Further Research Needed on HIV and Aging

HIV is often regarded as a disease of young people, due to its status as a drug-related or sexually transmitted disease. However, the number of people over age 50 who are infected with HIV is significant--and growing--according to an article in the Sept. 15, 2005 issue of Clinical Infectious Diseases.

The increasing number of older people diagnosed with HIV may be due to a couple of factors. The development of highly active antiretroviral therapy (HAART) has probably contributed to HIV-infected patients' survival into old age. Older patients are also more likely to adhere to their medication, resulting in good immune responses to the drugs. Finally, HIV infection is slowly starting to become more recognized as a potential diagnosis for older patients--previously, older patients weren't perceived as having risk factors for HIV and so were not tested for it.

"I would say that, on average, physicians are not aware that they need to be thinking about HIV as a possible diagnosis in their older patients," said author Nathalie Casau, MD. Older patients who have drastic weight loss may initially be misdiagnosed as having cancer, and it can take extensive--and expensive--testing for the doctor to rule out other diseases and arrive at a diagnosis of HIV, due to the lack of awareness of HIV in older people.

Data show that HIV-infected older people not taking HAART have double the risk of death compared with untreated young people with HIV. Therefore, failing to diagnose HIV or delaying HAART treatment could result in a higher mortality rate in older patients than in younger ones.

However, HAART treatment can result in its own set of problems for older HIV patients. Decreased kidney and liver function put older people at higher risk for drug toxicity. Pre-existing medical conditions, such as cardiac or psychiatric problems, may require other medications that could conflict with HIV drugs. "There are limited pharmacokinetic studies of HIV in older patients," said Casau. "Cardiac medications [and] psychiatric medications are dose-adjusted for age, but HIV medications are not," with the result that older patients usually receive the same dose of antiretroviral medication as younger patients. The appropriate dose of antiretroviral drugs for older HIV patients has yet to really be determined, and is "an area of future research," Casau said.

Areas in which future research into HIV in older people would be helpful are numerous. For instance, HIV-related bone density loss, cardiovascular disease and dementia, which are well-studied in younger patients, may progress differently in older HIV-infected individuals. And as physicians become better educated about diagnosing HIV in older patients, future studies will have more subjects from which to learn.

Source: Infectious Diseases Society of America (IDSA)