Glycative Stress, Glycated Hemoglobin, and Atherogenic Dyslipidemia in Patients with Hyperlipidemia

(1) Background: Diabetes mellitus (DM) is a significant health problem and is associated with dyslipidemia; however, the association between glycative stress, in terms of glycated hemoglobin (HbA1c), and atherogenic dyslipidemia in hyperlipidemic patients with and without DM has rarely been reported. (2) Methods: We prospectively recruited 949 hyperlipidemic patients from the Lipid Clinic of the National Taiwan University Hospital. HbA1c and fasting serum lipids, including total cholesterol (TC), high- and low-density lipoprotein cholesterol (HDL-C and LDL-C), small dense LDL-C (sdLDL-C), very low-density lipoprotein cholesterol (VLDL-C), triglycerides, and advanced glycation end-products (AGEs), were measured. After fasting for 10-14 h, all subjects except those with DM underwent a standard oral glucose tolerance test (OGTT) with 75 g of glucose loading. All subjects were asked to discontinue the use of lipid-lowering agents for 8 weeks before recruitment. (3) Results: Patients with DM had a higher prevalence of hypertension and higher levels of triglyceride, TC/HDL-C ratio, AGEs, VLDL-C, and sdLDL-C. Among patients with higher HbA1c, the serum VLDL-C, AGEs, and TC/HDL-C ratio were significantly higher than those with lower HbA1c. After adjustment for covariates, multiple logistic regression analyses revealed different groups of dysglycemia with higher HbA1c had a higher odds ratio for TC/HDL-C >= 5, sdLDL-C >= 75th percentile, VLDL-C >= 75th percentile and AGEs >= 75th percentile. (4) Conclusions: A higher HbA1c was associated with a significant increase in the risk of atherogenic dyslipidemia and AGEs levels in patients with hyperlipidemia. The findings can be very promising in clinical application.