Hyperlipoproteinemia is a condition of increased lipoprotein particles (fats) in the blood caused by an increased rate of synthesis or a decreased rate of lipoprotein breakdown. Because lipoproteins transport triglycerides and cholesterol in the plasma, an increased level may cause complications such as pancreatitis and atherosclerosis leading to coronary heart disease, myocardial infarction, stroke, and sudden death.
Lipids are a mixed group of biochemical substances manufactured by the body or derived from metabolism of ingested substances. The plasma lipids (cholesterols, triglycerides, phospholipids, and free fatty acids) are derived from dietary sources and lipid synthesis. Cholesterol and triglycerides are implicated in atherogenesis. Hyperlipemia, also known as hyperlipidemia, occurs with elevated plasma cholesterol or triglyceride levels or both and is present in all hyperlipoproteinemias.
Hyperlipidemia, an elevation of serum cholesterol or triglycerides, can be primary or secondary to another underlying condition. Lipoprotein elevation, or hyperlipoproteinemia, is described by five specific types: types I, II, III, IV, and V (Table 1).
Table 1 Types of Hyperlipoproteinemia
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Primary hyperlipoproteinemia results from rare genetic disorders. Secondary hyperlipoproteinemia occurs as a manifestation of other diseases, which include hypothyroidism, nephrotic syndrome, diabetes mellitus, alcoholism, glycogen storage disease (type I), Cushing syndrome, acromegaly, anorexia, renal disease, liver diseases, immunological disorders, stress, and the use of oral contraceptives or glucocorticoids.
Familial hypercholesterolemia (FH) is an autosomal disorder caused by mutations in the LDL receptor gene (LDLR), leading to increases in both total cholesterol and low-density lipoprotein levels. FH is associated with an increased risk of coronary artery disease. Mutations in the lipoprotein lipase (LPL) gene cause autosomal recessive hyperlipoproteinemia, whereas APOE mutations yield a dominant disorder with incomplete penetrance. A clinically identical phenotype is produced by mutations in the apolipoprotein B-100 gene (APOB). Other genetic and environmental factors may contribute.
Type I disease is a rare disorder that is present at birth. Type II disease usually causes symptoms in young adults in their 20s, but symptoms may begin as early as age 10 years. Symptoms from type III disease usually occur during the teenage years or early 20s. Type IV disease, more common than the other forms of hyperlipoproteinemia, occurs primarily in middle-aged men. Type V disease occurs in late adolescence or in the early 20s.
While there are no differences in incidence and prevalence in males and females, women with familial hypercholesterolemia are underrepresented in research and have to interrupt therapy during childbearing. Women also are less likely to be on guideline-recommended statin medications and less likely to be on nonstatin agents such as PCSK9 inhibitors as compared to men. As a result, women are less likely than men to achieve target low-density lipoprotein cholesterol (LDL-C) goals (Balla et al., 2020). While the condition is found in children, adolescents, and young adults, type IV is seen most often in middle-aged and older adults.
In general, Black persons are more likely to have hyperlipoproteinemia than White persons. People of Asian and Indian-Asian descent have lower prevalence than other groups in developed countries. Sexual and gender minority status has no known effect on the risk for hyperlipoproteinemia.
Hyperlipoproteinemia has a high prevalence in developed countries. Little is known about the prevalence in developing countries, but if trends in hyperlipoproteinemia follow obesity trends, prevalence will increase as developing regions become more urbanized.
ASSESSMENT
History
Take a thorough history of existing illnesses because secondary hyperlipoproteinemia is related to a number of other conditions. Ask if the patient has a history of renal or liver disease, diabetes mellitus, other endocrine diseases, or immune disorders. Determine the patient's height and weight, and calculate the body mass index.
Ask if the patient is taking corticosteroids or oral contraceptives and determine the extent of the patient's alcohol use. Because hyperlipoproteinemia is sometimes treated with a range of bile acid sequestrant medications, which can affect the absorption of other medications, ask if the patient is taking any of the following: warfarin, thiazides, thyroxine, beta-adrenergic blockers, fat-soluble vitamins, folic acid, diuretics, or digitoxin.
Symptoms of hyperlipoproteinemia vary, depending on which of the five types the patient has. Ask about recurrent bouts of severe abdominal pain, usually preceded by fat intake, or if the patient has experienced malaise, anorexia, or fever.
Observe general appearance for signs of obesity, which may be an exacerbating factor for hyperlipoproteinemia. Classic symptoms include opaque ring surrounding the corneal periphery (corneal arcus), xanthelasma (lipid deposit on the eyelid), and lipemia retinalis (creamy appearance of the retinal vessels). Inspection may reveal papular or eruptive deposits of fat (xanthomas) over pressure points and extensor surfaces; likely locations include the Achilles tendons, hand and foot tendons, elbows, knees, and hands and fingertips (where you may observe orange or yellow discolorations of the palmar and digital creases). Ophthalmoscopic examination typically reveals reddish-white retinal vessels. Palpate the abdomen for spasm, rigidity, rebound tenderness, liver or spleen tenderness, and hepatosplenomegaly. Check for signs of hypertension and hyperuricemia.
Psychosocial
Hyperlipoproteinemia is not an abrupt illness; it develops over years. The patient may have developed coping mechanisms during that time, but the patient may be anxious because of accelerated symptoms of atherosclerosis and CHD. Patients may have experienced the premature death of parents from this disorder and have long-lasting fears about their own early death. Body image disturbance may also occur because of obesity or the presence of unsightly xanthomas. Cigarette smoking and alcohol misuse and dependence are known to contribute to the condition. Assess patients' patterns of use and abuse, and assess their readiness and willingness to change.
Test | Normal Result | Abnormality With Condition | Explanation |
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Total cholesterol | Varies with age, ethnicity, and gender; desirable: < 200 mg/dL | Borderline high: 200–239 mg/dL; high: > 239 mg/dL | Used for screening and initial classification of risk of CHD; elevations determine hyperlipidemia; lipid and lipoprotein levels are collected after a 12-hr fast |
LDL cholesterol (LDL-C) | Optimal: < 100 mg/dL; desirable level: < 130 mg/dL | Borderline high risk: 130–159 mg/dL; high risk: > 159 mg/dL | Elevated levels are associated with increased risk for CHD; VLDL normal range: 10–31 mg/dL; lipid and lipoprotein levels are collected after a 12-hr fast |
High-density lipoprotein cholesterol (HDL-C) | Desirable: > 60 mg/dL; acceptable: 40–60 mg/dL | Low: < 40 mg/dL | Considered a major risk factor for CHD; high HDL-C (> 60 mg/dL) is considered protective; lipid and lipoprotein levels are collected after a 12-hr fast |
Triglycerides | <150 mg/dL | Borderline high risk: 150–199 mg/dL; high risk: 200–499 mg/dL; very high risk: > 500 mg/dL | Used for screening and initial classification of risk of CHD; elevations determine hyperlipidemia |
Other Tests: Electrocardiogram, genetic testing, ophthalmological examination
Diagnosis
DiagnosisReadiness for enhanced nutrition related to concern over lipoprotein accumulation and accelerated blockage of the coronary arteries as evidenced by expressing a desire to change dietary patterns
Outcomes
OutcomesNutritional status: Food and fluid intake, Nutrient intake; Knowledge: Medication; Knowledge: Disease process
PLANNING AND IMPLEMENTATION
The primary treatment is dietary management, weight reduction, increased physical activity, and the restriction of saturated animal fat and cholesterol intake. Adding polyunsaturated vegetable oils to the diet helps reduce LDL-C concentration. Secondary treatment is aimed at reducing or eliminating aggravating factors, such as alcoholism, diabetes mellitus, or hypothyroidism. To reduce risk factors that contribute to atherosclerosis, the regimen includes treating hypertension, implementing an exercise program, controlling blood sugar, and stopping tobacco use. For type V hyperlipoproteinemia, female patients are taken off oral contraceptives. Medications may also be prescribed to lower the plasma concentration of lipoproteins, either by decreasing their production or by increasing their removal from plasma.
Target levels for lipoprotein are shown in Table 2.
Table 2 Target Levels for Lipoprotein
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In rare instances, for patients who cannot tolerate medication therapy, surgical creation of an ileal bypass may be necessary to accelerate the loss of bile acids in the stool and lower plasma cholesterol levels. For children with severe disease, surgery to create a portacaval shunt may be performed as a last resort to decrease plasma cholesterol levels. Plasma exchanges may also be used to reduce cholesterol levels.
Pharmacologic Highlights
Medication or Drug Class | Dosage | Description | Rationale |
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Drugs that lower LDL-C | Varies with drug | Statins such as lovastatin, pravastatin, simvastatin, fluvastatin, and atorvastatin are the first line of therapy; bile acid sequestrant resins (cholestyramine, colestipol); nicotinic acid (niacin); 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors; estrogen in postmenopausal women | Lower the plasma concentration of lipoproteins either by decreasing their production or by increasing their removal from plasma |
Drugs that increase HDL-C | Varies with drug | Nicotinic acid (niacin), estrogen in postmenopausal women | Lower the plasma concentration of lipoproteins either by decreasing their production or by increasing their removal from plasma |
Teach the patient about ways to manage diet to control the disorder. Urge the patient to adhere to a 1,000- to 1,500-calorie daily diet and avoid excess sugar intake. Explain the components of the lipid profile and their ramifications and discuss various means of lowering VLDL and LDL levels and increasing HDL levels. Several dietary additions are thought to reduce LDL cholesterol, such as 1.5 cups of oatmeal with fiber-containing fruit (soluble fiber reduces LDL), 1.5 ounces of nuts (walnuts, almonds, peanuts, pecans), olive oil, and fatty fish containing omega-3 fatty acids such as mackerel, lake trout, herring, sardines, albacore tuna, and salmon.
Explain the prescribed medication regimen and provide verbal and written information to the patient or significant others. Refer to effective programs or support groups for controlling cigarette and alcohol use. Teach alternative methods of contraception to the female patient who can no longer use oral contraceptives. Encourage strategies for weight loss and weight maintenance.
A patient faces significant health threats unless the patient makes permanent lifestyle changes. Encourage the patient to verbalize fears, such as those concerning CHD. Offer support and provide clear explanations for the patient's questions about the lifestyle changes and consequences.
Evidence-Based Practice and Health Policy
Sergei, N., Pokrovsky, S., Afanasieva, O., & Ezhov, M. (2020). Therapeutic apheresis for management of Lp(a) hyperlipoproteinemia. Current Atherosclerosis, 22, 1–11.
Prevention
Teach the patient the importance of dietary and lifestyle changes. Refer the patient to a dietitian if appropriate. Provide information on smoking cessation and sensible drinking if appropriate. Discuss an exercise plan.
Medications
Be sure the patient understands all medications, including the dosage, route, action, adverse effects, and the need for routine laboratory monitoring for lipid profiles.
Complications
Teach the patient to report to the physician the occurrence of signs and symptoms of CHD, such as chest pain, shortness of breath, and changes in mental status. Teach the patient the need for follow-up serum cholesterol and serum triglyceride tests. Instruct the patient to maintain a stable body weight and to adhere to any dietary restrictions before undergoing cholesterol tests. Most tests require the patient to fast for 12 hours before the test.