Insulin resistance and cognition among HIV-infected and HIV-uninfected adult women: the Women's Interagency HIV Study

Trauma Across the Life Span and Multisystem Morbidity in Women With HIV

OBJECTIVE

Sexual and physical abuse are highly prevalent among women living with HIV (WLWH) and are risk factors for the development of mental health and substance use disorders (MHDs, SUDs), and cognitive and medical comorbidities. We examined empirically derived patterns of trauma, MHD, and SUD, and associations with later cognitive and health outcomes.

METHODS

A total of 1027 WLWH (average age = 48.6 years) in the Women's Interagency HIV Study completed the World Mental Health Composite International Diagnostic Interview from 2010 to 2013 to identify MHDs, SUDs, and age at onset of sexual and physical abuse. Then, cognitive impairment, cardiovascular/metabolic conditions, and HIV disease outcomes were assessed for up to 8.8 years. Latent class analysis identified patterns of co-occurring trauma, MHDs, and/or SUDs. Generalized estimating equations determined associations between these patterns and midlife cognitive and medical outcomes.

RESULTS

Six distinct profiles emerged: no/negligible sexual/physical trauma, MHD, or SUD (39%); preadolescent/adolescent sexual trauma with anxiety and SUD (22%); SUD only (16%); MHD + SUD only (12%); early childhood sexual/physical trauma only (6%); and early childhood sexual/physical trauma with later MHD + SUD (4%). Profiles including early childhood trauma had the largest number of midlife conditions (i.e., cognitive, cardiovascular, HIV-related). Preadolescent/adolescent sexual trauma with anxiety and SUD predicted both global and domain-specific cognitive declines. Only SUD without trauma predicted lower CD4, whereas childhood trauma with MHD + SUD predicted increased CD8.

CONCLUSIONS

WLWH have complex multisystem profiles of abuse, MHD, and/or SUD that predict midlife cognitive, metabolic/cardiovascular, and HIV outcomes. Understanding the interplay between these factors over time can identify risks and personalize preventative and treatment interventions.

HIV, Vascular Risk Factors, and Cognition in the Combination Antiretroviral Therapy Era: A Systematic Review and Meta-Analysis

OBJECTIVES

Mounting evidence indicates that vascular risk factors (VRFs) are elevated in HIV and play a significant role in the development and persistence of HIV-associated neurocognitive disorder. Given the increased longevity of people living with HIV (PLWH), there is a great need to better elucidate vascular contributions to neurocognitive impairment in HIV. This systematic review and meta-analysis examine relationships between traditional VRFs, cardiovascular disease (CVD), and cognition in PLWH in the combination antiretroviral therapy era.

METHODS

For the systematic review, 44 studies met inclusion criteria and included data from 14,376 PLWH and 6,043 HIV-seronegative controls. To better quantify the contribution of VRFs to cognitive impairment in HIV, a robust variance estimation meta-analysis (N = 11 studies) was performed and included data from 2139 PLWH.

RESULTS

In the systematic review, cross-sectional and longitudinal studies supported relationships between VRFs, cognitive dysfunction, and decline, particularly in the domains of attention/processing speed, executive functioning, and fine motor skills. The meta-analysis demonstrated VRFs were associated with increased odds of global neurocognitive impairment (odds ratio [OR ]= 2.059, p = .010), which remained significant after adjustment for clinical HIV variables (p = .017). Analyses of individual VRFs demonstrated type 2 diabetes (p = .004), hyperlipidemia (p = .043), current smoking (p = .037), and previous CVD (p = .0005) were significantly associated with global neurocognitive impairment.

CONCLUSIONS

VRFs and CVD are associated with worse cognitive performance and decline, and neurocognitive impairment in PLWH. Future studies are needed to examine these relationships in older adults with HIV, and investigate how race/ethnicity, gender, medical comorbidities, and psychosocial factors contribute to VRF-associated cognitive dysfunction in HIV.

Additive and Synergistic Cardiovascular Disease Risk Factors and HIV Disease Markers' Effects on White Matter Microstructure in Virally Suppressed HIV

BACKGROUND

It is unclear whether intermediate to high cardiovascular disease (CVD) risk and HIV disease status may have additive (ie, independent statistical effects concomitantly tested) or synergistic effects on white matter microstructure and cognition in virally suppressed HIV-infected (HIV+) men relative to sex and age-matched controls.

SETTING

Tertiary health care observational cohort.

METHODS

Eighty-two HIV+ men (mean age 55 ± 6 years, 10%-30% on various CVD drugs; 20% with previous CVD) and 40 HIV-uninfected (HIV-) men (none with previous CVD; 10%-20% on various CVD drugs) underwent diffusion tensor imaging and neuropsychological testing. A standard classification of intermediate to high CVD risk (CVD+ group) was based on the Framingham score ≥15% cutoff and/or a history of CVD. Fractional anisotropy (FA) and mean diffusivity (MD) were quantified in 11 white matter tracts.

RESULTS

Within the HIV- group, the CVD+ group had lower FA (P = 0.03) and higher MD (P = 0.003) in the corona radiata and higher MD in the corpus callosum (P = 0.02) and superior fasciculi (P = 0.03) than the CVD- group. Within the HIV+ group, the CVD+ group had lower FA in the superior fasciculi (P = 0.04) and higher MD in the uncinate fasciculus (P = 0.04), and lower FA (P = 0.01) and higher MD (P = 0.03) in the fornix than the CVD- group. The fornix alterations were also abnormal compared with the HIV- groups. The HIV+ CVD+ was more likely to have HIV-associated dementia. Older age, antihypertensive use, longer HIV duration, and higher C-reactive protein associated with lower FA and higher MD. Higher blood CD4 lymphocyte count and CD4/CD8 ratio associated with higher FA and lower MD.

CONCLUSIONS

In virally suppressed HIV, CVD risk factors have a mostly additive contribution to white matter microstructural alterations, leading to a different distribution of injury in HIV- and HIV+ persons with CVD. There was also evidence of a synergistic effect of CVD and HIV factors on the fornix white matter injury.

Non-HIV Comorbid Conditions and Polypharmacy Among People Living with HIV Age 65 or Older Compared with HIV-Negative Individuals Age 65 or Older in the United States: A Retrospective Claims-Based Analysis

The number of people living with HIV (PLWH) ≥65 years is increasing in the United States. By 2035, the proportion of PLWH in this age group is projected to be 27%. As PLWH live longer, they face age-related comorbidities. We compared non-HIV disease and medication burden among PLWH (n = 2359) and HIV-negative individuals (n = 2,010,513) ≥65 years using MarketScan® Medicare Supplemental health insurance claims from 2009 to 2015. Outcomes were common diagnoses and medication classes, prevalence of non-HIV conditions, number of non-HIV conditions, and daily non-antiretroviral therapy (ART) medications over a 1-year period. We examined age-standardized prevalence rates and prevalence ratios (PRs) and fit multivariable generalized linear models, stratified by sex. PLWH were younger (mean 71 vs. 76 years) and a larger proportion were men (81% vs. 45%). The most common diagnoses among both cohorts were hypertension and dyslipidemia. Most non-HIV conditions were more prevalent among PLWH. The largest absolute difference was in anemia (29.6 cases per 100 people vs.11.7) and the largest relative difference was in hepatitis C (PR = 22.0). Unadjusted mean number of non-HIV conditions and daily non-ART medications were higher for PLWH (4.61 conditions and 3.79 medications) than HIV-negative individuals (3.94 and 3.41). In models, PLWH had significantly more non-HIV conditions than HIV-negative individuals [ratios: men = 1.272, (95% confidence interval, 1.233-1.312); women = 1.326 (1.245-1.413)]. Among those with >0 daily non-ART medications, men with HIV had significantly more non-ART medications than HIV-negative men [ratio = 1.178 (1.133-1.226)]. The disease burden associated with aging is substantially higher among PLWH, who may require additional services to effectively manage HIV and comorbid conditions.

Impaired insulin sensitivity is associated with worsening cognition in HIV-infected patients

OBJECTIVE

To determine the association of insulin sensitivity and metabolic status with declining cognition in HIV-infected individuals.

METHODS

We conducted targeted clinical and metabolic measures in longitudinal plasma samples obtained from HIV-infected patients enrolled in the Central Nervous System HIV Anti-Retroviral Therapy Effects Research Study (CHARTER). Findings were validated with plasma samples from the Multicenter AIDS Cohort Study (MACS). Patients were grouped according to longitudinally and serially assessed cognitive performance as having stably normal or declining cognition.

RESULTS

Patients with declining cognition exhibited baseline hyperinsulinemia and elevated plasma c-peptide levels with normal c-peptide/insulin ratios, suggesting that insulin production was increased, but insulin clearance was normal. The association of hyperinsulinemia with worsening cognition was further supported by low high-density lipoprotein (HDL), high low-density lipoprotein/HDL ratio, and elevated cholesterol/HDL ratio compared to patients with stably normal cognition.

CONCLUSIONS

These findings suggest that hyperinsulinemia and impaired insulin sensitivity are associated with cognitive decline in antiretroviral therapy-treated HIV-infected patients.

Neurocognitive Complications of HIV Infection in Women: Insights from the WIHS Cohort

Although sex differences in brain function and brain disorders are well documented, very few studies have had adequate number of women to address sex-related factors contributing to HIV-associated brain dysfunction. Compared to men living with HIV (MLWH), women living with HIV (WLWH) may be at greater risk for cognitive dysfunction and decline due to biological factors (e.g., hormonal, immunologic) and issues common in underserved communities including poverty, low literacy levels, mental health and substance abuse, barriers to health-care services, and environmental exposures. To address this issue, we review relevant cross-sectional and longitudinal findings from the Women's Interagency HIV Study (WIHS), the largest study of the natural and treated history of WLWH, as well as other studies focusing on cognitive complications of HIV in women. We provide evidence that WLWH are more cognitively vulnerable than MLWH and that there are differences in the pattern of cognitive impairment. We next discuss factors that contribute to these differences, including biological factors (e.g., inflammation, hormonal, genetic) as well as common comorbidities (mental health, substance use, vascular and metabolic risk factors, coinfections and liver function, non-antiretroviral medications, and genetic markers). These findings demonstrate the importance of considering sex as a biological factor in studies of cognitive dysfunction and suggest avenues for future research.

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.

Lopinavir/Ritonavir Treatment Induces Oxidative Stress and Caspaseindependent Apoptosis in Human Glioblastoma U-87 MG Cell Line

Background:

Lopinavir and Ritonavir (LPV/r) treatment is widely used to prevent HIV mother-to-child transmission. Nevertheless, studies related to the impact of these compounds on patients, in particular in the foetus and newborns, are strictly required due to the controversial findings reported in the literature concerning possible neurologic side effects following the administration of these drugs.

Objectives:

In our study, we evaluated the impact of LPV/r treatment on the human glioblastoma U- 87 MG cell line.

Methods:

In order to evaluate the influence of Lopinavir and Ritonavir in terms of oxidative stress (ROS production), mitochondrial morphology and apoptotic cell death, the latter either in the presence or in the absence of caspase-3 and -9 inhibitors, we treated U-87 MG with increasing doses (0.1-1-10-25-50 µM) of Lopinavir and Ritonavir for 24h, either in single formulation or in combination. ROS production was measured by flow cytometry using H2DCFDA dye, mitochondrial morphology was evaluated using MitoRed dye and apoptotic cell death was monitored by flow cytometry using Annexin V-FITC and Propidium Iodide.

Results:

We observed that co-treatment with Lopinavir and Ritonavir (25 and 50 µM) promoted a significant increase in ROS production, caused mitochondrial network damage and induced apoptosis in a caspase-independent manner.

Conclusion:

Based on our findings, concordant with others reported in the literature, we hypothesize that LPV/r treatment could not be entirely free from side effects, being aware of the need of validation in in vivo models, necessary to confirm our results.

Microvascular Function in Aging Among Women Living with HIV

Combined antiretroviral therapy (CART) has turned HIV-infection to a treatable chronic disease during which many patients survive to middle and older age. However, they prematurely develop non-AIDS comorbidities such as cardiovascular disease, metabolic syndrome, diabetes, and HIV-associated neurocognitive disorders (HAND). Microcirculatory changes and endothelial dysfunction occur early both in HIV-infected and in aging patients, in whom they usually precede cardiovascular and neurocognitive impairments. Also, mild cognitive involvement has been reported in women during the menopausal transition. Disruption of the blood-brain barrier, as well as microvascular and cerebral blood flow changes, has been reported in HIV patients with HAND, including postmenopausal women. However, most studies addressing this issue included women aged less than 50 years. Whether HIV-infected women growing older with CART would be subsequently exposed to an increased progression of cognitive impairment overtime remains unknown.

Antiretroviral Therapy-induced Insulin Resistance and Oxidative Deoxy Nucleic Acid Damage in Human Immunodeficiency Virus-1 Patients

BACKGROUND AND OBJECTIVES

Insulin resistance (IR) is frequent in human immunodeficiency virus (HIV) infection and may be related to antiretroviral therapy (ART). Increased oxidative stress parameters and carbonyl protein are linked to insulin sensitivity. The present study is aimed to determine IR, its association with oxidative deoxy nucleic acid (DNA) damage in HIV-1-infected patients with different ART status.

MATERIALS AND METHODS

In this case-control study, a total 600 subjects were included. We used plasma levels of the oxidized base, 8-hydroxy-2-deoxyguanosine (8-OHdG), as our biomarker of oxidative DNA damage. 8-OHdG was measured with the highly sensitive 8-OHdG check enzyme-linked immunosorbent assay kit. IR was determined using homeostasis model assessment.

RESULTS

All subjects were randomly selected and grouped as HIV-negative (control group) (n = 300), HIV-positive without ART (n = 100), HIV-positive with ART first line (n = 100), and HIV-positive with ART second line (n = 100). IR and oxidative DNA damage were significantly higher in HIV-positive patients with second-line ART and HIV-positive patients with first-line ART than ART-naive patients. In a linear regression analysis, increased IR was positively associated with the increased DNA damage (odds ratio: 3.052, 95% confidence interval: 2.595-3.509) P < 0.001.

INTERPRETATION AND CONCLUSIONS

In this study, we observed that ART plays a significant role in the development of IR and oxidative DNA damage in HIV-positive patients taking ART. Awareness and knowledge of these biomarkers may prove helpful to clinicians while prescribing ART to HIV/AIDS patients. Larger studies are warranted to determine the exact role of ART in the induction of IR and DNA damage.

Elevated adiponectin prevents HIV protease inhibitor toxicity and preserves cerebrovascular homeostasis in mice

HIV protease inhibitors are key components of HIV antiretroviral therapies, which are fundamental in the treatment of HIV infection. However, the protease inhibitors are well-known to induce metabolic dysfunction which can in turn escalate the complications of HIV, including HIV associated neurocognitive disorders. As experimental and epidemiological data support a therapeutic role for adiponectin in both metabolic and neurologic homeostasis, this study was designed to determine if increased adiponectin could prevent the detrimental effects of protease inhibitors in mice. Adult male wild type (WT) and adiponectin-overexpressing (ADTg) mice were thus subjected to a 4-week regimen of lopinavir/ritonavir, followed by comprehensive metabolic, neurobehavioral, and neurochemical analyses. Data show that lopinavir/ritonavir-induced lipodystrophy, hypoadiponectinemia, hyperglycemia, hyperinsulinemia, and hypertriglyceridemia were attenuated in ADTg mice. Furthermore, cognitive function and blood-brain barrier integrity were preserved, while loss of cerebrovascular markers and white matter injury were prevented in ADTg mice. Finally, lopinavir/ritonavir caused significant increases in expression of markers of brain inflammation and decreases in synaptic markers in WT, but not in ADTg mice. Collectively, these data reinforce the pathophysiologic link from metabolic dysfunction to loss of cerebrovascular and cognitive homeostasis; and suggest that preservation and/or replacement of adiponectin could prevent these key aspects of HIV protease inhibitor-induced toxicity in clinical settings.

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.

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.

Human immunodeficiency virus (HIV) modulates the associations between insulin resistance and cognition in the current combination antiretroviral therapy (cART) era: a study of the Women's Interagency HIV Study (WIHS)

Cognitive impairment (CI) remains common despite access to combination antiretroviral therapy (cART); it has been linked to HIV-specific, HIV-related, and HIV-unrelated factors. Insulin resistance (IR) was associated with CI in the early cART era, when antiretroviral medications had greater mitochondrial and metabolic toxicity. We sought to examine these relationships in the current cART era of reduced antiretroviral toxicities. This study examined IR among non-diabetics in relation to a 1-h neuropsychological test battery among 994 women (659 HIV-infected and 335 HIV-uninfected controls) assessed between 2009 and 2011. The mean (standard deviation (SD)) age of the sample was 45.1 (9.3) years. The HIV-infected sample had a median interquartile range (IQR) cluster of differentiation 4 (CD4) T-lymphocyte count of 502 (310-727) cells/μL, and 54 % had undetectable plasma HIV RNA levels. Among all, the homeostasis model assessment (HOMA) of IR ranged from 0.25 to 37.14. In adjusted models, increasing HOMA was significantly associated with reduced performance on Letter-Number Sequencing (LNS) attention task (β = -0.10, p < 0.01) and on Hopkins Verbal Learning Test (HVLT) recognition (β = -0.10, p < 0.01) with weaker but statistically significant associations on phonemic fluency (β = -0.09, p = 0.01). An HIV*HOMA interaction effect was identified on the LNS attention task and Stroop trials 1 and 2, with worse performance in HIV-infected vs. HIV-uninfected women. In separate analyses, cohort members who had diabetes mellitus (DM) performed worse on the grooved pegboard test of psychomotor speed and manual dexterity. These findings confirm associations between both IR and DM on some neuropsychological tests and identify an interaction between HIV status and IR.

Investigation of menopausal stage and symptoms on cognition in human immunodeficiency virus-infected women

OBJECTIVE

We evaluated the separate and interactive associations of menopausal stage, menopausal symptoms, and human immunodeficiency virus (HIV) infection with cognition. We hypothesized that HIV-infected perimenopausal women would show the greatest cognitive difficulties and that menopausal symptoms would be inversely associated with cognition.

METHODS

This cross-sectional study included 708 HIV-infected and 278 HIV-uninfected premenopausal, perimenopausal, or postmenopausal women (64% African American; median age, 44 y) from the Women's Interagency HIV Study. Participants completed tests of verbal learning and memory, attention/processing speed, and executive function. We administered a menopausal symptom questionnaire that assessed anxiety, vasomotor, and sleep symptoms and obtained measures of depressive symptoms.

RESULTS

In multivariable regression analyses controlling for relevant covariates, HIV infection, but not menopausal stage, was associated with worse performance on all cognitive measures (P's < 0.05). Depressive symptoms were associated with lower cognitive performance on measures of verbal learning and memory, attention, and executive function (P's < 0.05); anxiety symptoms were associated with lower performance on measures of verbal learning and memory (P's < 0.05). Vasomotor symptoms were associated with worse attention (P < 0.05). HIV and anxiety symptoms interacted to influence verbal learning (P's < 0.05); elevated anxiety was associated with worse verbal learning in HIV-infected women only.

CONCLUSIONS

Vasomotor, depressive, and anxiety symptoms, but not menopausal stage, are associated with worse cognitive performance in both HIV-infected and HIV-uninfected women, although elevated anxiety symptoms are more associated with verbal learning deficits in HIV-infected women. Because cognitive problems can interfere with everyday functioning, including treatment adherence, it may be important to screen and treat anxiety in HIV-infected women.

Food insecurity with hunger is associated with obesity among HIV-infected and at risk women in Bronx, NY

BACKGROUND

Food insecurity, insufficient quality and quantity of nutritionally adequate food, affects millions of people in the United States (US) yearly, with over 18 million Americans reporting hunger. Food insecurity is associated with obesity in the general population. Due to the increasing prevalence of obesity and risk factors for cardiovascular disease among HIV-infected women, we sought to determine the relationship between food insecurity and obesity in this cohort of urban, HIV-infected and -uninfected but at risk women.

METHODS

Using a cross-sectional design, we collected data on food insecurity, body mass index and demographic and clinical data from 231 HIV-infected and 119 HIV-negative women enrolled in Bronx site of the Women's Interagency HIV Study (WIHS). We used multivariate logistic regression to identify factors associated with obesity.

RESULTS

Food insecurity was highly prevalent, with almost one third of women (110/350, 31%) reporting food insecurity over the previous six months and over 13% of women reported food insecurity with hunger. Over half the women were obese with a Body Mass Index (BMI) of ≥ 30. In multivariate analyses, women who were food insecure with hunger had higher odds of obesity (Adjusted odds ratio [aOR] =  2.56, 95% Confidence Interval [CI]  =  1.27, 5.20) after adjusting for HIV status, age, race, household status, income, drug and alcohol use.

CONCLUSION

Food insecurity with hunger was associated with obesity in this population of HIV-infected and -uninfected, urban women. Both food insecurity and obesity are independent markers for increased mortality; further research is needed to understand this relationship and their role in adverse health outcomes.

Designer adiponectin receptor agonist stabilizes metabolic function and prevents brain injury caused by HIV protease inhibitors

HIV protease inhibitors (PI) are fundamental to combination antiretroviral therapy, which has revolutionized HIV clinical care and produced significant reductions in HIV-associated morbidity and mortality. However, PI administration is frequently associated with severe metabolic impairment, including lipodystrophy, dyslipidemia, and insulin resistance; all of which can contribute to cardiovascular and neurologic co-morbidities. Experimental and epidemiological data support a potentially important role for the adipokine adiponectin in both metabolic and neurologic physiology. This study examined if ADP355, a novel, peptide-based adiponectin receptor agonist, could neutralize the detrimental effects of PI treatment in experimental animal models. Adult male C57BL/6 mice were subjected to a clinically relevant, 4-week regimen of lopinavir/ritonavir, with daily injections of ADP355 administered only during the final 2 weeks of PI exposure. Comprehensive metabolic, neurobehavioral, and biochemical analyses revealed that ADP355 administration partially reversed PI-induced loss of subcutaneous adipose tissue, attenuated PI-induced hyperinsulinemia, hypertriglyceridemia, and hypoadiponectinemia, and prevented PI-induced cognitive impairment and brain injury. Collectively, these data reinforce the link between metabolic co-morbidities and cognitive impairment and suggest that pharmacological reactivation of adiponectin pathways could remediate key aspects of PI-induced metabolic syndrome in clinical settings. Furthermore, therapeutic targeting of adiponectin receptors could show utility in reducing the prevalence and/or severity of HIV-associated neurocognitive disorders.

HIV and recent illicit drug use interact to affect verbal memory in women

OBJECTIVE

HIV infection and illicit drug use are each associated with diminished cognitive performance. This study examined the separate and interactive effects of HIV and recent illicit drug use on verbal memory, processing speed, and executive function in the multicenter Women's Interagency HIV Study.

METHODS

Participants included 952 HIV-infected and 443 HIV-uninfected women (mean age = 42.8, 64% African-American). Outcome measures included the Hopkins Verbal Learning Test-Revised and the Stroop test. Three drug use groups were compared: recent illicit drug users (cocaine or heroin use in past 6 months, n = 140), former users (lifetime cocaine or heroin use but not in past 6 months, n = 651), and nonusers (no lifetime use of cocaine or heroin, n = 604).

RESULTS

The typical pattern of recent drug use was daily or weekly smoking of crack cocaine. HIV infection and recent illicit drug use were each associated with worse verbal learning and memory (P < 0.05). Importantly, there was an interaction between HIV serostatus and recent illicit drug use such that recent illicit drug use (compared with nonuse) negatively impacted verbal learning and memory only in HIV-infected women (P < 0.01). There was no interaction between HIV serostatus and illicit drug use on processing speed or executive function on the Stroop test.

CONCLUSIONS

The interaction between HIV serostatus and recent illicit drug use on verbal learning and memory suggests a potential synergistic neurotoxicity that may affect the neural circuitry underlying performance on these tasks.

Tumor necrosis factor-induced cerebral insulin resistance in Alzheimer's disease links numerous treatment rationales

The evident limitations of the amyloid theory of the pathogenesis of Alzheimer's disease are increasingly putting alternatives in the spotlight. We argue here that a number of independently developing approaches to therapy-including specific and nonspecific anti-tumor necrosis factor (TNF) agents, apolipoprotein E mimetics, leptin, intranasal insulin, the glucagon-like peptide-1 mimetics and glycogen synthase kinase-3 (GSK-3) antagonists-are all part of an interlocking chain of events. All these approaches inform us that inflammation and thence cerebral insulin resistance constitute the pathway on which to focus for a successful clinical outcome in treating this disease. The key link in this chain presently absent is a recognition by Alzheimer's research community of the long-neglected history of TNF induction of insulin resistance. When this is incorporated into the bigger picture, it becomes evident that the interventions we discuss are not competing alternatives but equally valid approaches to correcting different parts of the same pathway to Alzheimer's disease. These treatments can be expected to be at least additive, and conceivably synergistic, in effect. Thus the inflammation, insulin resistance, GSK-3, and mitochondrial dysfunction hypotheses are not opposing ideas but stages of the same fundamental, overarching, pathway of Alzheimer's disease pathogenesis. The insight this provides into progenitor cells, including those involved in adult neurogenesis, is a key part of this approach. This pathway also has therapeutic implications for other circumstances in which brain TNF is pathologically increased, such as stroke, traumatic brain injury, and the infectious disease encephalopathies.

Brain injury caused by HIV protease inhibitors: role of lipodystrophy and insulin resistance

HIV-associated neurocognitive disorders (HAND) remain prevalent even with widespread use of combination antiretroviral therapy (ART), suggesting a potential role for co-morbidities in neurologic decline. Indeed, it is well established that ART drugs, particularly HIV protease inhibitors, can induce hyperlipidemia, lipodystrophy, and insulin resistance; all of which are associated with neurologic impairment. This study was designed to determine how metabolic dysfunction might contribute to cognitive impairment and to reveal specific metabolic co-morbidities that could be targeted to preserve brain function. Adult male C57BL/6 mice were thus treated with clinically relevant doses of lopinavir/ritonavir for 4 weeks, and subjected to thorough metabolic, neurobehavioral, and biochemical analyses. Data show that lopinavir/ritonavir resulted in manifestations of lipodystrophy, insulin resistance, and hyperlipidemia. Evaluation of neurologic function revealed cognitive impairment and increased learned helplessness, but not motor impairment following treatment with lopinavir/ritonavir. Further analyses revealed a significant linear relationship between cognitive performance and specific markers of lipodystrophy and insulin resistance. Finally, analysis of brain injury indicated that lopinavir/ritonavir treatment resulted in cerebrovascular injury associated with decreased synaptic markers and increased inflammation, and that the cerebral cortex was more vulnerable than the cerebellum or hippocampus. Collectively, these data reveal an intimate link between metabolic co-morbidities and cognitive impairment, and suggest that remediation of selective aspects of metabolic syndrome could potentially reduce the prevalence or severity HIV-associated neurocognitive disorders.

Cerebrovascular risk factors and brain microstructural abnormalities on diffusion tensor images in HIV-infected individuals

HIV-associated neurocognitive disorder remains prevalent in HIV-infected individuals despite effective antiretroviral therapy. As these individuals age, comorbid cerebrovascular disease will likely impact cognitive function. Effective tools to study this impact are needed. This study used diffusion tensor imaging (DTI) to characterize brain microstructural changes in HIV-infected individuals with and without cerebrovascular risk factors. Diffusion-weighted MRIs were obtained in 22 HIV-infected subjects aged 50 years or older (mean age = 58 years, standard deviation = 6 years; 19 males, three females). Tensors were calculated to obtain fractional anisotropy (FA) and mean diffusivity (MD) maps. Statistical comparisons accounting for multiple comparisons were made between groups with and without cerebrovascular risk factors. Abnormal glucose metabolism (i.e., impaired fasting glucose, impaired glucose tolerance, or diabetes mellitus) was associated with significantly higher MD (false discovery rate (FDR) critical p value = 0.008) and lower FA (FDR critical p value = 0.002) in the caudate and lower FA in the hippocampus (FDR critical p value = 0.004). Pearson correlations were performed between DTI measures in the caudate and hippocampus and age- and education-adjusted composite scores of global cognitive function, memory, and psychomotor speed. There were no detectable correlations between the neuroimaging measures and measures of cognition. In summary, we demonstrate that brain microstructural abnormalities are associated with abnormal glucose metabolism in the caudate and hippocampus of HIV-infected individuals. Deep gray matter structures and the hippocampus may be vulnerable in subjects with comorbid abnormal glucose metabolism, but our results should be confirmed in further studies.