What is Lipodystrophy?
Lipodystrophies are a group of rare conditions that affect very few people. They are characterised by a lack of subcutaneous fat (fat under the skin) with this being the main sign of the condition. This lack of fat may affect the whole body (generalised lipodystrophy) or certain areas of the body (partial lipodystrophy). Subcutaneous fat is part of the body‘s adipose tissue.
= in some areas
Patients with lipodystrophy have less fat – isn’t that a good thing? If you have too little subcutaneous body fat, it can make you very ill. We need a certain amount of body fat. Why? Because our fat has important functions which allow us to lead healthy lives with an even distribution of fat throughout the body. Lipodystrophy is characterised by partial or complete absence of adipose tissue. There are four main subtypes – congenital generalised lipodystrophy, acquired generalised lipodystrophy, acquired partial lipodystrophy and familial partial lipodystrophy – Some of these lipodystrophies have defined genetic markers and causes. With regard to the familial subtype genetic testing can help to identify the disease.
Lipodystrophies are always linked to a lack of subcutaneous fat. But the extent and location of fat loss depends on the form of lipodystrophy.
Adipose tissue is normally found in many parts of the body, including beneath the skin and surrounding the internal organs. It stores fat as a source of energy and also provides cushioning.
In losing fat under the skin, lipodystrophy patients have lost much of their energy storage capacity and once the remaining capacity is exceeded, excess energy is stored in other organs such as liver, spleen and muscles. In people with familial partial lipodystrophy for instance, adipose tissue is lost from the arms, legs, and hips giving these parts of the body a very muscular appearance. The fat that cannot be stored in the limbs builds up where subcutaneous fat remains such as in the neck and face. This abnormal fat distribution can begin anytime from childhood to adulthood.
Fat cells produce certain hormones. One of these is leptin. Leptin plays a crucial role in the regulation of how the body uses energy, the action of insulin plus sugar and fat metabolism. It further serves as an important signal of body energy stores, telling us when we’re full and do not need to eat more. In lipodystrophy patients, leptin can be absent or significantly reduced, so that all these processes going on in our body are not properly regulated. This leptin deficiency leads to extreme hunger in lipodystrophy patients without the possibility of gaining weight and storing excess energy correctly, under the skin.
Partial or complete absence of adipose tissue in lipodystrophy can lead to leptin deficiency.