Alterations of lipids and apolipoprotein CIII in very low density lipoprotein subspecies in type 2 diabetes.
OBJECTIVE
Very low density lipoprotein (VLDL) particles are heterogeneous, comprising two main subspecies, VLDL 1 (Sf 60-400) and VLDL 2 (Sf 20-60). The aim of the study was to examine the distribution and composition of VLDL subspecies in type 2 diabetes.


METHODS
We studied the composition and concentration of triglyceride-rich lipoproteins (TRLs) in 217 type 2 diabetic patients and 93 control subjects between 50 and 75 years of age. Lipoprotein subspecies were separated by density-gradient ultracentrifugation. Apolipoprotein (apo) CIII and apo E in plasma and apo CIII in TRL subspecies were measured by nephelometry and apo CII in serum by a commercial kit using a single radial immunodiffusion method.


RESULTS
The concentrations of VLDL 1, VLDL 2 and intermediate density lipoprotein were significantly increased in type 2 diabetes subjects, the change being most marked for VLDL 1. There was a strong linear correlation between VLDL 1 triglycerides and plasma triglycerides in both groups (r = 0.879, p < 0.001 and r = 0.899, p < 0.001). Diabetic subjects had markedly higher plasma ratios of apo CII:apo CIII and apo CIII:apo E. Despite elevated plasma apo CIII, type 2 diabetic subjects had a relative deficiency of apo CIII in all TRL subspecies, suggesting profound disturbances of apo CIII metabolism.


CONCLUSIONS
The elevation of VLDL 1 triglycerides is the major determinant of plasma triglyceride concentration in normal subjects and in type 2 diabetic individuals. Both apo CIII and apo E metabolism are disturbed in type 2 diabetes.
Hiukka
Anne
A
Department of Medicine, Division of Cardiology, Helsinki University Hospital and Biomedicum, Haartmaninkatu 8, 00029, Helsinki, Finland.
Fruchart-Najib
Jamila
J
Leinonen
Eeva
E
Hilden
Hannele
H
Fruchart
Jean-Charles
JC
Taskinen
Marja-Riitta
MR
D000368:Aged; D053305:Apolipoprotein C-III; D001056:Apolipoproteins C / Q000097:blood*; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005260:Female; D011345:Fenofibrate / Q000627:therapeutic use; D006801:Humans; D000960:Hypolipidemic Agents / Q000627:therapeutic use; D008055:Lipids / Q000097:blood*; D008079:Lipoproteins, VLDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D014280:Triglycerides / Q000097:blood
D053305:Apolipoprotein C-III; D001056:Apolipoproteins C; D000960:Hypolipidemic Agents; D008055:Lipids; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D011345:Fenofibrate