Study Links Fitness Level and HIV-related Dementia

More and more people with HIV are reaching their 50s and beyond thanks to advances in anti-retroviral therapies.  That is good news.  However, one of the long term impacts of living with the disease is a heightened risk of cognitive problems, such as dementia and functional decline. 

A new study shows that fitness level in HIV infected individuals is related to cognitive impairment.  These results suggest that something as simple as exercise may be able to stave off neurological decline in this growing segment of the aging population.

Scientists are not entirely sure why people with HIV experience a higher incidence of cognitive impairment.  It may be related to the virus or it could be a side effect of the extended anti-retroviral therapies necessary to keep HIV at bay, or perhaps it is the result of a combination of the two. 

Regardless of the cause, as the population of older adults with HIV increases, there is an urgent public health need to understand why some people are vulnerable to neurological impairment and whether behavioral factors can help prevent or slow the onset of these problems.

The new study – which was led by geriatrician Krupa Shah, M.D., M.P.H. and neuropsychologist  Mark Mapstone, Ph.D. and appears this month in the journal Aging and Disease – followed 37 HIV-infected patients over the age of 50.  

The participants underwent a battery of tests to establish their cognitive status.   The researchers then determined each individual’s fitness level by, among other things, accessing their peak aerobic capacity by measuring their oxygen consumption and heart rate while exercising on a treadmill.

The researchers found that there was a direct correlation between cardiovascular fitness and the level of their cognitive impairment -- individuals with lower peak aerobic capacity were more likely to have neurological problems, and vice versa.   While the link between fitness and cognitive problems in older adults has been observed in several studies, this is the first time this phenomenon was observed in individuals with HIV.