Plasma phospholipid transfer protein activity and small, dense LDL in type 2 diabetes mellitus.
BACKGROUND
Phospholipid transfer protein (PLTP) and cholesteryl ester transfer protein (CETP) remodel circulating lipoproteins and play a role in the antiatherogenic reverse cholesterol transport pathway. The present study determined whether abnormalities in the LDL subfraction pattern in type 2 diabetic patients were related to changes in lipid transfer proteins.


METHODS
Low-density lipoprotein (LDL) subfractions were measured by density gradient ultracentrifugation and plasma PLTP and CETP activities by radiometric assays in 240 diabetic patients and 136 controls.


RESULTS
The diabetic patients had lower LDL-I (P < 0.001) and higher LDL-III concentrations than the controls (P < 0.001). Plasma PLTP activity was increased (P < 0.001) whereas no significant differences were seen in CETP activity. In the diabetic patients, small, dense LDL-III correlated with plasma triglyceride (r = 0.18, P < 0.01), HDL (r = -0.14, P < 0.05), PLTP (r = 0.29, P < 0.001) and CETP activity (r = 0.15, P < 0.05). Linear regression analysis showed that plasma PLTP activity, triglyceride and age were the major determinants of LDL-III concentration (r2 = 28%, P < 0.001). The univariate relationship between CETP and LDL-III was no longer significant after adjusting for PLTP activity.


CONCLUSIONS
The increase in plasma PLTP activity was independently associated with small, dense LDL concentrations in type 2 diabetes. Hence, elevated PLTP activity might have both antiatherogenic and pro-atherogenic potential in these patients.
Tan
K C B
KC
Department of Medicine, University of Hong Kong. kcbtan@hkucc.hku.hk
Shiu
S W M
SW
Wong
Y
Y
D002352:Carrier Proteins / Q000097:blood*; D053480:Cholesterol Ester Transfer Proteins; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D006023:Glycoproteins; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood*; D008565:Membrane Proteins / Q000097:blood*; D008875:Middle Aged; D049294:Phospholipid Transfer Proteins
C506642:CETP protein, human; D002352:Carrier Proteins; D053480:Cholesterol Ester Transfer Proteins; D006023:Glycoproteins; D008077:Lipoproteins, LDL; D008565:Membrane Proteins; D049294:Phospholipid Transfer Proteins