MRI-Derived Fat Fraction Is Superior to Ultrasonography in Predicting Subclinical Atherosclerosis in Metabolically Healthy Non-alcoholic Fatty Liver Disease.

BACKGROUND

Subclinical atherosclerosis in metabolic dysfunction-associated steatotic liver disease (MASLD) is well established. However, its presence in patients with metabolically healthy non-alcoholic fatty liver disease (MH-NAFLD) remains unclear.

AIM

To determine the prevalence of subclinical atherosclerosis in patients with MH-NAFLD and to evaluate whether higher grades of hepatic steatosis are associated with increased carotid intima-media thickness (CIMT).

METHODS

In this prospective observational study, adults with ultrasonography (USG)-confirmed hepatic steatosis and no components of metabolic syndrome were compared with age- and sex-matched healthy controls. Hepatic steatosis was quantified using MRI-proton density fat fraction (MRI-PDFF), and subclinical atherosclerosis was assessed via CIMT. A CIMT ≥ 0.84 mm was considered elevated. Associations were evaluated using Spearman's correlation and hierarchical linear regression.

RESULTS

A total of 100 participants (median age 36.5 years, IQR 29.0-45.25) were enrolled: 50 with MH-NAFLD (28, 56% males) and 50 matched controls (31, 62% males). MRI-PDFF stratified MH-NAFLD patients as Grade 0 (8, 16%), Grade 1 (23, 46%), Grade 2 (11, 22%), and Grade 3 (8, 16%). Elevated CIMT was observed in 13 (26%) MH-NAFLD participants vs 1 (2%) control (p = 0.001). None of the patients with Grade 0 steatosis had elevated CIMT, whereas all with Grade 3 did. MRI-PDFF grading showed a strong correlation with CIMT (ρ = 0.80, p < 0.0001). In hierarchical regression, MRI-PDFF significantly improved CIMT prediction (ΔR² = 0.39, p < 0.001), while USG lost statistical significance.

CONCLUSION

MH-NAFLD is associated with increased CIMT. MRI-PDFF is a superior predictor of subclinical atherosclerosis compared to USG, highlighting its utility for vascular risk stratification.