An observational study in HIV-1-infection, Aging, Premature and Cognitive Impairment, sponsored by Vanderbilt University Medical Center. Completed at 1 site in United States. Open to participants aged 35 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2019-02-25.
Sponsored by Vanderbilt University Medical Center · Observational
It is estimated that by 2016, nearly 50% of HIV-positive individuals in the US will be aged 50 or older, and up to 60% of those will experience some degree of cognitive impairment as they age. The purpose of this study is to evaluate the contribution of the neuronal cholinergic receptor system to the cognitive impairments seen in adults aging with chronic HIV Infection. By using anti-cholinergic challenge drugs to reversibly "stress" cognitive functioning, the investigators hope to understand whether the presence of the HIV virus in the brain impairs the neural system necessary for normal cognition, more than would be expected from normal cognitive aging.
This study is intended to evaluate the involvement of the neuronal cholinergic receptor system in the accelerated cognitive aging profile seen in adults living with chronic HIV-1 infection. It is estimated by the CDC that by the year 2016, nearly 50% of the US' HIV-positive population will be 50 or older. The HIV-1 virus is known to enter the CNS very rapidly after initial infection, and cause a pattern of persistent neural inflammation, which is deleterious to neurons and glia. This damage is believed to be the basis of cognitive impairment associated with long-term chronic HIV infection, known as HIV-Associated Neurocognitive Disorders (HAND). Successful introduction of Anti-Retroviral Treatment (ART) has greatly reduced the likelihood of progressing to the most severe category of HAND (HIV-Associated Dementia), however the mild and moderate forms (Asymptomatic Neurocognitive Impairment and Mild Neurocognitive Disorder, respectively) are still fairly common even in adults declared "virally suppressed", with little to no detectable peripheral viral DNA/RNA. Prior studies have shown that over the lifetime, more than 50% of adults diagnosed with HIV will experience some degree of cognitive impairment as they age. Some of these changes may be due to cholinergic dysfunction. The acetylcholinergic receptor system is necessary for normal cognitive performance, and is active during working memory, executive functioning, attention, and learning tasks. It has been shown that as the human brain ages, cognitive ability begins to decline, and correlates with declining acetylcholinergic activity. The cholinergic theory of cognitive aging postulates that this loss of activity at cholinergic receptors with age is at least partly responsible for poorer cognitive performance in aging. I will use this model to examine the impact of HIV infection on cholinergic system functioning. This study will use a well-established anti-cholinergic drug challenge model to evaluate cognitive performance in domains of cognitive functioning relevant to cholinergic functioning. Under conditions of temporary muscarinic or nicotinic blockade, or a combination of both, I aim to explore the contribution of putative cholinergic receptor dysfunction to the observed symptoms of HAND. I also intend to determine whether age and HIV-status interact to produce an accelerated pattern of cholinergic cognitive aging that would indicate that older adults with HIV are at higher risk for more rapid cognitive aging than HIV-negative individuals. If successful, the outcome of this study would support the future exploration of novel pro-cholinergic medications to treat cognitive symptoms of HAND, which may improve quality of life for adults living with chronic HIV infection, as they survive into old age.
3,872 studies on the registry are indexed under Cognitive Dysfunction; 1,119 are open to participants now.
This study's enrollment of 22 is below the median of 150 across 997 observational studies indexed under Cognitive Dysfunction.
Browse Cognitive Dysfunction studies →Vanderbilt University Medical Center is the lead sponsor of 833 studies on the registry; 155 are open to participants now.
Of its 125 completed or terminated interventional studies of FDA-regulated products, 92 (74%) have results posted.
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HIV-Positive Healthy older adults and HIV-Negative Healthy older adults
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
The number of CD4 cells, a type of white blood cell, in a given amount of blood. It is used to follow how well the immune system is doing in HIV.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CD4 count
The number of CD4 cells, a type of white blood cell, in a given amount of blood. It is used to follow how well the immune system is doing in HIV.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients will be administered each of 4 possible treatments: high dose (5 mcg/kg) scopolamine, high dose (20 mg) mecamylamine, a low dose combination (2.5mcg/kg and 10 mg) of scopolamine and mecamylamine, or placebo.
Drug: Scopolamine Injectable Product · Drug: Mecamylamine Pill
Patients will be administered each of 4 possible treatments: high dose (5 mcg/kg) scopolamine, high dose (20 mg) mecamylamine, a low dose combination (2.5mcg/kg and 10 mg) of scopolamine and mecamylamine, or placebo.
Drug: Scopolamine Injectable Product · Drug: Mecamylamine Pill
2.5 or 5 mcg/kg of scopolamine via IV
10 or 20mg of mecamylamine orally
Cognitive Outcome - Lower verbal memory score
Cognitive performance will be more significantly impaired by study medications in HIV-positive participants relative to HIV-negative participants, indicating impairment of cholinergic neurotransmitter system.
Time frame: 2 hours
Age and HIV-Status Interaction - Slower CRTreaction time
Older age and positive HIV status will interact to more significantly impair cognitive performance as measured by reaction time on the Choice Reaction Time task under the influence of study medications, than either variable alone.
Time frame: 2 hours
Plan to share: No
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This study is completed, as verified in Feb 2019. You cannot join it, but the record below documents what was studied.
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