Association of dietary inflammatory index with dyslipidemia and atherogenic indices in Iranian adults: a cross-sectional study from the PERSIAN dena cohort

Abstract Background Dyslipidemia is a metabolic disorder that can lead to various chronic diseases. Anti-inflammatory diets may help prevent dyslipidemia; however, the evidence remains inconsistent. Therefore, the present study investigated the relationship between the Dietary Inflammatory Index (DII) and dyslipidemia, as well as the Atherogenic Index of Plasma (AIP). Methods A cross-sectional study was done among 3,178 Iranian adults aged 35–70 years who had resided in Dena County, Iran, for a minimum of nine months each year. Demographic data were collected from all participants, and anthropometric and biochemical parameters were measured for each subject using standardized methods. Dietary intake was assessed using 113-item and 127-item Food Frequency Questionnaires (FFQs) to calculate the DII. Results A significant trend was observed indicating increasing serum levels of total cholesterol (TC) (P < 0.001) and low-density lipoprotein cholesterol (LDL-C) (P = 0.002), along with decreasing levels of high-density lipoprotein cholesterol (HDL-C) (P = 0.024), as the DII quartiles elevated. Similarly, a significant association was found between higher DII scores and increased ratios of LDL/HDL (P < 0.001), TC/HDL (P < 0.001), and triglycerides (TG)/HDL-C (P = 0.03) in the serum. Furthermore, higher DII scores were linked to increased odds of hypercholesterolemia (OR = 1.3, P = 0.032), high LDL-C (OR = 1.31, P = 0.036), low-HDL-C (OR = 1.31, P = 0.006), high-TC/HDL-C (OR = 1.15, P = 0.016) ratio, and high-AIP (OR = 1.35, P = 0.001) values after adjusting for confounders. Nonetheless, no significant association was found between the DII score and the serum levels of TG, nor with the odds of having hypertriglyceridemia or a high LDL-C/HDL-C ratio. Conclusion Our findings revealed that higher DII scores are associated with higher AIP values and lipid biomarker levels, except for triglycerides. However, prospective cohorts and randomized controlled trials testing anti-inflammatory diets (e.g., Mediterranean adaptations for Iran) are needed to establish causality.