Lipodystrophy is a disorder of adipose (fatty) tissue characterized by complete or partial loss of body fat from various parts of the body in conjunction with pathological accumulation of fat in other distinct regions of the body.
The degree of fat loss may vary from very small depressed areas to near complete absence of adipose tissue with severe metabolic complications such as insulin resistance, diabetes, hypertriglyceridemia, and fatty liver.
The exact locations of fat tissue loss varies from person to person. Some people may have areas on their body that look very thin (face and arms), while other areas might appear large (hips or buttocks). Other people might have very little fat tissue on the lower areas of the body (legs and buttocks) and excess fat tissue on the upper areas of the body (abdomen, chin, and neck).
There are numerous forms of lipodystrophies, either genetic (inherited) or acquired. Acquired lipodystrophies do not have a direct genetic cause, but rather many different factors may be involved.
Acquired lipodystrophies can be caused by:
- Insulin injection Sites: Atrophy of subcutaneous fatty tissue leading to disfiguring excavations and depressed areas mayrarely occur at the site of insulin injections.
- HIV-associated lipodystrophy: in HIV-associated lipodystrophy syndrome there is lipoatrophy over the face and proximal muscles, and excessive deposition of subcutaneous fat around the neck, breast and abdomen. This complication occurs in HIV patients treated with a protease inhibitor but the exact pathogenesis is unknown.
- Acquired generalized lipodystrophy (AGL; Lawrence syndrome): AGL is characterized by fat loss affecting large areas of the body, particularly the face, arms, and legs. It appears secondarily during childhood, adolescence or adulthood, and as a result the syndrome is thought to be acquired.
- Acquired partial lipodystrophy (APL; Barraquer-Simons syndrome): It is a rare form of lipodystrophy, which usually first affects the head, and then spreads to the thorax