Pathophysiology of dyslipidemia and increased cardiovascular risk in HIV lipodystrophy: a model of 'systemic steatosis'.
OBJECTIVE
This review addresses a syndrome of dyslipidemia and lipodystrophy that has emerged in HIV-infected patients receiving highly active antiretroviral therapy (HAART). The term 'HIV/HAART associated dyslipidemic lipodystrophy (HADL)' describes this syndrome. Although HAART increases patient survival rates, their increased longevity and dyslipidemias place them at risk for cardiovascular disease. Identification of rationally based therapies requires an understanding of the mechanistic basis of HADL.


RESULTS
A case definition for HIV lipodystrophy, based on age, gender, duration of HIV disease, serum HDL cholesterol and anthropometry, provides high diagnostic sensitivity and specificity. The dyslipidemias, mainly hypercholesterolemia, hypertriglyceridemia and low-plasma HDL cholesterol, among HIV-infected patients in the pre- and post-HAART eras are summarized. Clinical studies of HADL patients show increased lipolysis, which increases free fatty acid transfer to liver for incorporation into lipoprotein triglycerides that are secreted, and to skeletal muscle where they impair normal insulin signaling. A model of HADL that includes preferential lipolysis in femoral-gluteal fat depots is presented. Relevant therapies include those that inhibit lipolysis (niacin) or increase hepatic fatty acid oxidation (fibrates).


CONCLUSIONS
HADL is one of several disorders characterized by dyslipidemia, insulin resistance, and lipodystrophy. The relative acuteness of HADL should facilitate identification of the sequence of metabolic changes that gives rise to the syndrome. Current evidence suggests that deranged energy storage in femoral-gluteal and other peripheral sites is important; the molecular details for the derangement are unknown but are under scrutiny by many investigators.
Balasubramanyam
Ashok
A
Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA.
Sekhar
Rajagopal V
RV
Jahoor
Farook
F
Jones
Peter H
PH
Pownall
Henry J
HJ
D000818:Animals; D023241:Antiretroviral Therapy, Highly Active; D002318:Cardiovascular Diseases / Q000503:physiopathology*; D004195:Disease Models, Animal; D006678:HIV / Q000472:pathogenicity; D015658:HIV Infections / Q000503:physiopathology*; D006801:Humans; D006949:Hyperlipidemias / Q000503:physiopathology*; D000960:Hypolipidemic Agents / Q000627:therapeutic use; D008060:Lipodystrophy / Q000503:physiopathology*; D012307:Risk Factors
D000960:Hypolipidemic Agents