The TyG Index, Dietary Vitamin E Intake, and LRP5 rs4988321 in Adults with MASLD: A Case-Control Study

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is related to insulin resistance, dyslipidemia, and oxidative stress. Vitamin E and low-density lipoprotein receptor-related protein 5 (LRP5) may be involved, but evidence remains limited. This study compared dietary vitamin E intake and LRP5 rs4988321 genotype distributions between adults with and without MASLD. Methods: This single-center case-control study included 59 adults with ultrasonographically confirmed MASLD and 47 controls. Vitamin E intake was assessed using two non-consecutive 24-h dietary recalls and a vitamin E-focused food frequency questionnaire. The rs4988321 variant was genotyped using a TaqMan assay. Group comparisons and multivariable models were used. Results: Vitamin E intake did not differ between groups using 24-h recalls (11.81 vs. 9.35 mg/day; p = 0.246) or the FFQ (16.47 vs. 17.58 mg/day; p = 0.834); only the recall-derived estimate was energy-adjusted and remained unassociated with MASLD. The rs4988321 genotype distributions were similar (p = 0.548). After adjustment for age, sex, genotype, and BMI, ALT, LDL cholesterol, and triglyceride levels were nominally higher in participants with MASLD. However, only ALT remained significant after false discovery rate correction (q = 0.021). In the BMI-adjusted logistic model, higher TyG index (OR = 2.360; 95% CI: 1.067-5.218; p = 0.034) and BMI (OR = 1.304; 95% CI: 1.108-1.535; p = 0.001) were associated with greater odds of MASLD. Conclusions: Dietary vitamin E intake and the rs4988321 genotype were not associated with MASLD status in this sample. ALT remained higher after multivariable adjustment, whereas the TyG and BMI associations were specific to the BMI-adjusted model.