Dyslipidemia is a disorder of lipoprotein metabolism, including lipoprotein overproduction or deficiency. Dyslipidemia may be manifested by elevation of the total cholesterol, the "bad" low-density lipoprotein (LDL) cholesterol and the triglyceride concentrations, and a decrease in the "good" high-density lipoprotein (HDL) cholesterol concentration in the blood.
Dyslipidemia comes under consideration in many situations including diabetes, a common cause of lipidemia. For adults with diabetes, it has been recommended that the levels of LDL, HDL, total cholesterol, and triglyceride be measured every year.
Optimal LDL cholesterol levels for adults with diabetes are less than 100 mg/dL (2.60 mmol/L), optimal HDL cholesterol levels are equal to or greater than 40 mg/dL (1.02 mmol/L), and desirable triglyceride levels are less than 150 mg/dL (1.7 mmol/L).
Lipid abnormalities in type 2 diabetes are characterized by high triglyceride concentrations, low high-density lipoprotein-cholesterol concentrations, and normal total and low-density lipoprotein-cholesterol (LDL-c) concentrations. LDL particles, however, are small and dense. Epidemiological evidence for these lipid abnormalities, and for the associations between lipid abnormalities and the increased risk of cardiovascular disease in type 2 diabetes, are presented. Most of the lipid abnormalities in type 2 diabetes can be explained by reduced action of insulin at the tissue level.
Lipid abnormalities in type 2 diabetes are characterized by:
- High triglyceride concentrations, particularly post-prandially (post-prandial lipaemia)
- Low high density lipoprotein-cholesterol (HDL-c) concentrations
- Normal total and low density lipoprotein-cholesterol (LDL-c) concentrations, but small dense LDL particles
This above biochemical picture has been termed "diabetic dyslipidaemia," although it should be noted that treated type 1 diabetes is not characterized by these lipid abnormalities. Many features of diabetic dyslipidaemia can be explained by reduced action of insulin at the tissue level. This could be due to insulin resistance, although relative insulin deficiency associated with pancreatic beta-cell dysfunction also contributes. Some features of diabetic dyslipidaemia, however, may not be due to insulin resistance.