Rationale, design, and preliminary results of the Iran-premature coronary artery disease study (I-PAD): A multi-center case-control study of different Iranian ethnicities

Fars is considered to be the largest ethnic group in Iran, estimated to comprise between 50% and 70% of the population, followed by Azari, as the second largest ethnic group (15% to 24%), Kurd from 7% to 10%, Gilak from 3% to 6%, Arab from 2% to 4%, Lor from 3% to 5%, and Turkman, Bakhtiari, Qashghaei, and Balouch each with 2%.13 Iran-premature coronary artery disease (I-PAD) study aims to investigate the frequency of premature CAD and its risk factors according to different ethnicities in Iran, so the results can be a gateway to some preventive and treatment strategies. Previous history of documented coronary artery disease such as coronary artery bypass surgery, balloon angioplasty, or percutaneous coronary intervention (PCI) was considered as exclusion criterion. Interviewers in hospitals completed our questionnaires that included questions on demographics like age, sex, ethnicity, religion, education, income, marriage status, and lifestyle behaviors such as any type of smoking, alcohol or drug use, and nutrition via Food Frequency Questionnaire (FFQ), physical activity by International Physical activity Questionnaire (IPAQ), anxiety level through Hospital Anxiety and Depression Scale (HADS), sleep disorders using the Pittsburgh Sleep Quality Index (PSQI), personal and family history of illnesses and used medications. Blood samples were taken to measure triglyceride (TG), total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDLc), and fasting blood sugar (FBS).