Clinical Manual for Management of the HIV-Infected ... - myCME.com

Abnormalities of Body-Fat Distribution
Background
Body-fat abnormalities are a recognized complication
of antiretroviral therapy (ART). These include central
fat accumulation, subcutaneous fat atrophy, and
the development of lipomas. Taken together, these
abnormalities in fat distribution and body shape have
been noted in up to 40-50% of patients treated with
ART. The etiology of these changes in body habitus is
not well understood, but research to date suggests that
it is multifactorial, with components related to specific
antiretroviral (ARV) medications, HIV-related immune
depletion and immune recovery, hormonal influences,
individual genetic predispositions, and non-HIV-related
factors such as diet and obesity. In fact, lipodystrophy
probably is not a single syndrome, but rather several
separate but interrelated clinical presentations.
Lipodystrophy may present as isolated fat accumulation
(lipoaccumulation), fat wasting (lipoatrophy), or a
combination of both. The most common morphologic
changes seen in fat accumulation are an enlarged
abdomen from central or visceral fat accumulation,
breast enlargement (gynecomastia), and development of
a dorsocervical fat pad (“buffalo hump”). Lipoatrophy
is seen most commonly as the loss of subcutaneous fat
in the face, arms, legs, and buttocks. Lipoatrophy differs
from the generalized wasting seen in advanced AIDS,
because lean cell mass generally is preserved.
Severe lipoaccumulation can cause discomfort and, in
some cases, impairment of breathing or other bodily
functions. It also may be associated with other metabolic
abnormalities, including dyslipidemia and the metabolic
syndrome. Both lipoaccumulation and lipoatrophy can
be disfiguring, can damage self-image and quality of life,
and can negatively influence ARV adherence.
Research into the causes and manifestations of
lipodystrophy has yielded varying results, in part
because there is no standard clinical case definition of
lipodystrophy. The prevalence of and risk factors for
lipodystrophy are not well understood. The condition
seems to develop more frequently in patients who are
older and have longer exposure to ART. In some studies,
lipodystrophy has been associated with lower nadir
CD4 count as well as with sex (central lipoaccumulation
may be more common in women). It has been
Section 4—Complications of Antiretroviral Therapy | 4–1
associated with protease inhibitors (PIs) and with
nucleoside reverse transcriptase inhibitors (NRTIs), but
does not appear to be associated with nonnucleoside
reverse transcriptase inhibitors (NNRTIs). However, it
may develop in patients who have never received PIs,
and occasionally in ARV-naive individuals. PIs appear
to be associated more commonly with fat accumulation,
whereas NRTIs, most notably stavudine, are associated
with lipoatrophy.
S: Subjective
The patient may report any of the following: abdominal
fat accumulation with change in waist size, increased
neck size, “buffalo hump,” and enlarged breasts; women
may note an increase in bra size. The patient also may
report sunken cheeks, temporal wasting, decreased arm
or leg circumference, prominence of veins in the arms
or legs, buttock flattening, and even pain in walking
because of atrophy of fat padding around the soles of
the feet. The patient may volunteer that these changes
are causing emotional distress.
Inquire about CD4 nadir, ARV medication history,
duration of and response to each regimen, and recent
medication adherence. Ask about past medical and
family history, specifically regarding hyperlipidemia,
diabetes or insulin resistance, other metabolic disorders,
and cardiovascular disease. Elicit the patient’s emotional
responses to the body shape changes.
O: Objective
Compare past and current weights. Calculate body
mass index. Measure and document waist and hip
circumferences; check waist-to-hip ratio. An abdominal
circumference >102 cm (39 inches) in men and >88
cm (35 inches) in women is the clinical definition of
abdominal obesity and is associated with the metabolic
syndrome. Waist-to-hip ratios >0.95 in men and >0.85
in women are associated with an increased risk of
coronary heart disease.
Examine the head, neck, back, breasts, and abdomen for
fat accumulation, especially looking for dorsocervical fat