A Guide to Primary Care of People with HIV/AIDS - Canadian Public ...

A Guide to Primary Care of People with HIV/AIDS
Chapter 6: Metabolic Complications of Antiretroviral Therapy
LIPODYSTROPHY
What is lipodystrophy?
Although lipodystrophy was first reported in the mid-
1990’s, investigators have not agreed on a standardized,
objective definition for this disorder. Most researchers
and clinicians loosely define lipodystrophy as any
significant change in body morphology that does not
result from either weight gain or weight loss. The general
term lipodystrophy now typically includes 3 subsets of
morphologic changes: generalized fat accumulation, focal
fat accumulation, and fat atrophy. Fat accumulation most
often occurs in the abdominal, breast, or dorsocervical
region. Fat atrophy most often occurs as buccal fat pad
atrophy (facial wasting) or subcutaneous fat wasting
in the buttocks or extremities. Because a standardized
definition for lipodystrophy is lacking, the incidence
varies depending on the exact criteria investigators use
to define lipodystrophy in their specific study. Tests for
abnormalities in body fat distribution have included
computed tomography (CT) scanning, magnetic resonance
imaging (MRI), bioelectrical impedance analysis (BIA),
DEXA (dual energy x-ray absorptiometry) scans, and
anthropometric measurements. The CT and MRI tests are
generally considered the most accurate, but not practical
for routine screening purposes, primarily because of their
high cost. Anthropometric measurements can estimate
visceral adipose tissue and subcutaneous adipose tissue
and can easily be performed in the clinic without major
costs. Despite the many options available for measuring
abnormalities in fat distribution, no technique has shown
adequate sensitivity and specificity to recommend
performing routinely.
What causes lipodystrophy in HIV-infected
persons?
Despite intense investigation, the exact pathogenesis of
lipodystrophy remains unclear. Initial reports linked PI use
with lipodystrophy, but subsequent reports have identified
lipodystrophy in patients who had never received a PI.
Several studies have shown that the most important risk
factors for development of lipodystrophy are a history of
severe immune suppression (nadir CD4 count