title: Metformin and improvement of the hepatic insulin resistance index independent of anthropometric changes.
abstract: OBJECTIVE
  To determine the change in the hepatic insulin resistance index (HIRI) after metformin treatment.
  
  
  METHODS
  In this retrospective cohort study, Mexican mestizo patients with a body mass index (BMI) of 25 kg/m(2) or greater were evaluated. Participants were classified into 2 groups: patients who received metformin and patients who did not. Both groups were followed up for a median of 6 months (range, 4-10 months). The HIRI was calculated at baseline and at follow-up in both groups. We evaluated the independent effect of metformin on HIRI after adjustment for the difference in basal and final values (DELTA) of BMI, waist circumference, glucose, and insulin.
  
  
  RESULTS
  A total of 71 patients were enrolled (51 [72%] female). Forty-one patients received metformin and 30 patients did not. Mean age was 36.3 ± 12.2 years and mean BMI was 42.2 ± 10.7 kg/m(2). After metformin treatment, HIRI significantly decreased from 38 ± 10.7 to 34.7 ± 9.5 (P = .03). In contrast, the control group had a nonsignificant increase in HIRI (37.6 ± 11.7 to 40.0 ± 14.0, P = .22). Weight significantly decreased in both groups (group 1: 114.6 ± 33.8 kg to 107.6 ± 28.9 kg, P<.01; group 2: 104.8 ± 28.5 kg to 98.9 ± 26.0 kg, P<.01). After BMI adjustment, the total metformin dosage correlated negatively with HIRI (r = -0.36, P = .03). Using a linear regression model (F = 6.0, r2 = 0.37, P = .002) adjusted for DELTA BMI and DELTA waist circumference, the administration of metformin resulted in independent improvement in the HIRI level (standardized β = -0.29, t = -2.0, P = .04).
  
  
  CONCLUSIONS
  Metformin improves HIRI independently of anthropometric changes. In persons with elevated HIRI levels, metformin may be considered among the treatment options.
authors: Department of Internal Medicine, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.
authors: Miguel Ángel
authors: MÁ
authors: Gómez-Sámano
authors: Alfonso
authors: A
authors: Gulias-Herrero
authors: Daniel
authors: D
authors: Cuevas-Ramos
authors: Hasan
authors: H
authors: Brau-Figueroa
authors: Roopa
authors: R
authors: Mehta
authors: Diana
authors: D
authors: Vargas-Gutiérrez
authors: Clara Elena
authors: CE
authors: Meza-Arana
authors: Jazmín María
authors: JM
authors: Nieves-Niebla
authors: María Olivia
authors: MO
authors: Vázquez-Hernández
mesh_terms: D000328:Adult; D000886:Anthropometry; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D008055:Lipids / Q000097:blood; D008099:Liver / Q000502:physiology*; D008137:Longitudinal Studies; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D012044:Regression Analysis; D012189:Retrospective Studies; D055105:Waist Circumference
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D008055:Lipids; D008687:Metformin