Treatment of dyslipidemia in patients with type 2 diabetes

Abstract

Type 2 diabetes is associated with significant cardiovascular morbidity and mortality. Although low-density lipoprotein cholesterol levels may be normal in patients with type 2 diabetes, insulin resistance drives a number of changes in lipid metabolism and lipoprotein composition that render low-density lipoprotein cholesterol and other lipoproteins more pathogenic than species found in patients without type 2 diabetes. Dyslipidemia, which affects almost 50% of patients with type 2 diabetes, is a cardiovascular risk factor characterized by elevated triglyceride levels, low high-density lipoprotein cholesterol levels, and a preponderance of small, dense, low-density lipoprotein particles. Early, aggressive pharmacological management is advocated to reduce low-density lipoprotein cholesterol levels, regardless of baseline levels. A number of lipid-lowering agents, including statins, fibrates, niacin, and bile acid sequestrants, are available to target normalization of the entire lipid profile. Despite use of combination and high-dose lipid-lowering agents, many patients with type 2 diabetes do not achieve lipid targets. This review outlines the characteristics and prevalence of dyslipidemia in patients with type 2 diabetes and discusses strategies that may reduce the risk of cardiovascular disease in this population.

Figure 1

Atherogenic dyslipidemia and changes in lipoprotein metabolism associated with type 2 diabetes mellitus [51]. Insulin resistance is associated with enhanced production of very-low-density lipoprotein (VLDL); a reduction in the catabolic rate of intermediate-density lipoprotein (IDL) and small, dense low-density lipoprotein (sdLDL); increased production of high-density lipoprotein (HDL) outweighed by increased catabolism. Adapted with permission from Adiels et al, Overproduction of very low-density lipoproteins is the hallmark of the dyslipidemia in the metabolic syndrome. Arterioscler Thromb Vasc Biol 28(7): 1225-1236 (2008) [14].

Figure 2

Prevalence of target low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) levels for patients with and without type 2 diabetes mellitus (T2DM): National Health and Nutrition Examination Survey 1999-2000. *P <0.001 vs patients with T2DM. Reprinted from Diabetes Res Clin Pract, 70(3), Jacobs MJ, et al, 263-269, Copyright 2005, with permission from Elsevier [27].

Figure 3

Prevalence of target low-density lipoprotein cholesterol (LDL-C) and combined LDL-C, high-density lipoprotein cholesterol (HDL-C) + triglyceride (TG) levels for patients with type 2 diabetes mellitus either treated or not treated for dyslipidemia: National Health and Nutrition Examination Survey 1999-2000 [27].