Association between dietary quality index-international (DQI-I) and cardiovascular diseases: insights from RaNCD cohort study.

Background: Preventing cardiovascular diseases (CVDs) is a key strategy in reducing the global burden of chronic diseases. Various factors play a role in the development of CVD, with diet being one of the most important. The aim of this study is to measure the association between the dietary quality index- international (DQI-I) and CVDs.

Methods: This cross-sectional study was conducted using data from the Ravansar Non-Communicable Disease Cohort Study (RaNCD). A total of 7,115 participants aged 35-65 years were examined, of whom 1,098 were patients and 6,017 were healthy individuals. The DQI-I was used to assess the quality of nutrition and important aspects of a high-quality diet. Logistic regression was used to compare the DQI-I total score and CVDs.

Results: The average score of the DQI-I was 60.53 ± 8.44 in healthy individuals and 61.87 ± 8.81 in CVD patients. The variety subgroup was 12.74 ± 4.77 in healthy individuals and 12.32 ± 4.74 in CVD patients. The adequacy subgroup was 33.34 ± 3.69 in healthy individuals and 32.97 ± 3.67 in CVD patients. The moderation and overall balance subgroup were lower in healthy individuals than in CVDs patients. Multivariable logistic regression showed that DQI-I total score increased the odds of CVD by 37% (OR = 1.37; 95% CI: 1.22-1.55).

Conclusion: The results showed that the total DQI-I score was higher in patients with CVD than in healthy individuals. However, the variety and adequacy subgroups of the DQI-I were higher in healthy individuals, suggesting an inverse association between these subgroups and the prevalence of CVD. This apparent contradiction highlights the complexity of diet quality and its impact on health.