September 19, 2012
Here's the bottom line on "accelerated aging" among people with HIV: It's probably not as bad as you think.
Plenty of scary headlines have made their way across the Internet in recent years, decrying the body-decaying effects of getting older and portraying the sense that HIV (or HIV meds) causes people to suffer these problems at far higher rates far earlier in their lives. And by "far earlier," some experts felt we were talking as many as 20 years earlier, according to some of the first research that explored the issue.
But the problem that often occurs with early research is that it's ... well, a bit premature in its findings. "There certainly is more of a trend for HIV-positive people to be a bit younger" when they develop certain health problems, says Amy Justice, M.D., Ph.D., a professor of medicine and public health at the Yale School of Medicine. "But when I say a bit younger, we're talking about somewhere between one and six years -- we're not talking about 20 or 30 years."
Justice should know: She is one of the world's leading researchers on aging and HIV. As the lead investigator of the massive Veterans Aging Cohort Study (VACS), it's her job to delve into one of the largest troves of information in existence and help us all better understand the ways in which HIV intersects with other health problems that emerge as we get older.
What she and her team have found is rewriting much of we thought we knew about aging and HIV. It's also helping us figure out some concrete steps we can take to prevent or treat health problems we associate with "premature aging."
To begin with, our whole approach to the idea of "early aging" misses the mark, Justice says. "If you talk to anyone who is a geriatrician -- who studies aging -- they will say this concept of 'premature aging' is a misnomer," she explains. "If you look at anyone with chronic disease, they look older than someone without chronic disease."
The problem, Justice says, is not that people with HIV are "getting older" more quickly. Instead, what happens is that HIV, like many other chronic illnesses (such as diabetes), sometimes triggers or worsens other health issues -- many of which we're naturally at greater risk for as we get older. "Are people who are sick and have HIV more frail, more likely to have problems with their health, than someone who's not? Of course they are," Justice says. "Why do we have to invoke 'premature aging' when we talk about that?"
Through her work with VACS, Justice and her colleagues have uncovered some of the most reliable information we've learned to date about the timing of various health problems in people with HIV.
Here's how the study works: More than 7,400 people living in or near eight U.S. cities are enrolled in VACS. The HIV-positive people are "matched" against HIV-negative people who otherwise have extremely similar characteristics (such as age, location and race). The study then follows these people over time and records when they develop various health complications.
When comparing the HIV-positive people to the HIV-negative people, VACS has found that HIV-positive people:
A slide from a presentation given by Amy Justice at an HIV/AIDS conference in 2012. (Click the image to enlarge it.) It compares the average age at which HIV-positive people and HIV-negative people enrolled in VACS were first diagnosed with certain key health problems. ("MI" is short for "myocardial infarction" -- i.e., a heart attack.)
This isn't the only research being done to make more accurate estimates of how much "earlier" people with HIV develop health problems. Less than two years ago, a major study funded by the National Cancer Institute found that previous estimates drastically overestimated how much earlier people with HIV develop certain cancers, because it didn't properly take people's ages into account.
But why is it that studies such as VACS manage to find such a smaller age difference than earlier studies had found? Which findings should you believe more?
To determine whether HIV-positive people have a "greater" risk of developing certain health problems as they get older, researchers have to compare those HIV-positive people to a group of HIV-negative people. Who those HIV-negative people are, and what measurements researchers use to examine them, makes all the difference.
People with HIV who are visiting a Veterans Affairs hospital in Los Angeles are likely to be very different from your average HIV-negative people living in a Massachusetts suburb. For instance, they're more likely to be people of color; they're more likely to be from an inner city; and they're also just more likely to be sick in the first place, since they're the ones visiting a hospital.
Another slide from a presentation given by Amy Justice at an HIV/AIDS conference in 2012. (Click the image to enlarge it.) It shows some of the key results from a study published in the Annals of Internal Medicine that corrected earlier research which drastically overestimated how much earlier people with HIV develop certain cancers, because it didn't properly take people's ages into account.
All of these kinds of factors -- race, location, gender, income, access to health care, average age, you name it -- can impact the risk a person has of developing a health problem. Sure, an HIV-positive black man working a low-wage job and living in an unsafe neighborhood in Los Angeles may develop heart disease many, many years earlier than an HIV-negative white man living in a million-dollar home in Weston, Mass. But is it the HIV that's to blame?
Studies like VACS try to level the playing field by comparing groups of people who are as similar as possible in every measurable way -- except that one group has HIV and the other does not. Very few studies like this exist, because finding enough HIV-positive and HIV-negative people to match in this way is extremely difficult (not to mention extremely expensive).
VACS is not the be-all, end-all of studies on aging and HIV. Researchers are constantly looking for ways to refine their studies, enroll more volunteers and make their results more reliable. But as you saw in the list above, what we've learned so far is enough to dispel some widely held myths about HIV and aging. It's also enough to give researchers some insight into how people with HIV can reduce the risk that they'll develop various health problems as they get older.
"'Premature aging' -- I think it frightens the living daylights out of people," Justice says. "It suggests there's nothing you can do: You'll be 70 when you're 50, and when you're 70, you'll be 90. I don't think that's useful in clinical care."
In hopes of helping HIV-positive people and their health care providers combat this feeling of helplessness in the face of the relentless passage of time, Justice and her colleagues have developed a tool called the VACS Index Calculator. The tool, which is available online -- and even has a mobile-friendly version -- pulls together all of the research VACS has done to date and attempts to answer the question: "What are my odds of dying?"
A screen shot of the VACS Index Calculator.
OK, yes, it's a terrifying concept: You check off a bunch of boxes -- age, sex, race, CD4 count, HIV viral load, liver enzymes and so forth -- and the calculator spits out a single number called your "five-year mortality risk." In other words, your risk of dying within the next five years.
But here's why the tool isn't remotely as terrifying as it seems: It's not a prediction. It's just VACS telling you, "Among the people in our study who are similar to you, this many passed away within five years." Which means you and your health care provider have the power to change those odds.
"It's a way of gauging your overall burden of disease, your overall susceptibility to further injury," Justice explains. "Whether the [cause] is treatment toxicity, HIV disease progression, diabetes, smoking, alcohol -- it reflects all of those things, in terms of looking at their injury on your major organ systems. And, by determining what else is going on in your situation, helping you pinpoint what things you might be able to do to improve it."
The VACS Index Calculator is still in development; Justice hopes over time to add features that may delve more deeply into people's behaviors and life habits, and offer some suggestions about changes they can make to reduce their mortality risk and stay as healthy as possible. She encourages people to use the tool, offer comments on how it can be made even more useful for them (there's a survey link within the tool), and discuss the calculator's results with their health care provider.
"I think the more information you can give patients directly and the more time they have to think about what questions they may have for their providers when they go to see them, the better, the higher quality, the more meaningful the interaction is, and the more likely the behaviors [that increase their health risks] will really change," Justice says.
In the meantime, Justice and her VACS colleagues -- as well as a number of other research teams around the country -- will continue their efforts to more reliably explore the real risks of HIV-positive people developing various health problems as they age.