Longitudinal association of dietary habits and the risk of cardiovascular disease among Iranian population between 2001 and 2013: the Isfahan Cohort Study

There has been a steady rise in the incidence of cardiovascular disease (CVD) in the Iranian population. The aim of this study is to investigate the association between Global Dietary Index (GDI) and CVD risk among the Iranian adult population. This study was conducted based on Isfahan Cohort Study, a longitudinal study that collected data between 2001 and 2013 on 6405 adults. Dietary intakes were assessed by a validated food frequency questionnaire to calculate GDI. All participants were followed every two years by phone call to ask about death, any hospitalization, or cardiovascular events to examine CVD events. The Average age of participants was 50.70 ± 11.63 and the median of GDI score was 1 (IQR: 0.29). A total of 751 CVD events (1.4 incidence rate, per 100 person-year) occurred during 52,704 person-years of follow-up. One-unit GDI increase was associated with a higher risk of MI by 72% (HR: 1.72; 95% CI 1.04–2.84), stroke by 76% (HR: 1.76; 95% CI 1.09–2.85) and CVD by 30% (HR: 1.48; 95% CI 1.02–2.65). In addition, a one-unit GDI increase was associated with a higher risk of coronary heart disease more than 2 times (HR: 2.32; 95% CI 1.50–3.60) and CVD mortality and all-cause mortality over than 3 times [(HR: 3.65; 95% CI 1.90–7.01) and (HR: 3.10; 95% CI 1.90–5.06), respectively]. Higher GDI had a significant relationship with the increased risk of CVD events and all-cause mortality. Further epidemiological studies in other populations are suggested to confirm our findings.