Lipodystrophy

What is lipodystrophy?

Lipodystrophy (also called lipoatrophy) usually infers loss of fat. The fat layer is subcutaneous (it lies underneath the skin). Loss of subcutaneous fat leads to an increased definition of the structures underneath (muscle and bone) and presents as one or more depressions in the skin. If all the underlying structures are affected, it is called panatrophy.

Lipodystrophy may be congenital (the tendency to lose fat is present at birth) or acquired (the loss of fat occurs later in life). Lipodystrophy can affect all of the body (generalised lipodystrophy) or just parts of the body (partial lipodystrophy).

Detailed classification of lipodystrophy is difficult.

Acquired localised lipodystrophy

Lipodystrophy is most commonly acquired following an injection or after an episode of panniculitis. The cause is often unknown.

Steroid injection

A dent due to localised fat loss may appear at the site of corticosteroid injection. This can be avoided by making sure the injection is within muscle tissue and not in subcutaneous fat.

Insulin injections

Diabetics may experience localised lipodystrophy at repeated injection sites.

Other injections

Lipodystrophy has been reported to follow injections with penicillin, iron, growth hormone, vaccines and acupuncture.

Panniculitis

Panniculitis is the term used for inflammation of subcutaneous fat. It is sometimes followed by permanent loss of fat. Fat atrophy is particularly likely in lupus panniculitis (lupus profundus) and some forms of morphoea.

Progressive hemifacial atrophy (Parry-Romberg syndrome)

Progressive hemifacial atrophy is characterised by thinning of the skin, fatty tissue and underlying bony structures of one side of the face. Onset is usually during childhood. The cause is unknown.

Atrophy due to steroid injection

Subcutaneous morphoea

Lupus panniculitis

Generalised acquired lipodystrophies

These are rare.

Generalised lipodystrophy (Lawrence syndrome)

Generalised lipodystrophy is a rare disorder with loss of fat during childhood and adolescence. Females are affected more often than males. It may occur following infections such as chicken pox, measles and whooping cough. Often it is associated with elevation of blood cholesterol and diabetes.

Partial lipodystrophy (Barraquer-Simons syndrome)

Partial lipodystrophy usually occurs around ten years of age after a viral illness. Fat is lost from the face and trunk, but the legs and hips are spared. Fat may accumulate in the legs and hips in women. Females are affected three times more often than males. One-third of patients develop kidney disease (membranoproliferative glomerulonephritis with hypocomplementaemia)

Partial lipodystrophy is also associated with auto-immune disorders including systemic lupus erythematosus, hypothyroidism and rheumatoid arthritis.

Lipodystrophy associated with human immunodeficiency virus

This form of lipodystrophy is associated with longterm treatment with antiretroviral drugs (protease inhibitors and nucleoside reverse transcriptase inhibitors), and human immunodeficiency virus (HIV) may contribute. The exact mechanism is not known. Fat is lost from the face, arms, legs and buttocks. Fat may accumulate on the neck and upper back.

Congenital lipodystrophy

Congenital lipodystrophy can be generalised or partial. Recent advances have identified some genetic abnormalities.

Generalised congenital lipodystrophy (Berardinelli-Seip syndrome)

Generalised congenital lipodystrophy is a rare disorder with gene mutations of seipin or AGPAT2 gene. It is characterised by high levels of insulin (insulin resistance) and high levels of blood fats. It results in gigantism (acromegaly), enlarged liver and kidneys, pancreatitis, acanthosis nigricans and increased body hair (hypertrichosis) as well as generalised loss of body fat.

Partial congenital lipodystrophy

Familial partial lipodystrophy is associated with metabolic syndrome (syndrome X) including hypertension, insulin resistance, diabetes and severe hypertriglyceridemia resulting in pancreatitis and premature coronary artery disease. Sometimes partial loss of fat results in other areas of fat enlarging to compensate.

Familial partial lipodystrophy spares the face and is inherited as an autosomal dominant disorder (half of the children of an affected individual will also be affected). There are two subtypes:

• Type 1 (Kobberling syndrome), with fat loss from the extremities, and central obesity. It has only been reported in females.
• Type 2 (Dunnigan syndrome), with fat loss from the extremities, abdomen, and thorax. This is due to a mutation of lamin A/C gene or PPAR gamma gene (part of the nuclear membrane within the cell). Mutations in this gene can result in a variety of other rare diseases including muscular dystrophy, cardiomyopathy, neuropathy and (progeria and are collectively termed laminopathies.

Other types of congenital partial lipodystrophy have also been described including SHORT syndrome and mandibular-acral dysplasia.

Treatment of lipodystrophy

The treatment depends on the cause of the lipodystrophy. It can involve:

• Cosmetic procedures such as fat transfer (moving fat from one part of the body to another using flaps and grafts), injectable fillers and implants
• Managing diabetes and high cholesterol
• Altering HIV treatments
• Medication such as anabolic steroids.