Clinical Trial: The Effect of Vitamin D Supplementation on HIV-associated Platelet Hyperreactivity

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: The Effect of Vitamin D Supplementation on HIV-associated Platelet Hyperreactivity

Brief Summary: Platelets play pivotal role in atherosclerosis and acute cardiovascular events. Platelet hyperreactivity and increase platelet-monocyte aggregate (PMA) formation are found in HIV infected patients, which may contribute to the excess cardiovascular risk. Low level of vitamin D has been associated with the presence of cardiovascular diseases. The aim of our study is to determine the effect of vitamin D supplementation on platelet activation, platelet reactivity and platelet-leukocyte complex formation in asymptomatic HIV-infected patients treated with ART

Detailed Summary:

  1. Study design A prospective intervention study. HIV-infected patients using ART and who come for follow-up at the Teratai HIV clinic will be asked to participate in the study. All study participants will receive vitamin D supplementation (soft gel capsule containing cholecalciferol 400 IU) to be consumed 2 soft gel capsules daily for three consecutive months. The effect on the platelet parameters specified above will be determined before start cholecalciferol supplementation and after three months.
  2. Duration of study Usually, 150 HIV-infected patients are treated with ART every week at the Teratai HIV clinic of the Hasan Sadikin Hospital Bandung Indonesia. Between half January 2014 and end of February 2014, 50 patients will be enrolled in this study. We hypothesize that this period is long enough to include 50 patients for the present study. Supplementation will take place between March and May and analysis will be done in June and July. A summary of duration of study is depicted in the study timeline.
  3. Study population The study population consists of adult HIV-infected patients treated with ART enrolled at HIV polyclinic at Hasan Sadikin General Hospital, Bandung, Indonesia.
  4. Sample size calculation Our sample size calculation is based on the primary outcome, which is the area under the curve (AUC) of the platelet reactivity curve with P-selectin (CD62P) as platelet activation marker and ADP as platelet agonist. In a cohort of Dutch HIV-infected patients we found a mean AUC of 2500 with an SD of 660. Assuming that a decrease in AUC of 2500 to 2100 upon supplementation of vitamin D is clinically relevant, a sample size of 23 would be sufficient using a paired design with α 0.05 and a power of 80%.

  5. Method
    Sponsor: Universitas Padjadjaran

    Current Primary Outcome: The effect of vitamin D supplementation on HIV-associated platelet hyperreactivity [ Time Frame: Three months ]

    Mean Fluorescence Intensity of the platelet reactivity curve before and after receiving vitamin D


    Original Primary Outcome: Same as current

    Current Secondary Outcome: The effect of vitamin D supplementation in platelet-monocyte aggregate formation [ Time Frame: three months ]

    Mean fluorescence intensity of platelet-monocyte aggregate before and after vitamin D supplementation


    Original Secondary Outcome: The effect of vitamin D supplementation on HIV-associated platelet hyperreactivity [ Time Frame: three months ]

    Mean Fluorescence Intensity of platelet-monocyte aggregate before and after receiving vitamin D


    Information By: Universitas Padjadjaran

    Dates:
    Date Received: August 12, 2014
    Date Started: December 2013
    Date Completion:
    Last Updated: August 15, 2014
    Last Verified: August 2014