People with HIV who achieve viral suppression under antiretroviral therapy have a life expectancy and a disability-free life expectancy almost similar to those of HIV-negative people in South Africa. They also have a greater chance of living a longer and healthier life than people with HIV not reaching viral suppression while on treatment. This is what a recent study from South Africa, published in The Lancet HIV, has found. The authors say that this study is the first to reveal an association between HIV viral suppression and years lived without disability among people with HIV in sub-Saharan Africa.
The large-scale roll-out of antiretroviral therapy in sub-Saharan Africa has led to a longer life expectancy among people with HIV, most of whom are now ageing. However, one of the unanswered questions, in a context where the benefits of antiretroviral therapy might be unevenly distributed, is the extent to which these benefits are seen in individuals not achieving viral suppression.
This knowledge gap brought an international partnership of researchers, led by Dr Collin Payne from the Australian National University, to examine how both HIV and viral suppression lead to differences in life expectancy and in disability-free life expectancy among people who are ageing with HIV in South Africa.
The investigators used data from The Health and Ageing in Africa: a Longitudinal Study of an INDEPTH (HAALSI) community, a major population-based cohort study which is ongoing in rural parts of the Mpumalanga province of South Africa, where HIV prevalence can be as high as 15%. More precisely, Payne and colleagues analysed data from people aged over 40 who were interviewed at baseline (2014-2015) and follow-up (2018-2019) of the HAALSI study, or had died between these two survey periods, to compare life expectancy, but also life expectancy without disability in people who had or did not have HIV.
The primary measure of disability was based on respondents’ self-reported Activities of Daily Living (ADL) which are fundamental skills required to independently care for oneself. People who have difficulty with any one of the six skills (eating, bathing, mobility, etc.) are considered disabled.
In total, 4,322 individuals were eligible for the study: 54% were women and 46% were men. Of the entire cohort, 23% were HIV-positive. On average, respondents with HIV were younger and slightly less likely to report disability than their HIV-negative counterparts. Of the respondents with HIV, 59% were virally suppressed and 41% were not (i.e a viral load of at least 200 copies).
The study found that at age 45, an HIV-negative man could expect to live to the age of 72, which translates into almost seven years longer than the life expectancy of a man with HIV. However, behind this grouping by HIV status alone, analysis of viral suppression revealed other realities:
- With a suppressed viral load, a 45-year-old man with HIV might reach age 69, that is, three years less than the 72 years expected for an HIV-negative man.
- By contrast, a 45-year-old HIV-positive man with an unsuppressed viral load could expect to live to only 62, that is, nearly a decade less than an HIV-negative man the same age.
- A 45-year-old woman with HIV and a suppressed viral load could expect to reach age 77, just one year less than an HIV-negative woman.
- Compared with their HIV-negative counterparts the same age, women with HIV who were not virally suppressed were expected to live nearly seven years less.
For both women and men, the trends in life expectancy by HIV status and viral load at age 65 were similar, but due to the overall lower remaining life expectancy at that age, the magnitude of differences was smaller.
Turning to estimates of disability-free life expectancy, taking into account Activities of Daily Living, Payne and colleagues found substantial differences between respondents living with HIV and HIV-negative counterparts:
- A 45-year-old man with HIV and a suppressed viral load could expect to reach age 66 without disability, compared with only age 60 for a man who was not virally suppressed.
- For those alive at age 65, a man with HIV could expect to live to age 76 without disability – similar to an HIV-negative man – if his viral load was suppressed. However, without a suppressed viral load, this expectation dropped to 73.
- The same trends were observed for women, although the differences were smaller in magnitude.
Given these substantial differences, the researchers further explored healthy life expectancy. When physical function was assessed through physical tests (gait speed and grip strength) rather than the Activities of Daily Living, the differences in healthy life expectancy were similar to the findings above.
The first take-home message from this study is that HIV viral suppression under antiretroviral therapy is key to prolonging life in South Africa.
The second is that people with HIV’s control over their viral load has a substantial positive impact on health and wellbeing later in life. In an African context where social and health services are extremely weak, this may have significant positive implications.
However, a commentary published alongside the study calls for caution so as to not suggest that people with HIV viral suppression have a life expectancy and a disability-free life expectancy equal to those in HIV-negative individuals. Dr Jepchirchir Kiplagat and Professor Amy Justice point to a previous US study in which some people with HIV had a similar life expectancy to the general population, but major co-morbidities at a much younger age.
They also highlight that the South African study was done in a population with low HIV care retention rates and the lowest viral suppression rates in the country, and that life expectancy in the study sample was lower than the South African average. Therefore, those respondents with viral suppression “might be exceptionally healthy individuals: with more socio-economic resources, better nutrition, lower alcohol consumption and less tuberculosis than those with detectable virus (and, possibly, even than those without HIV). The study might be attributing differences in survival and disability-free survival partly due to these comorbid factors to detectable virus versus undetectable virus.”
This is not to underestimate the significance of the study. As Payne and colleagues say: "These results highlight the tremendous benefits of ART for population health in high-HIV-prevalence contexts and reinforce the need for continued work in making ART treatment accessible to ageing populations."
Payne CF et al. Differences in healthy longevity by HIV status and viral load among older South African adults: an observational cohort modelling study. The Lancet HIV 9: e709-e716, 2022.
Kiplagat J & Justice A. HIV viral suppression is key to healthy longevity. The Lancet HIV 9: e672-e673, 2022.