HIV infection is associated with higher than expected cardiovascular event rates and lowered platelet counts. These conditions are associated with an elevation of mean platelet volume (MPV). The present study compares MPV in HIV-infected and uninfected women and identifies factors influencing MPV values in HIV-infected women.
A total of 234 HIV-infected and 134 HIV-uninfected participants from the Women's Interagency HIV Study (WIHS) had MPV values obtained. HIV-infected women were older, more likely to have diabetes, and have higher triglyceride levels than HIV-uninfected women.
The mean platelet count was lower in HIV infected vs. uninfected women (249/µl 95% CI 238, 259 vs. 276/µl 95% CI 265, 287, p<0.01). Adjusted mean MPV values were lower in the HIV- infected than in the uninfected group (8.66 fl 95% CI 8.52, 8.79 vs. 9.05 fl 95% CI 8.87, 9.24). In multiple regression analysis after adjusting for other covariates, MPV was positively associated with platelet count, and negatively with HIV infection (model R2=0.20 p<0.01). In multiple regression analysis confined to HIV-infected women, a lower MPV was independently associated with history of AIDS defining illness (R2=0.28 p=0.03), but not with CD4 nadir count or HAART use.
HIV-infected women have lower MPV values than-uninfected women suggesting impaired production rather than increased destruction. Higher than expected cardiovascular event rates, cannot be attributed to greater platelet reactivity as measured by MPV.