Effect of insulin treatment on plasma oxidized LDL/LDL-cholesterol ratio in type 2 diabetic patients.
OBJECTIVE
In type 2 diabetes mellitus, oxidized LDL/LDL-Cholesterol ratio, an accurate estimation of in vivo LDL oxidation, has been reported elevated and associated with macrovascular disease. Because insulin therapy induces significant modification of lipid metabolism, in type 2 diabetes, we evaluated the effect of insulin treatment on oxidized LDL/LDL-C ratio in type 2 diabetic patients and analyzed the results in comparison with the modifications induced by insulin on glycaemia, plasma lipids and LDL receptors.


METHODS
Plasma oxidized LDL concentrations were measured by sandwich ELISA in 21 type 2 diabetic patients before and 3 months after the introduction of insulin therapy, and in 27 age-matched controls.


RESULTS
Type 2 diabetic patients had, compared to controls, significantly increased oxidized LDL/LDL-C ratio (P<0.0001). Three months after insulin treatment, oxidized LDL/LDL-C ratio was significantly reduced (21.1+/-4.7 vs. 24.0+/-5.8 U/mmol, P<0.01). This reduction was strongly associated, in multivariate analysis, with reduction of LDL(TG/cholesterol ratio) (P=0.008), and to a lesser extent with the decrease of LDL fructosamine (P=0.034), but not with the increase of the number of LDL receptors.


CONCLUSIONS
In the present study we demonstrate for the first time a lowering effect of insulin therapy on oxidized LDL/LDL-C ratio in type 2 diabetic patients. This decrease is mainly associated with the reduction of LDL TG-enrichment, and to a lesser extent with the decrease of LDL glycation, but not with the insulin-induced increase in number of LDL receptors.
Galland
F
F
Department of Endocrinology and Metabolic Disease, Hôpital du Bocage, BP 77908, 21079 Dijon Cedex, France. francoisegalland@aol.com
Duvillard
L
L
Petit
J M
JM
Lagrost
L
L
Vaillant
G
G
Brun
J M
JM
Gambert
P
P
Vergès
B
B
D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy*; D004797:Enzyme-Linked Immunosorbent Assay; D005500:Follow-Up Studies; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use*; D008077:Lipoproteins, LDL / Q000097:blood*; D008875:Middle Aged; D008970:Molecular Weight; D012016:Reference Values; D014280:Triglycerides / Q000097:blood
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D007004:Hypoglycemic Agents; D007328:Insulin; D008077:Lipoproteins, LDL; D014280:Triglycerides; C099252:oxidized low density lipoprotein