Association of Pro-Inflammatory Diets With Increased Risk of Metabolic Dysfunction-Associated Steatohepatitis: Evidence From a Prospective Cohort Study.

Chronic inflammation underlies the initiation of steatohepatitis in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Diet-induced inflammation has been highlighted as a contributor to the development of hepatic steatosis. However, its involvement in steatohepatitis risk remains unstudied. This longitudinal analysis included 1130 individuals with MASLD from the Ravansar Non-Communicable Disease cohort, who were followed from 2015 to 2023. At baseline, MASLD was assessed using the hepatic steatosis index (HSI), a validated non-invasive scoring system. Usual dietary intakes were collected using a validated food frequency questionnaire (FFQ). The diet's potential to modulate inflammation-related biomarkers was assessed using the dietary inflammatory index (DII). The acNASH index was employed as a more accurate and effective assessment for steatohepatitis risk in individuals with MASLD. After controlling for confounders, DII scores were significantly associated with changes in weight, ALT, and acNASH scores. Each one-point increment in the DII score was independently associated with a 0.45% (95% CI: 0.10-0.80; p-value: 0.012) increase in weight, 2.27% (95% CI: 0.19-4.35; p = 0.032) increase in ALT, and 1.96% (95% CI: 0.36-3.55; p = 0.016) increase in acNASH scores. For each 1% weight gain, the acNASH score increased by 0.63% (95% CI: 0.37-0.88; p < 0.001). Weight changes mediated 10.1% of the total relationship between the DII scores and percentage changes in acNASH score (p < 0.001). The association between DII scores and acNASH scores remained statistically significant across all strata of gender, socioeconomic status, and physical activity levels (p < 0.05). This study demonstrated a direct association between diet-induced inflammation and increased steatohepatitis risk in patients with MASLD. These findings highlight the importance of promoting anti-inflammatory dietary patterns and weight management as feasible strategies to reduce the risk of steatohepatitis in patients with MASLD in clinical practice.