Objectives: Among virally suppressed HIV-infected persons, we examined the relationship between obesity and alterations in key clinical markers of immune activation and inflammation. These markers have also been associated with excess HIV-related cardiovascular disease and mortality.
Methods: We evaluated data from virally suppressed participants in the Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy, including inflammatory biomarkers (interleukin-6 and highly sensitive C-reactive protein), monocyte biomarkers [soluble CD163 (sCD163), sCD14], and monocyte immunophenotypes. We assessed associations with these immunologic measures and obesity, via logistic regression preadjustment and postadjustment for demographic and clinical factors, homeostatic model assessment of insulin resistance, and leptin levels.
Results: Among 452 evaluable participants, median (interquartile range) age was 41 (36-48) years, CD4 cell count was 475 (308-697) cells/μl, and 21% were obese (BMI ≥ 30 kg/m). In univariable models, obesity, smoking, and lower CD4 cell count were associated with higher measures of inflammation and monocyte activation. After adjustment, obesity remained independently associated with elevated levels (highest vs. lower two tertiles) of interleukin-6 [odds ratio (OR) 1.96; P = 0.02], highly sensitive C-reactive protein (OR 2.79; P < 0.001) and sCD163 (OR 1.94; P = 0.02), and elevated frequency of CD14CD16 (OR 1.77; P = 0.03) and CD14dimCD16 (OR 1.97; P = 0.01). Adjusting for homeostatic model assessment of insulin resistance and leptin modestly affected associations for obesity with inflammation and monocyte activation.
Conclusion: Obesity was prevalent and independently associated with greater monocyte activation and systemic inflammation. Research is needed to determine how adipose tissue excess is functionally related to persistent immunologic abnormalities among HIV-infected persons with viral suppression.