The PERSIAN Guilan Cohort Study (PGCS)

The Guilan cohort study was conducted on 10520 men and women between 35-70 years of age in Guilan province and Some'e Sara county, northern Iran, from October 8, 2014 to January 20, 2017 as part of the Prospective Epidemiological Research Studies in Iran (PERSIAN). Eligible participants were contacted over the phone and were invited to refer to the cohort center. Demographic information was inquired during the phone call. Upon arrival of participants at the cohort center, consent forms were filled out and additional data on demographic characteristics, socio-economic status, employment, fuel status and location, lifestyle habits, and sleep and food habits were obtained. Blood pressure and anthropometric indices were measured. Finally, biological samples were collected. There was a participation rate of 83.2%, and a 15-year active follow-up was planned for all of the participants. The results showed that 53.5% of the participants were female and 56.1% of the participants were rural residents. A total of 1738 participants (16.5%) were illiterate. Of the total cohort participants, 4543 (43.2%) were hypertensive. Hypertension was defined as a systolic blood pressure ≥140 mm Hg or a diastolic blood pressure ≥90 mm Hg, or a prior diagnosis of hypertension by a health professional, or taking antihypertensive medications. Approximately one-third of participants (n=3435 or 32.7%) were obese, and most were females (n=2647, 77.1%). Prevalence of diabetes (defined as fasting blood sugar equal or higher than 126 mg/dL or history of diagnosis with diabetes or taking glucose lowering medication) was 24.1% (20.2 % in males and 27.3% in females). We also obtained laboratory samples for basic and genetic scientific research. According to laboratory evaluations, 3,585 (34.1%) of the participants had hematuria, and most of them were women (n=2151 or 60%). The preliminary results of our study demonstrate a high prevalence of metabolic risk factors for Non-Communicable Diseases and mainly cardiovascular diseases in Guilan province, which merit detailed investigation of their intricate relationships. The population-based design of the study as well as its large sample size were the main strengths of our cohort study that makes these investigations feasible. Researchers interested in using the information are invited to visit the following websites: http://www.gums. ac.ir/cohort and http://persiancohort.com/.