title: Acetylsalicylic acid therapy: influence of metformin use and other variables on urinary 11-dehydrothromboxane B2 levels.
abstract: BACKGROUND
  The effect of acetylsalicylic acid (ASA) may be measured through the analysis of urinary concentrations of 11-dehydrothromboxane B2 (11-dhTXB2), a metabolite of thromboxane A2, which is a potent platelet aggregant agent. It has been suggested that metformin (an oral antidiabetic drug) could improve oxidative stress and control platelet activation in type 2 diabetic patients, potentially reducing cardiovascular risk. We determined the concentrations of urinary 11-dhTXB2 in type 2 diabetic patients taking ASA and its concentrations with metformin use and several other clinical variables (hypertension, age, gender, smoking, body mass index, insulin and statin use), considering a reduction of at least 75% in the concentrations of this marker as a target, compared to results before ASA intake.
  
  
  METHODS
  Urinary concentrations of 11-dhTXB2 of 81 type 2 diabetic patients were measured before and at 15 days taking 100 mg of aspirin daily.
  
  
  RESULTS
  Most patients who presented a reduction of 11-dhTXB2 above 75% were under metformin use. This reduction was achieved in 51.5% of patients taking this drug, against 20.0% in the patients who were not (p=0.027). The analysis of the other variables did not show a significant difference. The use of metformin appears to play a role in the reduction of 11-dhTXB2 concentrations in type 2 diabetic patients.
  
  
  CONCLUSIONS
  According to previous reports, hyperglycemia control seems to be a determinant factor for the success of ASA therapy, given the influence of metformin in the reduction of 11-dhTXB2 concentrations.
authors: Clinical and Toxicological Analysis Department, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil; Rede Sarah de Hospitais de Reabilitação, Belo Horizonte, Brazil.
authors: Lillian Harboe
authors: LH
authors: Gonçalves
authors: Clinical and Toxicological Analysis Department, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil. Electronic address: marcosvfs02@yahoo.com.br.
authors: Marcos Vinícius Ferreira
authors: MV
authors: Silva
authors: Clinical and Toxicological Analysis Department, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors: Rita Carolina Figueiredo
authors: RC
authors: Duarte
authors: Clinical and Toxicological Analysis Department, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors: Luci Maria S
authors: LM
authors: Dusse
authors: Clinical and Toxicological Analysis Department, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors: Ana Paula
authors: AP
authors: Fernandes
authors: Santa Casa Hospital, Belo Horizonte, Brazil.
authors: Adriana A
authors: AA
authors: Bosco
authors: Clinical and Toxicological Analysis Department, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors: Karina Braga
authors: KB
authors: Gomes
authors: Clinical and Toxicological Analysis Department, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors: Maria das Graças
authors: Md
authors: Carvalho
mesh_terms: D001241:Aspirin / Q000494:pharmacology* / Q000627:therapeutic use; D001692:Biological Transport / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000378:metabolism / Q000652:urine*; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D007333:Insulin Resistance; D007408:Intestinal Absorption / Q000187:drug effects; D008297:Male; D008687:Metformin / Q000494:pharmacology* / Q000627:therapeutic use; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects; D012307:Risk Factors; D013929:Thromboxane B2 / Q000031:analogs & derivatives* / Q000652:urine
chemical_list: D007004:Hypoglycemic Agents; D013929:Thromboxane B2; C049235:11-dehydro-thromboxane B2; D008687:Metformin; D005947:Glucose; D001241:Aspirin
keywords: 11-Dehydrothromboxane B(2); Acetylsalicylic acid; Diabetes mellitus; Metformin