Insulin resistance potentiates the effect of remnant cholesterol on cardiovascular mortality in individuals without diabetes.

Background and Aims: Remnant cholesterol (RC) and insulin resistance (IR) have been independently associated with cardiovascular risk. Here, we evaluated the role of IR and RC on cardiovascular disease (CVD) mortality.
Methods: We conducted an analysis of 16,113 individuals ≥20 years without diabetes from the National Health and Nutrition Examination Survey (NHANES-III/IV). RC levels were calculated using total cholesterol, non-HDL-c, and LDL-c; IR was defined as HOMA2-IR≥2.5 and CVD mortality as a composite of cardiovascular and cerebrovascular mortality. Multiple linear regression was used to assess the relationship between HOMA2-IR and RC and Cox regression models to assess their joint role in CVD mortality. Causally ordered mediation models were used to explore the mediating role of IR in RC-associated CVD mortality.
Results: We identified an association between higher HOMA2-IR and higher RC levels. The effect of IR on CVD mortality was predominant (HR 1.32, 95%CI 1.18-1.48) and decreased at older ages (HR 0.934, 95%CI 0.918-0.959) compared to RC (HR 0.983, 95%CI 0.952-1.014). Higher risk of CVD mortality was observed in individuals with IR but normal RC (HR 1.37, 95%CI 1.25-1.50) and subjects with IR and high RC (HR 1.24, 95%CI 1.13-1.37), but not in subjects without IR but high RC. In mediation models, HOMA2-IR accounted for 78.2% (95%CI 28.11-98.89) of the effect of RC levels on CVD mortality.
Conclusions: Our findings suggest that RC potentiates the risk of CVD mortality through its effect on whole-body insulin sensitivity, particularly among younger individuals.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)