Dyslipidemias are a group of disorders characterised by an imbalance of lipids in the blood, e.g., low-density-lipoprotein (LDL) and triglycerides. Higher LDL levels are associated with a higher risk of cardiovascular disease. Higher triglyceride levels combined with low high-density-lipoprotein (HDL) cholesterol or high LDL cholesterol is associated with atherosclerosis, the buildup of fatty deposits in artery walls that increases the risk for heart attack, peripheral artery disease (PAD) and stroke.
Dyslipidemia most often manifests as elevated levels of lipids. Dysbetalipoproteinemia is a rare combined hyperlipidemia (HLP type 3) characterised by high levels of cholesterol and triglycerides, and an increased risk of progressive atherosclerosis and premature cardiovascular disease. Severe dyslipidemia is defined as LDL-C levels ≥190 mg/dL. Specific examples of dyslipidemia include familial hypercholesterolemia and phytosterolemia.
Diabetes can lower the beneficial HDL cholesterol levels and raise triglycerides and LDL cholesterol levels, leading to diabetic dyslipidemia which increases the risk for heart disease and stroke.
Abnormal levels of lipoproteins may be related to genetic alterations in 40% to 60% of dyslipidemia cases.
Several genes have been implicated in increasing the genetic risk of developing cardiovascular disease: Rare genetic variants in the LDLR gene are identified as conferring a higher risk of cardiovascular disease, while variants in the APOA5 gene are associated with high triglyceride levels. LDLR, ApoB, PCSK9 and LDLRAP1 have all been proven to be implicated in familial hypercholesterolemia. Mutations in ABCG5 and ABCG8 are associated with phytosterolemia.
Refractory refers to disease that is progressing despite active treatment.
