757 
The Effects of Caloric Restriction on the Hypermetabolism of HIV Lipodystrophy
Lisa Kosmiski*, S Stotz, and T Horton
Univ of Colorado Hlth Sci Ctr, Denver, US
Background: We have previously shown that resting energy
expenditure (REE) is increased in HIV lipodystrophy.
This hypermetabolism could be the result of an
inadequate storage capacity for fuel secondary to atrophy of subcutaneous fat
and could therefore be alleviated by short-term caloric restriction. We
hypothesized that short-term caloric restriction would result in a
significantly greater decrease in REE in patients with HIV lipodystrophy
as compared with HIV-infected and healthy controls.
Methods: In this ongoing cross-sectional study, REE was
measured in the overnight fasted state by indirect calorimetry
after 3 days on a eucaloric diet (55% carbohydrate,
30% fat, 15% protein) and after 3 days on a similar diet but reduced in
calories by 50%. Body composition was assessed by DEXA. Group characteristics
were compared by 1-way ANOVA. Energy expenditure response to dietary
manipulation was compared using 2-way repeated measures ANOVA.
Results:
|
|
HIV LD
(9 M, 1 F)
|
HIV+ controls
(4 M, 2 F)
|
Healthy controls
(8 M, 2 F)
|
|
Age (years)
|
50.9±4.0
|
38.8±4.7*
|
37.9±10.1**
|
|
BMI (kg/m2)
|
22.6±3.3
|
23.0±1.8
|
24.4±2.7
|
|
CD4 cell count (x106/L)
|
578±321
|
428±177
|
Not done
|
|
HIV-1 RNA levels
|
<20 (20, 200)
|
<20 (20,20)
|
Not done
|
|
REE (kcal/kg LBM)
|
34.4±4.5
|
31.9±2.6
|
29.1±3.2††
|
|
% of body fat in trunk
|
69.4±4.8
|
51.6±7.9†
|
44.4±7.9††
|
|
% of body fat in extremities
|
21.1±4.7
|
40.9±8.3*
|
50.0±7.2††
|
Data
are means ± SD except HIV-1 RNA levels which are reported as median values with
25th and 75th percentiles in parentheses. HIV lipodystrophy vs HIV-infected
patients without lipodystrophy (HIV+
controls):*p <0.005, †p <0.001. HIV-LD vs
healthy controls: **p <0.005,
††p <0.001.
REE
(kcal/kg LBM) after eucaloric and hypocaloric
feeding.
|
Group
|
Eucaloric period
|
Hypocaloric period
|
|
LD
|
33.6±3.3
|
30.8±3.0*
|
|
HIV-C
|
30.4±1.9
|
30.2±1.7
|
|
C
|
27.9±2.7
|
29.0±2.7
|
*p <0.05 for change in EE within lipodystrophy group and for lipodystrophy
group compared to both control groups
Conclusions:
HIV-infected patients with lipodystrophy and hypermetabolism
have a significantly greater reduction in REE upon caloric restriction than do
HIV-infected and healthy controls. This suggests that energy intake and resting
energy expenditure may be uniquely coupled in patients with lipodystrophy
as a mechanism to dissipate calories that cannot be stored in a normal manner.
Better understanding of this coupling would have important implications for
weight regulation in general.
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