Effects of Sleep Health on Cognitive Function in HIV+ and HIV- Adults

What is known from the existing literature about how sleep is measured in HIV care? A scoping review

The HIV care landscape has significantly altered over the past 30 years with advances in HIV medical treatment. Despite these medical advances, people living with HIV experience a significant number of issues that affect their health-related quality of life, including sleep. Although poor sleep quality is common, there remains a lack of understanding of how to identify sleep issues in order to improve outcomes for people living with HIV. A scoping review of three databases as well as the grey literature yielded 2932 articles, of which 60 met the inclusion criteria. The following themes were identified: range of methods used to assess sleep, self-reported sleep measures and objective measures of sleep. The review found that a number of different measures of sleep were used within the research, the most commonly used being the Pittsburgh Sleep Quality Index. Due to the variety of approaches being used to measure sleep (n=18) there was a lack of consistency in what aspects of sleep were being explored, and in many cases why the measure of sleep was chosen. Furthermore, there was a lack of meaningful clinical recommendations as to how these findings could be used to improve outcomes for people living with HIV.

An overview of neurocognitive impairment in older people living with HIV

Background

With improved survival among People Living with HIV (PLHIV), many are confronted with age associated comorbidities and geriatric syndromes. Neurocognitive impairment is one of the three most frequent conditions that affects quality of life of PLHIV despite achieving viral suppression. Healthcare providers face challenges in early identification of neurocognitive impairment, performing comprehensive assessment and managing older PLHIV.

Objectives

This paper aims to review available evidence regarding aetiology and management of older PLHIV who develop neurocognitive impairment, suggest improvements on current management and postulate future study direction.

Methods

A PubMed search for original articles and Clinical Guidelines was conducted from September 2021 to August 2022 using a combination of keywords related to neurocognitive impairment in PLHIV. The citations from all selected articles were reviewed for additional studies.

Results

Older PLHIV tend to be frailer than their uninfected counterparts, are plagued with multi-morbidity and are at increased risk of cognitive impairment. The aetiologies for neurocognitive impairment are multifactorial, multi-dimensional and complex. The management of neurocognitive impairment in older PLHIV involves identifying and optimizing predisposing factors, physical function, social and psychological health with appropriate care navigation.

Conclusion

Identification and management of neurocognitive impairment in older PLHIV through interdisciplinary collaboration among stakeholders is important. This exemplifies an integrated model of care for older PLHIV and promotes the notion of living well beyond viral suppression.

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.

A meta-analysis of gray matter volume abnormalities in HIV patients

HIV infection is known to have significant effects on central nervous system. This study conducted a meta-analysis of whole voxel-based morphometry (VBM) in HIV patients (N = 435) and HIV-uninfected controls (N = 397). This study observed a reduction of limbic lobe, cingulate gyrus, frontal lobe, middle frontal gyrus, sub-lobar, insula, inferior frontal gyrus and superior frontal gyrus volume in HIV patients. These morphological differences may be responsible for cognitive decline in HIV patients, as these brain regions are closely related to motor and memory functions. These results contribute to a better understanding of the neural mechanisms underlying brain injury in HIV patients and could help develop targeted brain targets, provide more personalized treatment and predict neurodevelopmental outcomes.

Poor subjective sleep reported by people living with HIV is associated with impaired working memory

Poor sleep can undermine health and may be especially disruptive to those with chronic conditions including HIV infection. Here, clinically well-described people living with HIV [PLWH] (74 men, 35 women) and healthy control (38 men, 35 women) participants were administered the Pittsburgh Sleep Quality Index (PSQI), a validated measure of subjective sleep with a global score ≥5 able to distinguish good from poor sleepers. In addition, participants completed a battery of neuropsychological tests. PLWH (6.8 ± 3.7) had higher global PSQI scores than healthy controls (4.1 ± 2.8): 39.7 % of uninfected controls and 68.8 % of PLWH had a PSQI≥5 indicative of poor sleep. There were no relations between the global PSQI score and any evaluated variables among uninfected individuals or with demographic or HIV-related variables in PLWH. Instead, a higher global PSQI score among PLWH was associated with worse "Quality of Life" scores [Global Assessment of Functioning (GAF, p=0.0007), Medical Outcomes Study survey (21-item short form, SF-21, p<0.0001), and Activities of Daily Living-Instrumental (ADL-I, p=0.0041)] and higher Beck Depression Index (BDI, p<0.0001) depressive symptoms. Further, in PLWH, higher global PSQI scores were associated with poor performance on a working memory task, the digit backward span (p=0.0036). In PLWH, the 5 variables together explained 32.3 % of the global PSQI score variance; only 3 variables - the SF-21, BDI, and digit backward scores - explained 30.6 % of the variance. To the extent that poor subjective sleep contributes to impaired working memory in HIV, we speculate that this impairment may be ameliorated by improved sleep health.

Preventing Neurocognitive Decline in Adults Aging with HIV: Implications for Practice and Research

Mild to moderate forms of neurocognitive impairment persist among people living with HIV (PLWH), despite being virally suppressed on antiretroviral therapy. PLWH are disproportionally impacted by physiological and psychosocial comorbidities compared to those without HIV. As adults live longer with HIV, the neurocognitive burden of physiological and psychosocial stressors can impair everyday functioning and may contribute to the development of neurodegenerative diseases such as Alzheimer's disease. This article outlines neurocognitive consequences of everyday stressors in PLWH. While some lifestyle factors can exacerbate inflammatory processes and promote negative neurocognitive health, novel interventions including the use of cannabinoids may be neuroprotective for aging PLWH who are at risk for elevated levels of inflammation from comorbidities. Studies of integrated neurocognitive rehabilitation strategies targeting lifestyle factors are promising for improving neurocognitive health, and may over time, reduce the risk of Alzheimer's disease in PLWH.

Sleep Disturbances and Chronic Pain in People with HIV: Implications for HIV-Associated Neurocognitive Disorders

Purpose of Review

Antiretroviral therapy has significantly reduced morbidity and mortality in people with HIV. Despite being virally suppressed, sleep disturbances, chronic pain, and neurocognitive impairments persist which can negatively impact quality of life for people with HIV. This article presents relevant literature related to sleep disturbances and chronic pain in people with HIV. The potential impact of these comorbidities on cognition is discussed with implications for managing HIV-associated neurocognitive disorder (HAND).

Recent Findings

People with HIV and chronic pain report greater insomnia and depressive symptoms compared to those without chronic pain. The neurotoxic effects of HIV itself and sleep and chronic pain induced inflammation can contribute to poorer cognitive outcomes.

Summary

Sleep disturbances and chronic pain are prevalent conditions in people with HIV that may perpetuate the development and exacerbation of HAND. Sleep and pain interventions may preserve cognitive function and improve quality of life for people aging with HIV.

Objective and subjective sleep measures are associated with neurocognition in aging adults with and without HIV

Objective: Poor sleep quality is related to worse neurocognition in older adults and in people with HIV (PWH); however, many previous studies have relied only on self-report sleep questionnaires, which are inconsistently correlated with objective sleep measures. We examined relationships between objective and subjective sleep quality and neurocognition in persons with and without HIV, aged 50 and older. Method: Eighty-five adults (PWH n = 52, HIV-negative n = 32) completed comprehensive neuropsychological testing to assess global and domain-specific neurocognition. Objective sleep quality was assessed with wrist actigraphy (total sleep time, efficiency, sleep fragmentation) for five to 14 nights. Subjective sleep quality was assessed with the Pittsburgh Sleep Quality Index. Results: Objective and subjective sleep measures were unrelated (p's > 0.30). Compared to HIV-negative participants, PWH had greater sleep efficiency (80% vs. 75%, p = 0.05) and were more likely to be using prescription and/or over the counter sleep medication (p = 0.04). In the whole sample, better sleep efficiency (p < 0.01) and greater total sleep time (p = 0.05) were associated with better learning. Less sleep fragmentation was associated with better learning (p < 0.01) and recall (p = 0.04). While PWH had slightly stronger relationships between total sleep time and sleep fragmentation, it is not clear if these differences are clinically meaningful. Better subjective sleep quality was associated with better executive function (p < 0.01) and working memory (p = 0.05); this relationship was primarily driven by the HIV-negative group. Conclusions: Objective sleep quality was associated with learning and recall whereas subjective sleep quality was associated with executive function and working memory. Therefore, assessing objective and subjective sleep quality could be clinically useful, as they are both related to important domains of cognition frequently impacted in HIV-associated neurocognitive disorders as well as neurodegenerative disorders associated with aging. Future studies should evaluate if behavioral sleep interventions can improve neurocognition.

Sleep Disturbance in the Context of HIV: A Concept Analysis

Due to the differing definitions of the concept of sleep disturbance among people living with human immunodeficiency virus (HIV), reviewers in this area have not reached any firm conclusions. The study aimed to clarify and provide a stronger foundation for the definition of sleep disturbance in the context of HIV to enhance the concept’s development. Following Beth Rodgers’ concept analysis guidelines, two leading databases were searched, and 73 articles were used for this concept analysis. The attributes, surrogate terms, antecedents, and consequences of sleep disturbance have been identified using thematic analysis. In this analysis, two main attributes of sleep disturbance in the context of HIV were identified: a) subjective measures, including reduced total sleep time, difficulty falling asleep, nighttime and early morning awakenings, feeling sleepy and poorly rested after a night’s sleep, frequent arousals, and irritability, and b) objective measures, including changes in sleep architecture and sleep continuity. Five antecedents of sleep disturbance in the context of HIV were identified.

Meanwhile, the consequences of sleep disturbance in HIV are listed based on the frequency the points occur within the reviewed articles. The list is as follows: fatigue and pain; reduced neurocognitive functions; reduced health outcome and quality of life; poor anti-retroviral (ARV) therapy adherence; daytime sleepiness; depression, anxiety, and maladaptive coping; increased disease progression and cardiovascular mortality; and social phobia, living arrangement and sexual dysfunction. An improved understanding of sleep disturbance in the context of HIV will be beneficial in directing analysts to develop research plans. At the same time, the knowledge gaps identified in the analysis provided a solid basis for further study intending to fill in these gaps.

Effect of multi-epitope derived from HIV-1 on REM sleep deprivation-induced spatial memory impairment with respect to the level of immune factors in mice

Objectives

Sleep deprivation (SD) has a negative impact on cognitive functions including learning and memory. Many studies have shown that rapid-eye-movement (REM) SD also disrupts memory performance. In this study, we aimed to investigate the effect of multi-epitope Gag-Pol-Env-Tat derived from Human immunodeficiency virus 1 (HIV-1) on REM SD-induced spatial memory impairment with respect to the levels of interleukin-4 (IL-4), interleukin-17 (IL-17), interferon-gamma (IFN-γ), immunoglobulin G1 (IgG1), immunoglobulin G2a (IgG2a), and lymphocyte proliferation in NMRI mice. We used multi-epitope Gag-Pol-Env-Tat derived from HIV-1 because Gag-Pol-Env-Tat immunogen sequence is one of the most sensitive immunogen sequences of HIV-1 that can significantly augment cellular and humoral immune systems, leading to the improvement of cognitive functions.

Materials and Methods

Morris water maze apparatus was used to assess spatial memory, and multi-platform apparatus was used to induce RSD for 24 hr. Multi-epitope derived from HIV-1 was subcutaneously injected at the dose of 20 µgr/ml, once and fourteen days before RSD.

Results

RSD impaired spatial memory and injection of multi-epitope derived from HIV-1 reversed this effect. RSD decreased IL-4, IgG1, and IgG2a levels, while multi-epitope derived from HIV-1 reversed these effects. Multi-epitope derived from HIV-1 also increased lymphocyte proliferation and decreased IL-17 levels in both control and RSD mice.

Conclusion

Multi-epitope derived from HIV-1 may improve memory performance via induction of anti-inflammatory immune response.

Daytime Sleep Behaviors and Cognitive Performance in Middle- to Older-Aged Adults Living with and without HIV Infection

PURPOSE

We investigated whether daytime sleep behaviors (DSBs) such as frequent daytime sleepiness or napping are associated with worse cognitive performance, and whether HIV infection moderates this relationship.

METHODS

Among 502,507 participants in the UK Biobank study, we identified 562 people living with HIV infection (PLWH; M _age= 50.51±7.81; 25.09% female; 78.83% white) and extracted 562 uninfected controls who matched on age, sex, ethnic background, social-economic status, and comorbidities. DSB burden was assessed based on answers to two questions on DSBs. Participants who answered "sometimes" or "often/usually" to one of them were considered to have poor DSB burden, or otherwise were considered not having any. A composite cognition score was computed by averaging the available standardized individual test results from four neurocognitive tests: ie, a reaction time test for information processing speed, a pairs matching test for visual episodic memory, a fluid intelligence test for reasoning, and a prospective memory test. Mixed-effects models with adjustment for the variables used in extracting matched uninfected controls were performed to test the hypotheses.

RESULTS

Having poor DSB burden was associated with a 0.15 - standard deviation (SD) decrease in cognitive performance (p = 0.006). People living with HIV infection (PLWH) also performed worse on the cognitive tasks than uninfected controls, with an effect size similar to that of having poor DSB burden (p = 0.003). HIV infection significantly modified the negative association between DSB burden and cognition (p for interaction: 0.008). Specifically, the association between DSB burden and cognition was not statistically significant in uninfected controls, whereas PLWH who reported having poor DSB burden had a 0.28 - SD decrease in cognitive performance compared to PLWH who did not.

CONCLUSION

HIV infection significantly increased the adverse association between DSBs and cognitive performance. Further studies are needed to investigate the potential mechanisms that underlie this interaction effect and whether poor DSBs and worse cognitive performance are causally linked.

Racial differences in health and cognition as a function of HIV among older adults

The present study investigated the contribution of health risk factors (using the Charlson Comorbidity Index [CCI]) on cognitive outcomes in a sample of 380 HIV-positive (HIV+; n = 221) and HIV-seronegative (HIV-; n = 159) African American and European American adults aged 50+.

Participants were recruited from HIV clinics and community advertisements. HIV status was confirmed by serological testing. Self-report and chart history review was used to gather information about medical ssscomorbidities. The Charlson Comorbidity Index (CCI) was used to create a comorbidity score. Participants were administered a brief cognitive test battery.

As expected, health risks were greater among those with HIV. There was a HIV × Race interaction on CCI scores, such that in the HIV + group, European Americans had significantly higher CCI scores (M = 3.74; SD = 2.1) than African American HIV + participants (M = 2.70; SD = 1.9). However, in the HIV - group, African Americans had significantly higher CCI scores (M = 2.20; SD = 1.1) than HIV - European American participants (M = 1.80; SD = 1.2). Also, consistent with hypotheses, across the entire sample CCI score was significantly associated with global cognition (β = -.24, p = .02).

Study results underscore the importance of considering HIV serostatus in studies examining racial disparities in health, and how multiple medical risks relate to cognitive outcomes. Neuropsychologists evaluating patients living with HIV should consider how the presence of multiple medical comorbidities may contribute to the course of cognitive decline as people age.

Sleep health and cognitive function among people with and without HIV: the use of different machine learning approaches

STUDY OBJECTIVES

We investigated associations between actigraphy-assessed sleep measures and cognitive function in people with and without HIV using different analytical approaches to better understand these associations and highlight differences in results obtained by these approaches.

METHODS

Cognitive and 7-day/night actigraphy data were collected from people with HIV (PWH) and lifestyle-similar HIV-negative individuals from HIV and sexual health clinics in the United Kingdom/Ireland. A global cognitive T-score was obtained averaging the standardized individual cognitive test scores accounting for sociodemographics. Average and SD of 11 sleep measures over 7 days/nights were obtained. Rank regression, partial least-squares (PLS) regression, random forest, sleep dimension construct, and latent class analysis (LCA) were applied to evaluate associations between global T-scores and sleep measures.

RESULTS

In 344 PWH (median age 57 years, 86% males), average sleep duration, efficiency, and wake after sleep onset were not associated with global T-scores according to rank regression (p = 0.51, p = 0.09, p = 0.16, respectively). In contrast, global T-scores were associated with average and SD of length of nocturnal awakenings, SD of maintenance efficiency, and average out-of-bed time when analyzed by PLS regression and random forest. No associations were found when using sleep dimensions or LCA. Overall, findings observed in PWH were similar to those seen in HIV-negative individuals (median age 61 years, 67% males).

CONCLUSIONS

Using multivariable analytical approaches, measures of sleep continuity, timing, and regularity were associated with cognitive performance in PWH, supporting the utility of newer methods of incorporating multiple standard and novel measures of sleep-wake patterns in the assessment of health and functioning.

Multimodality assessment of sleep outcomes in people living with HIV performed using validated sleep questionnaires

Studies conducted in people living with HIV (PLHIV) report high rates of sleep disturbance, without a clear explanation as to cause or effect. Therefore, we proposed use of multiple validated questionnaires that would allow a more comprehensive evaluation of sleep quality in PLHIV. We administered eight validated sleep and wellbeing questionnaires, recording different aspects of sleep in order to provide a comprehensive description of sleep quality, quantity, daytime functioning, wakefulness, and general wellbeing. Associations with demographics and clinical data were analyzed by univariable/multivariable analyses. Of 254 subjects 99% were male (98% men who have sex with men), 88% white, mean age 41 (SD ± 9.9) years, HIV duration eight years (SD ± 6.3), 94% were on antiretroviral therapy, mean CD4 cell count was 724 cells/mm³, 81% had HIV RNA<40 copies/ml, 72% were university educated, and 60% used 'chemsex' drugs. Almost half (45%) reported poor sleep quality, 22% insomnia, 21% daytime sleepiness, and 33% fatigue. As individual factors, HIV duration ≥10 years, anxiety, depression, and recreational drug use were associated with poor quality sleep, fatigue, and poorer functional outcomes (p ≤ 0.05). The prevalence of sleep disturbance was high in our cohort of PLHIV. Sleep disturbance was associated with longer duration of HIV infection, depression, anxiety, and recreational drug use.

Sleep, Prospective Memory, and Immune Status among People Living with HIV

Background: Persons living with HIV (PLWH) frequently report sleep complaints, but objective measurements are still lacking regarding sleep continuity, total sleep time per 24 h, and the links with both prospective memory performance and HIV infection parameters. Methods: PLWH (n = 96) and control (n = 96) groups (balanced for gender and age) were monitored by 24h-actigraphy for at least seven consecutive days. The prospective memory performance was assessed through a naturalistic, activity-based task performed twice a day on the actigraph. Results: PLWH had greater sleep latency and worse sleep continuity (higher fragmentation index) for night-time sleep and longest daytime nap (mean duration of the longest nap). Comparable results were reported for the prospective memory task; better performance scores were associated with several sleep parameters in controls but not in PLWH. Finally, within the PLWH group, being a long sleeper per 24 h (total sleep time > 8 h including more and long daytime naps) was associated with a greater severity of the disease (lower CD4 nadir and more frequent history of AIDS-defining events). Conclusions: These findings indicate that PLWH have more fragmented sleep and that the severity of HIV infection is associated with increased sleep duration.

Effects of treatment of sleep disorders on sleep, psychological and cognitive functioning and biomarkers in individuals with HIV/AIDS and under methadone maintenance therapy

BACKGROUND

Poor sleep is a major complaint of people with human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) and undergoing methadone maintenance therapy (MMT). We tested the impact of three different sleep-improving interventions (trazodone; sleep hygiene training; sleep hygiene training + trazodone) on sleep, psychological functioning and biomarkers in males with HIV and undergoing MMT.

METHODS

A total of 75 male outpatients (mean age: 39.6 years) participated in a 12 week intervention. Participants were randomly assigned to one of the following conditions: trazodone 50 mg/d (TRAZ); sleep hygiene training (SHT); sleep hygiene training and trazodone (SHT + TRAZ). At baseline, and six and 12 weeks later, participants completed questionnaires covering subjective sleep and daytime sleepiness, and symptoms of depression and anxiety. In parallel, their cognitive performance (working memory; sustained attention) was assessed. Biomarkers (cortisol, BNDF, CD4⁺) were assessed at baseline and at the end of the study.

RESULTS

Over time, sleep disturbances decreased and daytime functioning and overall sleep quality improved. More specifically, both sleep disturbances and daytime functioning improved in the two SHT conditions from baseline to week 6. Daytime functioning remained stable from week 6 to week 12. Over time, in all conditions symptoms of depression and anxiety declined from baseline to week 6 and remained lower from week 6 to week 12. Daytime sleepiness, symptoms of insomnia and sleep-disordered breathing remained unchanged. Sustained attention performance improved over time from baseline to week 6 and remained high through to week 12. Biomarkers remained unchanged.

CONCLUSIONS

In males with HIV and undergoing MMT, treating sleep disturbances over a period of six to 12 weeks had a positive impact on aspects of sleep disturbance, symptoms of depression and anxiety, and cognitive performance. The results indicate that sleep hygiene training, either as stand-alone or in combination with trazodone, can produce positive results.

Poor Quality of Sleep Among HIV-Positive Persons in Ethiopia

BACKGROUND

In comparison to the general population, persons living with HIV show a higher prevalence of poor quality of sleep, with estimates from 24.1-100% vs in the normal population 10-40%. There are not enough data on the poor quality of sleep among HIV-infected persons in Ethiopia.

METHODS

Hospital-based cross-sectional study design was conducted among 336 HIV-infected persons in Mettu Karl Referral Hospital. Pittsburgh sleep quality index (PSQI), social phobia inventory (SPIN), changes in sexual functioning questionnaire short-form (CSFQ-14), Fagerstrom test for nicotine dependence (FTND), severity of dependence scale (SDS), and CAGE questionnaire (cut down, annoyed, guilty, eye opener) was used. Data were analyzed by SPSS 20 version. Bivariate and multivariable regressions were computed, and a significance level was declared at a point P-value of <0.05.

RESULTS

A total of 336 respondents completed all questionnaires with response rate 98.53%. A total of 192 participants (57.1%) had poor sleep quality. Concerning associated factors; positive for social phobia, sexual dysfunction, living alone, poor antiretroviral (ARV) treatment adherence, and drunken alcohol had a positive association with poor sleep quality.

CONCLUSION

Of the persons living with HIV (PLWH) in Mettu Karl Referral Hospital, 57.1% experienced poor sleep quality. Social phobia, living arrangement, sexual dysfunction, poor ARV treatment adherence, and use of alcohol showed a significant association with poor quality of sleep. The findings suggest that a longitudinal study will be needed to elucidate the causal relationship of variables, and routine screening of poor sleep quality among PLWH is highly recommended. Furthermore, integrating and launching mental health services at ART clinic is greatly important.

Cannabis use is associated with greater total sleep time in middle-aged and older adults with and without HIV: A preliminary report utilizing digital health technologies

Current literature on the effect of cannabis use on sleep quality is mixed, and few studies have used objectively-measured sleep measures or real-time sampling of cannabis use to examine this relationship. The prevalence of cannabis use among older adults and persons living with HIV has increased in recent years, and poor sleep quality is elevated in these populations as well. However, research examining cannabis-sleep relationships in these populations is lacking. Thus, we aimed to examine the relationship between daily cannabis use and subsequent objectively-measured sleep quality in middle-aged and older adults with and without HIV. In this pilot study, seventeen (11 HIV+, 6 HIV-) adults aged 50-70 who consumed cannabis completed four daily smartphone-based surveys for 14 days, in which they reported their cannabis use (yes/no) since the last survey. Participants also wore actigraphy watches during the 14-day period to objectively assess sleep quality (i.e., efficiency, total sleep time, and sleep fragmentation). In linear mixed-effects models, cannabis use was significantly associated with greater subsequent total sleep time (β=0.56; p=0.046). Cannabis use was not related to a change in sleep efficiency (β=1.50; p=0.46) nor sleep fragmentation (β=0.846, p=0.756) on days with cannabis use versus days without cannabis use. These preliminary results indicate cannabis use may have a positive effect on sleep duration in middle-aged and older adults. However, future studies with larger sample sizes that assess cannabis use in more detail (e.g., route of administration, dose, reason for use) are needed to further understand this relationship.

The Role of Brain Derived Neurotrophic Factor in HIV-Associated Neurocognitive Disorder: From the Bench-Top to the Bedside

Human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) remains prevalent in the anti-retroviral (ART) era. While there is a complex interplay of many factors in the neuropathogenesis of HAND, decreased neurotrophic synthesis has been shown to contribute to synaptic degeneration which is a hallmark of HAND neuropathology. Brain derived neurotrophic factor (BDNF) is the most abundant and synaptic-promoting neurotrophic factor in the brain and plays a critical role in both learning and memory. Reduced BDNF levels can worsen neurocognitive impairment in HIV-positive individuals across several domains. In this paper, we review the evidence from pre-clinical and clinical studies showing the neuroprotective roles of BDNF against viral proteins, effect on co-morbid mental health disorders, altered human microbiome and ART in HAND management. Potential applications of BDNF modulation in pharmacotherapeutic, cognitive and behavioral interventions in HAND are also discussed. Finally, research gaps and future research direction are identified with the aim of helping researchers to direct efforts to make these BDNF driven interventions improve the quality of life of patients living with HAND.