Sitosterolemia

Sitosterolemia General Information

Sitosterolemia is a very rare recessively inherited lipid metabolic disorder. People must understand the mechanism of this disease and its effects (consequences) in order to know how it is best to manage it; left untreated, the morbidity and mortality rates of the condition are significantly increased. Coronary heart diseases and other consequences lead to premature death. This medical condition, also known as phytosterolemia is characterized by decreased biliary excretion and hyperabsorption of dietary sterols causing other severe medical diseases, for example tuberous and tendon xanthomas, hypercholesterolemia, premature development of atherosclerosis and abnormal liver function and hematological exam result.

Important levels of plant sterols (called phytosterols) were discovered in various tissues, especially in the blood. The cases of Sitosterolemia are few and usually misdiagnosed with hyperlipidemia or even undiagnosed. Because this is a genetic condition, no sex predilection exists. The disease manifests at any age, although signs and symptoms were reported in patients younger than 1 year. This metabolic disorder has no race or ethnic predilection, being reported in Chinese, Amish and Japanese patients. Sitosterolemia was first described in 1975. If you still have questions regarding this chapter we recommend you to contact your health care provider or any other trained specialist in metabolic abnormalities.

Sitosterolemia Symptoms

Knowing the signs and symptoms of a medical condition may help you notice a problem before it reaches severe stages. Genetic disorders usually manifest in the first year of life, but they may sometimes be mistaken with other medical conditions. The first obvious sign of this condition is high blood cholesterol, characteristic for other diseases. Sitosterolemia has common clinical characteristics with the well-known homozygous familial hypercholesterolemia (also known as FH). For example, in the first 10 years of life, the patient may accuse development of tendon xanthomas and later, development of atherosclerosis. A specific sign of people diagnosed with Sitosterolemia is that they have very high levels of plant sterols (avenosterol, sitosterol, stigmasterol, campesterol etc) and normal to moderate elevated total sterol levels. Also, different types of xanthomas can appear at any age, not only in childhood.

Children and adults may experience subcutaneous xanthomas on the buttocks or in other unusual locations, for example extensor tendons of the hand and Achilles tendon. Some patients may accuse decreased range of motion with possible swelling, redness or warmth of joints because of arthritis. Also, splenomegaly, premature hardening of arteries and hemolytic episodes may develop in time. Without a treatment, the symptoms of Sitosterolemia get worse and lead to significantly high mortality and morbidity rates. If a patient has had previous myocardial infarction, he or she may experience premature coronary vascular diseases, for example congestive heart failure. All the mentioned signs and symptoms are usually experienced by most of the patients, although particular signs were reported.

Sitosterolemia Treatment

Genetic health problems are usually difficult to correct, although they are commonly detected a year after birth. An early diagnosis followed by the adequate treatment option improves the symptoms in a short period of time, avoiding the severe complications that develop if the disorder is left untreated. When dealing with a disease similar to Sitosterolemia, you are advised to contact your health care provider as soon as possible. He or she may recommend you to consult with a cardiologist (if coronary artery diseases have developed), rheumatologist (if the patient experiences arthritic symptoms), nutritionist (who educates patients regarding low plant sterol diet), hematologist (if the patient has anemia, hypersplenism, hemolysis or thrombocytopenia), lipid disorder specialist and medical geneticist, or metabolic disease specialist. They must all work together to set the exact diagnosis and to establish the correct treatment option for each particular case.

In most cases, Sitosterolemia is easily mistaken with other similar disorders and this is why the health care provider or any other trained health professional must perform several tests to rule out other possible conditions. Sitosterolemia can be treated in different ways: with pharmacologic agents, dietary changes or/and surgical approach. Also, the secondary medical disorders caused by this disease must be properly treated. Usually, as a first step in treating Sitosterolemia, specialists will reduce strictly the intake of foods that have a rich content in plant sterols, for example avocados, olives and vegetable oils. Dieticians advise the patients to eliminate margarine, shellfish, chocolate, seeds and nuts. People suffering from this metabolic disorder are allowed to consume cereal products that do not contain germ and food derived from animal sources (that have cholesterol as the dominant sterol). Sometimes, when the dietary treatment alone is not efficient, competitive inhibitory agents (for example Sitostanol) or bile acid-binding resins (such as Colestipol or Cholestyramine prescribed as Prevalite, LoCHOLEST or Questran) are considered.

In 2003, a new cholesterol absorption inhibitor, called Ezetimibe (and prescribed as Zetia), was released on the market. It has been proved that 10 mg/day administrated in patients who are older than 10 years old is very efficient and tolerable. Bile acid-binding resins are actually agents used as lipid-regulating drugs that modify the concentration of lipids in blood. Cholesterol absorption inhibitors are agents that inhibit dietary cholesterol absorption from the small intestine. All these types of medications must be taken as the doctor ordered and as the prescription indicates. Strictly follow your prescribed treatment option and your chances for a fast recovery will be increased. The expectations are usually high if Sitosterolemia is discovered before it advances to severe stages. You must also avoid forgetting a dose or overdosing; otherwise, you may develop severe adverse effects that interfere in the process of treating this medical disorder (effects that delay your recovery). Before taking any medicine, read carefully the composition to see if it contains a substance that is not tolerated by your body. It is advisable to do some allergy tests before proceeding with a therapy. The levels of plant sterols in the organism can also be decreased by using ileal bypass.