The levels of MDA-LDL in circulating immune complexes predict myocardial infarction in the VADT study

Circulating immune complexes (IC) containing modified forms of LDL (mLDL) are strongly pro-inflammatory and strong predictors of cardiovascular disease (CVD) progression in type 1 diabetes. The present study was undertaken to determine whether the levels of oxidized LDL (oxLDL), malondialdehyde-LDL (MDA-LDL) and advanced glycation end products-LDL (AGE-LDL) in IC predict incident CVD events in type 2 diabetes (VADT cohort).

Levels of mLDL in IC were measured in 907 patients of the VADT cohort, a median of two years after entry into the study. Participants were followed for an average of 3.7 years for vascular outcomes. Hazard ratios (HRs) for CV endpoints in relation to mLDL-IC quartiles were calculated by Cox proportional hazard models. The primary composite CVD endpoint included documented myocardial infarction (MI); stroke; death from CVD; congestive heart failure; cardiac, cerebrovascular, or peripheral VD surgical intervention; inoperable CVD; and amputation for ischemic gangrene. During follow-up, 4.7% and 16.8% of participants had an MI or a composite endpoint, respectively. After adjustments by conventional risk factors, individuals in the highest quartile of MDA-LDL-IC were at higher risk of MI [HR = 2.44 (95% CI: 1.03, 5.77)] and composite endpoint [HR = 1.71 (95% CI: 1.04, 2.80)], relative to individuals in the lowest quartile. Similar comparisons for oxLDL and AGE-LDL levels yielded HR values of 1.08 and 1.31 for MI and 0.91 and 1.34 for composite endpoint.

Our study indicates that high levels of MDA-LDL in isolated IC predict future MI and acute CV events in patients with type 2 diabetes.