Rpf. Dullaart et al., EFFECT OF ADIPOSITY ON PLASMA-LIPID TRANSFER PROTEIN ACTIVITIES - A POSSIBLE LINK BETWEEN INSULIN-RESISTANCE AND HIGH-DENSITY-LIPOPROTEIN METABOLISM, European journal of clinical investigation, 24(3), 1994, pp. 188-194
The mechanisms responsible for the decreased high density lipoprotein
(HDL) cholesterol levels associated with obesity and insulin resistanc
e are not well understood. Lecithin: cholesterol acyltransferase (LCAT
) and cholesterol ester transfer protein (CETP) are key factors in the
esterification of cholesterol in HDL and the subsequent transfer of c
holesteryl ester towards apolipoprotein B-containing lipoproteins. Pho
spholipid transfer protein (PLTP) may be involved in the regulation of
HDL particle size. We therefore measured the activities of LCAT, CETP
and PLTP using exogenous substrate assays, as well as lipids, lipopro
teins, insulin and C-peptide in fasting plasma from eight healthy obes
e men (body mass index >27 kg m(-2)) and 24 non-obese subjects. The ob
ese men had lower levels of HDL cholesterol (P<0.05) and higher levels
of plasma triglycerides (P<0.05), insulin (P<0.05) and C-peptide (P<0
.01), as compared to the quartile of subjects with the lowest body mas
s index (BMI <22.4 kg m(-2)). CETP and PLTP activities were elevated i
n the obese men by 35% (P<0.01) and by 15% (P<0.05), respectively. LCA
T activity was comparable among the quartiles. Linear regression analy
sis showed that CETP activity was positively correlated with body mass
index (P<0.02), fasting blood glucose (P<0.05) and plasma C-peptide (
P<0.05). PLTP activity was positively related to body mass index (P<0.
01), waist to hip circumference ratio (P<0.001), as well as to fasting
blood glucose (P<0.05) and plasma C-peptide (P<0.05). It is concluded
that the activities of CETP and PLTP are influenced by adiposity and
possibly by insulin resistance. Elevated lipid transfer protein activi
ties may provide a mechanism that contributes to alterations in HDL in
insulin resistant states.