Lipodystrophy definition and facts
- Lipodystrophy refers to medical problem where there is an abnormal distribution of fat in the body. This can refer both to fat loss (lipoatrophy) and abnormal accumulation of fat tissue.
- The disease may be inherited genetically, (for example, familial partial lipodystrophy or FPLD), or acquired. If inherited it may be present at birth (congenital).
- You can get the acquired form after an infection, autoimmune illness, trauma, or repeated pressure or injury on a specific area of the body. (For example, if you have diabetes and you give yourself insulin shots in the same spot every day, you may get lipodystrophy at the injection site.)
- Generalized lipodystrophy happens throughout the body, while the partial form only affects one area of the body.
- If you are infected with HIV (human immunodeficiency syndrome) you have a risk of developing lipodystrophy associated with antiretroviral treatment (for example, protease inhibitors or PIs) for HIV infection. Antiretroviral HIV treatment is directed precisely against the virus that causes HIV.
- Many individuals with lipodystrophy have low blood levels of leptin, a hormone produced by fat cells that's involved in how body fat is regulated.
- A range of biochemical processes (metabolic) abnormalities that affect the health of individuals with this syndrome can include insulin resistance, diabetes (diabetes mellitus), and elevated levels of blood lipids (such as high cholesterol).
- The drug metreleptin (Myalept) has been approved by the US FDA in conjunction with dietary therapy for the treatment of patients with congenital generalized or have the acquired generalized form of the disease who are leptin-deficient.
What is generalized lipodystrophy?
Lipodystrophy is a term that refers to abnormalities of the fat (adipose) tissue in the body. It is a group of rare conditions that are characterized by progressive loss or redistribution of fat, mainly from the tissues beneath the skin (subcutaneous tissues), but loss of fat surrounding the internal organs (visceral fat) also is possible.
What is inherited (familial) lipodystrophy?
Inherited lipodystrophy results from a genetic cause.
- Congenital generalized lipodystrophy (CGL, the Berardinelli-Seip syndrome) is inherited as an autosomal recessive trait.
- There also are several types of the familial partial lipodystrophy (FPLD), such as FPLD type 1 (Kobberling's syndrome), FPLD type 2 (Dunnigan's syndrome), and other rare types of the disease.
What is acquired lipodystrophy?
Acquired lipodystrophy is a form of the syndrome that is not genetic, but develops as a response to another condition. The acquired forms include:
- Acquired generalized lipodystrophy (AGL), or Lawrence syndrome
- Acquired partial lipodystrophy (Barraquer-Simons syndrome) is a disorder that leads to loss of fat in the upper trunk and face, which begins in childhood or adolescence.
- Lipodystrophy induced by protease inhibitors used in HIV infection treatment; this can involve both fat loss and abnormal fat buildup for the patient with HIV.
- Localized, or partial, lipodystrophy, such as at an injection site (for example, from cortisone injection), which typically does not affect the overall health of the patient.
Types of lipodystrophy
There are many different types of lipodystrophy. It can be acquired, or genetic (inherited). The inherited form may be present at birth or develop during childhood (congenital). It may result in fat loss in only one area of the body or throughout the body (generalized).
- Generalized lipodystrophy refers to the situation in which the fat tissue throughout the body is affected (sometimes mistaken for weight or fat gain).
- Partial, or localized, lipodystrophy affects only one area of the body and is not associated with abnormal health generally.
Genetic Disease and Counseling
Genetic diseases or disorders are caused by changes in whole, or in a part of a person's DNA sequence away from its normal sequence. There are hundreds of genetic diseases, syndromes, and disorders. Sometimes a when a person knows that a certain condition runs in their family (hereditary, genetic, or familial) he or she may want to get tested for that particular genetic condition. Sometimes your doctor may recommend genetic testing and counseling if you have a genetic predisposition (it makes you susceptible for the disease) for a certain disease, particularly if it's deadly, like breast cancer.
How common is lipodystrophy?
In general, lipodystrophy syndromes are rare.
- Generalized lipodystrophy (whether inherited or acquired) is estimated to affect less than one out of every one million people.
- Approximately 250 cases of acquired partial lipodystrophy have been reported.
- HIV-associated lipodystrophy is more common, but it is difficult to estimate how common it actually is. Estimates of lipodystrophy associated with HIV have ranged from 10% to over 80% of patients infected with HIV.
What causes lipodystrophy?
Genetic mutations that cause inherited lipodystrophy
Congenital generalized lipodystrophy is a result of specific genetic mutations that are passed from one generation to the next (inherited). Mutations in the genes known as AGPAT2 and BSCL2 account for the majority (about 95%) of cases of CGL. Mutations in other genes, including CAV1 and PTRF, have also been associated with this form of the disease.
Generalized lipodystrophy and leptin deficiency
Leptin is a natural chemical that is responsible for the metabolism of fat. Some patients with generalized lipodystrophy have been shown to be deficient in a substance known as leptin. Low leptin levels cause abnormalities in the body's metabolism, which creates excess fat. This excessive fat tissue, as mentioned previously, can cause metabolic complications and diseases like insulin resistance, diabetes, high cholesterol, fatty liver disease, and heart disease.
Acquired lipodystrophy causes
Acquired lipodystrophy syndrome has been reported after infections; diseases in which your immune system attacks your body (autoimmune disease); injury (trauma); or if pressure is put on, or repeated injections placed in same place on your body (for example, if you have diabetes and you give yourself insulin shots on the same place on your skin every day, you might get it at the injection site). Sometimes, doctors and clinicians don't know what caused the trigger event.
Medical treatment with antiretroviral drugs, for example protease inhibitors (PIs) and nucleoside RT inhibitors (NRTIs) for HIV infection has been found to cause lipodystrophy in patients infected with the HIV virus.
What are the signs and symptoms of the types of lipodystrophy?
The characteristic symptom of lipodystrophy is the loss of or abnormal distribution of fat. Loss of fat also is referred to as lipoatophy. In the congenital (inherited) form, the loss of fat causes an abnormal appearance that's usually noticed within the first two years of life. Depending upon the exact cause, the abnormalities may be seen all over the body or localized to one area. For example, some individuals may have areas on their body that appear thin, while other areas might appear larger (where the excessive fat is located). Others might have very little fat on the lower areas of the body and excess fat on the upper areas. Some people will have reduced fat all over the body.
Congenital generalized lipodystrophy symptoms
Children with the condition may have other associated symptoms and signs, for example, the child may:
- Want and devours food (has a voracious appetite)
- Grow faster and is taller than his or her piers (accelerated linear growth)
- Have an increased metabolic rate
- Have advanced bone age
- Have a belly that sticks out (protrudes)
- Have highly developed muscles (prominent musculature)
- Go through puberty early (precocious sexual development)
- Have mental retardation
- Have dark, velvety skin patches (acanthosis nigricans)
In generalized lipodystrophy, fat can be found in abnormal locations in the body including the heart, kidneys, liver, and pancreas. The presence of fat deposits in these organs can cause problems such as:
Acquired generalized lipodystrophy symptoms
Acquired generalized lipodystrophy has signs and symptoms similar to the inherited forms, but occurs in previously healthy children or adults. In all forms of lipodystrophy, women appear to be more severely affected than men.
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Are there tests to diagnose lipodystrophy?
To make the medical diagnosis of lipodystrophy the doctor will first examine the abnormal appearance caused by changes in fat loss or gain, and then he or she will look for the characteristic clinical symptoms and signs.
Blood tests to measure leptin levels as well as to confirm the presence of other metabolic problems (like insulin resistance, diabetes, or elevated blood lipid levels) are other important diagnostic tests, but not all patients with lipodystrophy have low levels of leptin.
Genetic testing may be performed to evaluate whether a genetic mutation is present in a patient that causes the inherited form.
How are the different types of lipodystrophy treated and managed?
- Generalized lipodystrophy: In 2014, the US Food and Drug Administration (FDA) approved a drug called metreleptin for injection (Myalept) as replacement therapy to treat the complications of leptin deficiency. Metreleptin is used in addition to dietary changes for patients with the congenital generalized or acquired generalized type. Metreleptin is given by injection and is an analog of human leptin produced by recombinant DNA technology. T-cell lymphoma has occurred in patients with the acquired type who had immunodeficiency before beginning metreleptin treatment. Common side effects of metreleptin can include:
- Diet and lipodystrophy: There is no diet plan or therapy that reverses the symptoms of lipodystrophy, but a low-fat diet is recommended for people with the disorder.
- Treatment of associated diseases: Medical treatment of any associated metabolic abnormalities, including diabetes or high blood cholesterol, is the same as for other patients with these health problems. These treatments include both lifestyle modifications and medications.
- Acquired lipodystrophy: Your doctor will tailor your treatment based upon the specific cause. For example, if you give yourself insulin shots don't use the same location on the skin every time.
- Treatment for HIV patients: There are several treatments described for HIV-associated lipodystrophy. HIV treatment options include thiazolidinedione drugs (such as pioglitazone [Actos]), growth hormone, growth hormone-releasing hormone, metformin (Glucophage), and recombinant human leptin.
- Surgery: Surgical treatments have also been used to improve the cosmetic appearance in some people.
What is the prognosis and lifespan for a person with lipodystrophy?
It is difficult to estimate the health prognosis for a given person with lipodystrophy because there are many different kinds of the disorder. Moreover, the health of people is affected to varying degrees. Prognosis or outcome on the patient health will be dependent upon the severity of the disorder as well as the extent of associated problems, such as diabetes, HIV, or other diseases and health problems. Prognosis is also dependent upon the treatment of any associated health conditions. to estimate the health prognosis for a given person with lipodystrophy because there are many different kinds of the disorder. Moreover, the health of people is affected to varying degrees. Prognosis or outcome on the patient's health will be dependent upon the severity of the disorder as well as the extent of associated problems, such as diabetes, HIV, or other diseases and health problems. Prognosis is also dependent upon the treatment of any associated health conditions.
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