title: Thrombin generation in morbid obesity: significant reduction after weight loss.
abstract: BACKGROUND
  Patients with morbid obesity (MO; body mass index > 40 kg m(-2)) suffer from an increased risk of cardiovascular disease, stroke, venous thromboembolism and all-cause mortality.
  
  
  OBJECTIVE
  Because weight loss by bariatric surgery reduces cardiovascular and all-cause mortality, we hypothesized that the plasmatic clotting system might be involved in cardiovascular risk.
  
  
  METHODS
  Thirty-six MO patients [mean age 42 (+/-13) years; 29 female) were investigated before and 2 years after bariatric surgery. Thrombin generation was measured with a commercially available assay (Technothrombin-TGA,Technoclone). Metabolic parameters and parameters of the hemostatic system, such as tissue factor (TF), TF pathway inhibitor (TFPI), plasminogen activator inhibitor-1 (PAI-1) and prothrombinfragment 1.2 (F1.2), were determined. To investigate associations of changing parameters, deltas were calculated.
  
  
  RESULTS
  Metabolic parameters improved with a mean weight loss of 41 (+/-19) kg. Postoperatively, the lag phase was significantly extended compared with preoperative values [median (25th-75th percentile), 7 (4-12) vs. 12 (7-19) min, P = 0.005]. Peak thrombin decreased after weight loss from 345 (232-455) to 282 (111-388) nm (P = 0.015) and the area under the curve from 3962 (3432-5023) to 3227 (2202-4030) nm thrombin (P < 0.001). TF, PAI-1 and F1.2 significantly decreased after weight loss. Analyses of the deltas showed a significant correlation between peak thrombin and total cholesterol (r = 0.50), triglycerides (r = 0.46) and HbA1c (r = 0.55). Moreover, an inverse correlation was found between insulin resistance and the lag phase (r = -0.46).
  
  
  CONCLUSIONS
  Thrombin generation, a marker of the overall coagulation potential, decreased significantly with weight reduction. This might, at least in part, explain the decreased risk of cardiovascular disease after bariatric surgery.
authors.affiliation: Department of Internal Medicine I, Rudolfstiftung Hospital Vienna, Austria.
authors.forename: L
authors.initials: L
authors.lastname: Ay
authors.forename: H-P
authors.initials: HP
authors.lastname: Kopp
authors.forename: J-M
authors.initials: JM
authors.lastname: Brix
authors.forename: C
authors.initials: C
authors.lastname: Ay
authors.forename: P
authors.initials: P
authors.lastname: Quehenberger
authors.forename: G-H
authors.initials: GH
authors.lastname: Schernthaner
authors.forename: I
authors.initials: I
authors.lastname: Pabinger
authors.forename: G
authors.initials: G
authors.lastname: Schernthaner
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D015415:Biomarkers / Q000097:blood; D001777:Blood Coagulation; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology* / Q000517:prevention & control; D016022:Case-Control Studies; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009767:Obesity, Morbid / Q000097:blood / Q000150:complications / Q000601:surgery*; D011446:Prospective Studies; D013917:Thrombin / Q000378:metabolism*; D013997:Time Factors; D016896:Treatment Outcome; D015431:Weight Loss
chemical_list: D015415:Biomarkers; D013917:Thrombin