The synergistic effects of HIV, diabetes, and aging on cognition: implications for practice and research

Mechanisms underlying HIV-associated cognitive impairment and emerging therapies for its management

People living with HIV are affected by the chronic consequences of neurocognitive impairment (NCI) despite antiretroviral therapies that suppress viral replication, improve health and extend life. Furthermore, viral suppression does not eliminate the virus, and remaining infected cells may continue to produce viral proteins that trigger neurodegeneration. Comorbidities such as diabetes mellitus are likely to contribute substantially to CNS injury in people living with HIV, and some components of antiretroviral therapy exert undesirable side effects on the nervous system. No treatment for HIV-associated NCI has been approved by the European Medicines Agency or the US Food and Drug Administration. Historically, roadblocks to developing effective treatments have included a limited understanding of the pathophysiology of HIV-associated NCI and heterogeneity in its clinical manifestations. This heterogeneity might reflect multiple underlying causes that differ among individuals, rather than a single unifying neuropathogenesis. Despite these complexities, accelerating discoveries in HIV neuropathogenesis are yielding potentially druggable targets, including excessive immune activation, metabolic alterations culminating in mitochondrial dysfunction, dysregulation of metal ion homeostasis and lysosomal function, and microbiome alterations. In addition to drug treatments, we also highlight the importance of non-pharmacological interventions. By revisiting mechanisms implicated in NCI and potential interventions addressing these mechanisms, we hope to supply reasons for optimism in people living with HIV affected by NCI and their care providers.

Neurocognitive Impairment and Associated Factors Among People Living with HIV: A Systematic Review and Meta-Analysis of African Studies

Background

Neurocognitive impairment (NCI) is one of the most common neurological complications in HIV-positive individuals, particularly in resource-limited countries. Neurocognitive impairments can occur at any stage of HIV infection, although the risk increases as the infection progresses. However, in Africa, there are few studies with highly variable and inconsistent results. Therefore, this study aimed to determine the prevalence and factors associated with NCI among HIV-positive people in Africa.

Methods

For this systematic review and meta-analysis, we used PubMed/Medline, Scopus, Web of Science, the Cochrane Library, Embase, and PsycINFO to comprehensively search a number of papers. Studies reporting the prevalence of NCI and its factors were included in the estimation of the pooled prevalence. A consistent data extraction format was created in Microsoft Excel to extract the data, which was then imported into STATA 11 statistical software for analysis. The heterogeneity was evaluated using the I2 test, and a random effect meta-analysis model was employed to calculate the pooled prevalence of NCI because the included studies showed significant heterogeneity.

Results

In all, Africa had a pooled prevalence of NCI of 45.15% (95% CI: 36.86, 53.43). According to the subgroup analysis of this study, West Africa had the lowest frequency, at 42.40% (95% CI: 22.03, 62.77), whereas Central and South Africa had the highest prevalence, at 49.33% (95% CI: 10.72-87.95).

Conclusion

In Africa, the cumulative prevalence of NCI was high. Being a woman, not having a formal education, those with only an elementary education, being older, having late-stage HIV, and abusing drugs were all often associated with NCI. The average burden of NCI in Africa is high and that would be a significant figure for interventional actions in the area.

Effects of aerobic exercise on quality of life of people with HIV-associated neurocognitive disorder on antiretroviral therapy: a randomised controlled trial

BACKGROUND

HIV-associated neurocognitive disorder (HAND) negatively impacts quality of life (QoL) of people living with HIV who are on antiretroviral therapy (ART). Behavioural intervention adjunct to ART may improve QoL of people with HAND. We determine the effect of a 12-week aerobic exercise programme on QoL in people with HAND who were receiving ART.

TRIAL DESIGN

This was a parallel-group, randomised controlled trial with concealed allocation and intention-to-treat analysis.

METHODS

We identified 73 participants diagnosed with HAND. Participants were sampled from an earlier study that examined the prevalence of HAND according to the Frascati criteria. Participants were randomised and allocated to an intervention of 12-weeks of aerobic exercise, comprising three 20-60 min sessions per week of moderate-intensity aerobic exercise using a cycle ergometer. The primary outcome was QoL, which was evaluated using the World Health Quality of Life Questionnaire (WHOQoL)-BREF.

RESULTS

Participants in the exercise (n = 39) and control (n = 35) groups had similar sociodemographic characteristics (p > 0.05). Following the 12-week aerobic exercise programme, participants in the exercise group had improved physical (p < 0.001), psychological (p = 0.008) and environmental (p = 0.001) domains of the QoL (p = 0.001) and overall QoL (p = 0.001) relative to the control group. Similarly, participants in the exercise group had lower depression scores than participants in the control group. Depression scores in the exercise group were still lower 3 months post-intervention (p = 0.007). Only the improvements in physical (p = 0.02) and psychological (p = 0.007) domains of QoL were sustained at 3 months post-intervention.

CONCLUSIONS

Aerobic exercise improves the QoL of people with HAND. To ensure sustained benefits, people with HAND may need to engage in long-term physical exercise. Trial registration The trial is registered with the PAN African Trial Registry (PACTR). Date: 01/09/2020, ID: PACTR202009483415745.

A systematic review and meta-analysis of HIV associated neurocognitive disorders (HAND) among people with HIV in Ethiopia

Background

Ethiopia, being in the Sub Saharan region of Africa, is one of the countries with a substantial burden of HIV infection. Because of the high burden of HIV and poor health care settings, HAND is prevalent as demonstrated in various cross-sectional studies. However, no review has been conducted to report the consolidated magnitude of HAND among people with HIV in Ethiopia. Therefore, this systematic review and meta-analysis aimed to estimate the prevalence of HAND in Ethiopia.

Methods

Following the PRISMA guidelines, we systematically reviewed and meta-analyzed studies that investigated the prevalence of HAND in Ethiopia from PubMed, Google Scholar, Science Direct, HINARI, EMBASE, and Cochrane library databases. We also looked at the reference lists of the included studies to include other relevant studies. Subgroup analysis was performed based on publication year, study location, and sample size. Heterogeneity across studies was evaluated using the I2 test. Potential publication bias was assessed using Egger’s test and visual inspection of symmetry in the funnel plots.

Results

In the present meta-analysis, 627 articles were initially identified and evaluated. Of these, 8 studies that met the inclusion criteria were included in the final analysis. The pooled prevalence of HAND in people with HIV in Ethiopia was 39.15% (95% CI 29.36, 48.94). The highest prevalence observed in the Southern Nations, Nationalities, and Peoples’ Region (SNNPR) with 53.20% (95% CI 25.96, 80.44) followed by others 34.87% (Tigray, Addis Ababa, and Oromia) (95% CI 33.49, 36.24) and Amhara 34.07% (95% CI 25.39, 42.74).The funnel plot was asymmetrical. However, Egger’s regression tests provided no evidence of publication bias in the prevalence of HAND.

Conclusion

In this meta-analysis, the pooled prevalence of HAND, in Ethiopia, was high. Older age, substance use, advanced stages of the disease, and lack of education were the main determinants of HAND in Ethiopia. Health education, early screening of people with HIV, and training of health professionals working in hospitals on HAND are highly recommended.

Driving habits, cognition, and health-related quality of life in middle-aged and older adults with HIV

Cognitive impairment is known to increase with aging in people living with HIV (PLWH). Impairment in cognitive domains required for safe driving may put PLWH at risk for poor driving outcomes, decreased mobility, and health-related quality of life (HRQoL). This study described the driving behaviors of middle-aged and older PLWH and examined correlations between driving behaviors and cognitive functioning (Aim 1), and driving behaviors and HRQoL domains (Aim 2). A sample of 260 PLWH ages 40 and older completed a comprehensive assessment including a battery of cognitive tests, an HRQoL measure, and a measure of self-reported driving habits. Associations between driving habits, cognitive function, and HRQoL domains were examined. While 212 (81.54%) participants reported currently driving, only 166 (63.85%) possessed a driver's license. Several significant correlations emerged between driving habits and both cognitive and HRQoL variables, with a general pattern suggesting that current greater driving exposure was associated with better cognitive functioning and HRQoL. Given consistent associations that emerged between the social functioning HRQoL domain and several driving habits, multivariable regression was conducted to examine the unique association between an index of greater driving exposure (i.e., days driven per week) and social functioning, adjusting for potential confounders (race, income, education, depression, and global cognition). Results showed that more days driven per week was a significant, independent correlate of higher social functioning. Understanding the factors underlying driving behaviors in PLWH may contribute to interventions to promote better mobility and improved access to care.

Metabolic Risk Factors as Differential Predictors of Profiles of Neurocognitive Impairment Among Older HIV+ and HIV- Adults: An Observational Study

OBJECTIVE

Neurocognitive performance among older persons, including those living with HIV (people living with HIV [PLWH]), exhibits significant heterogeneity, suggesting subpopulations with differing profiles of neurocognitive impairment (NCI). Metabolic factors are associated with NCI, but their relationships to cluster-derived NCI profiles are unknown.

METHOD

Participants (144 PLWH and 102 HIV uninfected) aged 50+ years completed a neuropsychological battery assessing seven cognitive domains. Latent class analysis (LCA) identified NCI profiles separately by HIV serostatus and in a combined sample. Obtained classes were examined against the Montreal Cognitive Assessment (MoCA) and diagnoses of HIV-associated neurocognitive disorders (HAND). Multinomial regression identified metabolic predictors of classification.

RESULTS

LCA identified three latent classes in each participant sample: Class1Multidomain NCI (high probability of impairment across multiple domains), Class 2Learning & Recall NCI (high probability of impairment in learning and recall), and Class 3NC Unimpaired (low probability of NCI across all domains). Severity of NCI implied by classes corresponded with MoCA scores and HAND diagnoses. In analyses on the combined sample, compared to HIV-uninfected individuals, PLWH were more likely to be in Class1Multidomain NCI. Among PLWH, those with dyslipidemia and hypertension had greater odds of classification in Class 1Multidomain NCI while those with central obesity had higher odds of classification in Class 2Learning & Recall NCI; metabolic syndrome approached significance as a differential predictor. Regardless of HIV status, individuals with diabetes were more likely to be in Class 1Multidomain NCI.

CONCLUSIONS

Metabolic risk factors confer heightened risk of NCI in HIV infection. Interventions to reduce metabolic risk may improve neurocognitive outcomes among PLWH.

Patterns and Predictors of Cognitive Function Among Virally Suppressed Women With HIV

Cognitive impairment remains frequent and heterogeneous in presentation and severity among virally suppressed (VS) women with HIV (WWH). We identified cognitive profiles among 929 VS-WWH and 717 HIV-uninfected women from 11 Women's Interagency HIV Study sites at their first neuropsychological (NP) test battery completion comprised of: Hopkins Verbal Learning Test-Revised, Trail Making, Symbol Digit Modalities, Grooved Pegboard, Stroop, Letter/Animal Fluency, and Letter-Number Sequencing. Using 17 NP performance metrics (T-scores), we used Kohonen self-organizing maps to identify patterns of high-dimensional data by mapping participants to similar nodes based on T-scores and clustering those nodes. Among VS-WWH, nine clusters were identified (entropy = 0.990) with four having average T-scores ≥45 for all metrics and thus combined into an "unimpaired" profile (n = 311). Impaired profiles consisted of weaknesses in: (1) sequencing (Profile-1; n = 129), (2) speed (Profile-2; n = 144), (3) learning + recognition (Profile-3; n = 137), (4) learning + memory (Profile-4; n = 86), and (5) learning + processing speed + attention + executive function (Profile-5; n = 122). Sociodemographic, behavioral, and clinical variables differentiated profile membership using Random Forest models. The top 10 variables distinguishing the combined impaired vs. unimpaired profiles were: clinic site, age, education, race, illicit substance use, current and nadir CD4 count, duration of effective antiretrovirals, and protease inhibitor use. Additional variables differentiating each impaired from unimpaired profile included: depression, stress-symptoms, income (Profile-1); depression, employment (Profile 2); depression, integrase inhibitor (INSTI) use (Profile-3); employment, INSTI use, income, atazanavir use, non-ART medications with anticholinergic properties (Profile-4); and marijuana use (Profile-5). Findings highlight consideration of NP profile heterogeneity and potential modifiable factors contributing to impaired profiles.

The Increase of HIV-1 Infection, Neurocognitive Impairment, and Type 2 Diabetes in The Rio Grande Valley

The Human Immunodeficiency Virus (HIV-1) infection remains a persistent predicament for the State of Texas, ranking seventh among the most documented HIV cases in the United States. In this regard, the Rio Grande Valley (RGV) in South Texas is considered as one of the least investigated areas of the state with respect to HIV infection and HIV associated comorbidities. Considering the 115% increase in average HIV incidence rates per 100,000 within the RGV from 2007-2015, it is worth characterizing this population with respect to their HIV-1 infection, HIV-1 Associated Neurocognitive Disorders (HAND), and the association of treatment with combined antiretroviral therapy (cART). Moreover, the increased rate of Type-2 Diabetes (T2D) in the RGV population is intertwined with that of HIV-1 infection facing challenges due to the lack of knowledge about prevention to inadequate access to healthcare. Hence, the role of T2D in the development of HAND among the people living with HIV (PLWH) in the RGV will be reviewed to establish a closer link between T2D and HAND in cART-treated patients of the RGV.

Combination of HIV-1 and Diabetes Enhances Blood Brain Barrier Injury via Effects on Brain Endothelium and Pericytes

Despite combined antiretroviral therapy (ART) achieving efficient HIV replication control, HIV-associated neurocognitive disorders (HAND) continue to be highly prevalent in HIV-infected patients. Diabetes mellitus (DM) is a well-known comorbidity of HAND in HIV-infected patients. Blood brain barrier (BBB) dysfunction has been linked recently to dementia development, specifically in DM patients. BBB injury exists both in HIV and DM, likely contributing to cognitive decline. However, its extent, exact cellular targets and mechanisms are largely unknown. In this report, we found a decrease in pericyte coverage and expression of tight junction proteins in human brain tissues from HIV patients with DM and evidence of HAND when compared to HIV-infected patients without DM or seronegative DM patients. Using our in vitro BBB models, we demonstrated diminution of barrier integrity, enhanced monocyte adhesion, changes in cytoskeleton and overexpression of adhesion molecules in primary human brain endothelial cells or human brain pericytes after exposure to HIV and DM-relevant stimuli. Our study demonstrates for the first-time evidence of impaired BBB function in HIV-DM patients and shows potential mechanisms leading to it in brain endothelium and pericytes that may result in poorer cognitive performance compared to individuals without HIV and DM.

COMT Val158Met Polymorphism, Cardiometabolic Risk, and Nadir CD4 Synergistically Increase Risk of Neurocognitive Impairment in Men Living With HIV

OBJECTIVE

The Val allele of the Val158Met single-nucleotide polymorphism of the catechol-o-methyltransferase gene (COMT) results in faster metabolism and reduced bioavailability of dopamine (DA). Among persons living with HIV, Val carriers display neurocognitive deficits relative to Met carriers, presumably due to exacerbation of HIV-related depletion of DA. COMT may also impact neurocognition by modulating cardiometabolic function, which is often dysregulated among persons living with HIV. We examined the interaction of COMT, cardiometabolic risk, and nadir CD4 on neurocognitive impairment (NCI) among HIV+ men.

METHODS

Three hundred twenty-nine HIV+ men underwent COMT genotyping and neurocognitive and neuromedical assessments. Cohort-standardized z scores for body mass index, systolic blood pressure, glucose, triglycerides, and high-density lipoprotein cholesterol were averaged to derive a cardiometabolic risk score (CMRS). NCI was defined as demographically adjusted global deficit score of ≥0.5. Logistic regression modeled NCI as a function of COMT, CMRS, and their interaction, covarying for estimated premorbid function, race/ethnicity, and HIV-specific characteristics. Follow-up analysis included the 3-way interaction of COMT, CMRS, and nadir CD4.

RESULTS

Genotypes were 81 (24.6%) Met/Met, 147 (44.7%) Val/Met, and 101 (30.7%) Val/Val. COMT interacted with CMRS (P = 0.02) such that higher CMRS increased risk of NCI among Val/Val [odds ratio (OR) = 2.13, P < 0.01], but not Val/Met (OR = 0.93, P > 0.05) or Met/Met (OR = 0.92, P > 0.05) carriers. Among Val/Val, nadir CD4 moderated the effect of CMRS (P < 0.01) such that higher CMRS increased likelihood of NCI only when nadir CD4 <180.

DISCUSSION

Results suggest a tripartite model by which genetically driven low DA reserve, cardiometabolic dysfunction, and historical immunosuppression synergistically enhance risk of NCI among HIV+ men, possibly due to neuroinflammation and oxidative stress.

Cognitive Trajectory Phenotypes in Human Immunodeficiency Virus-Infected Patients

OBJECTIVE

The presentation of cognitive impairments in HIV-infected individuals has transformed since the introduction of antiretroviral therapies. Although the overall prevalence of cognitive impairments has not changed considerably, frank dementia is now infrequent, and milder forms of cognitive impairments predominate. Mechanistic insights to the underlying causes of these residual cognitive impairments have been elusive, in part due to the heterogenous etiology of cognitive dysfunction in this population. Here, we sought to categorize longitudinal change in HIV-infected patients based on the performance in specific cognitive domains.

DESIGN

This study consisted of 193 participants from the CHARTER cohort with detailed demographic, clinical, and neuropsychological testing data obtained from 2 study visits interspersed by ∼6 months. Cognitive testing assessed executive function, learning and delayed recall, working memory, verbal fluency, speed of information processing, and motor skills. Change scores were calculated for each domain between the 2 study visits. Dimension reduction and clustering was accomplished by principal component analysis of change scores and k-means clustering to identify cognitive domains that group together and groups of subjects with similar patterns of change.

RESULTS

We identified 4 distinct cognitive change phenotypes that included declines in: (1) verbal fluency, (2) executive function (3) learning and recall, and (4) motor function, with approximately equal numbers of participants in each phenotype.

CONCLUSIONS

Each of the 4 cognitive change phenotypes identify deficits that imply perturbations in specific neural networks. Future studies will need to validate if cognitive change phenotypes are associated with alterations in associated neural pathways.

Neurocognitive SuperAging in Older Adults Living With HIV: Demographic, Neuromedical and Everyday Functioning Correlates

OBJECTIVES

Studies of neurocognitively elite older adults, termed SuperAgers, have identified clinical predictors and neurobiological indicators of resilience against age-related neurocognitive decline. Despite rising rates of older persons living with HIV (PLWH), SuperAging (SA) in PLWH remains undefined. We aimed to establish neuropsychological criteria for SA in PLWH and examined clinically relevant correlates of SA.

METHODS

734 PLWH and 123 HIV-uninfected participants between 50 and 64 years of age underwent neuropsychological and neuromedical evaluations. SA was defined as demographically corrected (i.e., sex, race/ethnicity, education) global neurocognitive performance within normal range for 25-year-olds. Remaining participants were labeled cognitively normal (CN) or impaired (CI) based on actual age. Chi-square and analysis of variance tests examined HIV group differences on neurocognitive status and demographics. Within PLWH, neurocognitive status differences were tested on HIV disease characteristics, medical comorbidities, and everyday functioning. Multinomial logistic regression explored independent predictors of neurocognitive status.

RESULTS

Neurocognitive status rates and demographic characteristics differed between PLWH (SA=17%; CN=38%; CI=45%) and HIV-uninfected participants (SA=35%; CN=55%; CI=11%). In PLWH, neurocognitive groups were comparable on demographic and HIV disease characteristics. Younger age, higher verbal IQ, absence of diabetes, fewer depressive symptoms, and lifetime cannabis use disorder increased likelihood of SA. SA reported increased independence in everyday functioning, employment, and health-related quality of life than non-SA.

CONCLUSIONS

Despite combined neurological risk of aging and HIV, youthful neurocognitive performance is possible for older PLWH. SA relates to improved real-world functioning and may be better explained by cognitive reserve and maintenance of cardiometabolic and mental health than HIV disease severity. Future research investigating biomarker and lifestyle (e.g., physical activity) correlates of SA may help identify modifiable neuroprotective factors against HIV-related neurobiological aging. (JINS, 2019, 25, 507-519).

Prevalence of Cognitive Impairment and Its Predictors among HIV/AIDS Patients on Antiretroviral Therapy in Jimma University Medical Center, Southwest Ethiopia

Background

Cognitive impairment among human immunodeficiency virus (HIV) infected patients can lead to treatment nonadherence, faster progression of the illness, disability, and bed ridden state if we fail to detect it early. However, there is scarcity of previous published studies in Ethiopia on the assessment of cognitive impairment among HIV-positive patients. Hence, this study aimed to determine the prevalence and associated factors of cognitive impairment among HIV-positive patients receiving antiretroviral therapy (ART) at Jimma University Medical Center, Ethiopia.

Methods

Hospital-based cross-sectional study was conducted among 328 HIV-positive patients attending Jimma University Medical Center, Ethiopia. Data were collected from a face-to-face interview and review of medical records using semistructured questionnaire. Validated International HIV Dementia Scale (IHDS) was used to screen for cognitive impairment. Data was analyzed using SPSS version 20.

Results

A total of 328 (191 females and 137 males) HIV-positive patients were included in the study with a response rate of 97.04%. The prevalence of cognitive impairment among HIV-positive patients was 35.7%. Factors significantly associated with cognitive impairment were age group of 41-64 years (adjusted odds ratio [AOR] = 3.1, 95% confidence interval [CI] (1.3, 7.4)], plasma HIV-1 RNA load between 1.7log10 and 3log10 copies/ml [AOR = 2.2, 95% CI (1.1,4.3)] and ≥ 3log10 copies/ml [AOR = 7.5, 95% CI (2.6, 21.5)], khat chewing [AOR = 4.4, 95% CI (2.3, 8.3)], and clinical stage III of the disease [AOR = 5.6, 95% CI (1.7, 19.2)].

Conclusion

Despite the use of ART, the burden of cognitive impairment among HIV patients was high. Older age, khat chewing, advanced stage of the disease, and higher viral load were the independent factors associated with cognitive impairment. Thus, continuous screening of cognitive impairment, identification of the possible risk factors, and proper management strategy should be designed.

Trends and predictors of non-communicable disease multimorbidity among adults living with HIV and receiving antiretroviral therapy in Brazil

INTRODUCTION

People living with HIV (PLHIV) on antiretroviral therapy (ART) experience high rates of non-communicable diseases (NCDs). These co-morbidities often accumulate and older adults may suffer from multimorbidity. Multimorbidity has been associated with loss of quality of life, polypharmacy, and increased risk of frailty and mortality. Little is known of the trends or predictors NCD multimorbidity in PLHIV in low- and middle-income countries.

METHODS

We examined NCD multimorbidity in adult PLHIV initiating ART between 2003 and 2014 using a multi-site, observational cohort in Brazil. NCDs included cardiovascular artery disease, hyperlipidemia (HLD), diabetes, chronic kidney disease, cirrhosis, osteoporosis, osteonecrosis, venous thromboembolism and non-AIDS-defining cancers. Multimorbidity was defined as the incident accumulation of two or more unique NCDs. We used Poisson regression to examine trends and Cox proportional hazard models to examine predictors of multimorbidity.

RESULTS

Of the 6206 adults, 332 (5%) developed multimorbidity during the study period. Parallel to the ageing of the cohort, the prevalence of multimorbidity rose from 3% to 11% during the study period. Older age, female sex (adjusted hazard ratio (aHR) = 1.30 (95% confidence interval (CI) 1.03 to 1.65)) and low CD4 nadir (<100 vs. ≥200 cells/mm3 aHR = 1.52 (95% CI: 1.15 to 2.01)) at cohort entry were significantly associated with increased risk of multimorbidity. Among patients with incident multimorbidity, the most common NCDs were HLD and diabetes; however, osteoporosis was also frequent in women (16 vs. 35% of men and women with multimorbidity respectively).

CONCLUSIONS

Among adult PLHIV in Brazil, NCD multimorbidity increased from 2003 to 2014. Females and adults with low CD4 nadir were at increased risk in adjusted analyses. Further studies examining prevention, screening and management of NCDs in PLHIV in low- and middle-income countries are needed.

Empiric neurocognitive performance profile discovery and interpretation in HIV infection

The measurement and determinants of HIV-associated neurocognitive disorders (HAND) are under intense debate. We used latent profile analysis (LPA) and machine learning to define neurocognitive performance profiles and identify their associated risk factors in HIV patients receiving antiretroviral therapy (ART). Neurocognitive performance was assessed by a multidomain neuropsychological test battery. LPA was used to define individual neurocognitive profiles. Random forest analyses (RFA) identified the most important factors distinguishing each profile. Three profiles emerged from the LPA: profile 1 (P1, n = 159) achieved the highest performance, while profile 2 (P2, n = 163) had lowered executive functions and verbal memory, and profile 3 (P3, n = 59) was globally impaired. RFA achieved good prediction (area under the curve ≥ 0.80) only for global impairment (P3). Non-North American descent was the dominant predictor of P3, followed by factors coinciding with non-North American descent (female sex and toxoplasma seropositivity). Additional predictors included unemployment, current depressive symptoms, lower nadir CD4, and longstanding HIV. Restricting analyses to North Americans pointed to the additional importance of ART achieving high CSF levels and older age in prediction of P3. HAND diagnoses were most common in the globally impaired profile (P3 = 89.8%), followed by the group with reduced higher-order neurocognitive performance (P2 = 16.6%). Thus, implementation of LPA and RFA empirically distinguished three distinct neurocognitive performance profiles in this HIV-infected cohort while also highlighting potential risk factors and their relative importance to neurocognitive impairment. These data-driven analytical methods pointed to discernible demographic, HIV- and treatment-related risk factor constellations in patients born outside and within North America that might influence diagnostic and therapeutic decisions.

Impact of glycemic status on longitudinal cognitive performance in men with and without HIV infection

OBJECTIVES

To determine the relationship between glycemic status and cognitive performance in men living with HIV (MLWH) and without HIV infection.

DESIGN

A prospective HIV/AIDS cohort study in four US cities between 1999 and 2016.

METHODS

Glycemic status was categorized as normal glucose, impaired fasting glucose, controlled diabetes mellitus and uncontrolled diabetes mellitus at each semiannual visit. Cognitive performance was evaluated using nine neuropsychological tests which measure attention, constructional ability, verbal learning, executive functioning, memory and psychomotor speed. Linear mixed models were used to assess the association between glycemic status and cognition.

RESULTS

Overall, 900 MLWH and 1149 men without HIV were included. MLWH had significantly more person-visits with impaired fasting glucose (52.1 vs. 47.9%) and controlled diabetes mellitus (58.2 vs. 41.8%) than men without HIV (P < 0.05). Compared with men with normal glucose, men with diabetes mellitus had significantly poorer performance on psychomotor speed, executive function and verbal learning (all P < 0.05). There was no difference in cognition by HIV serostatus. The largest effect was observed in individuals with uncontrolled diabetes mellitus throughout the study period, equivalent to 16.5 and 13.4 years of aging on psychomotor speed and executive function, respectively, the effect of which remained significant after adjusting for HIV-related risk factors. Lower CD4+ nadir was also associated with worse cognitive performance.

CONCLUSION

Abnormalities in glucose metabolism were more common among MLWH than men without HIV and were related to impaired cognitive performance. Metabolic status, along with advanced age and previous immunosuppression, may be important predictors of cognition in the modern antiretroviral therapy era.

Using the Theoretical Domains Framework to identify barriers and facilitators to exercise among older adults living with HIV

People with HIV are living longer. However, co-morbidities are often more prevalent and severe than in the general population and have greater impacts on health status. Although compelling evidence exists about the health benefits of exercise in the HIV literature, many people living with HIV tend to be physically inactive. The purpose of this study was to use the Theoretical Domains Framework to investigate the barriers and facilitators to participation in exercise of older people living with HIV. This qualitative study involved in-depth, semi-structured interviews with 12 adults aged 45 years and older recruited from HIV organizations and health centres. Data were analyzed thematically using the Theoretical Domains Framework, and two investigators independently coded transcripts. Six prominent domains were identified from the interviews: Social influences, environmental context and resources, reinforcement, intentions, social and professional role, and knowledge. Themes emerging from the interviews fit into all 14 domains of the Theoretical Domains Framework, and 67% of themes fit into the six most prominent domains. The participants had a working knowledge of exercise and its health benefits but were unfamiliar with specific exercise parameters. The majority identified environmental or resource constraints as salient barriers for participation in exercise programmes. Co-morbidities, injuries, and the side effects of HIV disease and medication were also acknowledged as barriers. Stigma and discrimination from friends, family, people within the LGBTQ community, and health care providers were commonly discussed. Participants spoke of the importance of social support to facilitate participation in exercise programmes. Other facilitators included using technology and incorporating exercise into day-to-day activities. People aging with HIV experience many barriers to exercise. Those designing exercise interventions for people aging with HIV should incorporate strategies to address these obstacles.

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.

Aging and Neurocognitive Functioning in HIV-Infected Women: a Review of the Literature Involving the Women's Interagency HIV Study

HIV-infected women may be particularly vulnerable to certain types of neurocognitive impairments which may be exacerbated by aging and other predictors. Within the context of cognitive reserve, this article examines issues surrounding women as they age with HIV. For this, a review of 12 recent studies (2013-2016) using data from the Women's Interagency HIV Study (WIHS), the largest cohort study comparing HIV-infected and demographically matched uninfected women, is presented that specifically examines neurocognition. In general, HIV-infected women are more vulnerable to developing neurocognitive impairments than uninfected women; other factors that may contribute to these neurocognitive impairments include recent illicit drug use, reading level (educational quality/cognitive reserve), stress, PTSD, insulin resistance, liver fibrosis, and age. Surprisingly, when examined in some analyses, age × HIV interactions were not observed to impact neurocognitive performance, findings largely consistent in the literature; however, longitudinal analyses of these data have yet to be performed which may yield future insights of how cognitive reserve may be compromised over time. Yet, with insulin resistance, liver fibrosis, stress, and other known predictors of poorer neurocognition also occurring more with advanced age, in time, the synergistic effect of age and HIV may be more robust and observable as this population ages.

Modeling aging in HIV infection in nonhuman primates to address an emerging challenge of the post-ART era

The advent of antiretroviral therapy (ART) has dramatically improved both quality and length of life for subjects infected with human immunodeficiency virus (HIV), delaying or preventing progression to acquired immunodeficiency syndrome (AIDS). However, the virus induces aging-related changes to the immune system which confound treatment. Additionally, the normal physiologic events that occur during aging lead to deficiencies in immunity which not only exacerbate HIV pathogenesis but also trigger a variety of comorbidities. Here, the synergistic linkage between aging and HIV infection is examined in regard to the immunological and pathological mechanisms that drive both senescence and disease progression. The use of NHPs to investigate potential therapeutic strategies to control the deleterious consequences of aging with HIV infection is also reviewed.

"HIV Is Not Going to Kill Me, Old Age Is!": The Intersection of Aging and HIV for Older HIV-Infected Adults in Rural Communities

Older adults with HIV/AIDS living in rural areas face unique challenges to accessing HIV care and medications, and suffer greater mortality than non-rural HIV-infected individuals. This qualitative study examined the intersection of aging and HIV to identify factors that affect overall health, engagement in care, and medication adherence among this understudied population. Qualitative interviews were conducted by phone with 29 HIV-positive adults over the age of 50 living in U.S. rural counties and analyzed using thematic content analysis. Individuals reported complex medical needs in addition to their HIV and noted difficulty discerning whether symptoms were associated with HIV or aging. Although reported medication adherence rates were high, participants also cited several barriers to maintaining adherence. Given the increase in rural individuals living with HIV, interventions are needed to address the complex intersection of aging and HIV, especially for those in rural environments.

Aging With HIV in the Era of Antiretroviral Treatment: Living Conditions and the Quality of Life of People Aged Above 50 Living With HIV/AIDS in Switzerland

The aim of this cross-sectional study was to identify the living conditions and the quality of life of people aged more than 50 who were living with HIV in Switzerland. Participants were consecutively sampled through different HIV-specific sites. Seventy-two HIV-positive persons filled in an anonymous standardized questionnaire, either paper-pencil or online. Descriptive and inferential statistics were calculated. Quality of life was rated quite high (M = 14.9, SD = 4.14). The multivariate regression analyses showed that mental and physical health problems, long-term living with HIV, having a high degree of needed support, and financial problems decreased quality of life, and perceived available social support was an important predictor in maintaining quality of life. In addition to current offers to support mental health and social networks, efforts to integrate people of working age into the labor market and efforts to reduce stigma and the social marginalization of older HIV-positive people should be fostered.

The neurobiology of HIV and its impact on cognitive reserve: A review of cognitive interventions for an aging population

The medications used to treat HIV have reduced the severity of cognitive deficits; yet, nearly half of adults with HIV still exhibit some degree of cognitive deficits, referred to as HIV-associated neurocognitive disorder or HAND. These cognitive deficits interfere with everyday functioning such as emotional regulation, medication adherence, instrumental activities of daily living, and even driving a vehicle. As adults are expected to live a normal lifespan, the process of aging in this clinical population may exacerbate such cognitive deficits. Therefore, it is important to understand the neurobiological mechanisms of HIV on cognitive reserve and develop interventions that are either neuroprotective or compensate for such cognitive deficits. Within the context of cognitive reserve, this article delivers a state of the science perspective on the causes of HAND and provides possible interventions for addressing such cognitive deficits. Suggestions for future research are also provided.