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Diagnosing dyslipoproteinemia
Quantitation of cholesterol and triglycerides in very-low-density lipoprotein (VLDL), LDL, HDL, and chylomicrons
Identification of LpX
Classifying hyperlipoproteinemias (lipoprotein phenotyping)
Evaluating patients with abnormal lipid values (cholesterol, triglyceride, HDL, LDL)
Quantifying lipoprotein a (Lp[a]) cholesterol
Lipoprotein metabolism profile analysis adds practical information about the etiology of cholesterol and/or triglyceride elevation. In some patients, increased serum lipids reflect elevated levels of intermediate-density lipoprotein (IDL), very-low-density lipoprotein (VLDL), lipoprotein a (Lp[a]), or even the abnormal lipoprotein complex-LpX. These elevations can be indicative of a genetic deficiency in lipid metabolism or transport, nephrotic syndrome, endocrine dysfunction or even cholestasis. Identification of the lipoprotein associated with lipid elevation is achieved using the gold-standard methods, which include ultracentrifugation, selective precipitation, electrophoresis, and direct measurement of cholesterol and triglycerides in isolated lipoprotein fractions. Proper characterization of a patient's dyslipidemic phenotype aids clinical decisions and guides appropriate therapy.
Classifying the hyperlipoproteinemias into phenotypes places disorders that affect plasma lipid and lipoprotein concentrations into convenient groups for evaluation and treatment. A clear distinction must be made between primary (inherited) and secondary (liver disease, alcoholism, metabolic diseases) causes of dyslipoproteinemia. Lipoprotein profiling will identify the presence of Lp(a) and LpX and distinguish between the following dyslipidemias:
-Exogenous hyperlipemia (Type I)
-Familial hypercholesterolemia (Type IIa)
-Familial combined hyperlipidemia (Type IIb)
-Familial dysbetalipoproteinemia (Type III)
-Endogenous hyperlipemia (Type IV)
-Mixed hyperlipemia (Type V)
Age | 2-9 years | 10-17 years | >18 years |
Total Cholesterol (mg/dL) | * Acceptable: <170 Borderline high: 170-199 High: > or =200 | ** Desirable: <200 Borderline high: 200-239 High: > or = 240 | |
Triglycerides (mg/dL) | * Acceptable: <75 Borderline high: 75-99 High: > or =100 | * Acceptable: <90 Borderline high: 90-129 High: > or =130 | ** Normal: <150 Borderline high: 150-199 High: 200-499 Very high: > or =500 |
LDL Cholesterol (mg/dL) | * Acceptable: <110 Borderline high: 110-129 High: > or =130 | *** Desirable: <100 Above Desirable: 100-129 Borderline high: 130-159 High: 160-189 Very high: > or =190 | |
LDL Triglycerides (mg/dL) | < or = 50 | < or = 50 | |
Apolipoprotein B (mg/dL) | * Acceptable: <90 Borderline high: 90-109 High: > or =110 | *** Desirable: <90 Above Desirable: 90-99 Borderline high: 100-119 High: 120-139 Very high: > or =140 | |
HDL Cholesterol (mg/dL) | * Low: <40 Borderline low: 40-45 Acceptable: > 45 | *** Males: > or =40 Females: > or =50
| |
VLDL Cholesterol (mg/dL) | <30 | <30 | |
VLDLTriglycerides (mg/dL) | <90 | <120 | |
Beta VLDL Cholesterol (mg/dL) | <15 | <15 | |
Beta VLDL Triglycerides (mg/dL) | <15 | <15 | |
Chylomicron Cholesterol | Undetectable | Undetectable | |
Chylomicron Triglycerides | Undetectable | Undetectable | |
Lp(a) cholesterol | <5 | <5 | |
LpX | Undetectable | Undetectable |
Reference values have not been established for patients that are <2 years of age.
* Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents
** National Cholesterol Education Program (NCEP)
***National Lipid Association
For discussion of primary disorders associated with dyslipidemias see Lipids and Lipoproteins in Blood Plasma (Serum) in Special Instructions.
Patients with increased Lp(a) cholesterol values have been associated with increased risk for the development of atherothrombotic disease. Aggressive LDL reduction is the recommended treatment approach in most patients with increased Lp(a).
Lipoprotein-X (LpX) is an abnormal lipoprotein that appears in the sera of patients with obstructive jaundice, and is an indicator of cholestasis. The presence of LpX will be reported if noted during Lp(a) cholesterol analysis.
Reference values are based on fasting collections; it is essential that the patient fasts for 12 to 14 hours before the specimen collection.
Cholesterol results can be falsely decreased in patients with elevated levels of N-acetyl-p-benzoquinone imine (NAPQI), a metabolite of acetaminophen, N-acetylcysteine (NAC), and metamizole.
1. Grundy SM, Stone NJ, Bailey AL, et al: 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation 2019 Jun 18;139(25):e1082-e1143
2. Expert panel on integrated guidelines for cardiovascular health and risk reduction in children and adolescents: summary report. Pediatrics. 2011 Dec;128 Suppl 5:S213-S256
3. Rosenson RS, Najera SD, Hegele RA: Heterozygous familial hypercholesterolemia presenting as chylomicronemia syndrome. J Clin Lipidol. 2017 Jan - Feb;11(1):294-296. doi: 10.1016/j.jacl.2016.12.005
4. Hopkins PN, Brinton EA, Nanjee MN: Hyperlipoproteinemia type 3: the forgotten phenotype. Curr Atheroscler Rep. 2014 Sep;16(9):440. doi: 10.1007/s11883-014-0440-2
5. Gotoda T, Shirai K, Ohta T, Kobayashi J, Yokoyama S, Oikawa S, et al: Diagnosis and management of type I and type V hyperlipoproteinemia. J Atheroscler J Atheroscler Thromb. 2012;19(1):1-12