Context: Nonalcoholic fatty liver disease (NAFLD) is associated with coronary artery calcification (CAC) in cross-sectional studies. However, whether NAFLD itself affects CAC development or progression remains unknown.
Objective: This study investigated the longitudinal association between NAFLD and CAC score.
Design and setting: This study is a longitudinal cohort study performed in a healthcare center.
Participants: Among 1732 subjects who underwent serial CAC evaluation, we evaluated 846 subjects with NAFLD and 886 subjects without NAFLD, as diagnosed via ultrasonography.
Main outcome measures: CAC score was compared at baseline and follow-up. In subjects without calcification (CAC score = 0) at baseline, any incidental calcification (CAC score >0) at follow-up was defined as development of CAC. In subjects with CAC (CAC score > 0) at baseline, confirmed CAC aggravation was defined as progression. Logistic regression analysis was performed.
Results: More subjects with NAFLD than without showed CAC development or progression (48.8 vs 38.4%; P < .001). The impact of NAFLD on a change in CAC score significantly differed according to the CAC score at baseline. In subjects without calcification at baseline, NAFLD significantly affected the development of calcification (odds ratio, 1.49; 95% confidence interval, 1.01-2.21; P = .045) after adjusting for traditional metabolic risk factors. However, in subjects with baseline CAC, NAFLD did not significantly affect progression (P = .734). Additionally, the severity of NAFLD was important. The severity of NAFLD was dose-dependently associated with the development of CAC (P for trend = .043).
Conclusions: NAFLD plays a role in the early development of CAC, but not the progression. Ultrasonographic severity of NAFLD is dose-dependently associated with CAC development in subjects with a CAC score of 0 at baseline, independent of traditional risk factors.