Remnant cholesterol and cardiovascular and all-cause mortality in Korean adults

Abstract Background Although previous studies have reported that remnant cholesterol (RC) is associated with cardiovascular disease, studies on RC and various mortality related outcomes including cardiovascular mortality in the general population are scarce and most of them are limited to Western populations. Purpose This study aims to evaluate the effect of RC on mortality related outcomes in a relatively young and middle-aged Korean population. Methods This cohort study included 268,219 subjects (mean age, 38 years and 50.6% men) who were enrolled in the Kangbuk Samsung Health Study between 2003 and 2016. Fasting RC was calculated as total cholesterol minus high-density lipoprotein cholesterol minus low-density lipoprotein cholesterol (LDLC). Results The median RC was 0.47 mmol/L (18 mg/dL) and the prevalence of ≥ 1 mmol/L RC was 11.4%. During the median FU of 6.7 years, high RC (RC ≥ 0.47 mmol/L) significantly increased the risk of multivariable-adjusted cardiovascular mortality compared with low RC (HR[95% CI], 1.43[1.07, 1/93]). Compared with the lowest quintile (RC <0.31 mmol/L), the HRs for cardiovascular mortality were 1.95[0.78, 4.84], 2.47[1.03, 5.91], 2.39[1.00, 5.72], and 2.84[1.19, 6.78] in the second, third, fourth, and highest quintiles, respectively. The HRs for all-cause mortality in the 3rd, 4th, and highest quintiles remained significant (1.24[0.97, 1.59], 1.38[1.08, 1.76], 1.34[1.05, 1/71], and 1.32[1.03, 1.69] in the 2nd, 3rd, 4th, and highest quintiles, respectively). However, there was no significant risk for cancer mortality between RC quintiles. Notably, subgroup analysis showed that individuals with high RC and high hsCRP and high RC and high lipoprotein(a) had a more than twofold and threefold increased risk of cardiovascular mortality, respectively, compared with low RC and low hsCRP and low RC and low lipoprotein(a). Conclusions High RC was significantly associated with increased risk of cardiovascular and all-cause mortality, but not with cancer mortality. In particular, high hsCRP and high lipoprotein(a) weighted the risk association between high RC and cardiovascular mortality.