Lipodystrophy syndromes are a group of genetic or acquired disorders in which the body is unable to produce and maintain healthy fat tissue. The medical condition is characterized by abnormal or degenerative conditions of the body's adipose tissue. A more specific term, lipoatrophy ("lipo" is Greek for "fat", and "dystrophy" is Greek for "abnormal or degenerative condition"), is used when describing the loss of fat from one area (usually the face). This condition is also characterized by a lack of circulating leptin which may lead to osteosclerosis. The absence of fat tissue is associated with insulin resistance, hypertriglyceridemia, non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome. Types Lipodystrophy can be divided into the following types: Congenital lipodystrophy syndromes Congenital generalized lipodystrophy (Berardinelli-Seip syndrome) Familial partial lipodystrophy Marfanoid–progeroid–lipodystrophy syndrome Chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature syndrome Acquired lipodystrophy syndromes Acquired partial lipodystrophy (Barraquer-Simons syndrome) Acquired generalized lipodystrophy Centrifugal abdominal lipodystrophy (Lipodystrophia centrifugalis abdominalis infantilis) Lipoatrophia annularis (Ferreira-Marques lipoatrophia) Localized lipodystrophy HIV-associated lipodystrophy Epidemiology Congenital lipodystrophy (due to inherited genetic defect) is estimated to be extremely rare, possibly affecting only one per million persons. Acquired lipodystrophy is much more common, especially affecting persons with HIV infection. Pathogenesis Due to an insufficient capacity of subcutaneous adipose tissue to store fat, fat is deposited in non-adipose tissue (lipotoxicity), leading to insulin resistance. Patients display hypertriglyceridemia, severe fatty liver disease and little or no adipose tissue. Average patient lifespan is approximately 30 years before death, with liver failure being the usual cause of death. In contrast to the high levels seen in non-alcoholic fatty liver disease associated with obesity, leptin levels are very low in lipodystropy. Insulin injections A lipodystrophy can be a lump or small dent in the skin that forms when a person performs injections repeatedly in the same spot. These types of lipodystrophies are harmless and can be avoided by changing (rotating) the locations of injections. For those with diabetes, using purified insulins may also help. One of the side-effects of lipodystrophy is the rejection of the injected medication, the slowing down of the absorption of the medication, or trauma that can cause bleeding that, in turn, will reject the medication. In any of these scenarios, the dosage of the medication, such as insulin for diabetics, becomes impossible to gauge correctly and the treatment of the disease for which the medication is administered is impaired, thereby allowing the medical