Relationships between inflammation, immune activation, and bone health among HIV-infected adults on stable antiretroviral therapy.

backgroundThe aim was to determine the association between bone health and inflammation, T-cell activation, and monocyte activation among HIV-infected persons on stable antiretroviral therapy.

methodsWe performed a cross-sectional analysis of all the subjects enrolling in the Stopping Atherosclerosis and Treating Unhealthy bone with RosuvastatiN in HIV trial with available skeletal assessments by dual-energy x-ray absorptiometry, inflammation, and immune activation markers. Analyses used were Wilcoxon rank-sum tests, Spearman correlation coefficients, and linear regression.

resultsOne hundred forty-two subjects were included: 78% men, 69% African American, median age 46.3 years, CD4 count 604 cells per microliter, and 77% with undetectable HIV-1 RNA. Twenty-three percent had osteopenia/osteoporosis at the hip, and 21% had this at the lumbar spine. Soluble vascular cell adhesion molecule-1 was correlated with hip (r = -0.22) and spine (r = -0.23) bone mineral density (BMD), and bone turnover markers (r = 0.20-0.33; all P < 0.05). No significant correlations were observed between the BMD and T-cell activation (%CD38HLA-DR on CD4 or CD8 T cells), monocyte activation (CD14CD16, sCD14, and sCD163), or inflammatory markers [interleukin (IL)-6, tumor necrosis factor-α, highly sensitive C-reactive protein, D-dimer, receptor activator of NF-kB ligand, osteoprotegerin, soluble tumor necrosis factor-RI and II]. In regression models including traditional bone risk factors, hip BMD was associated with age, race, and body mass index; spine BMD was associated with race, family history of hip fracture, trunk fat, tenofovir, and HIV RNA; bone resorption (c-terminal collagen crosslinks) was associated with intracellular adhesion molecule-1 and trunk fat; bone formation (P1NP) was associated with soluble vascular cell adhesion molecule-1, trunk and limb fat (P ≤ 0.05).

conclusionsFuture studies should evaluate the longitudinal association of the adhesion molecules to further elucidate potential contributory mechanisms of bone loss among HIV-infected persons on stable antiretroviral therapy.