Background: The role of nonalcoholic fatty liver disease (NAFLD) as a mediator in the association between various unhealthy lifestyles and major adverse cardiovascular events and all-cause death remains unclear.
Methods and results: This study used data from the UK Biobank, with follow-up until the end of 2021. It involved the calculation of unweighted and weighted lifestyle scores using the Cox model to classify participants on the basis of these scores. Additionally, the research assessed the mediation effect proportion of NAFLD using the difference method and examined the interaction and joint effects of lifestyle and NAFLD on health outcomes. Among the 134 616 enrolled participants, 4024 had records of major adverse cardiovascular events, while among the 130 144 participants included in the analysis of all-cause death, 6697 deaths occurred. The proportions of the association between overall lifestyle and major adverse cardiovascular events mediated by NAFLD were 19.4% and 21.7% (95% CI, 16.2-22.6 and 17.8-25.7) for scores 1 and 2, respectively, and those for all-cause death were 14.1% and 10.1% (95% CI, 11.3-17.1 and 7.9-12.2). After fully adjusting for traditional cardiovascular risk factors, the mediating effects declined across both outcomes. The associations between overall lifestyle and outcomes were stronger among those of the non-NAFLD group, and significant interactions were observed between overall lifestyle and NAFLD status. The joint analysis revealed that patients with NAFLD with unhealthy lifestyle had the highest risk of major adverse cardiovascular events and all-cause death.
Conclusions: Improving lifestyle and addressing metabolic risk factors are essential for cardiovascular risk management in patients with NAFLD.
Keywords: all‐cause death; cardiovascular disease; lifestyle; mediation analysis; nonalcoholic fatty liver disease.