Psychological stress is associated with high levels of IL-6 in HIV-1 infected individuals on effective combined antiretroviral treatment

Abstract

This study explores the role of psychological stress in the circulating levels of interleukin-6 (IL-6) in a group of HIV-1 infected individuals on effective cART. We developed a cross-sectional study with 50 individuals with confirmed diagnosis of HIV-1 infection ≥1 and ≤8 years, on continuous cART for >1 and <8 years and with plasma viral load <50 copies/mL for at least 1 year. Clinical, behavioral and psychological variables were collected to control their possible indirect contribution in the relationship between psychological stress and IL-6. Pearson correlation and univariate/multivariate logistic regressions were performed. Eighty-eight percent of the subjects were male: median (IQR) age: 39.0 (32.7-42.2), years since HIV-1 infection: 3.4 (2.1-7.0), years on cART: 2.5 (1.6-5.7), CD4 cell count: 709.0 (573.5-881.0) cell/mm(3), plasma levels of IL-6: 7.0 (0-12.2) pg/ml. A strong correlation between IL-6 and psychological stress was found (r=.81). Psychological stress (coef: 0.49; SD: 0.05), anxiety/depression (0.37; 0.08) and unhealthy diet (2.94; 1.38) were associated with higher levels of IL-6. In the multivariate model psychological stress remained strongly associated with IL-6 (R(2): 59%). In conclusion, individuals with psychological stress presented high levels of IL-6 and psychological stress was the only variable which remained strongly associated with IL-6. This strong relationship suggests evidence for a mechanism through which psychological stress might contribute to the health's impairment of HIV-infected individuals on effective cART.