OVERVIEW
Hyperlipoproteinemia type II is the most common clinical condition and is closely related to atherosclerosis and is divided into two types, IIa and IIb.
Etiology
1. Hyperlipoproteinemia type IIa: metabolic disorder defective disease, low density lipoprotein (LDL) receptor defective, can be proved by fibroblast culture. It can also be secondary to Cushing’s syndrome, hypothyroidism, and glucocorticoid application.
2. Hyperlipoproteinemia type IIb: the primary etiology is unknown. Secondary etiology can be diabetes mellitus, liver disease, kidney disease, etc.
Symptoms
Hyperlipoproteinemia type IIa: Pure syngeneics present with symptoms in early childhood, while heterozygous syngeneics often present between the ages of 20 and 50 years. Typical symptoms include blepharoplakia, nodular xanthomas, tendon xanthomas, and atherosclerosis, which occurs mainly in the coronary arteries.
Examination
Serum clear, cholesterol and β-lipoproteins are markedly elevated, apo-β and LDL cholesterol are elevated, and triglycerides are normal. In hyperlipoproteinemia IIa, serum is clear, cholesterol and β-lipoprotein are markedly elevated, apo-β and LDL cholesterol are elevated, and triglycerides are normal. In hyperlipoproteinemia type IIb, the serum is either clear or cloudy, with elevated cholesterol, triglycerides, LDL, and pre-β-lipoproteins (VLDLS).
Diagnosis
1. Hyperlipoproteinemia type IIa with clear serum, markedly elevated cholesterol and beta-lipoproteins, elevated apo-beta and LDL cholesterol, and normal triglycerides.
2. Hyperlipoproteinemia type IIb, with serum clear or cloudy, elevated cholesterol, triglycerides, LDL, and pre-β-lipoproteins (VLDLS).
Treatment
1. Hyperlipoproteinemia type IIa
Only fat containing more than 60% of polyunsaturated fatty acids should be consumed. Maximum cholesterol intake is 300mg/d. Drugs: simvastatin 20mg/d. Combination of colesevelam (cholestyramine), niacin and its derivatives may be effective.
2. Hyperlipoproteinemia type IIb
Clofibrate (Antomin) or lovastatin can be used to lower VLDLS, and it is important to reduce sugar intake and weight loss to normal range.
Prognosis
1. Hyperlipoproteinemia type IIa
The earlier the onset of the disease, the worse the prognosis. Children usually die of coronary embolism and myocardial infarction before puberty.
2. Hyperlipoproteinemia type IIb
Proper diet and weight reduction can help.