Levels of oxidized LDL and advanced glycation end products-modified LDL in circulating immune complexes are strongly associated with increased levels of carotid intima-media thickness and its progression in type 1 diabetes.
OBJECTIVE
High cholesterol levels in circulating immune complexes (IC), surrogate markers of modified LDL, are associated with increased carotid intima-media thickness (IMT) and cardiovascular events in type 1 diabetes. Different modifications of LDL are involved in IC formation, but which of these are predictive of vascular events is not known. Therefore, we measured oxidized LDL (oxLDL), advanced glycation end products-modified LDL (AGE-LDL), and malondialdehyde-modified LDL (MDA-LDL) in IC and determined their relationship with increased carotid IMT and compared the strength of the association with that observed with conventional risk factors.


METHODS
Levels of oxLDL, AGE-LDL, and MDA-LDL were measured in circulating IC isolated from sera of 479 patients of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) cohort, collected at baseline. Internal and common carotid IMT were measured 8 and 14 years later by DCCT/EDIC.


RESULTS
OxLDL, AGE-LDL, and MDA-LDL levels in circulating IC were significantly correlated with diabetes duration, BMI, and lipid and blood pressure, but not with age. Multivariate logistic regression models indicated that individuals in the highest versus lowest quartile of oxLDL and AGE-LDL in IC had a 6.11-fold [confidence interval (CI) 2.51-14.8] and a 6.4-fold (CI 2.53-16.2) increase in the odds of having high carotid IMT, respectively, after adjusting for conventional risk factors. Parallel analyses resulted in odds ratios of 2.62 (CI 1.24, 5.55) for LDL-C, 1.45 (CI 0.69, 3.03) for diastolic blood pressure, and 2.33 (CI 1.09, 4.99) for A1C.


CONCLUSIONS
OxLDL and AGE-LDL in circulating IC were significantly associated with progression and increased levels of carotid IMT in type 1 diabetes.
Lopes-Virella
Maria F
MF
Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA. virellam@musc.edu
Hunt
Kelly J
KJ
Baker
Nathaniel L
NL
Lachin
John
J
Nathan
David M
DM
Virella
G
G
D000328:Adult; D000936:Antigen-Antibody Complex / Q000097:blood* / Q000276:immunology; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000276:immunology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000000981:diagnostic imaging / Q000276:immunology; D018450:Disease Progression; D005260:Female; D017127:Glycation End Products, Advanced / Q000097:blood* / Q000276:immunology; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood* / Q000276:immunology; D016015:Logistic Models; D008297:Male; D008315:Malondialdehyde / Q000097:blood / Q000276:immunology; D012307:Risk Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging* / Q000276:immunology; D017540:Tunica Media / Q000000981:diagnostic imaging* / Q000276:immunology; D014463:Ultrasonography
D000936:Antigen-Antibody Complex; D017127:Glycation End Products, Advanced; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D008315:Malondialdehyde