The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio as a predictor of all cause and cardiovascular mortality in United States adults with NAFLD: a prospective cohort study.

Background: The non-HDL cholesterol to HDL cholesterol ratio (NHHR) is a novel composite lipid index. However, its relationship with mortality, particularly in individuals with non-alcoholic fatty liver disease (NAFLD), remains unclear. The aim of this study was to explore the association between NHHR and both all-cause and cardiovascular mortality in adults with NAFLD in the United States.

Methods: This study included 12,648 adult participants with NAFLD from the National Health and Nutrition Examination Survey (NHANES) database (1999-2018). Multivariate Cox proportional hazards models and restricted cubic spline (RCS) methods were employed to assess all-cause and cardiovascular mortality. Subgroup analyses were performed to verify the consistency of these associations.

Results: Over a median follow-up of 99.27 months, 1,659 participants died from all causes, including 460 from cardiovascular disease. RCS analysis revealed a U-shaped relationship between NHHR and all-cause mortality, no association was found between NHHR and cardiovascular mortality. The inflection points for all-cause mortality were 2.67. Subgroup analysis showed that a stronger association between NHHR and all-cause mortality in those with diabetes(P = 0.048).

Conclusions: NHHR is associated with all-cause mortality in NAFLD patients, with distinct non-linear relationships, while it is not associated with cardiovascular mortality. NHHR monitoring may be valuable for assessing mortality risk, particularly in those with diabetes.