title: The effects of metformin on inflammatory mediators in obese adolescents with insulin resistance: controlled randomized clinical trial.
abstract: OBJECTIVE
  To compare serum concentrations of inflammatory cytokines, interleukin 6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), adiponectin, and tumor necrosis factor alpha (TNFalpha), before and after 3 months treatment with metformin in obese adolescents with insulin resistance (IR).
  
  
  METHODS
  This was a randomized, double-blinded, clinical trial of two groups of obese adolescents with IR, aged 9-18 years: a placebo group (n=14) and a metformin group (n=12) who received 500 mg metformin every 12 h for 3 months. Anthropometric and biochemical (metabolic and inflammatory cytokines) assessments were compared at the beginning and end of treatment.
  
  
  RESULTS
  After 3 months of treatment, body mass index (kg/m2) was reduced in both groups: placebo group (32.82 +/- 6.37-32.10 +/- 6.52; p=0.011) and metformin group (33.44 +/- 5.82-32.71 +/- 5.77; p=0.015). Serum fasting insulin concentrations (pmol/L) increased in the placebo group (189.45 +/- 112.64-266.06 +/- 167.79; p=0.01) and showed a slight decrease in the metformin group (256.82 +/- 113.89-229.25 +/- 86.53; p=0.64). Adiponectin concentrations (microg/mL) decreased in the placebo group (13.17 +/- 7.31-5.65 +/- 6.69; p=0.02), while these remained stable in the metformin group (8.57 +/- 3.98-7.86 +/- 6.23; p=0.64). In the metformin group, significant reductions were found in the variances of serum TNFalpha concentrations (p=0.006; Levene test).
  
  
  CONCLUSIONS
  These results suggest that treating obese adolescents with IR using metformin for 3 months is an option for patients without response to traditional lifestyle change because metformin improves inflammatory activity, which is an etiological factor in cardiovascular disease development.
authors.affiliation: Hospital Regional de Alta Especialidad del Bajío, Endocrinología Pediátrica, León, Guanajuato, Mexico. evialola@hotmail.com
authors.forename: Maria Lola
authors.initials: ML
authors.lastname: Evia-Viscarra
authors.forename: Edel Rafael
authors.initials: ER
authors.lastname: Rodea-Montero
authors.forename: Evelia
authors.initials: E
authors.lastname: Apolinar-Jiménez
authors.forename: Nathalie
authors.initials: N
authors.lastname: Muñoz-Noriega
authors.forename: Leticia Margarita
authors.initials: LM
authors.lastname: García-Morales
authors.forename: Constanza
authors.initials: C
authors.lastname: Leaños-Pérez
authors.forename: Mireya
authors.initials: M
authors.lastname: Figueroa-Barrón
authors.forename: Dolores
authors.initials: D
authors.lastname: Sánchez-Fierros
authors.forename: Juan Gerardo
authors.initials: JG
authors.lastname: Reyes-García
mesh_terms: D052242:Adiponectin / Q000097:blood; D000293:Adolescent; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D018836:Inflammation Mediators / Q000097:blood*; D007333:Insulin Resistance; D008297:Male; D055118:Medication Adherence; D008687:Metformin / Q000009:adverse effects / Q000627:therapeutic use*; D009765:Obesity / Q000188:drug therapy* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: C499918:ADIPOQ protein, human; D052242:Adiponectin; D007004:Hypoglycemic Agents; D018836:Inflammation Mediators; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein; D008687:Metformin