Evaluation of flow-mediated dilatation (FMD)
The FMD evaluation was made in each participant in early morning after overnight fasting period in a standard ultrasound room by expert sonographer before starting other steps of study (blood sampling) as described in previous literature 8,9 . An android compatible linear transducer (Philips Lumify L12-4 [12–4 mHz]; Philips Ultrasound Inc., Bothell, WA) was used to evaluation of vessel diameter. The normal diameter of the brachial artery was measured over about 5 cm of the antecubital fossa and therefore the evaluation point was marked. Thereafter the sphygmomanometer cuff was placed to proximal site of evaluation point and inflated to above 50 mmHg of normal blood pressure for five minutes as explained in previous literature8,9 . After 5 minutes of ischemia period cuff was deflated and the ultrasound probe was placed to marked point for measurement of post-ischemic diameter of brachial artery. The enlargement of diameter equal or over than 5% was accepted as normal response and lower than 5% was accepted as abnormal vascular response to ischemia which indicates abnormal endothelial function8,9 .