Association between dietary quality index - international (DQI-I) and fatty liver indices: results from the Ravansar...

Adherence to an appropriate diet is among the most effective strategies for managing patients with non-alcoholic fatty liver disease (NAFLD). The Diet Quality Index-International (DQI-I) was developed to provide a comprehensive assessment of dietary quality on a global scale. The present study aimed to investigate the association between the DQI-I and non-invasive markers of liver function in adults. This cross-sectional study was conducted on 6,484 adults who participated in Ravansar Non-Communicable Diseases (RaNCD) cohort study in western Iran. The Diet Quality Index-International (DQI-I) score was calculated based on participants' dietary data obtained from a Food Frequency Questionnaire (FFQ). NAFLD predictor indices including Hepatic Steatosis Index (HSI), Fatty Liver Index (FLI), fibrosis-4 index (FIB-4), and Aspartate Aminotransferase to Platelet Ratio Index (APRI), were calculated using established formulas. The association between DQI-I score and its subgroups with NAFLD predictor indices was assessed using linear regression models adjusted for potential confounders. The findings of this study indicated that in the adjusted model (Model 2), SGPT (β = 0.0020, P = 0.003), HSI (β = 0.0014, P < 0.001), and FLI (β = 0.006, P < 0.001) levels showed a significant positive association with the total DQI-I score. Although these positive associations may appear counterintuitive, they could be influenced by confounding factors such as higher BMI in participants with higher DQI-I scores. Additionally, a one-unit increase in total DQI-I score was associated with a decrease in FIB-4 (β = -0.0018, P = 0.004), AST/ALT ratio (β = -0.0020, P < 0.001), and no significant change in APRI (β = -0.0007, P = 0.222). Among the DQI-I subgroups, a one-unit increase in both the variety and adequacy components was associated with a significant increase in SGPT, HSI, and FLI, whereas FIB-4, APRI, and AST/ALT ratio decreased on average. In the moderation subgroup, a one-unit increase was associated with a non-significant change in FIB-4 (β = -0.0008, P = 0.374). According to our results, there was a statistically significant inverse association between DQI-I scores and fibrosis-related indices, while paradoxically showing a positive association with steatosis-related markers.