Non-alcoholic fatty liver and fibrosis is associated with cardiovascular structure and function in young adults

Non-alcoholic fatty liver disease shares many risk factors with other metabolic disorders. We sought to establish whether non-alcoholic fatty liver disease may be associated with cardiovascular health independently of other known risk factors.

In this prospective, population-based cohort of young adults, controlled attenuation parameter-defined liver steatosis, transient elastography-defined liver fibrosis, echocardiography, carotid ultrasonography, and pulse wave analysis were assessed at age 24 years. We examined associations between liver and cardiovascular measures, with and without accounting for demographics, body mass index, alcohol, smoking, blood pressure, lipidemia, glycemia, and inflammation.

We included 2047 participants (mean age 24.4 y; 36.2% female): 212 (10.4%) had steatosis, whereas 38 (1.9%) had fibrosis. Steatosis was associated with cardiovascular measures after adjusting for demographics, but with more comprehensive adjustment, steatosis only remained associated with stroke index [β (95% CI) of -1.85 (-3.29, -0.41) mL/m2] and heart rate [2.17 (0.58, 3.75) beats/min]. Fibrosis was associated with several measures of cardiovascular structure and function after full adjustment for risk factors, including left ventricular mass index [2.46 (0.56, 4.37) g/m2.7], E/A ratio [0.32 (0.13, 0.50)], tricuspid annular plane systolic excursion [0.14 (0.01, 0.26) cm], carotid intima-media thickness [0.024 (0.008, 0.040) mm], pulse wave velocity [0.40 (0.06, 0.75) m/s], cardiac index [-0.23 (-0.41, -0.06) L/min⋅m2], and heart rate [-7.23 (-10.16, -4.29) beats/min].

Steatosis was not associated with measures of cardiovascular structure and function nor with subclinical atherosclerosis after adjusting for known cardiovascular risk factors. Fibrosis, however, was associated with several cardiovascular measures, including indicators of subclinical atherosclerosis, even after full adjustment. Further follow-up will help determine whether cardiovascular health worsens later with steatosis alone.