Because of gaps in our understanding of aging with HIV, there is much to be learned from simply observing people living with HIV who are receiving regular care over time. Currently, the Canadian HIV and Aging Cohort (CTN 272-2) is underway as a prospective, observational study funded by a team grant on HIV and healthy living by CIHR. This study has recruited over 1,000 HIV+ and HIV- participants. By following participants for up to 12 years, this study will compare the rates of cardiovascular events — such as heart attack, stroke, and angina or chest pain — between those living with and without HIV. Secondarily, researchers hope to compare rates of diabetes, kidney failure, and decreased bone health as well as the mechanisms and characteristics of these diseases in both groups.
Recognizing that gender is a major determinant of aging, in 2019, the Canadian HIV and Aging Cohort was expanded to increase recruitment of women. Its objectives were also broadened to include determinants of frailty and the impact of diet and gender on aging with HIV, as well as new immune pathways that could affect aging. You can read more about this cohort study in this blog post.
Beginning in 2019 following a team grant from CIHR, CTN 314 is the first geriatric cohort of people living with HIV in Canada, and focuses on people over 65 years of age. With strong participation from community, CTN 314 aims to understand the physical, mental, cognitive, and social aspects of health and how they interact to affect wellbeing.
On the other end of the age spectrum, CTN 281 focuses on children and youth who acquired HIV at or around the time of birth and the impact of early versus late initiation of antiretroviral therapy. Outcomes of interest in the study include the HIV viral reservoirs and biomarkers linked to aging and immune exhaustion. This study continues to yield important knowledge on the impact of aging with HIV from a very young age.
The Canadian Observational Cohort (CANOC) Collaboration (CTN 242) is a national partnership of nine cohorts across Canada. This collaborative cohort, which concluded at the end of 2022, followed more than 10,000 people with HIV who are accessing ART. Almost 50% of HIV+ Canadians who accessed treatment since 2000 are included under the CANOC umbrella. A variety of different studies and projects have accessed the CANOC cohort. Investigating comorbidities, aging-associated changes, and HIV care and management within the cohort is helping inform clinical and research priorities.
Analyses and publications from CANOC have been instrumental in the current understanding of Canadians aging with HIV. A collaboration between CANOC and cohorts in the UK, Europe, and the US, looked at the effect of HIV subtype on long-term outcomes. Another analysis looked for differences in clinical outcomes in people living with HIV and HCV with and without a history of injection drug use. CANOC also participated in another large cohort collaboration to understand the rates of, and factors related to, end-stage kidney disease in North American adults with HIV.
Another cohort in which the CTN is involved is the Cellular Aging and HIV Comorbidities in Women and Children (CARMA) Cohort. This cohort is a large, federally funded study that is looking at a wide range of risk factors associated with health problems in HIV+ women as well as children exposed to ART during development. A sub-study of this cohort, the CARMA-ENDO study (CTN 277) compared the prevalence of endocrine, metabolic, and reproductive complications between women living with and without HIV. These complications increase with age and may be more common in HIV-positive people. By collecting markers of accelerated cellular aging — telomere length and alterations in mitochondrial DNA — CTN 277 researchers are looking for possible explanations for this difference. Results from CTN 277, a study in women living with HIV, showed that almost two-thirds of the study participants had higher levels of blood lipids, like cholesterol. The authors highlighted the importance of addressing this metabolic risk factor, as well as smoking, in order to prevent long-term consequences to cardiovascular health. More about HIV and cardiovascular health is available below.
The Canadian HIV Women’s Sexual and Reproductive Health Cohort Study (CHIWOS; CTN 262) is a large, community-based prospective cohort study supported by the CTN. The broad aim of this study is to look at the distribution, use, and factors related to women-centered HIV services and how these services affect health outcomes in Canadian women living with HIV. In relation to HIV and aging, the CHIWOS group is researching the relationship between premature ovarian failure and menopause and HIV, among other projects. The CHIWOS team has published over 50 peer-reviewed publications since the study’s launch.
In 2022, a collaboration between the CHIWOS and CARMA cohorts was launched (The British Columbia CARMA–CHIWOS Collaboration [BCC3]; CTN 335). This study aims to use a collaborative approach to understand how biological, clinical, and social factors interact to support healthy aging in women living with HIV. The CTN 335 team have developed YouTube videos describing exactly what participants can expect.