AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Hyperlipoproteinemia is a metabolic disorder characterized by abnormally elevated concentrations of specific lipoprotein particles in the plasma.

Pathophysiology

Hyperlipidemia (ie, elevated plasma cholesterol or triglyceride levels or both) is present in all hyperlipoproteinemias. The primary form includes chylomicronemia, hypercholesterolemia, dysbetalipoproteinemia, hypertriglyceridemia, mixed hyperlipoproteinemia, and combined hyperlipoproteinemia. Other diseases, such as diabetes mellitus, pancreatitis, renal disease, and hypothyroidism, cause the secondary form.

Frequency

United States

This condition has a high frequency in developed countries.

Mortality/Morbidity

• If uncontrolled, higher mortality occurs from cardiovascular and cerebrovascular diseases.
• Abnormalities of the vascular system can develop, including ischemic cardiac disease. Obtaining appropriate medical evaluation is important, especially in patients younger than 40 years who have a prominent corneal arcus, xanthelasma, or lipemia retinalis.

Race

African Americans are affected more frequently than whites.

Sex

No sexual preponderance exists.

Age

Hyperlipoproteinemia may be present in children and young adults but is seen more frequently in later life.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

Clinical manifestations of the hyperlipoproteinemias are caused by the deposition of lipids in the vascular system and the eye.

Physical

• Corneal arcus, lipemia retinalis, and xanthelasma are the most common ocular abnormalities.
• Lipemia retinalis is primarily caused by an elevation of the serum triglyceride levels, which imparts a milky color to the blood.
• • The changes are usually not seen until the triglyceride level reaches at least 2000 mg/dL in the early stages; they are best observed in the peripheral fundus. The vessels initially appear salmon-pink, but, when the triglyceride level rises further, they become whitish.
  • These changes, which begin in the periphery, progress toward the posterior pole as the triglyceride level rises. In severe cases, the vessels are creamy white, and differentiating the arteries from the veins is difficult. The findings can fluctuate widely from day to day, depending on the triglyceride level.
  • The fundus abnormalities, which improve as the triglyceride levels return to normal, provide a method of following the patient's course and response to therapy.
• Xanthelasma is a deposition of lipid in the eyelid, usually the upper medial lid. The lesions may be excised, but recurrences are common. With primary excisions, recurrences of up to 40% have been reported, and secondary excision recurrences are even higher. Of the initial failures, 20% are within the first year.

Causes

Risks appear to include diet, stress, physical inactivity, and smoking.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Differentiate the primary and secondary forms of hyperlipoproteinemia.

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• Measure plasma lipid and lipoprotein levels while the patient is on a regular diet after an overnight fast of 12-16 hours. Abnormal lipoprotein patterns can often be identified after determining serum cholesterol and triglyceride levels and visual inspection of the plasma sample (stored at 4°C).
• In some cases, performing electrophoresis and ultracentrifugation of whole plasma specimens may be necessary to help establish a diagnosis.

Imaging Studies

• Ophthalmologists generally do not order imaging studies.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical Care

• Systemic
• • Drugs are used to lower cholesterol and triglyceride levels.
  • Because of the possibility of adverse effects and the question of whether the triglyceride level is an independent risk factor for atherosclerosis, many physicians use drugs to reduce the triglyceride level only when the level exceeds 500 mg/100 mL.
  • Examples of these drugs include lovastatin, pravastatin, and simvastatin.
• Supportive
• • Weight reduction and a diet low in saturated fat and cholesterol are advocated.
  • Patients should avoid alcohol and estrogen in certain types of hyperlipoproteinemias.

Surgical Care

Ileal bypass surgery and plasmapheresis to lower elevated serum lipids are used in selected cases of familial hypercholesterolemia. Only experienced physicians should use these therapies.

Consultations

Internist or family practitioner

Diet

A low-fat diet is recommended, including fruit, vegetables, chicken, and fish.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Drugs are used to lower cholesterol and triglyceride levels. Because of the possibility of adverse effects and the question of whether the triglyceride level is an independent risk factor for atherosclerosis, many physicians use drugs to reduce the triglyceride level only when the level exceeds 500 mg/100 mL.

Drug Category: HMG-CoA reductase inhibitors

These agents are competitive inhibitors of 3-hydroxy-3-methyl Co-A reductase, an enzyme that catalyzes the rate-limiting step in cholesterol biosynthesis, resulting in up-regulation of LDL receptors in response to the decrease in intracellular cholesterol. The HMG-CoA reductase inhibitors are indicated for the secondary prevention of cardiovascular events and for the treatment of hypercholesterolemia and mixed dyslipidemia.

A number of HMG-CoA reductase inhibitors are indicated for patients with homozygous familial hypercholesterolemia as an adjunct to other lipid-lowering treatments. However, these agents may be less effective in patients with rare homozygous familial hypercholesterolemia, possibly because these patients are lacking functional LDL receptors, making it more likely to raise serum transaminases.

Drug Category: Nicotinic acid derivatives

Niacin (vitamin B-3) inhibits the hepatic secretion of VLDL cholesterol. Niacin is effective in most categories of hyperlipidemia. Niacin has been demonstrated to lower LDL cholesterol by 32%, lower triglycerides by 20-50%, and raise HDL cholesterol by 43%. Niacin lowers lipoprotein (a) levels, which may be of some clinical importance because lipoprotein (a) levels have been associated with coronary heart disease in numerous epidemiological studies. The clinical benefit of lowering lipoprotein (a) levels has not been determined.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Outpatient Care

• With this chronic condition, long-term follow-up care is important.
• Periodic blood lipid levels are imperative.

In/Out Patient Meds

• Most cases are controlled with diet, exercise, and medication.

Patient Education

• For excellent patient education resources, see eMedicine's Cholesterol Center. Also, visit eMedicine's patient education articles High Cholesterol, Understanding Your Cholesterol Level, Lifestyle Cholesterol Management, and Understanding Cholesterol-Lowering Medications.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Early detection may prevent later problems.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• Bron AJ. Corneal changes in the dislipoproteinaemias. Cornea. 1989;8(2):135-40. [Medline].
• Brownstein S, Jackson WB, Onerheim RM. Schnyder's crystalline corneal dystrophy in association with hyperlipoproteinemia: histopathological and ultrastructural findings. Can J Ophthalmol. Aug 1991;26(5):273-9. [Medline].
• Crispin SM. Lipid deposition at the limbus. Eye. 1989;3 (Pt 2):240-50. [Medline].
• Feldman EB. Nutrition and diet in relation to hyperlipidemia and atherosclerosis. In: Shields M, Olson JA, Shike M. Modern Nutrition in Health and Disease. 8^th ed. 1992.
• Gronemeyer A, Arsene S, Le Lez ML, Rateau J. [Central retinal artery occlusion or branch retinal artery occlusion in the young associated with high lipoprotein (a) levels]. J Fr Ophtalmol. Sep 2002;25(7):727-30. [Medline].
• Jünemann A, Küchle M, Naumann GO. Epithelial iron line in juvenile corneal arcus lipoides. Cornea. Sep 1995;14(5):540-2. [Medline].
• Wu CW, Lin PY, Liu YF, Liu TC, Lin MW, Chen WM, et al. Central corneal mosaic opacities in Schnyder's crystalline dystrophy. Ophthalmology. Apr 2005;112(4):650-3. [Medline].

Article Last Updated: Aug 14, 2007