About
Bradford
  HIV/AIDS
Articles
  Alternative
Therapies
  HIV/AIDS
Videos
  HIV/AIDS
Links
  HIV/AIDS
News

Introduction:
Positively Positive
- Living with HIV
  Out
About
HIV
  Resume/
Curriculum Vitae:
HIV / AIDS Involvements
  Biography   HIV/AIDS
News Archive
HIV/AIDS News Bradford McIntyre
   



www.catie.ca

Study in HIV-positive women links heart health to brain functioning

11 November 2011 - Although the widespread availability of potent combination therapy for HIV infection (commonly called ART or HAART) greatly prolongs the survival of people, it does not rid the body of HIV. Moreover, despite treatment, subtle changes to the immune system caused by HIV persist. One of these changes may be unnecessary activation of the immune system. As cells of the immune system are dispersed throughout the body, persistent immune activation over many years has the potential to weaken organs.

One organ that is the focus of particular concern is the brain. In the time before ART was available in high-income countries, an extreme and devastating form of neurocognitive decline called dementia was feared by HIV-positive people. Although ART has made HIV-related dementia uncommon, several studies have found that subtle cognitive dysfunction may be relatively common in HIV-positive people, even those who are highly adherent to ART. Some researchers and HIV-positive people worry that mild neurocognitive impairment today may pave the path for more severe neurocognitive impairment as HIV-positive people age.

A team of researchers in the U.S. has been monitoring the health of several thousand women, some who have HIV and others who are at high risk for infection with HIV. They conducted preliminary neurocognitive assessments and extensive monitoring of the overall health of women in their study, particularly cardiovascular health.

As cardiovascular disease grows worse, the carotid arteries, which supply oxygen-rich blood to the brain, can become clogged and narrowed because of sticky deposits called plaque, made from debris and cholesterol. As a result of the buildup of plaque, less blood flows to the brain. The researchers assessed the health of the carotid arteries. They found that, in general, HIV-positive women had poorer neurocognitive test results and that these were linked to poorer cardiovascular health. Their findings, if confirmed in a long-term study, raise the possibility of future clinical trials to prevent or treat cardiovascular disease so that neurocognitive functioning in HIV-positive people, particularly women, may be maintained or improved.

Study details

As part of the Women's Interagency HIV Study (WIHS), researchers enrolled 3,766 women, both HIV positive and HIV negative, in the following six American cities:

  • the Bronx
  • Brooklyn
  • Chicago
  • Los Angeles
  • San Francisco
  • Washington, DC

Every six months, participants were extensively interviewed and underwent physical exams and other health assessments. By collecting data from these participants on a regular basis, a large dataset has accumulated. From time to time, researchers analyse the information that has amassed to learn about trends in different aspects of HIV-positive women's health. This CATIE News bulletin focuses on a neurological sub-study of WIHS that enrolled 1,282 women, distributed as follows:

  • HIV positive: 891 women
  • HIV negative: 391 women

For the neurological sub-study, ultrasound scans of the carotid arteries (in the neck) were performed along with some neuropsychological tests.

The study team did not provide a complete profile of the volunteers in the neurological sub-study, but we do know that the women were, on average, around 41 years of age.

Results

The research team found that, in general, HIV-positive women had poor neurocognitive test results compared to HIV-negative women. This difference appeared to be influenced by poorer cardiovascular health among HIV-positive women.

A sticky growth called plaque, made up of LDL-cholesterol and cellular debris, can build up along the wall of arteries. Over many years plaques can increase in size and impede the flow of blood as arteries narrow and become less flexible. As less blood flows, tissues become starved of oxygen and nutrients; as a result, they do not function as well and can even die.

In the present study, researchers found that the buildup of plaque in the carotid artery and a narrowing of the carotid artery were linked to worse neurocognitive function. This negative effect of cardiovascular disease was profoundly significant. Indeed, the research team commented that the effect of cardiovascular disease on neurocognitive impairment in symptom-free participants was akin to the decreased neurocognitive function they had seen in people with AIDS.

In general, the team did not find that specific classes of anti-HIV drugs had a significant impact on neurocognitive functioning. Future studies need to be designed to properly assess this, as there is at least one study suggesting that the anti-HIV drug efavirenz (Sustiva, Stocrin and in Atripla) is associated with a degree of neurocognitive impairment.

The WIHS neurologic sub-study confirmed findings from another sub-study, from a clinical trial called SMART. However, the SMART neurologic sub-study had only 122 HIV-positive women.

The WIHS study, with its focus on HIV-positive women just entering middle age, is important because it has found an association between carotid artery disease and neurocognitive impairment. Among HIV- negative people, such impairment does not usually appear until at least 15 years later, according to the WIHS team.

Don't press the panic button

It is important to note that the present study design was cross-sectional. That is, assessments were generally done at one point in time rather than many points over several years. Cross-sectional studies cannot provide definitive answers to important scientific questions. However, they are a first step to establishing that there is a problem and they lay the foundation for undertaking studies of a more rigorous nature.

Also, comprehensive neurocognitive assessments were not performed in the present study. Therefore, its findings are not definitive and should not be a cause for alarm.

Why such early artery problems?

As HIV is a chronic infection, it causes continuous and excessive inflammation that affects the immune system. Anti-HIV therapy is not able to completely suppress this excess inflammation. Over the long term, particularly if risk factors for cardiovascular disease are present (such as smoking, substance use, poor diet and being overweight), the harmful effect of these risk factors on overall health, especially cardiovascular health, is likely amplified by HIV infection.

Back to the brain

Studies on neurocognitive impairment in HIV-positive women who are monitored over several years need to be done, and in the future such studies should do at least the following:

  • continue to assess the cardiovascular health of both middle-aged and older women
  • be comprehensive, include MRI (magnetic resonance imaging) scans and explore the functioning of different parts of the brain
  • extend the present study's findings

If the findings from the WIHS neurological sub-study are confirmed in a longitudinal study, it might be possible to reverse neurocognitive impairment in some HIV-positive women by dealing with issues related to cardiovascular health. This possibility should not be surprising because among elderly HIV-negative people who have a buildup of plaque and narrowing in their carotid arteries, interventions-usually surgery-to reverse this have helped improve cognitive functioning. Note that such surgery can sometimes have adverse effects. However, if carotid artery disease is caught early in HIV-positive people, before serious symptoms appear, then safer means of improving cardiovascular health-quitting smoking, changes to the diet, aerobic exercise and treating co-morbidities such as diabetes, high-blood pressure and kidney disease-could be tested for their impact on neurocognitive impairment.

-Sean R. Hosein

REFERENCES:

  1. Polak JF, Pencina MJ, O'Leary DH, et al. Common carotid artery intima-media thickness progression as a predictor of stroke in multi-ethnic study of atherosclerosis. Stroke. 2011 Nov;42(11):3017-21.
  2. Polak JF, Pencina MJ, Pencina KM, et al. Carotid-wall intima-media thickness and cardiovascular events. New England Journal of Medicine . 2011 Jul 21;365(3):213-21.
  3. Kaplan RC, Sinclair E, Landay AL, et al. T cell activation predicts carotid artery stiffness among HIV-infected women. Atherosclerosis . 2011 Jul;217(1):207-13.
  4. Mangili A, Polak JF, Skinner SC, et al. HIV infection and progression of carotid and coronary atherosclerosis: the CARE study. Journal of Acquired Immune Deficiency Syndromes . 2011 Oct 1;58(2):148-53.
  5. Heaton RK, Franklin DR, Ellis RJ, et al. Effects of traumatic brain injury on cognitive functioning and cerebral metabolites in HIV-infected individuals. Journal of Neurovirology. 2011 Feb;17(1):3-16.
  6. Heaton RK, Clifford DB, Franklin DR, et al. HIV-associated neurocognitive disorders persist in the era of potent antiretroviral therapy: CHARTER Study. Neurology . 2010 Dec 7;75(23):2087-96.
  7. Ellis RJ, Badiee J, Vaida F, et al. CD4 nadir is a predictor of HIV neurocognitive impairment in the era of combination antiretroviral therapy. AIDS . 2011 Sep 10;25(14):1747-51.
  8. Ciccarelli N, Fabbiani M, Di Giambenedetto S, et al. Efavirenz associated with cognitive disorders in otherwise asymptomatic HIV-infected patients. Neurology . 2011 Apr 19;76(16):1403-9.
  9. Libby P, Ridker PM, Hansson GK. Progress and challenges in translating the biology of atherosclerosis. Nature. 2011 May 19;473(7347):317-25.
  10. Becker JT, Kingsley L, Mullen J, et al. Vascular risk factors, HIV serostatus, and cognitive dysfunction in gay and bisexual men. Neurology . 2009 Oct 20;73(16):1292-9.
  11. Crystal HA, Weedon J, Holman S, et al. Associations of cardiovascular variables and HAART with cognition in middle-aged HIV-infected and uninfected women. Journal of Neurovirology . 2011 Oct;17(5):469-76.
  12. Sander K, Bickel H, Förstl H, et al. Carotid-intima media thickness is independently associated with cognitive decline. The INVADE study. International Journal of Geriatric Psychiatry. 2010 Apr;25(4):389-94.
  13. Dempsey RJ, Vemuganti R, Varghese T, et al. A review of carotid atherosclerosis and vascular cognitive decline: a new understanding of the keys to symptomology. Neurosurgery . 2010 Aug;67(2):484-93.
  14. Haley AP, Tarumi T, Gonzales MM, et al. Subclinical atherosclerosis is related to lower neuronal viability in middle-aged adults: a 1H MRS study. Brain Research . 2010 Jul 16;1344:54-61.
  15. Landgraff NC, Whitney SL, Rubinstein EN, et al. Cognitive and physical performance in patients with asymptomatic carotid artery disease. Journal of Neurology . 2010 Jun;257(6):982-91.
  16. Sojkova J, Najjar SS, Beason-Held LL, et al. Intima-media thickness and regional cerebral blood flow in older adults. Stroke . 2010 Feb;41(2):273-9.
  17. Grunwald IQ, Papanagiotou P, Reith W, et al. Influence of carotid artery stenting on cognitive function. Neuroradiology . 2010 Jan;52(1):61-6.
  18. Baracchini C, Mazzalai F, Gruppo M, et al. Carotid endarterectomy protects elderly patients from cognitive decline: A prospective study. Surgery . 2011 Sep 21. [Epub ahead of print].
  19. Goldberg JB, Goodney PP, Kumbhani SR, et al. Brain injury after carotid revascularization: outcomes, mechanisms, and opportunities for improvement. Annals of Vascular Surgery . 2011 Jan;53(1):61-70.

###

CATIE-News is written by Sean Hosein, with the collaboration of other members of the Canadian AIDS Treatment Information Exchange, in Toronto.

From Canadian AIDS Treatment Information Exchange (CATIE). For more information visit CATIE's Information Network at http://www.catie.ca

Source: CATIE: CANADIAN AIDS TREATMENT INFORMATION EXCHANGE


...positive attitudes are not simply 'moods'

Site Map

Contact Bradford McIntyre.

Web Design by Trevor Uksik

Copyright © 2003 - 2024 Bradford McIntyre. All rights reserved.

DESIGNED TO CREATE HIV & AIDS AWARENESS