APOC3 and heart disorder: In the Copenhagen City Heart Study, heterozygous carriers of APOC3 inactivating mutations had 43% lower levels of remnant cholesterol and 36% lower risk of ischaemic heart disease, with mediation analysis suggesting that remnant cholesterol could mediate up to 54% of the cardiovascular benefit of APOC3 genetic inactivation.14 However, this study did not measure remnant cholesterol directly, but estimated it using the Friedewald Formula introducing measurement error which typically leads to underestimation of the proportion mediated.