The effects of green cardamom supplementation on blood pressure and endothelium function in type 2 diabetic patients A study protocol for a randomized controlled clinical trial

Introduction: Cardamom possesses antioxidant, anti-inflammation, and blood pressure lowering properties, which might improve endothelial function in type 2 diabetic patients. However, no study has examined the effect of cardamom on diabetic patients. The present study aimed to examine the effects of 10-week green cardamom intake on blood pressure, concentrations of inflammatory and endothelial function biomarkers in type 2 diabetes mellitus patients, and its potential mechanisms. Methods and Analysis Design: Eighty overweight or obese patients with type 2 diabetes mellitus (aged 30-60 years) will be recruited into the trial and will assign to receive either cardamom (3 g/day, 6 capsules) or placebo (rusk powder, 6 capsules) for a period of 10 weeks. Systolic blood pressure and diastolic blood pressure, asymmetric dimethylarginine, and nitric oxide will be measured. Serum inflammatory markers namely interleukin 6, tumor necrosis factor-alpha, high-sensitivity C-reactive protein, and factors related to endothelial function including intercellular adhesion molecule-1, vascular cell adhesion molecule 1, CD62 antigen-like family member E, and cluster of differentiation 163 will be measured at baseline and at the end of the trial. Sociodemographic, International Physical Activity Questionnaire, and three 24-hour dietary recall questionnaires will be collected for each participant. Ethics and dissemination: The study has been approved by The Ethics Committee of Tehran University of Medical Sciences (IR. TUMS.REC.1395.2700). Each participant will sign a written informed consent at the beginning of the study. At the end of the study, results will be published timely manner.