We just got some very good news on HIV and life expectancy in the U.S.: People living with HIV who begin antiretroviral therapy with a relatively healthy CD4 count can now expect to live just as long, on average, as their HIV-negative counterparts.
The less-good news: Many people do not begin antiretroviral therapy with a CD4 count of 500 cells/mm3 or higher.
The even-less-good news: Relative to their HIV-negative peers, substantially more of an HIV-positive person’s lifespan is likely to be spent managing a significant comorbidity, such as cancer, cardiovascular disease, diabetes, or major organ disease.
This mix of hopeful and discouraging findings provides a new snapshot of lifespan and quality of life for people living with HIV in the U.S., as well as key health areas in need of further attention. It was presented on March 11 at this year’s Conference on Retroviruses and Opportunistic Infections (CROI 2020) by epidemiologist Julia Marcus, Ph.D., M.P.H., an assistant professor at Harvard Medical School.
Study Construction: A 1:10 Comparison of Americans Receiving Health Care
Marcus’ study was conducted in partnership with researchers from Kaiser Permanente, a massive U.S. integrated health care company serving millions of patients in several U.S. regions, predominantly focused in California. They focused on three specific regions when pulling their data: Northern California, Southern California, and the Mid-Atlantic. They also targeted a 21st-century timeframe for the study, restricting the data to a period running from 2000 to 2016.
In total, 39,000 HIV-positive Kaiser Permanente members age 21 or older were matched with 387,767 HIV-negative members of similar age, sex, and race. The average age of the entire cohort was 41; although there was racial diversity (45% white, 25% Black, 24% Latinx, 5% Asian), participants were mostly male (88%), and no data were available regarding transgender identification. Risk demographics loosely resembled those of the current U.S. epidemic, with 70% of the cohort identifying as men who have sex with men, 20% as heterosexual, and 8% as people who inject drugs.
In analyzing morbidity and mortality data, Marcus et al sought to answer two questions:
- Has overall life expectancy improved for people living with HIV since the late 2000s, when HIV status reduced lifespan by an average of 13 years?
- How many years of an HIV-positive person’s life can be considered “healthy”—i.e., free of major comorbidities—relative to HIV-negative people?
Study Findings: Large Improvements in Lifespan, But Large Differences in Comorbidity-Free Years
The answer to the life expectancy question was an unambiguous yes: People living with HIV in the U.S. continue to close the lifespan gap with the HIV-negative population. Specifically, within this cohort of people age 21 or older:
Overall life expectancy for people living with HIV improved from 71 in the 2008-2010 period (and 59 in the 2000-2003 period) to 77 in the 2014-2016 period.
By comparison, life expectancy for HIV-negative people was 86 in the 2014-2016 period, shrinking the HIV status lifespan gap to 9 years.
Among people who started HIV treatment with a CD4 count of 500 or higher, life expectancy in the 2011-2016 period was 87, compared to 85 for HIV-negative people.
In the 2011-2016 period, people who started HIV treatment at that higher CD4 count lived an average of 11 years longer relative to the overall HIV-positive cohort.
The answer to the comorbidity question was more complex—and more sobering. Marcus et al focused their analyses on six categories of incident health complications:
- cardiovascular disease
- chronic kidney disease
- chronic liver disease
- chronic lung disease
They found that, in the 2014-2016 period, people living with HIV developed their first comorbidity at age 36, on average—16 years earlier than HIV-negative people. The 16-year gap was the same in this more recent period as it was in the 2000-2003 period, although the age of first comorbidity incidence increased (equally) for both HIV-positive and HIV-negative people in the intervening years.
Notably, although starting HIV treatment at a CD4 count of 500 or higher erased the overall life expectancy gap with HIV-negative people, it did not reduce the overall gap in comorbidity-free years.
“We were surprised by how wide the gap is,” Marcus said. “Even though we’ve seen substantial, robust data from many studies showing higher incidence of comorbidities in people with HIV versus those without HIV, we were really struck by the difference in the number of years that people live without these comorbidities.”
In the Weeds: Gaps Between HIV+ and HIV- People Vary by Comorbidity
While the overall gap in comorbidity-free years between people living with HIV and HIV-negative people was wide, that width varied between comorbidities—as did the extent to which the gap size changed over time, and the effect of starting HIV treatment with a high CD4 count.
Specifically, three of the six complications exhibited a gap that closed only slightly from the 2000-2003 period to the 2014-2016 period:
- chronic liver disease: 24-year gap in 2014-2016 (average age at onset was 79 among HIV-negative people vs. 55 among people living with HIV)
- chronic kidney disease: 17-year gap (age at onset was 79 vs. 62)
- chronic lung disease: 14-year gap (age at onset was 63 vs. 47)
The other three complications exhibited a gap that had narrowed over time, but was still substantial:
- cancer: 9-year gap in 2014-2016, improving from a 20-year gap in 2000-2003
- average age at onset in 2014-2016 was 80 among HIV-negative people vs. 71 among people living with HIV
- cardiovascular disease: 8-year gap in 2014-2016, improving from an 18-year gap in 2000-2003
- average age at onset in 2014-2016 was 82 among HIV-negative people vs. 74 among people living with HIV
- diabetes: 8-year gap in 2014-2016, improving from a 15-year gap in 2000-2003
- average age at onset in 2014-2016 was 73 among HIV-negative people vs. 65 among people living with HIV
Marcus noted that for just two of the comorbidities—cancer and cardiovascular disease—treatment initiation at a CD4 count of 500 or higher delayed the average age of incidence and further closed the gap with HIV-negative people.
The Takeaway: Great News, But Also a Reminder of Our Current Challenges
Taken as a whole, these encouraging life expectancy findings show that, for people with access to quality health care who begin HIV treatment early, a normal life span isn’t just possible—it’s quite likely. “Our results are likely generalizable to the broader insured population,” Marcus noted.
However, even within this cohort of members of a major U.S. health care organization, only 29% had a CD4 count of 500 or higher when they started antiretroviral therapy. That will temper the rosy message somewhat, although there’s still good news in the overall shrinking of the life-expectancy gap to under a decade between people living with HIV and HIV-negative people. The need for improvements in access to and retention in HIV care are clear.
In addition, the size and persistence of the gaps we see in comorbidity-free years provide a stark reminder about the work researchers and health care providers have ahead of them in adequately preventing, diagnosing, and managing significant health complications in people who are living with HIV. We are solidly in an era in which an HIV diagnosis no longer has to mean a shorter life; the challenge we now face is to also ensure that an HIV diagnosis doesn’t mean a less-healthy life.