Fatty liver predicts the risk for cardiovascular events in middle-aged population: a population-based cohort study

Abstract

Objective: We investigated if the differences in liver fat content would predict the development of non-fatal and fatal atherosclerotic endpoints (coronary heart disease and stroke).

Design, setting and participants: Our study group is a population-based, randomly recruited cohort (Oulu Project Elucidating Risk of Atherosclerosis, OPERA), initiated in 1991. The cohort consisted of 988 middle-aged Finnish participants.

Intervention: Total mortality and hospital events were followed up to 2009 based on the registry of the National Institute for Health and Welfare and the National death registry.

Main outcome measure: The severity of hepatic steatosis was measured by ultrasound and divided into three groups (0-2). Cox regression analysis was used in the statistical analysis.

Results: In the follow-up of years 1991-2009, 13.5% of the participants with non-fatty liver, 24.2% of participants having moderate liver fat content and 29.2% of the participants having severe fatty liver experienced a cardiovascular event during the follow-up time (p<0.001). Severe liver fat content predicted the risk for future risk of cardiovascular event even when adjusted for age, gender and study group (HR 1.92, CI 1.32 to 2.80, p<0.01). When further adjustments for smoking, alcohol consumption, low-density lipoprotein-cholesterol, body mass index and systolic blood pressure were conducted, the risk still remained statistically significant (HR 1.74, CI 1.16 to 2.63, p<0.01). Statistical significance disappeared with further adjustment for QUICKI.

Conclusions: Liver fat content increases the risk of future cardiovascular disease event in long-term follow-up but it is seems to be dependent on insulin sensitivity.

Figure 1

Kaplan-Meier cumulative survival rates censored for cardiovascular death in participants with no fat in the liver, moderate fat content and severe fat content. CVD was the cause of death in 3.6% of the participants (26/720) with non-fatty liver and 8.1% of the participants (10/124) with moderate liver fat content, while 12.5% of the participants with severe fatty liver (18/144). Cox regression analysis is used for adjustments. M1 (model 1): adjusted for study group, age and gender. M2 (model 2): further adjustments for smoking, alcohol consumption, systolic blood pressure, LDL-cholesterol level and body mass index. M3 (model 3): further adjustment for QUICKI. CVD, cardiovascular disease; QUICKI, quantitative insulin sensitivity check index. **p<0.01, *p<0.05.