Inherited lipodystrophies and the metabolic syndrome.

Lipodystrophies represent a heterogeneous group of diseases characterized by an abnormal subcutaneous fat distribution, the extent of which can vary from localized, to partial, to generalized lipoatrophy. Whereas partial and generalized lipodystrophies are each associated with metabolic abnormalities, the localized form is not. These metabolic changes include insulin resistance with type 2 diabetes, acanthosis nigricans, dyslipidaemia predominantly consisting of hypertriglyceridaemia (associated with the onset of pancreatitis) and depressed HDL cholesterol, liver steatosis and hypertension. Affected women are often hirsute and this can be associated with the presence of polycystic ovarian syndrome (PCOS). Most of these clinical features are present to some extent in patients with the common metabolic syndrome. As the prevalence of metabolic syndrome far outweighs that of lipodystrophy, the diagnosis of this rare disorder may often be overlooked with the affected patient diagnosed as merely being 'yet' another case of metabolic syndrome. In this article, we draw attention to the importance of recognizing patients with lipodystrophy who present with metabolic abnormalities, as both the diagnostic as well as the therapeutic approach of these patients differ profoundly from patients with the metabolic syndrome.