Associations between subcutaneous fat density and systemic inflammation differ by HIV serostatus and are independent of fat quantity.

OBJECTIVES: Adipose tissue (AT) density measurement may provide information about AT quality among people living with HIV. We assessed AT density and evaluated relationships between AT density and immunometabolic biomarker concentrations in men with HIV.
DESIGN: Cross-sectional analysis of men enrolled in the Multicenter AIDS Cohort Study.
METHODS: Abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) density (Hounsfield units, HU; less negative = more dense) were quantified from computed tomography (CT) scans. Multivariate linear regression models described relationships between abdominal AT density and circulating biomarker concentrations.
RESULTS: HIV+ men had denser SAT (-95 vs -98 HU HIV-, P < 0.001), whereas VAT density was equivalent by HIV serostatus men (382 HIV-, 462 HIV+). Historical thymidine analog nucleoside reverse transcriptase inhibitor (tNRTI) use was associated with denser SAT but not VAT. In adjusted models, a 1 s.d. greater SAT or VAT density was associated with higher levels of adiponectin, leptin, HOMA-IR and triglyceride:HDL cholesterol ratio and lower hs-CRP concentrations in HIV- men. Conversely, in HIV+ men, each s.d. greater SAT density was not associated with metabolic parameter improvements and was significantly (P < 0.05) associated with higher systemic inflammation. Trends toward higher inflammatory biomarker concentrations per 1 s.d. greater VAT density were also observed among HIV+ men.
CONCLUSIONS: Among men living with HIV, greater SAT density was associated with greater systemic inflammation independent of SAT area. AT density measurement provides additional insight into AT density beyond measurement of AT quantity alone, and may have implications for metabolic disease risk.