HIV is no longer the death sentence it once was: antiretroviral therapy (ARTs) have become so sophisticated that HIV-infected people have a normal life expectancy. However, now that HIV is a manageable, chronic disease, there is a shift in the focus of HIV research. Jason Baker, an associate professor of medicine at the University of Minnesota, has been researching one of the new, main causes of death in HIV-infected people: cardiovascular disease (CVD). He spoke about the latest research in CVD in HIV positive cohorts.
Nowadays, approximately one third of deaths in HIV-infected people are cancer-related, and another third are related to cardiovascular disease (CVD). These data reflect the causes of death of the general population, however, there is a possible increased risk for HIV-positive patients. Baker suggests that HIV infection itself, and possibly use of certain antiretroviral medications can eventually increase the risk of certain cardiovascular complications over a number of years. However, the rates in HIV-infected people compared to the general population is only a marginal increase. The cause of CVD is varied. However, systemic inflammation can increase risk of complications later. HIV could be a driver for inflammation; damaging cells that the body doesn’t fully recover from.
The SUN study, which Baker has worked on, looked at calcium in the coronary arteries in an HIV cohort. The findings suggest that monocytes, a type of white blood cell, may be activated by HIV and increase CVD risk. Baker suggests that there is a possibility that it is the damage from HIV that causes inflammation as opposed to ARTs.
However, inflammation may not be the only factor contributing to CVD among HIV patients: there is research that suggests that long periods on ARTs may increase CVD risk through metabolic changes. The START study, which Baker works on along with the Desmond Tutu HIV Centre, studied the effects of ART, as well as untreated HIV infection, for CVD risk and other complications. The study found that starting ARTs as soon as possible was extremely effective for reducing clinical risk overall; especially in the ageing population. CVD events were rare overall in START, but Baker hopes to study this further with longer follow-up of patients enrolled in the study.
South Africa is at forefront of antiretroviral therapy and therefore has an interest in the diseases that arise in people managing HIV as a chronic condition. The success of ARTs has reduced AIDS mortality and increased the prevalence of HIV in the population. In addition, CVD in South Africa is influenced by high rates of hypertension. How HIV and ART interact with this risk may lead to important differences in CVD risk among HIV+ patients in South Africa, such as a greater risk for heart failure for example. Now, our concerns will start to shift to managing age-related HIV issues.
Different geographies will have different concerns regarding the cause and profile of cardiovascular disease in their community. There is a large population of tuberculosis infected people in South Africa, and TB is the largest cause of death amongst its HIV-infected population. This will be a special consideration for South Africa, however, inflammation is a prominent symptom of TB disease.
We thank Baker for his engaging presentation and wish him luck with his future research.
Written by Caroline Reid