Abstract

CONTEXT
The pathogenesis and function of dorsocervical sc adipose tissue (DSAT) accumulation in HIV-infected patients is not known. Previous investigations using either UCP-1 expression or positron emission tomography have been inconclusive as to whether this depot represents brown adipose tissue (BAT). We investigated DSAT gene expression, including DIO2, a deiodinase that contributes to increased thermogenesis in brown fat, and simultaneously determined [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) uptake in lipodystrophic HIV and healthy control subjects.
DESIGN
Thirteen HIV-infected and three non-HIV-infected men were recruited. HIV-infected subjects had evidence of significant lipodystrophy, including fat atrophy of the face, arms, and legs, and/or fat accumulation of the neck and abdomen. Subjects were cooled, followed by [¹⁸F]FDG positron emission tomography/computed tomography, fat biopsy of DSAT, and measurement of resting energy expenditure (REE). HIV-infected subjects were characterized as lipohypertrophic and lipoatrophic and compared.
RESULTS
Mean standardized uptake value of [¹⁸F]FDG and UCP-1 expression were not significantly different in DSAT among the groups. However, lipohypertrophic subjects demonstrated increased expression of DIO2 in DSAT compared with lipoatrophic subjects (P = 0.03). Among HIV-infected patients, DIO2 expression was strongly related to REE (r = 0.78, P = 0.002) and was a predictor of REE in multivariate modeling controlling for age, TSH, and lean body mass (r² = 0.79, P = 0.008). One control subject demonstrated typical BAT in the supraclavicular area.
CONCLUSIONS
Adipose tissue accumulating in the dorsocervical area in HIV lipodystrophy does not appear to be classical BAT. However, DIO2 expression is increased in DSAT among patients with HIV lipodystrophy, particularly those with increased visceral adiposity, and is positively associated with energy expenditure.

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Publisher Full Text

Authors

Torriani M, Fitch K, Stavrou E, Bredella MA, Lim R, Sass CA, Cypess AM, Grinspoon S

Institution

Division of Musculoskeletal Imaging and Intervention and Program in Nutritional Metabolism, Massachusetts General Hospital Longfellow 207, Boston, Massachusetts 02114, USA.

Source

The Journal of clinical endocrinology and metabolism 97:4 2012 Apr pg E602-7

MeSH

Adipose Tissue, Brown
Adiposity
Atrophy
Back
Biopsy
Cohort Studies
Energy Metabolism
Fluorodeoxyglucose F18
Glucose
HIV-Associated Lipodystrophy Syndrome
Humans
Hypertrophy
Iodide Peroxidase
Male
Middle Aged
Obesity, Abdominal
Positron-Emission Tomography and Computed Tomography
Subcutaneous Fat
Tissue Distribution
Up-Regulation

Pub Type(s)

Comparative Study
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22259052