Premature Aging and HIV

It may seem strange to read that an HIV infection can cause premature aging, but it seems to be true. Furthermore, premature aging isn't simply a matter of HIV causing a series of symptoms that are usually found in older adults. Instead, the overall health of individuals with even well-controlled HIV infections is similar to that of people without HIV who are approximately 15 years older.

Some of the common health problems of aging that also occur earlier in younger people with HIV include:

• Cognitive difficulties - HIV can lead to problems with thought processes, memory, and loss of brain volume.
• Bone fragility - People with HIV have a higher than average risk of osteoporosis and fractures.
• Diabetes - Diabetes is more common in people with HIV, although it is not known how much of that is due to the infection and how much is due to side effects of HAART.
• Cardiovascular disease - Partially because of the changes in lipid profiles caused by some HIV medications, HIV positive people are at an increased risk of coronary artery disease and other cardiovascular problems.
• Kidney failure - The elevated risk of kidney failure is due both to the direct effects of the disease and to enhanced susceptibility to infections that indirectly affect the kidneys - such as hepatitis.

Many people with HIV have one or more of these conditions of premature aging - something known as polypathology. Although polypathology is also seen in older HIV negative adults, it occurs an average of 15 years earlier in people who are infected with HIV - in people with a median age of 40 instead of a median age of 55 in the uninfected.

Premature aging can occur in HIV positive individuals whether or not they are taking antiretroviral medications. In fact, some classes of antiretroviral drugs may contribute to premature aging symptoms.

Why Does HIV Cause Premature Aging?

There are several hypotheses for why HIV may cause premature aging. Two of the most well-explored ones are mitochondrial toxicity and immunosenescence.

Mitochondrial toxicity is thought to be caused primarily by use of NRTIs, but it also seems to occur in HIV patients who are not taking that class of drugs.

Mitochondria are the energy stations of the cell - they make one of the chemicals that our bodies need to keep going. In people suffering from mitochondrial toxicity, these little factories begin to shut down and become less productive. Mitochondrial toxicity has been linked to a number of symptoms of premature aging, including insulin problems and lipodystrophy.

Immunosenescence refers to the decline of the immune system that normally occurs with age, but which occurs faster in individuals who are HIV positive. It causes immunosuppression as well as a chronic state of inflammation that can have negative effects on overall health.

Low-level inflammation also is a sign of aging in HIV-negative adults. However, it is thought that constant activation of the immune system by HIV is one of the reasons why it occurs in those who are HIV positive at a younger age.