Bariatric Surgery on obesity-and Diabetes-associated Abnormalities of Hemostasis, Inflammation and Vascular Function.
Condition: Surgery; Obesity Associated Disorder; Coagulation Disorder; Diabetes Complications
MeSH terms: Hemostatic Disorders; Blood Coagulation Disorders; Diabetes Mellitus; Obesity; Diabetes Complications; Inflammation
Study type: Interventional

Summary: 
      The goal of this prospective cohort study is to examine circulating biomarkers before and
      after weight loss in patients with obesity, with or without concomitant diabetes, undergoing
      bariatric surgery. The main questions that are being addressed are:

        -  Do biomarkers of hemostasis, including coagulation, fibrinolysis, and platelet function
           improve following surgery and if so, is that improvement more pronounced in patients
           with diabetes?

        -  Do biomarkers of endothelial function and other aspects of vascular function improve
           following surgery and if so, is that improvement more pronounced in patients with
           diabetes?

        -  Do biomarkers of inflammation, including markers of adipocyte function, improve
           following surgery and if so, is that improvement more pronounced in patients with
           diabetes?

        -  The possible role of circulating extracellular vesicles reflecting biological functions
           above will also be investigated (optional) Participants will be asked to attend in total
           five study visits before and after surgery including a final visit at two years
           post-surgery. Comparisons will be performed within- as well as between groups.
    

Detailed description: 
      In this single centre, prospective, parallel group, cohort study, patients meeting the
      eligibility criteria are recruited at the department of surgery at Ersta hospital, Stockholm,
      Sweden. Patients with obesity and type 2 diabetes (T2D) are matched for age and sex with the
      group of patients with obesity without T2D. During the study the participants attend five
      study visits: at baseline, at the morning of surgery (after two weeks of low calory diet), 6
      weeks, 1 year and 2 years after surgery. At each study visit a nurse records blood pressure,
      weight, height, and waist/hip circumferences. In addition, the nurse recalls the medical
      history and any medication use including contraceptive hormones and analgesics. Fat mass is
      determined using bioelectric impedance. Venous blood samples are collected with the patients
      in the supine position after overnight fasting and at least 20 minutes of rest. For later
      analyses, 25 mL of blood is collected in citrate tubes and centrifuged for 20 min at 2000 x g
      in room temperature. Plasma aliquots are subsequently stored at minus 80 degrees Celsius.
      Blood test regarding values at baseline (not the primary outcome variables) will be analysed
      at the local hospital laboratory. Examples of those basic variables are concentrations of
      glucose, insulin, blood cell counts and lipids.
    

Intervention name(s): Laparoscopic Roux-en-y gastric bypass
Intervention type(s): Procedure
Intervention description(s): Obesity surgery
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Bariatric surgery; Fibrinolysis