Insomnia symptoms and biomarkers of monocyte activation, systemic inflammation, and coagulation in HIV: Veterans Aging Cohort Study

Abstract

Background Insomnia may be a risk factor for cardiovascular disease in HIV (HIV-CVD); however, mechanisms have yet to be elucidated. Methods We examined cross-sectional associations of insomnia symptoms with biological mechanisms of HIV-CVD (immune activation, systemic inflammation, and coagulation) among 1,542 people with HIV from the Veterans Aging Cohort Study (VACS) Biomarker Cohort. Past-month insomnia symptoms were assessed by the item, "Difficulty falling or staying asleep?,"with the following response options: "I do not have this symptom"or "I have this symptom and. . .""it doesn't bother me,""it bothers me a little,""it bothers me,""it bothers me a lot."Circulating levels of the monocyte activation marker soluble CD14 (sCD14), inflammatory marker interleukin-6 (IL-6), and coagulation marker D-dimer were determined from blood specimens. Demographic- and fully-adjusted (CVD risk factors, potential confounders, HIV-related factors) regression models were constructed, with log-transformed biomarker variables as the outcomes. We present the exponentiated regression coefficient (exp[b]) and its 95% confidence interval (CI). Results We observed no significant associations between insomnia symptoms and sCD14 or IL-6. For D-dimer, veterans in the "Bothers a Lot"group had, on average, 17% higher D-dimer than veterans in the "No Difficulty Falling or Staying Asleep"group in the demographicadjusted model (exp[b] = 1.17, 95%CI = 1.01-1.37, p = .04). This association was nonsignificant in the fully-adjusted model (exp[b] = 1.09, 95%CI = 0.94-1.26, p = .27). Conclusion We observed little evidence of relationships between insomnia symptoms and markers of biological mechanisms of HIV-CVD. Other mechanisms may be responsible for the insomnia- CVD relationship in HIV; however, future studies with comprehensive assessments of insomnia symptoms are warranted.