A common apolipoprotein B signal peptide polymorphism modifies the relation between plasma non-esterified fatty acids and triglyceride concentration in men

Insulin and non-esterified fatty acids (NEFA) are important regulators of t riglyceride metabolism. The relations between these compounds and the effec t of a common 3 amino acid deletion in the apolipoprotein B (ApoB) signal p eptide (SP) following an oral glucose challenge have been investigated. The frequency of the shorter SP-24 allele was 32% (95% C.I. 29.5-36.5) in 725 subjects undergoing an oral glucose tolerance test (OGTT). Fasting plasma t riglyceride concentration was positively correlated with fasting plasma ins ulin concentration and negatively with the degree of plasma NEFA suppressio n following the glucose challenge. Linear regression analysis showed the re lation between triglyceride concentration and NEFA suppression, but not the relation between triglyceride concentration and fasting insulin, to be alt ered by the SP polymorphism in men but not in women. The strength of the as sociation was dependent on the number of SP-24 alleles. with SP-24 homozygo tes showing the greatest dependence (men P = 0.031, women P = 0.914). It wa s proposed that the complex regulation of very low density lipoprotein (VLD L) output by NEFA and by insulin may explain. at least in part, the conflic ting reports concerning the presence of the ApoB SP polymorphism, fasting s erum lipids and ischaemic heart disease (IHD). (C) 2000 Elsevier Science Ir eland Ltd. All rights reserved.