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

Association Between Metformin Use and Cognitive and Physical Function in Persons with HIV and Diabetes

Older persons with HIV (PWH) experience high rates of cognitive impairment and frailty, and accelerated decline in physical function compared with the general population. Metformin use has been associated with beneficial effects on cognitive and physical function among older adults without HIV. The relationship between metformin use on these outcomes in PWH has not been evaluated. AIDS Clinical Trials Group (ACTG) A5322 is an observational cohort study of older PWH with annual assessments for cognition and frailty, including measures of physical function (e.g., gait speed and grip strength). Participants with diabetes who were prescribed antihyperglycemic medications were included in this analysis to evaluate the association between metformin and functional outcomes. Cross-sectional, longitudinal, and time-to-event models were used to evaluate the relationship between metformin exposure with cognitive, physical function, and frailty outcomes. Ninety-eight PWH met inclusion criteria and were included in at least one model. No significant associations between metformin use, frailty, physical, or cognitive function were noted in unadjusted or adjusted cross-sectional, longitudinal, or time-to-event models (p > .1 for all models). This study is the first to examine the association between metformin use on functional outcomes among older PWH. Although it did not ascertain significant associations between metformin use and functional outcomes, our small sample size, restriction to persons with diabetes, and lack of randomization to metformin therapy were limitations. Larger randomized studies are needed to determine whether metformin use has beneficial effects on cognitive or physical function in PWH. Clinical Trial Registration numbers: 02570672, 04221750, 00620191, and 03733132.

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.

Risk for incident diabetes is greater in prediabetic men with HIV than without HIV

BACKGROUND

Diabetes mellitus is a major comorbidity in people with HIV (PWH). Hyperglycemia below diabetic range defines prediabetes (prediabetes mellitus). We compared the progression from prediabetes mellitus to diabetes mellitus in PWH and people without HIV (PWOH).

METHODS

Fasting glucose was measured semiannually in the MACS since 1999. Men with prediabetes mellitus (fasting glucose between 100 and 125 mg/dl, confirmed within a year by fasting glucose in the prediabetes mellitus range or HbA1c between 5.7 and 6.4%) were included. The first visit with prediabetes mellitus was the baseline visit. Incident diabetes mellitus was defined as fasting glucose at least 126 mg/dl, confirmed at a subsequent visit, or self-reported diabetes mellitus, or use of anti-diabetes mellitus medication. We used binomial transition models to compare the progression from prediabetes mellitus to diabetes mellitus by HIV serostatus, adjusted for age, number of previous prediabetes mellitus to diabetes mellitus transitions, ethnicity, BMI, family history of diabetes mellitus, and hepatitis C virus (HCV) infection.

RESULTS

Between 1999 and 2019, 1584 men (793 PWH; 791 PWOH) with prediabetes mellitus were included. At baseline, PWH were younger (48 vs. 51 years, P < 0.01), had lower BMI (26 vs. 27), were more frequently nonwhite (47 vs. 30%), and HCV-infected as per last measure (8 vs. 4%) than PWOH (all P < 0.01). Over a median 12-year follow-up, 23% of participants developed diabetes mellitus. In adjusted analyses, the risk for incident diabetes mellitus was 40% (95% CI: 0--80%) higher among PWH than PWOH (P = 0.04).

CONCLUSION

Among men with prediabetes mellitus, PWH had an increased risk of incident diabetes mellitus adjusted for competing risk factors, warranting the evaluation of diabetes mellitus prevention strategies.

The Intersection of Cognitive Ability and HIV: A Review of the State of the Nursing Science

ABSTRACT

Neurocognitive problems have been endemic to the HIV epidemic since its beginning. Four decades later, these problems persist, but currently, they are attributed to HIV-induced inflammation, the long-term effects of combination antiretroviral therapy, lifestyle (i.e., physical activity, drug use), psychiatric, and age-associated comorbidities (i.e., heart disease, hypertension). In many cases, persons living with HIV (PLWH) may develop cognitive problems as a function of accelerated or accentuated normal aging and lifestyle rather than HIV itself. Nonetheless, such cognitive impairments can interfere with HIV care, including medication adherence and attending clinic appointments. With more than half of PLWH 50 years and older, and 30%-50% of all PLWH meeting the criteria for HIV-associated neurocognitive disorder, those aging with HIV may be more vulnerable to developing cognitive problems. This state of the science article provides an overview of current issues and provides implications for practice, policy, and research to promote successful cognitive functioning in PLWH.

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.

Metabolic Syndrome and Cardiovascular Disease Impacts on the Pathophysiology and Phenotype of HIV-Associated Neurocognitive Disorders

Evidence from epidemiological studies on the general population suggests that midlife cardiovascular disease (CVD) and/or metabolic syndrome (MetS) are associated with an increased risk of cognitive impairment and dementia later in life. In the modern combined antiretroviral therapy (cART) era, as in the general population, CVD and MetS were strongly and independently associated with poorer cognitive performances of sustained immunovirologically controlled persons living with human immunodeficiency viruses (PLHIVs). Those findings suggest that CV/metabolic comorbidities could be implicated in the pathogenesis of HIV-associated neurocognitive disorders (HAND) and might be more important than factors related to HIV infection or its treatment, markers of immunocompetence, or virus replication. The association between CVD/MetS and cognition decline is driven by still not well-understood mechanisms, but risk might well be the consequence of increased brain inflammation and vascular changes, notably cerebral small-vessel disease. In this review, we highlight the correspondences observed between the findings concerning CVD and MetS in the general population and virus-suppressed cART-treated PLHIVs to evaluate the real brain-aging processes. Indeed, incomplete HIV control mainly reflects HIV-induced brain damage described during the first decades of the pandemic. Given the growing support that CVD and MetS are associated with HAND, it is crucial to improve early detection and assure appropriate management of these conditions.

Gait Speed Decline Is Associated with Hemoglobin A1C, Neurocognitive Impairment, and Black Race in Persons with HIV

Gait speed declines at a faster rate in persons with HIV (PWH) than in the general population but the risk factors associated with this decline are not well understood. In the AIDS Clinical Trials Group (ACTG) A5322 (HAILO, HIV Infection, Aging, and Immune Function Long-term Observational Study), an observational cohort study of PWH ≥40 years of age, those who developed slow gait during the first 3 years of follow-up were compared with persons who maintained normal speed. Associations with demographic and clinical covariates were assessed using multivariable logistic regression. Of 929 participants, 81% were men, 31% Black, and 20% Hispanic. Median age was 51 years [interquartile range (IQR) = 46-56]. At study entry, 92% had plasma HIV RNA <50 copies/mL with median CD4 count 631 cells/mm³ (IQR = 458-840). At study entry, 7% of participants had slow gait, 16% had neurocognitive impairment (NCI), and 12% had diabetes. Over 3 years, 87% maintained normal gait speed, 3% maintained a slow gait, 6% developed a slow gait, and 4% improved from slow to normal gait speed. In multivariable models, hemoglobin A1C (HbA1C) percentage, per one unit increase [odds ratio (OR) = 1.36; 95% confidence interval (CI) = 1.03-1.81; p = .033], NCI (OR = 3.47; 95% CI = 1.57-7.69 p = .002), and black versus white race (OR = 2.45; 95% CI = 1.08-5.59; p = .032) at entry were significantly associated with development of slow gait compared with those maintaining normal gait speed. The association between baseline HbA1C and development of slow gait speed highlights an intervenable target to prevent progression of physical function limitations.

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.