -174G>C IL-6 polymorphism as a marker for 'vulnerable' individuals at risk of age- and obesity-related diseases. An association between -174G>C IL-6 polymorphism and weight loss after bariatric surgery has been demonstrated.
  
  
  OBJECTIVE
  We investigated the impact of -174G>C IL-6 polymorphism on weight loss, body composition, fluid distribution and cardiometabolic changes in obese subjects, after laparoscopic adjustable gastric banding (LAGB) surgery.
  
  
  METHODS
  A total of 40 obese subjects were studied at baseline and at 6 months follow-up after LAGB surgery. Cardiometabolic and genetic assessment of -174G>C IL-6 polymorphism, anthropometric, body composition and fluid distribution analysis were performed.
  
  
  RESULTS
  After LAGB surgery, significant reductions in weight (Δ%=-11.66 ± 7.78, P<0.001), body mass index (P<0.001), total and trunk FM (kg, %) (Δ% of total FM=-22.22 ± 12.15, P<0.01), bone mineral density (T-score) (P<0.001), resting metabolic rate (RMR) (P<0.01), and total body water and intracellular water (TBW, ICW) (P<0.05) were observed. At baseline, C(-) carriers of IL-6 polymorphism had a significantly higher RMR (P<0.05), free FM (kg), but less total and trunk FM (%), higher body cell mass (BCM), content of TBW (L) and ECW (extracellular water)/ICW ratio compared with C(+) carriers (P<0.001). After LAGB, C(+) carriers had a significantly stronger reduction of total FM (kg), but lower bone density, compared with C(-) carriers (P<0.05).
  
  
  CONCLUSIONS
  Beyond the relationship between -174G>C IL-6 polymorphism and body composition, this study provides first evidence about the association of IL-6 variant with fluid distribution, at baseline, and FM and bone density loss in obese subjects at 6 months follow-up after LAGB surgery. LAGB was less effective if the subjects were carrying risk genotypes, C(-) carriers, for obesity, suggesting a role of genetic variations on bariatric surgery outcomes.
authors: Department of Neuroscience, Division of Human Nutrition, University of Rome Tor Vergata, Rome, Italy.
authors: L
authors: L
authors: Di Renzo
authors: M G
authors: MG
authors: Carbonelli
authors: A
authors: A
authors: Bianchi
authors: L
authors: L
authors: Iacopino
authors: R
authors: R
authors: Fiorito
authors: N
authors: N
authors: Di Daniele
authors: A
authors: A
authors: De Lorenzo
mesh_terms: D000328:Adult; D001823:Body Composition / Q000235:genetics*; D015992:Body Mass Index; D015519:Bone Density; D005260:Female; D005500:Follow-Up Studies; D015391:Gastroplasty / Q000379:methods*; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D007558:Italy / Q000453:epidemiology; D010535:Laparoscopy; D008297:Male; D009767:Obesity, Morbid / Q000453:epidemiology / Q000235:genetics / Q000378:metabolism* / Q000601:surgery; D018579:Patient Selection; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011795:Surveys and Questionnaires; D015431:Weight Loss / Q000235:genetics*
chemical_list: D015850:Interleukin-6