Use of EndoPAT for Measurements of Endothelial Dysfunction in HIV Infected Children and Healthy Controls

Study Objectives and Hypothesis Our objective is to determine whether HIV infected youth have higher level of endothelial dysfunction, as measured by Peripheral Arterial Tonometry, when compared to age matched healthy controls. We also aim to gather preliminary data on whether endoPAT measurements of endothelial dysfunction are independently associated with HIV and antiretroviral factors, and with markers of inflammation and traditional cardiovascular disease risk.

Specific Aim 1:

To compare endothelial function, as measured by endoPAT, between HIV-infected youth and matched healthy controls.

Hypothesis: HIV infected youths will have impaired endothelial function compared to age matched healthy controls.

Specific Aim 2:

To determine risk factors of endothelial dysfunction by evaluating: 1) risk factors specific to HIV such as disease stage, cluster of differentiation 4 (CD4) count, HIV viral load, specific ART regimen, perinatally acquired versus behaviorally acquired infection; 2) markers of cardiovascular disease risk such as smoking, lipid levels, insulin resistance; 3) markers of inflammation and immune activation Hypothesis: Endothelial dysfunction will correlate with advanced HIV disease stage, use of protease inhibitors and worse traditional cardiovascular disease risk factors including lipids, insulin resistance, and smoking.

Specific Aim 3:

To assess whether endothelial function changes over a period of 24 weeks in HIV infected youths and controls.

Hypothesis: Endothelial dysfunction will progress over time in HIV-infected children but not in healthy controls.

Study Design This is a 24-week observational cohort study to gather preliminary data on the prevalence and risk factors for endothelial dysfunction in HIV-infected youths. Children enrolled will be between the ages of 8 and 30 years and either congenitally or behaviorally infected with HIV, on continuous ART for at least 6 months and with HIV-1 RNA <1,000 copies/mL. We will also enroll an age- and gender-matched group of healthy controls. A total of 50 HIV-infected children/young adults and 50 matched controls will be enrolled.

Evaluations will be performed at two time points: baseline and week 24. At both visits, evaluations will be similar. We will collect demographic data and medical history including date of birth, sex, gender, CD4 cell count nadir, past and current ART and non-ART medication history, HIV stage based on the CDC guidelines, HIV diagnosis date and method of HIV acquisition, alcohol, smoking and drug habits, as well as family history of cardiovascular disease or diabetes. We will record clinical measurements including blood pressure, physical examination abnormalities, waist and hip circumferences and tanner stage. Subjects will undergo laboratory measurements of lipids levels and markers of insulin resistance in a fasting state (>8 hrs fast except for water and medications), as well as inflammation and immune activation markers (hsCRP, Interleukin 6 or IL-6, sCD14). HIV RNA and CD4 cell count will be collected from clinical records. Plasma and serum will be stored for possible future measurements of other inflammation and cardiovascular markers. We will perform endothelial function measurements by PAT as recommended by the manufacturer.

Controls will be recruited from the community using Institutional Review Board (IRB)-approved flyers, as uninfected siblings or relatives of the HIV-infected patients, or from physician referrals.