Spring 2007
As we age, there are common body changes that often result in physiological vulnerabilities and medical conditions as well as an increased risk of illnesses and diseases. For people with HIV, there is the added complexity of hidden effects from the virus itself or from the medications used to control HIV and prevent complications. It is not always possible to sort out a single cause for a specific problem in each individual, and multiple factors probably interact to influence the outcome. In this article I will discuss the effects of common aging processes, the known effects of the virus, and the results of certain HIV treatments. Fortunately, in many cases it is possible to address these comorbidities in beneficial ways.
HIV: The virus attacks CD4 cells, and their reduced number makes people with HIV more vulnerable to infection, especially those who are older. So a normal process is accelerated and results in immunosenescence, or premature aging of the immune system.
Treatment: Combinations of HIV meds known as HAART (highly active antiretroviral therapy) can reduce but not eliminate the ongoing damage to CD4 cells. Sometimes older patients do not restore their CD4 counts to as high a level or as quickly as younger patients.
HIV: Although in earlier days there was HIV-associated wasting disease, with HIV treatment there may not be enough virus left to affect muscle tissue directly. Disuse and disability are the more likely culprits. Sometimes the effect of peripheral neuropathy (nerve damage in the hands and feet) can mimic muscle problems when walking. HAART has been linked to changes in body shape (see article).
Treatment: Newer HAART regimens, at least in developed countries, have replaced those most likely to cause unwanted body changes, but switching drugs may not change body shape. Even when these drugs are avoided from the onset of therapy, there are still other contributing factors. Recently there has been increased use of products that can be injected under the skin of the face to replace lost fat cells.
HIV: There are some reports of accelerated bone loss in people with HIV, and studies are under way using sophisticated measures to determine how frequently this occurs.
Treatment: Calcium tablets in addition to high-calcium diets have been recommended. In cases of major bone loss (osteoporosis), there are medications that can be taken a few times or even just once a month to reverse the condition.
HIV: Although the virus may be present in liver cells, most damage is from the common coinfection with hepatitis, especially hepatitis C. HIV meds can also lead to liver problems, particularly Viramune (in women with higher CD4 counts) and Aptivus.
Treatment: Besides recommending alcohol and drug abstinence, it is possible to treat hepatitis with available drugs or to avoid hepatitis A and B with a vaccine. Switching HIV meds may be necessary in some cases.
HIV: HIV has been associated with a specific type of kidney disease known as HIV-associated nephropathy. Although this condition is relatively uncommon, it appears to be more frequent in African-Americans than in other groups.
Treatment: HAART has resulted in some improvement in kidney function. Viread has been linked to minor loss in kidney function and should be avoided in people with kidney problems.
HIV: It is controversial whether HIV itself can affect blood pressure, but HIV drugs can increase blood lipids (see below), leading to hypertension.
Treatment: Guidelines for treatment of hypertension have been established, and lowering blood pressure, both systolic and diastolic, has been found to decrease the risk of heart attack and stroke. Most blood pressure drugs can be used in people taking HIV meds, although the class called calcium channel blockers can be problematic with certain protease inhibitors.
HIV: In people who have progressed to AIDS, total cholesterol and LDL cholesterol tend to be lower. Successful HAART regimens usually restore lipid levels. Certain protease inhibitors, however, have been shown to elevate cholesterol and triglycerides, possibly leading to hypertension.
Treatment: Most experts recommend continuing the HAART regimen but adding a statin drug, such as Pravachol, but certain other statins interact with protease inhibitors and should be avoided. Another class of drugs, called fibrates, might be necessary if triglycerides remain substantially elevated. Switching to a different protease inhibitor or to a non-nucleoside reverse transcriptase inhibitor are other alternatives. As with blood pressure, cholesterol-lowering guidelines exist and it makes sense to apply them to people with HIV.
HIV: Treatment with protease inhibitors has been associated with glucose intolerance. Such treatment could exacerbate a tendency toward the metabolic syndrome.
Treatment: If possible, a switch in regimen can be considered. With a successful HAART regimen, however, it may be better to continue the therapy and attempt to control glucose intolerance with weight reduction, exercise, and dietary changes. Such a strategy would also improve lipid and blood pressure abnormalities. There are also medications that are quite effective in controlling blood sugar.
HIV: Recent reports suggest that there may be an increase in the frequency of heart attacks in people with HIV. Although initially it was thought that this was most likely the result of the effect of HAART on cardiovascular risk factors, more recently it has been suggested that the virus itself may be having a direct negative effect on cardiovascular disease frequency.
Treatment: This observation would suggest that optimal HAART therapy is the best approach to minimizing heart attack risk, as well as continuing to address the known cardiac risk factors where possible.
Richard Havlik is a medical epidemiologist formerly with the National Institute on Aging.