BACKGROUND - Greater adipose tissue is associated with increased circulating high-sensitivity C-reactive protein (hsCRP) levels in HIV-infected adults on antiretroviral therapy (ART), but the relationship between adiposity and other inflammation biomarkers is not well-characterized.
METHODS - We measured total and regional adipose tissue deposits using dual energy X-ray absorptiometry (DXA) and serum levels of interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) receptor 1 and 2, macrophage inflammatory protein-1α (MIP-1α), macrophage chemotactic protein-1 (MCP-1), soluble CD14 and hsCRP in a cohort of adults on long-term ART. Regression models were adjusted for age, sex, CD4(+) T-cell count, smoking status, protease-inhibitor-use and daily use of either non-steroidal anti-inflammatory drugs or aspirin.
RESULTS - The majority (77%) of the 85 study participants were male, median CD4(+) T-cell count was 500 cells/μl (IQR 315-734) and median BMI was 25.1 kg/m(2) (IQR 22.7-28.1). DXA measurements of total fat mass were positively associated with serum hsCRP (β=1.82, P<0.01) and MIP-1α (β=1.36, P<0.01), but negatively associated with soluble CD14 (β=0.90, P<0.01). Results were similar for trunk fat, limb fat and serum leptin level. The positive relationship between DXA measurements and TNF-α receptor 1 approached significance (P≤0.07 for all). There was no consistent relationship between adiposity and serum IL-6, TNF-α receptor 2 or MCP-1 levels.
CONCLUSIONS - Total and regional adiposity was associated with serum hsCRP, but not other inflammatory cytokines shown to predict morbidity and mortality in treated HIV. Greater adiposity is associated with higher MIP-1α and lower soluble CD14 levels, possibly reflecting an important role for cells of the monocyte/macrophage lineage.