Lipodystrophy



Lipodystrophy


Monique J. Vanaman Wilson

Monica Boen

Mitchel P. Goldman



BACKGROUND

Lipodystrophy is defined as a change in the distribution of subcutaneous adipose tissue due to either congenital or acquired disorders. Redistribution of fat may be seen in only a few parts of the body as in partial lipodystrophy, or the entire body may be involved in a condition called generalized lipodystrophy. Localized lipodystrophy is limited to one area on the body. “Lipoatrophy” and “lipodystrophy” are often used interchangeably, but it is important to note that lipoatrophy is defined specifically as loss of subcutaneous fat, whereas lipodystrophy involves an increase or decrease in the deposition of adipose tissue.1 There are several causes of lipodystrophy that include rare genetic disorders, medications, and autoimmune conditions. Currently, one of the most prevalent forms of lipodystrophy occurs in patients with human immunodeficiency syndrome (HIV) on antiretroviral therapy (ART).

As adipose tissue plays several crucial roles in the body, including energy storage, glucose homeostasis, and regulation of inflammation, changes in adipose distribution can lead to widespread complications.2 A majority of the lipodystrophy disorders have associated metabolic abnormalities such as insulin resistance, hyperlipidemia, and a high metabolic demand. Metabolic complications include nonalcoholic fatty liver disease, diabetes mellitus, and atherosclerosis.3

The lipodystrophy disorders can cause significant psychological distress that negatively affects a patient’s quality of life. For example, HIV-associated lipodystrophy has been shown to have a negative impact on a patient’s self-esteem, social contacts, and daily activites.4 The standard treatment of lipodystrophy disorders includes dietary modifications and exercise, as well as medications to control associated diabetes mellitus and hyperlipidemia.5,6 In recent years injectable fillers have been used to add volume to cosmetically sensitive areas, such as the face and arms, in patients with lipodystrophy. Several fillers are available to address this issue, including autologous fat, hyaluronic acid (HA) fillers,
collagen stimulators, and semipermanent and permanent fillers. Abnormal fat deposition has been treated successfully with liposuction. Management of lipodystrophy requires a multidisciplinary approach and can lead to dramatic improvement in quality of life.


PRESENTATION

Patients with generalized lipoatrophy present with a generalized paucity or absence of adipose tissue during infancy in the congenital form or at any age in the acquired form. Veins are prominent and muscles are well defined, particularly on the extremities. Patients with associated hyperinsulinemia also present with acromegaly, namely, large acra and mandible. Another presenting sign is excessive appetite. Female babies may present at birth with clitoromegaly with or without hirsutism. During puberty, females may present with amenorrhea or polycystic ovary disease.

Those with acquired generalized lipoatrophy may present at any age. Generalized loss of fat is observed. The patients often describe a history of a preceding illness. Many of the similar features seen in the congenital form are present: hyperinsulinemia, diabetes mellitus, acromegaly, prominent veins, acanthosis nigricans, hirsutism, and prominent muscular definition.




PATHOGENESIS

Adipose tissue serves a variety of functions in the body, many of which were coincidentally discovered in the study of lipodystrophy syndromes. Several hormones and inflammatory markers that play a key role in metabolic hemostasis, such as interleukin (IL)-6, tumor necrosis factor (TNF)-α, leptin, and adiponectin, are secreted by adipose tissue.1 Thus, dysfunction in adipose tissue leads to the metabolic abnormalities seen in the lipodystrophy disorders.

The adipocytokines, leptin and adiponectin, regulate energy metabolism and are usually decreased in the lipodystrophy syndromes.11 Leptin inhibits appetite, stimulates energy expenditure, and decreases glucose and body weight.20 Similarly, adiponectin promotes insulin sensitivity and energy expenditure and decreases hepatic gluconeogenesis.21

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Jun 29, 2020 | Posted by in Dermatology | Comments Off on Lipodystrophy
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