Vascular risk factors, HIV serostatus, and cognitive dysfunction in gay and bisexual men

Clinical and neuroimaging correlates of cognition in HIV

This study investigated whether HIV-positive participants, stable on combined antiretroviral therapy (cART), showed cognitive impairments relative to HIV-negative controls; and whether clinical and neuroimaging factors correlated with cognitive function in the HIV-positive participants. One hundred and twenty-six white men who have sex with men, of whom 78 were HIV-positive and stable on cART and 48 were HIV negative, were recruited to this cross-sectional study. The median age of HIV-positive participants in this study was 47. They underwent clinical and neuropsychological evaluation and magnetic resonance imaging of the brain, including diffusion tensor imaging (DTI). Cognitive scores for both groups were compared, and regression models were run to explore the influence of clinical, psychiatric, lifestyle, and neuroimaging variables on cognition. The prevalence of neurocognitive impairment, using the multivariate normative comparison criteria, was 28% in HIV-positive participants and 5% in HIV-negative participants. After covarying for age, years of education, and non-English speaking background, there were significant differences between the HIV group and the controls across four cognitive domains. The HIV group showed significantly higher mean diffusivity (MD) and lower fractional anisotropy (FA) than the control group on DTI. Although anxiety levels were clinically low, anxiety and DTI measures were the only variables to show significant correlations with cognitive function. In the HIV group, poorer cognitive performance was associated with higher MD and lower FA on DTI and higher (albeit clinically mild) levels of anxiety. Our findings suggest that white matter changes and subtle anxiety levels contribute independently to cognitive impairment in HIV.

Is treated HIV infection still toxic to the brain?

Clinically apparent HIV infection, accompanied by CNS opportunistic infections and HIV encephalopathy, was often associated with profound structural and functional brain effects prior to the introduction of anti-retroviral therapy (ART). With treatment, HIV structural and functional brain effects are smaller and have not been as easily detected. With near complete elimination of CNS opportunistic infections, the HIV neuroimaging research community now grapples with the problem of detecting subtler structural and functional changes against a background of persisting confounds, such as comorbidities and clinical features common in the HIV infected population. This situation also raises the question of whether imaging measure changes that are reported as HIV brain effects are purely related to viral infection, rather than originating from confounding effects that might include age, substance use, hepatitis C coinfection, cerebrovascular risk factors, ART, premorbid cognitive skills and illness duration. In addition to cohort characteristics, variation in image acquisition and analysis techniques may also contribute to study outcome heterogeneity. We review the potential effects of these confounds on detection of HIV infection effects and discuss strategies to avoid or mitigate the effects of these confounds. We then present a systematic approach to measurement, design and analysis in HIV neuroimaging studies, combining both experimental and statistical control techniques to determine if HIV infection effects persist, fluctuate or worsen in groups achieving viral suppression from ART.

Depression, lifestyle factors and cognitive function in people living with HIV and comparable HIV-negative controls

Objectives

We investigated whether differences in cognitive performance between people living with HIV (PLWH) and comparable HIV‐negative people were mediated or moderated by depressive symptoms and lifestyle factors.

Methods

A cross‐sectional study of 637 ‘older’ PLWH aged ≥ 50 years, 340 ‘younger’ PLWH aged < 50 years and 276 demographically matched HIV‐negative controls aged ≥ 50 years enrolled in the Pharmacokinetic and Clinical Observations in People over Fifty (POPPY) study was performed. Cognitive function was assessed using a computerized battery (CogState). Scores were standardized into Z‐scores [mean = 0; standard deviation (SD) = 1] and averaged to obtain a global Z‐score. Depressive symptoms were evaluated via the Patient Health Questionnaire (PHQ‐9). Differences between the three groups and the effects of depression, sociodemographic factors and lifestyle factors on cognitive performance were evaluated using median regression. All analyses accounted for age, gender, ethnicity and level of education.

Results

After adjustment for sociodemographic factors, older and younger PLWH had poorer overall cognitive scores than older HIV‐negative controls (P < 0.001 and P = 0.006, respectively). Moderate or severe depressive symptoms were more prevalent in both older (27%; P < 0.001) and younger (21%; P < 0.001) PLWH compared with controls (8%). Depressive symptoms (P < 0.001) and use of hashish (P = 0.01) were associated with lower cognitive function; alcohol consumption (P = 0.02) was associated with better cognitive scores. After further adjustment for these factors, the difference between older PLWH and HIV‐negative controls was no longer significant (P = 0.08), while that between younger PLWH and older HIV‐negative controls remained significant (P = 0.01).

Conclusions

Poorer cognitive performances in PLWH compared with HIV‐negative individuals were, in part, mediated by the greater prevalence of depressive symptoms and recreational drug use reported by PLWH.

Geriatric Syndromes in People Living with HIV Associated with Ageing and Increasing Comorbidities: Implications for Neurocognitive Complications of HIV Infection

Long-term survival of treated people living with HIV (PLWH) currently approaches that of the general population. The average age of PLWH is currently in the mid-50s in resource-rich countries and is predicted that over 40% of PLWH will be older than 60 within a decade. Similar trends have been confirmed in all communities of PLWH with access to antiretroviral therapies. However, the positive impact on survival has been challenged by several developments. Ageing PLWH have clinical features similar to the general population about 5-10 years older. In addition to the earlier occurrence of common age-related conditions common geriatric syndromes have also impacted this population prematurely. These are often difficult to evaluate and manage conditions usually of multifactorial aetiology. They include polypharmacy, frailty, impaired mobility and falls, sarcopenia, sensory impairment, and increasingly, non-dementing cognitive decline. Cognitive decline is of particular concern to PLWH and their care providers. In the general geriatric population cognitive impairment increases with age and occurs in all populations with a prevalence of over 25% in people over 80. Effective treatments are lacking and therefore minimizing risk factors plays an important role in maintaining healthspan. In the general population geriatric syndromes may increase the risk of cognitive decline. The corollary is that decreasing the risk of their development may limit cognitive impairment. Whether a similar status holds in PLWH is uncertain. This chapter will address the question of whether common geriatric syndromes in PLWH contribute to cognitive impairment. Common risk factors may provide clues to limit or delay cognitive decline.

Everyday Multitasking Abilities in Older HIV+ Adults: Neurobehavioral Correlates and the Mediating Role of Metacognition

Objective

The prevalence of older adults living with HIV is rising, as is their risk for everyday functioning problems associated with neurocognitive dysfunction. Multitasking, the ability to maintain and carry out subgoals in support of a larger goal, is a multidimensional skill ubiquitous during most real-life tasks and associated with prefrontal networks that are vulnerable in HIV. Understanding factors associated with multitasking will improve characterization of HIV-associated neurocognitive disorders. Metacognition is also associated with frontal systems, is impaired among individuals with HIV, and may contribute to multitasking.

Method

Ninety-nine older (≥50 years) adults with HIV completed: the Everyday Multitasking Test (MT), a performance-based measure during which participants concurrently attempt four everyday tasks (e.g., medication management) within a time limit; a comprehensive neuropsychological battery; measures of metacognition regarding their MT performance (e.g., metacognitive knowledge and online awareness).

Results

Better global neuropsychological performance (i.e., average T-score across all domains) was associated with better Everyday MT total scores (rho = 0.34; p < .001), as was global metacognition (rho = 0.37, p < .01). Bootstrapping mediation analysis revealed global metacognition was a significant partial mediator between neurocognition and Everyday MT (b = 0.09, 95% confidence interval [CI] = 0.01, 0.25). Specifically, metacognitive knowledge (but not online awareness) drove this mediation (b = 0.13, 95% CI = 0.03, 0.27).

Conclusions

Consistent with findings among younger persons with HIV, neuropsychological performance is strongly associated with a complex, laboratory-based test of everyday multitasking, and metacognition of task performance was a pathway through which successful multitasking occurred. Interventions aimed at modifying metacognition to improve daily functioning may be warranted among older adults with HIV.

HIV Neuroinfection and Alzheimer's Disease: Similarities and Potential Links?

Environmental factors such as chemicals, stress and pathogens are now widely believed to play important roles in the onset of some brain diseases, as they are associated with neuronal impairment and acute or chronic inflammation. Alzheimer’s disease (AD) is characterized by progressive synaptic dysfunction and neurodegeneration that ultimately lead to dementia. Neuroinflammation also plays a prominent role in AD and possible links to viruses have been proposed. In particular, the human immunodeficiency virus (HIV) can pass the blood-brain barrier and cause neuronal dysfunction leading to cognitive dysfunctions called HIV-associated neurocognitive disorders (HAND). Similarities between HAND and HIV exist as numerous factors involved in AD such as members of the amyloid and Tau pathways, as well as stress-related pathways or blood brain barrier (BBB) regulators, seem to be modulated by HIV brain infection, leading to the accumulation of amyloid plaques or neurofibrillary tangles (NFT) in some patients. Here, we summarize findings regarding how HIV and some of its proteins such as Tat and gp120 modulate signaling and cellular pathways also impaired in AD, suggesting similarities and convergences of these two pathologies.

Peripheral and cerebrospinal fluid immune activation and inflammation in chronically HIV-infected patients before and after virally suppressive combination antiretroviral therapy (cART)

Cerebrospinal fluid (CSF)/plasma HIV-RNA ratio has been associated with residual neurocognitive impairment on cART, leading us to hypothesize a specific peripheral and/or CSF immune feature in patients with high CSF/plasma ratio (≥ 1). In patients with diverse pre-cART CSF/plasma ratio (61/70 with CSF/plasma ratio < 1, L-CSF, 9/70 with CSF/plasma ratio ≥ 1, H-CSF), we investigated the effects of 12 months of effective cART on peripheral and CSF inflammatory markers, on T cell activation/maturation and HIV/CMV-specific intracellular cytokine pattern. We also studied the possible clinical association between peripheral/CSF pro-inflammatory milieu and neurocognitive screening tests (MMSE, FAB, IHDS). Prior to cART, the two groups were comparable for peripheral and CSF inflammation, T cell activation/proliferation and maturation, and HIV/CMV-specific response. Upon cART initiation, both H-CSF and L-CSF featured a significant reduction in plasma TNF-α and circulating CD8 activation, with a redistribution of memory/naïve T cell subsets in L-CSF alone. In the CSF compartment, cART seemed able to reduce pro-inflammatory cytokine/chemokine levels in both H-CSF and L-CSF patients. Interestingly, despite a reduction in the pro-inflammatory milieu, no changes were shown in neurocognitive screening tests in both patients' groups. We hereby show that 12-month cART is able to reduce intratechal and peripheral pro-inflammatory burden; a longer cART exposure and a more comprehensive neuropsychological evaluation might be necessary to gain a broader insight into the possible effects on neurocognitive performance.

Redefining Aging in HIV Infection Using Phenotypes

Purpose of review

This article critically reviews the utility of “phenotypes” as behavioral descriptors in aging/HIV research that inform biological underpinnings and treatment development. We adopt a phenotypic redefinition of aging conceptualized within a broader context of HIV infection and of aging. Phenotypes are defined as dimensions of behavior, closely related to fundamental mechanisms, and, thus, may be more informative than chronological age. Primary emphasis in this review is given to comorbid aging and cognitive aging, though other phenotypes (i.e., disability, frailty, accelerated aging, successful aging) are also discussed in relation to comorbid aging and cognitive aging.

Recent findings

The main findings that emerged from this review are as follows: (1) the phenotypes, comorbid aging and cognitive aging, are distinct from each other, yet overlapping; (2) associative relationships are the rule in HIV for comorbid and cognitive aging phenotypes; and (3) HIV behavioral interventions for both comorbid aging and cognitive aging have been limited.

Summary

Three paths for research progress are identified for phenotype-defined aging/HIV research (i.e., clinical and behavioral specification, biological mechanisms, intervention targets), and some important research questions are suggested within each of these research paths.

Aged Chinese-origin rhesus macaques infected with SIV develop marked viremia in absence of clinical disease, inflammation or cognitive impairment

BACKGROUND

Damage to the central nervous system during HIV infection can lead to variable neurobehavioral dysfunction termed HIV-associated neurocognitive disorders (HAND). There is no clear consensus regarding the neuropathological or cellular basis of HAND. We sought to study the potential contribution of aging to the pathogenesis of HAND. Aged (range = 14.7-24.8 year) rhesus macaques of Chinese origin (RM-Ch) (n = 23) were trained to perform cognitive tasks. Macaques were then divided into four groups to assess the impact of SIVmac251 infection (n = 12) and combined antiretroviral therapy (CART) (5 infected; 5 mock-infected) on the execution of these tasks.

RESULTS

Aged SIV-infected RM-Ch demonstrated significant plasma viremia and modest CSF viral loads but showed few clinical signs, no elevations of systemic temperature, and no changes in activity levels, platelet counts or weight. Concentrations of biomarkers of acute and chronic inflammation such as soluble CD14, CXCL10, IL-6 and TNF-α are known to be elevated following SIV infection of young adult macaques of several species, but concentrations of these biomarkers did not shift after SIV infection in aged RM-Ch and remained similar to mock-infected macaques. Neither acute nor chronic SIV infection or CART had a significant impact on accuracy, speed or percent completion in a sensorimotor test.

CONCLUSIONS

Viremia in the absence of a chronic elevated inflammatory response seen in some aged RM-Ch is reminiscent of SIV infection in natural disease resistant hosts. The absence of cognitive impairment during SIV infection in aged RM-Ch might be in part attributed to diminishment of some facets of the immunological response. Additional study encompassing species and age differences is necessary to substantiate this hypothesis.

HIV-associated neurocognitive disorder

PURPOSE OF REVIEW

HIV-associated neurocognitive disease is the most active topic for neuroAIDS investigations at present. Although impairment is mild in patients successfully treated with modern antiviral regimens, it remains an ongoing problem for HIV patients. It is important to update the emerging research concerning HIV-associated neurocognitive disease.

RECENT FINDINGS

The virus enters the brain during acute infection, with evidence for abnormal functioning that may occur early and often persists. Direct relationships with ongoing viral infection continue to be monitored, but chronic inflammation often associated with monocytes and macrophages appears to be the most likely driver of cognitive dysfunction. Appreciation for cerebrovascular disease as a significant comorbidity that is associated with cognitive deficits is increasing. Neuroimaging is actively being developed to address detection and measurement of changes in the brain. Optimal combined antiretroviral treatment therapy has vastly improved neurologic outcomes, but so far has not been demonstrated to reverse the remaining mild impairment. Inflammatory and vascular mechanisms of cerebral dysfunction may need to be addressed to achieve better outcomes.

SUMMARY

Ongoing research is required to improve neurological outcomes for persons living with HIV. It is likely that interventions beyond antiviral approaches will be required to control or reverse HIV-associated neurocognitive disease.

HIV-Associated Neurocognitive Disorder

In the last two decades, several advancement studies have increased the care of HIV-infected individuals. Specifically, the development for preparation of combination antiretroviral therapy has resulted in a dramatic decline in the rate of deaths from AIDS. The term “HIV-associated neurocognitive disorder” (HAND) has been used to distinguish the spectrum of neurocognitive dysfunction associated with HIV infection. HIV can pass to the CNS during the early stages of infection and last in the CNS. CNS inflammation and infection lead to the development of HAND. The brain can serve as a sanctuary for ongoing HIV replication, even when the systemic viral suppression has been achieved. HAND can remain in patients treated with combination antiretroviral therapy, and its effect on survival, quality of life, and everyday functioning make it a significant unresolved problem. This chapter discusses details of the computational modeling studies on mechanisms and structures of human dopamine transporter (hDAT) and its interaction with HIV-1 trans activator of transcription (Tat).

Cognitive functions in newly diagnosed patients with HIV infection in a tertiary health facility: Assessment using community screening interview for dementia

INTRODUCTION

Neurocognitive dysfunction is a detrimental complication of HIV infection. In this study we attempt to characterize the pattern of cognitive dysfunction in a sample of Nigerian patients with newly diagnosed HIV infection.

METHODS

We conducted a prospective study in which 50 patients with newly diagnosed HIV infection were studied along with 50 normal control subjects. The participants were evaluated with the medical history, general, physical and neurological examination. Laboratory evaluation and chest X-Ray were done for all patients. The Community Screening Interview for Dementia (CSID) questionnaire was administered to all the study participants.

RESULTS

About 70% of the patients were in advanced disease stage. The mean age (SD) of the patients and controls in years were 36.44 ± 8.22 and 35.40 ± 11.53 respectively. More than half (56%) of the patients had secondary level of education (12 years of education). About 20% of the patients had severe neurocognitive impairment while 48% had minor neurocognitive disorder. The patients with HIV infection performed poorly in the domains of language, memory, orientation, attention/calculation and praxis relative to controls (p < 0.05).There were no significant effect of gender, age, sex and level of education on cognitive functions in the patients (p > 0.05) but the presence of opportunistic infections had negative impact on the performances on orientation and total CSID scores in the patients with HIV infection (p < 0.05).

CONCLUSION

Patients with newly diagnosed HIV infection have poor cognitive functions when compared to normal controls and some presence of opportunistic infections in the patient is a significant risk factor for cognitive impairment.

Clinical Relevance of Total HIV DNA in Peripheral Blood Mononuclear Cell Compartments as a Biomarker of HIV-Associated Neurocognitive Disorders (HAND)

The pathogenesis of HIV-associated neurocognitive disorders is complex and multifactorial. It is hypothesized that the critical events initiating this condition occur outside the brain, particularly in the peripheral blood. Diagnoses of HIV-induced neurocognitive disorders largely rely on neuropsychometric assessments, which are not precise. Total HIV DNA in the peripheral blood mononuclear cells (PBMCs), quantified by PCR, correlate with disease progression, which is a promising biomarker to predict HAND. Numerous PCR assays for HIV DNA in cell compartments are prone to variation due to the lack of standardization and, therefore, their utility in predicting HAND produced different outcomes. This review evaluates the clinical relevance of total HIV DNA in circulating mononuclear cells using different published quantitative PCR (qPCR) protocols. The rationale is to shed light on the most appropriate assays and sample types used to accurately quantify HIV DNA load, which predicts severity of neurocognitive impairment. The role of monocytes as a vehicle for trafficking HIV into the CNS makes it the most suitable sample for determining a HAND associated reservoir. Studies have also shown significant associations between monocyte HIV DNA levels with markers of neurodamage. However, qPCR assays using PBMCs are cheaper and available commercially, thus could be beneficial in clinical settings. There is need, however, to standardise DNA extraction, normalisation and limit of detection.

Cortical brain atrophy and intra-individual variability in neuropsychological test performance in HIV disease

To characterize the relationship between dispersion-based intra-individual variability (IIVd) in neuropsychological test performance and brain volume among HIV seropositive and seronegative men and to determine the effects of cardiovascular risk and HIV infection on this relationship. Magnetic Resonance Imaging (MRI) was used to acquire high-resolution neuroanatomic data from 147 men age 50 and over, including 80 HIV seropositive (HIV+) and 67 seronegative controls (HIV-) in this cross-sectional cohort study. Voxel Based Morphometry was used to derive volumetric measurements at the level of the individual voxel. These brain structure maps were analyzed using Statistical Parametric Mapping (SPM2). IIVd was measured by computing intra-individual standard deviations (ISD's) from the standardized performance scores of five neuropsychological tests: Wechsler Memory Scale-III Visual Reproduction I and II, Logical Memory I and II, Wechsler Adult Intelligence Scale-III Letter Number Sequencing. Total gray matter (GM) volume was inversely associated with IIVd. Among all subjects, IIVd -related GM atrophy was observed primarily in: 1) the inferior frontal gyrus bilaterally, the left inferior temporal gyrus extending to the supramarginal gyrus, spanning the lateral sulcus; 2) the right superior parietal lobule and intraparietal sulcus; and, 3) dorsal/ventral regions of the posterior section of the transverse temporal gyrus. HIV status, biological, and cardiovascular disease (CVD) variables were not linked to IIVd -related GM atrophy. IIVd in neuropsychological test performance may be a sensitive marker of cortical integrity in older adults, regardless of HIV infection status or CVD risk factors, and degree of intra-individual variability links with volume loss in specific cortical regions; independent of mean-level performance on neuropsychological tests.

Chronic Tobacco-Smoking on Psychopathological Symptoms, Impulsivity and Cognitive Deficits in HIV-Infected Individuals

HIV-infected individuals (HIV+) has 2-3 times the rate of tobacco smoking than the general population, and whether smoking may lead to greater psychiatric symptoms or cognitive deficits remains unclear. We evaluated the independent and combined effects of being HIV+ and chronic tobacco-smoking on impulsivity, psychopathological symptoms and cognition. 104 participants [27 seronegative (SN)-non-Smokers, 26 SN-Smokers, 29 HIV+ non-Smokers, 22 HIV+ Smokers] were assessed for psychopathology symptoms (Symptom Checklist-90, SCL-90), depressive symptoms (Center for Epidemiologic Studies-Depression Scale, CES-D), impulsivity (Barratt Impulsiveness Scale, BIS), decision-making (The Iowa Gambling Task, IGT, and Wisconsin Card Sorting Test, WCST), and cognition (seven neurocognitive domains). Both HIV+ and Smoker groups had higher SCL-90 and CES-D scores, with highest scores in HIV+ Smokers. On BIS, both HIV+ and Smokers had higher Total Impulsiveness scores, with higher behavioral impulsivity in Smokers, highest in HIV+ Smokers. Furthermore, across the four groups, HIV+ Smokers lost most money and made fewest advantageous choices on the IGT, and had highest percent errors on WCST. Lastly, HIV+ had lower z-scores on all cognitive domains, with the lowest scores in HIV+ Smokers. These findings suggest that HIV-infection and chronic tobacco smoking may lead to additive deleterious effects on impulsivity, psychopathological (especially depressive) symptoms and cognitive dysfunction. Although greater impulsivity may be premorbid in HIV+ and Smokers, the lack of benefits of nicotine in chronic Smokers on attention and psychopathology, especially those with HIV-infection, may be due to the negative effects of chronic smoking on dopaminergic and cardio-neurovascular systems. Tobacco smoking may contribute to psychopathology and neurocognitive disorders in HIV+ individuals.

Changing clinical phenotypes of HIV-associated neurocognitive disorders

HIV-associated neurocognitive disorder (HAND) remains a common cause of cognitive impairment and persists in 15-55% of HIV+ individuals in the combination antiretroviral therapy (CART) era. CART is now the primary treatment for HAND, but it is effective in only a subset of patients. In the pre-CART era, HIV-associated dementia was the most common form of HAND. However, in CART-treated patients, the prevalence of HIV-associated dementia has declined substantially, and milder stages of HAND, i.e., ANI and MND predominate. HIV+ patients with mild neurocognitive disorder (MND) can still have significant functional impairment in some activities of daily living. There have been several other significant changes in the clinical features of HAND in the CART era. The mean survival for an individual diagnosed with HIV dementia has increased dramatically. In HIV+ individuals on CART with a suppressed systemic viral load, the majority of individuals with HAND remain stable, with a small proportion showing deterioration. Extrapyramidal signs are now less common in patients with HAND on CART. In the CART era, HAND may have a mixed pattern of both cortical and subcortical features with greater deficits in executive functioning and working memory. Despite the milder clinical phenotype, in the CART era, patients with HAND still have persistent laboratory and neuroimaging abnormalities in the central nervous system even with systemic viral suppression. As the HIV+ patient population ages, cerebrovascular disease risk factors such as hypertension, diabetes, and hypercholesterolemia are increasingly recognized as risk factors for cognitive impairment in HIV+ patients on CART. HAND remains a common neurological condition globally in the CART era, necessitating the need for new animal models to examine pathogenesis and potential treatments for HAND.

Elevated Markers of Vascular Remodeling and Arterial Stiffness Are Associated With Neurocognitive Function in Older HIV+ Adults on Suppressive Antiretroviral Therapy

BACKGROUND

HIV is associated with elevated markers of vascular remodeling that may contribute to arterial fibrosis and stiffening and changes in pulse pressure (PP). These changes may, in turn, deleteriously affect autoregulation of cerebral blood flow and neurocognitive function.

METHODS

To evaluate these mechanisms, we studied markers of vascular remodeling, PP, and neurocognitive function among older (≥50 years of age) HIV-infected (HIV+, n = 72) and HIV-seronegative (HIV-, n = 36) adults. Participants completed standardized neurobehavioral and neuromedical assessments. Neurocognitive functioning was evaluated using a well-validated comprehensive battery. Three plasma biomarkers of vascular remodeling (ie, angiopoietin 2, Tie-2, and vascular endothelial growth factor, VEGF) were collected.

RESULTS

HIV+ and HIV- participants had similar levels of plasma angiopoietin 2 (P = 0.48), Tie-2 (P = 0.27), VEGF (P = 0.18), and PP (P = 0.98). In a multivariable regression model, HIV interacted with Tie-2 (β = 0.41, P < 0.01) and VEGF (β = -0.43, P = 0.01) on neurocognitive function, such that lower Tie-2 and higher VEGF values were associated with worse neurocognitive function for HIV+ participants. Greater Tie-2 values were associated with increased PP (r = 0.31, P < 0.01). In turn, PP demonstrated a quadratic association with neurocognitive function (β = -0.33, P = 0.01), such that lower and higher, relative to mean sample, PP values were associated with worse neurocognitive function.

CONCLUSIONS

These findings indicate that vascular remodeling and altered cerebral blood flow autoregulation contribute to neurocognitive function. Furthermore, HIV moderates the association between vascular remodeling and neurocognitive function but not the association between PP and neurocognitive function.

Cytomegalovirus and HIV: A Dangerous Pas de Deux

Human immunodeficiency virus (HIV)-infected adults who take stable antiretroviral therapy (ART) are at risk for early onset of age-related diseases. This is likely due to a complex interaction between traditional risk factors, HIV infection itself, and other factors, such as underlying immune dysfunction and persistent inflammation. HIV disrupts the balance between the host and coinfecting microbes, worsening control of these potential pathogens. For example, HIV-infected adults are more likely than the general population to have subclinical bursts of cytomegalovirus (CMV) replication at mucosal sites. Production of antigens can activate the immune system and stimulate HIV replication, and it could contribute to the pathogenesis of adverse outcomes of aging, like cardiovascular disease and neurocognitive impairment. Further investigation of the relationships between CMV, immune dysfunction, and unsuccessful aging during chronic HIV infection is warranted.

Association of long-term patterns of depressive symptoms and attention/executive function among older men with and without human immunodeficiency virus

Older HIV-infected men are at higher risk for both depression and cognitive impairments, compared to HIV-uninfected men. We evaluated the association between longitudinal patterns of depressive symptoms and attention/executive function in HIV-infected and HIV-uninfected men aged 50+ years to understand whether HIV infection influenced the long-term effect of depression on attention/executive function. Responses to the Center for Epidemiologic Studies-Depression scale and attention/executive function tests (Trail Making Test Part B and Symbol Digit Modalities Test) were collected semiannually from May 1986 to April 2015 in 1611 men. Group-based trajectory models, stratified by HIV status, were used to identify latent patterns of depressive symptoms and attention/executive function across 12 years of follow-up. We identified three depression patterns for HIV-infected and HIV-uninfected men (rare/never 50.0 vs. 60.6%, periodically depressed 29.6 vs. 24.5%, chronic high 20.5 vs.15.0%, respectively) and three patterns of attention/executive function for HIV-infected and HIV-uninfected men (worst-performing 47.4 vs. 45.1%; average 41.9 vs. 47.0%; best-performing 10.7 vs. 8.0%, respectively). Multivariable logistic regression models were used to assess associations between depression patterns and worst-performing attention/executive function. Among HIV-uninfected men, those in the periodically depressed and chronic high depressed groups had higher odds of membership in the worst-performing attention/executive function group (adjusted odds ratio [AOR] = 1.45, 95% CI 1.04, 2.03; AOR = 2.25, 95% CI 1.49, 3.39, respectively). Among HIV-infected men, patterns of depression symptoms were not associated with patterns of attention/executive function. Results suggest that HIV-uninfected, but not HIV-infected, men with chronic high depression are more likely to experience a long-term pattern of attention/executive dysfunction.

Simple screening for neurocognitive impairment in routine HIV outpatient care: is it deliverable?

Routine screening for psychological and cognitive difficulties is recommended in BHIVA guidelines but screening questions are not specified and studies give varied recommendations. Our aim was to see if simple screening in the routine clinic could help better direct our referrals to psychology and highlight those patients requiring, and likely to benefit from, further assessment. We introduced brief questions to assess neurocognitive impairment (NCI) and mood into routine HIV visits, with an onward referral pathway for further investigation for those screening positive. Routine attendees to HIV outpatient care over 12 weeks completed brief screening for depression (PHQ-2) and anxiety (GAD-2) and answered three short questions to screen for possible neurocognitive impairment (NCI-3Q). Patients screening positive underwent further screening via our psychologists and/or referral for neuropsychometric testing. Patient demographics, HIV markers and treatment history were recorded. 97 HIV outpatients were screened; 44 (45%) initially screened positive for NCI and/or mood. 29/44 (66%) were referred for further screening and/or psychological assessment and 21/29 (72%) of those engaged. The Montreal Cognitive Assessment (MoCA) and International HIV Dementia Scale (IHDS) were conducted on seven patients; four of these received full neuropsychometric testing. A detectable viral load was associated with positive neurocognitive screening. Rates of NCI and mood disorder among those who were tested were consistent with previous studies. The PHQ-2 and GAD-2 did detect mood problems; however, our results suggest the NCI-3Q questions alone are not good at detecting those with possible NCI. Screening for NCI remains practically difficult in the routine outpatient setting and this pilot supports the need for clearer guidelines on detecting HIV related NCI.

The association between physical activity and cognition in men with and without HIV infection

OBJECTIVES

HIV-associated neurocognitive disorders are highly prevalent, and physical activity (PA) is a modifiable behaviour that may affect neurocognitive function. Our objective was to determine the association between PA and neurocognitive function and the effect of HIV on this association.

METHODS

PA was assessed in the Multicenter AIDS Cohort Study with the International Physical Activity Questionnaire. A neuropsychological test battery assessed global impairment and domain-specific impairment (executive function, speed of processing, working memory, learning, memory, and motor function) every 2 years. Semiannually, the Symbol Digit Modalities Test and Trail Making Test Parts A and B were performed. Adjusted logistic regression models were used to assess the PA-neurocognitive function association. Using longitudinal data, we also assessed the PA category-decline of neurocognitive function association with multivariate simple regression.

RESULTS

Of 601 men, 44% were HIV-infected. Low, moderate, and high PA was reported in 27%, 25%, and 48% of the HIV-infected men vs. 19%, 32% and 49% of the HIV-uninfected men, respectively. High PA was associated with lower odds of impairment of learning, memory, and motor function [odds ratio (OR) ranging from 0.52 to 0.57; P < 0.05 for all]. The high PA-global impairment association OR was 0.63 [95% confidence interval (CI) 0.39, 1.02]. Among HIV-infected men only, across multiple domains, the high PA-impairment association was even more pronounced (OR from 0.27 to 0.49). Baseline high/moderate PA was not associated with decline of any domain score over time. HIV infection was marginally associated with a higher speed of decline in motor function.

CONCLUSIONS

A protective effect of high PA on impairment in neurocognitive domains was observed cross-sectionally. Longitudinal PA measurements are needed to elucidate the PA-neurocognitive function relationship over time.

Ghrelin, Amylin, Gastric Inhibitory Peptide and Cognition in Middle-Aged HIV-Infected and Uninfected Women: The Women's Interagency HIV Study

OBJECTIVE

To explore the gut-brain axis by examining gut hormone levels and cognitive test scores in women with (HIV+) and without (HIV-) HIV infection.

DESIGN/METHODS

Participants included 356 women (248 HIV+, 108 at risk HIV-) in the Brooklyn Women's Interagency HIV Study (WIHS) with measured levels of ghrelin, amylin and gastric inhibitory peptide (GIP), also known as glucose-dependent insulinotropic polypeptide. Cross-sectional analyses using linear regression models estimated the relationship between gut hormones and Trails A, Trails B, Stroop interference time, Stroop word recall, Stroop color naming and reading, and Symbol Digit Modalities Test (SDMT) with consideration for age, HIV infection status, Wide Range Achievement Test score (WRAT), CD4 count, insulin resistance, drug use, and race/ethnicity.

RESULTS

Among women at mid-life with chronic (at least 10 years) HIV infection or among those at risk, ghrelin, amylin and GIP were differentially related to cognitive test performance by cognitive domain. Better performance on cognitive tests was generally associated with higher ghrelin, amylin and GIP levels. However, the strength of association varied, as did significance level by HIV status.

CONCLUSION

Previous analyses in WIHS participants have suggested that higher BMI, waist, and WHR are associated with better cognitive function among women at mid-life with HIV infection. This study indicates that higher gut hormone levels are also associated with better cognition. Gut hormones may provide additional mechanistic insights regarding the association between obesity and Type 2 diabetes and cognition in middle-aged HIV+ and at risk HIV- women. In addition, measuring these hormones longitudinally would add to the understanding of mechanisms of actions of these hormones and their use as potential clinical tools for early identification and intervention on cognitive decline in this vulnerable population.

Neuronal Cell Death and Degeneration through Increased Nitroxidative Stress and Tau Phosphorylation in HIV-1 Transgenic Rats

The underlying mechanisms for increased neurodegeneration and neurocognitive deficits in HIV-infected people are unclear. Therefore, this study was aimed to investigate the mechanisms of increased neurodegeneration in 5-month old male HIV-1 Transgenic (Tg) rats compared to the age- and gender-matched wild-type (WT) by evaluating histological changes and biochemical parameters of the key proteins involved in the cell death signaling and apoptosis. Histological and immunohistochemical analyses revealed decreased neuronal cells with elevated astrogliosis in HIV-1 Tg rats compared to WT. Mechanistic studies revealed that increased levels of nitroxidative stress marker proteins such as NADPH-oxidase, cytochrome P450-2E1 (CYP2E1), inducible nitric oxide synthase (iNOS), the stress-activated mitogen-activated protein kinases such as JNK and p38K, activated cell-cycle dependent CDK5, hypoxia-inducible protein-1α, nitrated proteins, hyperphosphorylated tau, and amyloid plaques in HIV-Tg rats were consistently observed in HIV-1 Tg rats. Confocal microscopy and cell viability analyses showed that treatment with an antioxidant N-acetylcysteine or a specific inhibitor of iNOS 1400W significantly prevented the increased apoptosis of neuro-2A cells by HIV-1 Tat or gp120 protein, demonstrating the causal role of HIV-1 mediated nitroxidative stress and protein nitration in promoting neuronal cell death. Immunoprecipitation and immunoblot analysis confirmed nitration of Hsp90, evaluated as an example of nitrated proteins, suggesting possible involvement of nitrated proteins in neuronal damage. Further, activated p-JNK directly binds tau and phosphorylates multiple amino acids, suggesting an important role of p-JNK in tau hyperphosphorylation and tauopathy. These changes were accompanied with elevated levels of many apoptosis-related proteins Bax and cleaved (activated) caspase-3 as well as proinflammatory cytokines including TNF-α, IL-6 and MCP-1. Collectively, these results indicate that raised nitroxidative stress accompanied by elevated inflammation, cell death signaling pathway including activated p-JNK, C-terminal C99 amyloid fragment formation and tau hyperphosphorylation are responsible for increased apoptosis of neuronal cells and neurodegeneration in 5-month old HIV-Tg rats.

Visceral fat is associated with brain structure independent of human immunodeficiency virus infection status

The combined effects of human immunodeficiency virus (HIV), obesity, and elevated visceral adipose tissue (VAT) on brain structure are unknown. In a cross-sectional analysis of Multicenter AIDS Cohort Study (MACS) participants, we determined associations between HIV serostatus, adiposity, and brain structure. Men (133 HIV+, 84 HIV-) in the MACS Cardiovascular 2 and magnetic resonance imaging (MRI) sub-studies with CT-quantified VAT and whole brain MRI measured within 1 year were assessed. Voxel-based morphometry analyzed brain volumes. Men were stratified by elevated (eVAT, ≥100cm²) or "normal" (nVAT, <100cm²) VAT. Forward stepwise modeling determined associations between clinical and demographic variables and regional brain volumes. eVAT was present in 67% of men. Groups were similar in age and education, but eVAT men were more likely to be HIV+ and have hypertension, diabetes mellitus, body mass index >25 kg/m², smaller gray and white matter volumes, and larger cerebrospinal fluid volume than nVAT men. In multivariate analysis, hypertension, higher adiponectin, higher interleukin-6, age, diabetes mellitus, higher body mass index, and eVAT were associated with brain atrophy (p < 0.05, ordered by increasing strength of association), but HIV serostatus and related factors were generally not. No interactions were observed. Greater VAT was associated with smaller bilateral posterior hippocampus and left mesial temporal lobe and temporal stem white matter volume. Traditional risk factors are more strongly associated with brain atrophy than HIV serostatus, with VAT having the strongest association. However, HIV+ MACS men had disproportionately greater VAT, suggesting the risk for central nervous system effects may be amplified in this population.

Association of midlife smoking status with change in processing speed and mental flexibility among HIV-seropositive and HIV-seronegative older men: the Multicenter AIDS Cohort Study

Smoking is a potential risk factor for age-related cognitive decline. To date, no study has examined the association between smoking and cognitive decline in men living with human immunodeficiency virus (HIV). The aim of this present study is to examine whether smoking status and severity in midlife is associated with a rate of decline in cognitive processing speed among older HIV-seropositive and HIV-seronegative men who have sex with men. Data from 591 older HIV-seropositive and HIV-seronegative men who have sex with men from the Multicenter AIDS Cohort Study were examined. All participants had information on smoking history collected before age 50 years and at least 5 years of follow-up after age 50. Smoking history was categorized as never smoker, former smoker, and current smoker and cumulative pack years was calculated. The raw scores of three neuropsychological tests (Trail Making A, Trail Making B, and Symbol Digit Modalities tests) were log transformed (Trail Making A and B) and used in linear mixed models to determine associations between smoking history and at least subsequent 5-year decline in cognitive processing speed. There were no significant differences in the rates of neurological decline among never smokers, former smokers, and current smokers. Findings were similar among HIV-seropositive participants. However, an increase of 5 pack-years was statistically significantly associated with a greater rate of decline in the Trail Making Test B score and Composite Score (β -0.0250 [95% CI, -0.0095 to -0.0006] and -0.0077 [95% CI, -0.0153 to -0.0002], respectively). We found no significant association between smoking treated as a categorical variable (never smoked, former smoker, or current smoker) and a small change in every increase of 5 pack-years on measures of psychomotor speed and cognitive flexibility. To optimize healthy aging, interventions for smoking cessation should be tailored to men who have sex with men.

Prevalence and Correlates of Persistent HIV-1 RNA in Cerebrospinal Fluid During Antiretroviral Therapy

BACKGROUND

 Neurocognitive disorders remain common among human immunodeficiency virus (HIV)-positive adults, perhaps owing to persistent HIV-1 RNA in cerebrospinal fluid (CSF) during antiretroviral therapy (ART).

METHODS

 Using a single-copy assay, we measured HIV-1 RNA levels in CSF and plasma specimens from 220 HIV-positive adults who were taking suppressive ART. Fifty-five participants were tested twice.

RESULTS

 HIV-1 RNA was detected in 42.3% of CSF and 65.2% of plasma samples. Correlates of higher CSF HIV-1 RNA levels included higher nadir and current CD4⁺ T-cell counts, a plasma HIV-1 RNA level of ≥ 1 copy/mL, and a lower central nervous system penetration-effectiveness score (model P < .001). Worse neurocognitive performance was associated with discordance in HIV-1 RNA detection between plasma and CSF, lower overall CSF HIV-1 RNA level, and longer ART duration, among others (model P < .001). In the longitudinal subgroup, CSF HIV-1 RNA persisted in most participants (69%) over 7 months.

CONCLUSIONS

 Low-level HIV-1 RNA in CSF is common during suppressive ART and is associated with low-level HIV-1 RNA in blood, better immune status, and lower ART drug distribution into CSF. The association between HIV-1 RNA discordance and HIV-associated neurocognitive disorder (HAND) may reflect compartmentalization. The relationship between HAND, lower HIV-1 RNA levels in CSF, and lower CD4⁺ T-cell counts may reflect disturbances in the immune response to HIV-1 in the CNS.

Lipid Profiles and APOE4 Allele Impact Midlife Cognitive Decline in HIV-Infected Men on Antiretroviral Therapy

Elevated cholesterol and APOE ε4 genotype were independent risk factors for cognitive decline in antiretroviral therapy–adherent human immunodeficiency virus (HIV)-infected men aged 50–65 years, whereas higher high-density lipoprotein attenuated cognitive decline. Treatment of dyslipidemia may reduce midlife cognitive decline among HIV-infected individuals.

Background. Dyslipidemia and apolipoprotein E4 (APOEϵ4) allele are risk factors for age-related cognitive decline, but how these risks are modified by human immunodeficiency virus (HIV) infection is unclear.

Methods. In a longitudinal nested study from the Multicenter AIDS Cohort Study, 273 HIV type 1–infected (HIV⁺) men aged 50–65 years with baseline HIV RNA <400 copies/mL and on continuous antiretroviral therapy (ART) in ≥95% of follow-up visits were matched by sociodemographic variables to 516 HIV-uninfected (HIV^–) controls. The association between lipid markers (total cholesterol, low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], and triglycerides), APOE genotype, and cognitive decline in HIV infection was examined using mixed-effects models.

Results. The median baseline age of participants was 51, 81% were white, and 89% had education >12 years. HIV⁺ men had similar baseline total cholesterol and LDL-C, but lower HDL-C and higher triglycerides than controls (P < .001). Higher total cholesterol and LDL-C were associated with faster rates of cognitive decline (P < .01), whereas higher HDL-C attenuated decline (P = .02) in HIV⁺ men. In HIV⁺ men with elevated cholesterol, statin use was associated with a slower estimated rate of decline (P = .02). APOEϵ4 genotype accelerated cognitive decline in HIV⁺ but not HIV^– men (P = .01), with trajectories diverging from HIV^– ε4 carriers after age 50. Total cholesterol levels did not modify the association of ϵ4 genotype with decline (P = .9).

Conclusions. Elevated cholesterol and APOEϵ4 genotype are independent risk factors for cognitive decline in ART-adherent HIV⁺ men aged >50 years. Treatment of dyslipidemia may be an effective strategy to reduce cognitive decline in older HIV⁺ individuals.

CROI 2016: Neurologic Complications of HIV Infection

The brain remains a major target for HIV infection and a site of potential complications for HIV-infected individuals. Emerging data presented at the 2016 Conference on Retroviruses and Opportunistic Infections suggest that during the early stages of infection, activated CD4+ cells may traffic the virus into the central nervous system (CNS). HIV is detectable in cells and tissues of the CNS in some individuals despite suppressive antiretroviral treatment. A potential source of cerebrospinal fluid HIV escape may be compartmentalized HIV replication within macrophage lineage cells. Virally infected cells can traffic out of the CNS and may have the potential to reseed the systemic compartment. Additional modifiers of HIV-associated neurocognitive disorder (HAND) were identified, including female sex and hepatic dysfunction. Large epidemiologic studies reported an elevated risk of stroke among HIV-infected individuals, related to traditional vascular risk factors, history of recreational drug use, and HIV measures (lower CD4+ cell nadir and higher viral load). Brain imaging may provide a noninvasive means for detecting early changes in the brain associated with HIV infection and may assist in prognosis of HAND. Some potential adjunctive therapies to standard antiretroviral therapy for HIV-infected individuals were considered.

Determinants of reduced cognitive performance in HIV-1-infected middle-aged men on combination antiretroviral therapy

OBJECTIVE

The spectrum of risk factors for HIV-associated cognitive impairment is likely very broad and includes not only HIV/antiretroviral therapy-specific factors but also other comorbid conditions. The purpose of this current study was to explore possible determinants for decreased cognitive performance.

DESIGN AND METHODS

Neuropsychological assessment was performed on 103 HIV-1-infected men with suppressed viraemia on combination antiretroviral therapy for at least 12 months and 74 HIV-uninfected highly similar male controls, all aged at least 45 years. Cognitive impairment and cognitive performance were determined by multivariate normative comparison (MNC). Determinants of decreased cognitive performance and cognitive impairment were investigated by linear and logistic regression analysis, respectively.

RESULTS

Cognitive impairment as diagnosed by MNC was found in 17% of HIV-1-infected men. Determinants for decreased cognitive performance by MNC as a continuous variable included cannabis use, history of prior cardiovascular disease, impaired renal function, diabetes mellitus type 2, having an above normal waist-to-hip ratio, presence of depressive symptoms, and lower nadir CD4⁺ cell count. Determinants for cognitive impairment, as dichotomized by MNC, included cannabis use, prior cardiovascular disease, impaired renal function, and diabetes mellitus type 2.

CONCLUSION

Decreased cognitive performance probably results from a multifactorial process, including not only HIV-associated factors, such as having experienced more severe immune deficiency, but also cardiovascular/metabolic factors, cannabis use, and depressive symptoms.

HIV-associated neurocognitive disorder--pathogenesis and prospects for treatment

In the past two decades, several advancements have improved the care of HIV-infected individuals. Most importantly, the development and deployment of combination antiretroviral therapy (CART) has resulted in a dramatic decline in the rate of deaths from AIDS, so that people living with HIV today have nearly normal life expectancies if treated with CART. The term HIV-associated neurocognitive disorder (HAND) has been used to describe the spectrum of neurocognitive dysfunction associated with HIV infection. HIV can enter the CNS during early stages of infection, and persistent CNS HIV infection and inflammation probably contribute to the development of HAND. The brain can subsequently serve as a sanctuary for ongoing HIV replication, even when systemic viral suppression has been achieved. HAND can remain in patients treated with CART, and its effects on survival, quality of life and everyday functioning make it an important unresolved issue. In this Review, we describe the epidemiology of HAND, the evolving concepts of its neuropathogenesis, novel insights from animal models, and new approaches to treatment. We also discuss how inflammation is sustained in chronic HIV infection. Moreover, we suggest that adjunctive therapies--treatments targeting CNS inflammation and other metabolic processes, including glutamate homeostasis, lipid and energy metabolism--are needed to reverse or improve HAND-related neurological dysfunction.

Circulating HIV DNA Correlates With Neurocognitive Impairment in Older HIV-infected Adults on Suppressive ART

Older HIV-infected adults have a higher risk of neurocognitive impairment, but the underlying mechanisms are poorly understood. Here, we investigated the associations between levels of HIV DNA in peripheral blood, soluble markers of inflammation and cellular trafficking in blood and cerebrospinal fluid (CSF) and neurocognitive functioning among 18 younger (22–40 years) and 26 older (50–71 years) HIV-infected subjects, who were administered a comprehensive neurocognitive battery. Older HIV-infected individuals presented higher levels of inflammation in CSF and blood compared to younger individuals, but no difference was observed in HIV DNA levels. Among older participants, higher HIV DNA levels were significantly associated with more severe neurocognitive impairment (p = 0.005), particularly in the Executive Functions domain (p = 0.004). No association was observed between HIV DNA and neurocognition among younger individuals. Despite significantly increased inflammation observed in the older group, none of the inflammatory markers were associated with neurocognitive impairment among older HIV+ individuals (p > 0.05). Our study supports the involvement of peripheral HIV DNA reservoir in the pathogenesis of neurocognitive disorder during suppressive ART. Correlates of neurocognitive impairment might differ between younger and older adults, suggesting that future treatment and prevention strategies for HIV-associated neurocognitive disorders likely need to be tailored based on age.

Executive Dyscontrol of Learning and Memory: Findings from a Clade C HIV-positive South African Sample

OBJECTIVE

Although pre-clinical work suggests there might be differences in neurovirulence across HIV-1 clades, few studies investigate neuropsychological deficits in the globally predominant clade C infection. The purpose of this study was to investigate verbal learning and memory performance in HIV-positive individuals in Cape Town, South Africa, where clade C is the most prevalent subtype of the virus.

METHOD

Using a case-control design, we recruited 53 isiXhosa-speaking, cART-naïve HIV-positive adults and 53 demographically matched HIV-negative controls. Participants were administered a comprehensive neuropsychological test battery. The test of interest was the Hopkins Verbal Learning Test-Revised (HVLT-R); previous studies have used that instrument to identify executive dyscontrol of verbal learning and memory processes in clade B HIV-positive participants.

RESULTS

HIV-positive participants showed only partial impairment on the HVLT-R's learning/memory components (e.g., they recalled significantly fewer words across learning trials, but displayed relatively intact performance on delayed recall trials). They also displayed little executive dyscontrol over encoding and retrieval processes (e.g., there were no significant between-group differences on measures of semantic or serial clustering).

CONCLUSIONS

Post-cART era studies suggest that verbal learning and memory performance is impaired in clade B samples, at least partially due to executive dyscontrol over encoding and retrieval processes. We found few such impairments in the current clade C sample. These preliminary findings suggest different CNS vulnerability across clades that would have implications for delineating clade-specific neuropathological and neurocognitive clinical features.

Factors associated with neurocognitive test performance at baseline: a substudy of the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

We describe neuropsychological test performance (NP) in antiretroviral treatment (ART)-naïve HIV-positive individuals with CD4 cell counts above 500 cells/μL.

METHODS

In a neurology substudy of the International Network for Strategic Initiatives in Global HIV Trials (INSIGHT) Strategic Timing of AntiRetroviral Treatment (START) study, eight neurocognitive tests were administered. The primary measure of NP was the quantitative NP z-score (QNPZ-8), the average of the z-scores for the eight tests. Associations of baseline factors with QNPZ-8 scores were assessed by multiple regression. Mild neurocognitive impairment (NCI) was defined as z-scores < -1 in at least two of six cognitive domains.

RESULTS

A total of 608 participants had a median age of 34 years; 11% were women and 15% were black; the median time since HIV diagnosis was 0.9 years; the median CD4 cell count was 633 cells/μL; 19.9% had mild NCI. Better NP was independently associated with younger age, being white, higher body mass index (0.10 per 10 kg/m(2) higher), and higher haematocrit percentage (0.19 per 10% higher). Worse NP was associated with longer time since HIV diagnosis (-0.17 per 10 years), diabetes (-0.29) and higher Framingham risk score (-0.15 per 10 points higher). QNPZ-8 scores differed significantly between geographical locations, with the lowest scores in Brazil and Argentina/Chile.

CONCLUSIONS

This is the largest study of NP in ART-naïve HIV-positive adults with CD4 counts > 500 cells/μL. Demographic factors and diabetes were most strongly associated with NP. Unmeasured educational/sociocultural factors may explain geographical differences. Poorer NP was independently associated with longer time since HIV diagnosis, suggesting that untreated HIV infection might deleteriously affect NP, but the effect was small.

Does Older Age Confer an Increased Risk of Incident Neurocognitive Disorders Among Persons Living with HIV Disease?

OBJECTIVE

This study aimed to determine the combined effects of age and HIV infection on the risk of incident neurocognitive disorders.

METHOD

A total of 146 neurocognitively normal participants were enrolled at baseline into one of four groups based on age (≤ 40 years and ≥ 50 years) and HIV serostatus resulting in 24 younger HIV-, 27 younger HIV+, 39 older HIV-, and 56 older HIV+ individuals. All participants were administered a standardized clinical neuropsychological battery at baseline and 14.3 ± .2 months later.

RESULTS

A logistic regression predicting incident neurocognitive disorders from HIV, age group, and their interaction was significant (χ(2)[4] = 13.56, p = .009), with a significant main effect of HIV serostatus (χ(2)[1] = 5.01, p = .025), but no main effect of age or age by HIV interaction (ps > .10). Specifically, 15.7% of the HIV+ individuals had an incident neurocognitive disorder as compared to 3.2% of the HIV- group (odds ratio = 4.8 [1.2, 32.6]). Among older HIV+ adults, lower baseline cognitive reserve, prospective memory, and verbal fluency each predicted incident neurocognitive disorders at follow-up.

CONCLUSIONS

Independent of age, HIV infection confers a nearly fivefold risk for developing a neurocognitive disorder over approximately one year. Individuals with lower cognitive reserve and mild weaknesses in higher-order neurocognitive functions may be targeted for closer clinical monitoring and preventative measures.

Human immunodeficiency virus has similar effects on brain volumetrics and cognition in males and females

Most studies that have examined neuropsychological impairments associated with human immunodeficiency virus (HIV) have focused on males, yet females represent one of the largest groups of newly infected patients. Further, few studies have examined neuropsychological performance and neuroimaging outcomes among females compared to males in the modern era of highly active anti-retroviral therapy (HAART). The present study investigated neuropsychological performance and brain volumetrics among HIV+ males (n = 93) and females (n = 44) on stable HAART compared to HIV seronegative (HIV-) males (n = 42) and females (n = 49). Results revealed a significant effect of HIV on neuropsychological performance and neuroimaging measures. An effect of gender, independent of HIV status, was also observed for neuroimaging measures but not neuropsychological performance. Additionally, no significant differences in neuropsychological performance or brain volumetrics were seen between HIV+ males and females. No significant interaction was observed between HIV and gender on either neuropsychological or neuroimaging indices. Our results suggest that both HIV+ males and females treated with HAART experience similar outcomes in terms of brain integrity.

SL, Woods SP, Grant I, Jeste DV, Moore DJ. Physical Activity is Associated with Better Neurocognitive and Everyday Functioning Among Older Adults with HIV Disease

We examined the association between physical activity (PA), neurocognitive impairment (NCI), and instrumental activities of daily living (IADLs) among older HIV+ persons. One hundred older HIV+ adults completed the International Physical Activity Questionnaire, a neurocognitive battery, and IADL scale. Higher levels of moderate PA were associated with lower odds of NCI (p = 0.01), even when covariates were modeled. The association between moderate PA and NCI was driven by executive function (p = 0.04). Higher levels of moderate PA were also associated with lower odds of IADL Dependence (p = 0.03), although this fell to a trend (p = 0.08) when including covariates. Follow-up analysis showed those with both NCI and IADL Dependence had lower moderate PA than those with neither (p = 0.03). While these cross-sectional findings suggest PA is associated with better neurocognitive and everyday functioning in older HIV+ adults, longitudinal studies utilizing objective PA methods are needed to evaluate directionality and mechanisms.

Plasma and Cerebrospinal Fluid Biomarkers Predict Cerebral Injury in HIV-Infected Individuals on Stable Combination Antiretroviral Therapy

OBJECTIVES

HIV-associated brain injury persists despite combination antiretroviral therapy, but contributing factors remain poorly understood. We postulated that inflammation-associated biomarkers will be associated with cerebral injury on proton magnetic resonance spectroscopy in chronically HIV-infected subjects.

METHODS

Five biomarkers were measured in 197 HIV-infected subjects: soluble CD14, MCP-1, IP-10, MIP-1β, and fractalkine. Levels of N-acetyl aspartate (NAA), Choline (Cho), Myoinositol (MI), Glutamate + Glutamine (Glx), and Creatine (Cr) were acquired in the midfrontal cortex (MFC), frontal white matter, and basal ganglia (BG). Predictive models were built through linear regression, and the best models were chosen using the Akaike Information Criterion.

RESULTS

Increases in plasma or CSF MCP-1 were associated with lower NAA/Cr in the MFC and BG, whereas metabolite changes in the frontal white matter for NAA/Cr, GlxCr, and Cho/Cr were explained almost exclusively by a single factor, sCD14. Plasma and CSF levels of this factor were also significantly associated with Glx/Cr in MFC and BG. Higher CSF FKN was associated with higher NAA/Cr in BG. Best predictors for higher Cho/Cr in BG and MFC were CSF sCD14 and CSF MIP-1β. Plasma and CSF IP-10 were only associated with Cho/Cr in MFC. Of the 3 models that simultaneously accounted for both plasma and CSF, there were more associations between CSF biomarkers and magnetic resonance spectroscopy metabolites.

CONCLUSIONS

Markers of inflammation and immune activation, in particular MCP-1 and sCD14, predominantly reflecting CNS sources, contribute to the persistence of brain injury in a metabolite and region-dependent manner in chronically HIV-infected patients on stable combination antiretroviral therapy.

Is the atherosclerotic process accentuated under conditions of HIV infection, antiretroviral therapy, and protease inhibitor exposure? Meta-analysis of the markers of arterial structure and function

OBJECTIVE

To evaluate the apparent association of human immunodeficiency virus (HIV) infection, antiretroviral therapy (ART), and protease inhibitor (PI) exposure with the functional and structural markers of vasculature.

METHODS

A meta-analysis of the relationship between HIV infection, ART, and PI exposure and the functional and structural markers of vasculature. A systematic literature search was performed electronically using specific eligibility criteria. Weighted mean difference (WMD) and corresponding 95% confidence interval (CI) were calculated and combined appropriately.

RESULTS

Fifty-seven articles were included with nine different outcomes. Compared with HIV-negative patients, HIV-positive patients demonstrated significant elevated intima-media thickness (IMT) (WMD (95% CI) = 0.042 (0.028-0.057)), increased pulse wave velocity (PWV) (0.538 (0.283-0.792)), and reduced flow-mediated vasodilation (FMD) (-2.049 (-2.806 to -1.293)). Elevated IMT was observed in HIV patients receiving ART when compared with those naïve to ART in the 20- to 40-year-old age group (0.078 (0.033-0.123)), the >40-year-old age group (0.038 (0.018-0.057)), and the group comprising >50% males (0.070 (0.041-0.099)). In addition, ART resulted in an increased PWV in HIV patients receiving ART in the group with >50% male proportion (0.628 (0.405-0.851)). HIV patients exposed to PI showed a significant trend toward elevated IMT (0.033 (0.007-0.058)) and increased PWV (0.264 (0.118-0.410)) compared with those without PI exposure.

CONCLUSIONS

The atherosclerotic process was accentuated by elevated IMT, increased PWV, and reduced FMD under condition of HIV infection. Comparison of ART-receiving with ART-naïve patients showed a significant trend toward elevated IMT and increased PWV, especially under treatment with PI-containing drugs.

Diabetes and cognitive decline in a French cohort of patients infected with HIV-1

OBJECTIVE

We investigated the relationship of diabetes and prediabetes with cognitive performances, assessed through raw test and z scores and according to neurocognitive impairment (NCI) classification in a cohort of individuals infected with HIV.

METHODS

The ANRS CO3 Aquitaine cohort is a prospective hospital-based cohort of HIV-1-infected patients under routine clinical management in 6 public hospitals in southwestern France. Between 2007 and 2009, an ancillary study consisted of a neuropsychological battery of 10 tests at baseline and 2-year follow-up. The severity of NCI (normal, asymptomatic, mild, HIV dementia) was assessed according to international guidelines.

RESULTS

At baseline (400 patients, 33 with prediabetes, 39 with diabetes), in cross-sectional multivariable analyses, patients with diabetes performed significantly worse on 9 neuropsychological tests that assessed memory, executive functions, attention, psychomotor speed, language, and manual dexterity. Participants with prediabetes had worse performances compared with those who had normal glycemia in 5 tests. The longitudinal analysis of the association between glycemia status at baseline and change in cognitive performances over 2-year follow-up (n = 283) suggested that patients with diabetes also showed a slightly higher decline on 5 of the 10 tests, those involving executive functions and memory functioning. Glycemia status at baseline was not significantly associated with NCI severity in cross-sectional (p = 0.44) and longitudinal (p = 0.64) analyses.

CONCLUSIONS

In this hospital-based cohort of people living with HIV, diabetes, but not the other cardiovascular risk factors, is associated with worse cognitive performances in several cognitive domains and with larger decline in fewer domains over the short term.

Elevated rates of mild cognitive impairment in HIV disease

With the rising number of individuals in their 50s and 60s who are infected with HIV, concerns have emerged about possible increases in the rates of non-HIV-associated dementias. The current study examined the prevalence of mild cognitive impairment (MCI) in older HIV-infected adults, since MCI is an intermediate state between typical cognitive aging and dementia that emerges in this age range. Participants included 75 adults with HIV disease aged 50 years and older who were on combination antiretroviral therapy (cART) and had undetectable plasma viral loads and 80 demographically similar HIV-seronegative comparison subjects. Participants completed a research neuropsychological evaluation that was used to classify MCI according to the comprehensive diagnostic scheme described by Bondi et al. (J Alzheimers Dis 42:275-289, 2014). HIV-infected persons were over seven times more likely to have an MCI designation (16 %) than their seronegative counterparts (2.5 %). Within the HIV+ cohort, MCI had minimal overlap with diagnoses of asymptomatic neurocognitive impairment and was significantly associated with older age, lower Karnofsky Scale of Performance Scores, and mild difficulties performing instrumental activities of daily living (iADLs). HIV infection in older adults is associated with a notably elevated concurrent risk of MCI, which may increase the likelihood of developing non-HIV-associated dementias as this population ages further.

HIV effects on age-associated neurocognitive dysfunction: premature cognitive aging or neurodegenerative disease?

Marked improvements in survival and health outcome for people infected with HIV have occurred since the advent of combination antiretroviral therapy over a decade ago. Yet HIV-associated neurocognitive disorders continue to occur with an alarming prevalence. This may reflect the fact that infected people are now living longer with chronic infection. There is mounting evidence that HIV exacerbates age-associated cognitive decline. Many middle-aged HIV-infected people are experiencing cognitive decline similar that to that found among much older adults. An increased prevalence of vascular and metabolic comorbidities has also been observed and is greatest among older adults with HIV. Premature age-associated neurocognitive decline appears to be related to structural and functional brain changes on neuroimaging, and of particular concern is the fact that pathology indicative of neurodegenerative disease has been shown to occur in the brains of HIV-infected people. Yet notable differences also exist between the clinical presentation and brain disturbances occurring with HIV and those occurring in neurodegenerative conditions such as Alzheimer’s disease. HIV interacts with the aging brain to affect neurological structure and function. However, whether this interaction directly affects neurodegenerative processes, accelerates normal cognitive aging, or contributes to a worsening of other comorbidities that affect the brain in older adults remains an open question. Evidence for and against each of these possibilities is reviewed.

HIV-associated neurocognitive disorders: the relationship of HIV infection with physical and social comorbidities

The prevalence of HIV (human immunodeficiency virus) associated neurocognitive disorders (HAND) will undoubtedly increase with the improved longevity of HIV-infected persons. HIV infection, itself, as well as multiple physiologic and psychosocial factors can contribute to cognitive impairment and neurologic complications. These comorbidities confound the diagnosis, assessment, and interventions for neurocognitive disorders. In this review, we discuss the role of several key comorbid factors that may contribute significantly to the development and progression of HIV-related neurocognitive impairment, as well as the current status of diagnostic strategies aimed at identifying HIV-infected individuals with impaired cognition and future research priorities and challenges.

HIV-associated neurocognitive disorders: Five new things

HIV-associated neurocognitive disorders (HAND) remain an important cause of cognitive dysfunction. Current nomenclature for HAND includes HIV-associated dementia and milder forms known as asymptomatic neurocognitive impairment (ANI) and mild neurocognitive disorder (MND). ANI and MND remain highly prevalent despite combined antiretroviral therapy (cART). These mild forms of HAND must be diagnosed through neuropsychological testing. If a patient has HAND, it remains unclear whether using a cART regimen with theoretically superior CNS penetration improves the prognosis. Nevertheless, a CNS penetration effectiveness score for antiretrovirals is available. Other factors to consider when diagnosing and treating HIV infection and HAND include the HIV clade or subtype. Data suggest that HAND occurs more often in association with certain clades, and higher vigilance for cognitive dysfunction may be recommended. Finally, comorbidities, such as diseases associated with advanced age, other infections, and drug abuse, need to be considered as cofactors for cognitive dysfunction and treated accordingly.

Proteinuria is associated with neurocognitive impairment in antiretroviral therapy treated HIV-infected individuals

BACKGROUND

Proteinuria is a marker of vascular dysfunction that predicted increased cardiovascular mortality and is associated with neurocognitive impairment (NCI) in population-based studies. We examined associations between proteinuria and HIV-associated NCI.

METHODS

Multivariable logistic regression was used to examine associations between NCI at the first neurocognitive assessment (baseline) and simultaneous, clinically significant proteinuria [as random spot urine protein-to-creatinine ratios (UP/Cr) ≥200 mg/g] in a prospective multicenter observational cohort study. Generalized estimating equations were used to examine associations between baseline proteinuria and subsequent NCI among subjects without NCI at baseline. NCI was defined as a Z-score, derived from the combination of normalized scores from the Trailmaking A and B and the Wechsler Adult Intelligence Scale-Revised Digit Symbol tests.

RESULTS

A total of 1972 subjects were included in this analysis. Baseline proteinuria was associated with increased odds of NCI [odds ratio (OR): 1.41, 95% confidence interval (CI): 1.08 to 1.85; P = 0.01] and with subsequent NCI among subjects without NCI at baseline (OR: 1.39, 95% CI: 1.01 to 1.93; P = 0.046) in multivariable models adjusted for risk factors and potential confounders. Similar associations were evident when these analyses were limited to visits at which time study subjects maintained plasma HIV RNA levels <200 copies per milliliter.

CONCLUSIONS

The association between proteinuria and NCI observed in this study adds to a growing body of evidence implicating contributions by vascular disease to NCI in antiretroviral treated individuals. Studies examining interventions that improve vascular function are warranted.

Baseline CD4(+) T-cell count and cardiovascular risk factors predict the evolution of cognitive performance during 2-year follow-up in HIV-infected patients

BACKGROUND

The aim of our study was to better understand the dynamics between cardiovascular risk factors and immunological parameters in the evolution of cognitive performance in HIV+ patients.

METHODS

We conducted a prospective longitudinal study, consecutively enrolling asymptomatic HIV+ subjects during routine outpatient visits at two clinical centres. At baseline and after 2 years, all patients underwent a comprehensive neuropsychological battery. Common carotid intima-media thickness (cIMT) was also measured.

RESULTS

A total of 150 patients completed the study (77% males, median age 46 years, 20% with past AIDS-defining events, 95% on cART, 88% with HIV-RNA<50 copies/ml). After a 2-year follow-up, there was no difference in the proportion of patients with cognitive impairment (32% versus 33% at baseline; P=1.00). However, a significantly worse memory performance was observed (z score mean change -0.51, sd 1.05; P=0.001). At multivariate analysis, baseline dyslipidaemia (OR 2.7, 95% CI 1.1, 7.1; P=0.037) showed a significant association with a higher risk of memory impairment at 2-year follow-up, while higher baseline CD4(+) T-cell count (OR 0.80 per 100 cells/μl higher; 95% CI 0.66, 0.97; P=0.026) was found to be a protective factor, adjusting for the presence of a memory impairment at baseline. When the analysis was restricted to patients who did not change antiretroviral therapy during the study period (n=109), baseline cIMT (OR 14.6 per 0.1 mm higher; 95% CI 1.1, 189.9; P=0.041) also emerged as an independent risk factor for memory impairment at 2-year follow-up.

CONCLUSIONS

Immunological parameters and cardiovascular risk factors are independently associated with the evolution of cognitive status in HIV+ patients.

Factors related to HIV-associated neurocognitive impairment differ with age

Over 50% of HIV-infected (HIV+) persons are expected to be over age 50 by 2015. The pathogenic effects of HIV, particularly in cases of long-term infection, may intersect with those of age-related illnesses and prolonged exposure to combined antiretroviral therapy (cART). One potential outcome is an increased prevalence of neurocognitive impairment in older HIV+ individuals, as well as an altered presentation of HIV-associated neurocognitive disorders (HANDs). In this study, we employed stepwise regression to examine 24 features sometimes associated with HAND in 40 older (55-73 years of age) and 30 younger (32-50 years of age) HIV+, cART-treated participants without significant central nervous system confounds. The features most effective in generating a true assessment of the likelihood of HAND diagnosis differed between older and younger cohorts, with the younger cohort containing features associated with drug abuse that were correlated to HAND and the older cohort containing features that were associated with lipid disorders mildly associated with HAND. As the HIV-infected population grows and the demographics of the epidemic change, it is increasingly important to re-evaluate features associated with neurocognitive impairment. Here, we have identified features, routinely collected in primary care settings, that provide more accurate diagnostic value than a neurocognitive screening measure among younger and older HIV individuals.

Clinical practice guideline for the management of chronic kidney disease in patients infected with HIV: 2014 update by the HIV Medicine Association of the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.