This study was a done on a sample of Isfahan Cohort Study (ICS) participants. ICS has been started since 8 years ago (2001) as a part of baseline study of Isfahan Healthy Heart Program (IHHP).16
Participants ≥ 35 years that were selected via multi-stage cluster sampling from phase I of IHHP were included in ICS. Demographic and behavioral characteristics, blood pressure, body mass index(BMI) and routine laboratory tests like fasting blood sugar (FBS), 2 hour postprandial sugar, total cholesterol, LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), triglyceride (TG) and electrocardiography for all of the participants were done and recorded at the first year of ICS. Then, every 2 years, each of the participants was followed by phone for assessment of primary outcomes of this cohort that included fatal or non-fatal myocardial infarction, fatal or non-fatal stroke, sudden cardiac death and hospitalization. In 2007, the tests and measurements were repeated again.17
Among 599 (39.4%) ICS participants in Isfahan (rural and urban) who suffered from MetS and remained in the study (not missed the follow-ups), 350 (58.4%) patients were randomly selected. The same number of subjects were selected from the rest of population (921) who did not have MetS (38%). Fifteen participants had died since the last follow up. On the whole, 472 (68.9%) attended the examinations. IMT test and laboratory measurements were carried out for a randomly selected sub-sample of this population consisted of 44 patients with MetS and 44 participants without it. Random selection procedures were done via random sampling (Sampling Wizard) in SPSS15
software. According to ATPIII criteria, metabolic syndrome is defined as having at least three of the five criteria: 1- waist circumference>102cm in men and >88 cm in women, 2- serum triglyceride>150mg/dl, 3- HDL<40 mg/dl in men and<50mg/dl in women, 4- FBS>110 mg/dl, 5- Blood pressure>130/85 mmHg.18
Inclusion criteria were the followings: participating in ICS from 2001 with ATPIII criteria for Mets.18
Exclusion criteria were the followings: participant's dissatisfaction, history of stroke or other cerebrovascular problems, pregnancy, history of carotid operation or carotid stent. The case and control group's questionnaires were assessed and patients who didn't have exclusion criteria were invited via telephone call. Written informed consent was obtained from all participants. A questionnaire including demographic data, CVD risk factors, history of diabetes, hypertension, smoking, hyperlipidemia and duration of these disease and all of the previous treatments, was completed for all participants in both case and control groups. Physical examination including blood pressure, height, weight and waist circumference measurements was done for all subjects using standard methods.19
Ten milliliter of fasting blood was obtained from the participants and sent to the laboratory of Isfahan Cardiovascular Research Center and after centrifuge, was preserved at -70 degrees of centigrade for necessary laboratory tests (ghrelin, interleukin 6 and 10, adiponectin and hs-CRP). Ghrelin was measured using ELISA method and BioVendor kits. Then, all subjects in both case and control groups underwent vascular echocardiography for evaluation of carotid IMT. Carotid IMT was measured by a neurologist using Vivid-3 echocardiograph (Vivid 3-Japan) in both carotid arteries in three points: 1- terminal 2 cm of common carotid artery before the division of carotid flow, 2- carotid bulb in 2 cm from the part of carotid division, 3- internal carotid artery, 2 cm after carotid division. Normal carotid IMT is<0.9 mm and between 0.9-1.5 mm is considered abnormal. IL-6 and IL-10 were measured via ELIZA method using Medsystem kit (Bendermed-Austria). Adiponectin and ghrelin were measured via ELIZA method, using Biovendor kit (Germany) and hs-CRP was measured via immunoturbidimetry method with Autoanalyzer (Hitachi 902) with Pars Azmun kit (Iran). Data were analyzed via SPSS15
software with t-test, ANOVA and chi-Square for comparison between the two groups and linear regression models and Pearson correlation for finding relation between variables.