This is an observational cross-sectional study aimed at investigating the alterations of the carbamylated-HDL levels in T2DM patients, and comparing the concentration of carbamylated-HDL between the T2DM patients with CAD and without CAD to explore the association between carbamylated-HDL and risk of CAD in T2DM patients.

High-density lipoprotein (HDL) is involved in various atheroprotective processes, including reverse cholesterol transport, inhibition of lipid oxidation and inflammatory cytokine secretion, endothelial repair, and antiapoptotic function, which all contribute to the regression of plague burden. Recent studies have shown that oxidative stress and chronic inflammation - both implicated in the process of diabetes - can contribute to an irreversible post-translational modification called carbamylation. Carbamylation levels reflect the burden of enhanced inflammation, oxidative stress, and renal impairment, and can serve as a biomarker of certain pathological conditions. Several clinical studies have demonstrated positive associations between cardiovascular risk, mortality, and serum carbamylation-derived product levels in the general population and particularly in patients with kidney failure. Increasing evidence also shows that carbamylated lipoprotein plays a pivotal role in atherosclerosis.18 However, most studies concerning carbamylation have been performed under a kidney disease background. Whether HDL particles in patients with type 2 diabetes mellitus (T2DM) show enhanced carbamylation and whether this enhancement is associated with vascular complications remains unknown. Thus, in the present study, the investigators aim to test whether HDL experiences carbamylation in T2DM patients and investigated the pro-atherogenic effects of carbamylated HDL on endothelial-monocyte adhesion.

Inclusion Criteria:

1:Clinical diagnosis of T2DM (according to the criteria of the American Diabetes Association.)

Exclusion Criteria:

1. end-stage renal disease (ESRD)
2. acute coronary syndrome,
3. heart failure,
4. chronic viral or bacterial infection,
5. cancer,
6. immune system disorders

Between September 2018 to March 2019, a total of 242 consecutive T2DM patients who visited Shanghai Ruijin Hospital were enrolled in this study. All patients were tested by angiography, with CAD diagnosed if luminal diameter narrowing was estimated visually at ≥50% in a major epicardial coronary artery. Patients with end-stage renal disease (ESRD) (n = 9), acute coronary syndrome(n = 25), heart failure (n = 21), chronic viral or bacterial infection (n = 7), tumors(n = 8), or immune system disorders (n = 3) were excluded from this study. We included 40 age- and gender-matched healthy subjects to serve as the control group, who had normal blood pressure, serum fasting glucose, lipid profile, and renal function.