CTN 272-2: The Canadian HIV & Aging Cohort Study 2.0

About The Study

The Canadian HIV and Aging Cohort Study (CTN 272) is a long-term investigation of the determinants of aging in people living with HIV. The study, started in 2012, enrolled 850 participants living with HIV and 250 without HIV in 11 sites across Canada. The Canadian Institutes of Health Research granted a second round of funding to the study team, which prolongs funding of the cohort for another five years. In CTN 272-2, recruitment is expanded to increase the representation of women. While pursuing and expanding the original focus on cardiovascular disease, CTN 272-2 broadens its objectives to include determinants of frailty, and the impact of diet and gender on aging with HIV, as well as discovery of new immune pathways that could affect aging.

About The Disease

People living with HIV can now hope for near normal life expectancies. This transition of HIV to a chronic condition means that more information is needed about its effects throughout the lifespan. There is a need to understand which processes of aging are associated with HIV, and which can be targeted by new treatments. Researchers who study the mechanisms behind aging in the general population are moving beyond the investigation of single diseases to look at and understand aging as a group of interacting characteristics and mechanisms. Part of a more global understanding of aging is the concept of frailty, which refers to reduced function and health in older people.

Research suggests that an altered immune system, which is the reality for people living with HIV, is a significant determinant of frailty. Frailty also appears to be strongly correlated with cardiovascular disease risk, but it is unknown whether they share a common cause, especially in people living with HIV. On top of this, there are considerable differences between men and women when it comes to immune function in HIV and the overall aging process in general. For example, research suggests that women living with HIV are at higher risk of having a heart attack compared to men.

Study Approach

CTN 272-2 will extend the length of the original CTN 272 cohort study by five years and recruit an additional 50 women living with HIV. All participants already recruited in CTN 272 will be invited to take part in this extension. Participants in the study will attend two visits at two-year intervals; for those already enrolled, this will extend their participation by four years. At each visit, the data collection from the original study, which includes medical history, vital signs, and blood samples, will be repeated. Measurements of frailty and questionnaire data on nutrition and gender will also be collected. As in the original study, blood samples will be biobanked at each visit for future study.

The original CTN 272 study also had a number of smaller sub-studies where groups of eligible participants from the main cohort underwent extra testing. The extra tests provide the researchers with data to address more specific questions related to cardiovascular health. In CTN 272-2, these sub-studies will continue, with the addition of other non-invasive cardiovascular imaging tests for some participants. There will also be smaller studies that use biobanked samples to address questions about the immune system; no further testing is required for these sub-studies.