Ultrasound-detected fatty liver in young adults and long-term risk of atherosclerotic cardiovascular disease: The Young Finns Study

BACKGROUND: Fatty liver is the most common chronic liver disease globally and is associated with increased cardiovascular risk. Evidence specifically addressing fatty liver and cardiovascular outcomes in young adults from European population-based cohorts remains scarce. METHODS: Fatty liver was assessed by abdominal ultrasound in 2008 participants of the Young Finns Study (age 34-49 years) in 2011. Incident composite cardiovascular disease (CVD) and coronary heart disease (CHD) were ascertained from national registries through 2024. Cox proportional hazards regression was used to examine associations between fatty liver and incident outcomes, with sequential adjustment for sex, age, waist circumference, apolipoprotein B (apoB), and C-reactive protein (CRP). RESULTS: Fatty liver was detected in 377 participants (19%). Over a median follow-up of 13 years, 124 CVD events and 71 CHD events occurred. Fatty liver was associated with incident CVD (HR 1.76, 95% CI 1.20-2.57) and CHD (HR 2.10, 95% CI 1.30-3.39) after adjustment for sex and age. The CVD association was attenuated to non-significance after further adjustment for apoB (HR 1.39, 95% CI 0.91-2.13, p = 0.134). The CHD association remained significant after adjustment for apoB (HR 1.82, 95% CI 1.06-3.12, p = 0.031) and was unchanged after additional adjustment for CRP (HR 1.81, 95% CI 1.06-3.10, p = 0.031), but was slightly attenuated after additional adjustment for markers of insulin resistance, such as HOMA-IR (HR 1.72, p = 0.056). CONCLUSIONS: Fatty liver in young adults was associated with incident CHD after adjustment for atherogenic dyslipidaemia and systemic inflammation, with modest attenuation after adjustment for insulin resistance. The association with composite CVD was substantially attenuated after adjustment for apoB. These findings support fatty liver as a marker of later CVD risk in young adults.