Lipodystrophy

Lipodystrophy refers to two kinds of abnormal fat distribution in the body. In lipohypertrophy, fat accumulates in areas of the body in abnormal ways. In lipoatrophy, the patient loses an abnormal amount of fat in parts of their body.

Definition & Facts

Lipodystrophy can be inherited or it can be acquired. There are several types of lipodystrophy, and the symptoms of some begin in childhood. Two types of lipodystrophy- acquired generalized lipodystrophy (AGL) and acquired partial lipodystrophy (AP)- affect females much more often than males. APL is also called Barraquer-Simons syndrome. Localized lipodystrophy affects people of all ages.

Subtypes of AGL include panniculitis-associated acquired generalized lipodystrophy, idiopathic acquired generalized lipodystrophy and autoimmune-associated acquired generalized lipodystrophy.

Another type of acquired lipodystrophy is lipodystrophia centrifugalis abdominalis infantilis. This type of lipodystrophy strikes young children. It begins in the trunk and spreads to the chest and belly. In most patients, the condition resolves on its own. 

Lipoatrophia annularis is a loss of fat just beneath the skin in an upper extremity. This mostly affects women. HIV-associated lipodystrophy is a loss of fat suffered by people who have an HIV infection. Some medical experts believe this is due to the medications the patients take, while others claim it is due to the virus itself.

One form of congenital lipodystrophy is called Berardinelli–Seip syndrome. It is a very rare condition that presents as a lack of fat in the tissues beneath the skin. This type of lipodystrophy is found in about 1 in 10 million people around the world. There are four types of this condition, all of which are caused by a mutation in a gene.

In familial partial lipodystrophy, the loss of fat is found in the upper part of the patient’s body. The lower part of their body is unaffected. It is also caused by a mutation in a gene.

Symptoms & Complaints

People with AGL may also lose fat from the soles of their feet or the palms of their hands. Some people lose fat from their abdomen. The fat loss can be rapid or can take years to develop.

The loss of fat can make the person, who is often a child, look very unhealthy and older than they are. They may simultaneously have a voracious appetite and grow very quickly. However, they may also feel tired much of the time.

People with AGL often become insulin resistant, which can lead to dangerously elevated levels of triglycerides and diabetes mellitus that is hard to control. This out-of-control diabetes can manifest at the same time as the lipodystrophy or after it appears.

Patients can also develop a skin condition called acanthosis nigricans. In this condition the skin becomes dark, thick and velvety, especially in places where the skin is folded, like the groin or the underarms. 

Other patients with AGL have enlarged livers (hepatomegaly) because fat has accumulated in the liver. This can lead to cirrhosis or inflammation in the organ. Patients can also suffer from pancreatitis, whose symptoms are severe abdominal pain, chills, vomiting, jaundice, unexplained weight loss, and weakness.

Girls who have AGL sometimes develop polycystic ovary syndrome when they reach puberty. These girls have too much of the male hormone androgen in their bodies and suffer from irregular menstruation, ovarian cysts, oily skin, and an overgrowth of hair (hirsutism), especially on the chin and upper lip.

People with APL have normal fat distribution when they are born. This distribution continues during their early years but as they approach or enter adolescence they start to lose fat from their face. The loss then continues down their neck, chest, arms, and into the upper abdomen, though the areas beneath that are spared. Some women may have an abnormal amount of fat in their legs and hips. The fat is then reduced over months or years.

About a quarter of people with APL go on to develop a kidney disease called membranoproliferative glomerulonephritis. In this disease, the capillaries in the glomeruli are inflamed. Since the glomeruli remove waste from the blood as it flows through the kidneys, the disease makes it harder for the organs to perform this function. The waste then builds up in the blood. Patients find blood in their urine or dark urine. Their urine output is deceased, and parts of their bodies start to swell. Membranoproliferative glomerulonephritis can lead to kidney failure.

A white or yellow material called drusen can accumulate on the back of the retina in older people with APL. They can also develop macular degeneration. 

Causes

Medications and diseases, especially autoimmune diseases, can lead to acquired lipodystrophies, though sometimes there seems to be no cause. Some medical experts believe that some cases of acquired lipodystrophy have a genetic component, though this is uncertain. Genes whose mutations lead to congenital lipodystrophy include the CAV1 gene, the BSCK2 gene, and the AGPAT2 gene.

Diagnosis & Tests

Diagnosing lipodystrophy is done through physical examination and by taking the patient’s medical history. The emaciated appearance of some patients is also a clue when it comes to lipodystrophy.

Tests include blood tests to check the levels of the patient’s lipids, liver enzymes, glucose, and uric acid. Imaging tests much as magnetic resonance imaging (MRI) can help the doctor see the pattern of fat loss more clearly. Kidney biopsies are helpful in diagnosing people with APL.

Treatment & Therapy

Successful treatment of lipodystrophy depends on the participation of specialists such as pediatricians, nutritionists, heart doctors and even plastic surgeons.

Patients are sometimes given the synthetic, hormone metreleptin to treat their lipodystrophy, for people with this disease also have a deficiency in leptin. Leptin is a hormone that tells a person when they are full as they eat. Some patients with HIV-related lipodystrophy can be helped by human or synthetic growth hormones such as tesamorelin or somatropin.

Prevention & Prophylaxis