Cardiovascular Autonomic Dysfunction in Africans Infected with Human Immunodeficiency Virus

The Interplay of HIV and Long COVID in Sub-Saharan Africa: Mechanisms of Endothelial Dysfunction

PURPOSE OF REVIEW

Long COVID affects approximately 5 million people in Africa. This disease is characterized by persistent symptoms or new onset of symptoms after an acute SARS-CoV-2 infection. Specifically, the most common symptoms include a range of cardiovascular problems such as chest pain, orthostatic intolerance, tachycardia, syncope, and uncontrolled hypertension. Importantly, these conditions appear to have endothelial dysfunction as the common denominator, which is often due to impaired nitric oxide (NO) mechanisms. This review discusses the role of mechanisms contributing to endothelial dysfunction in Long COVID, particularly in people living with HIV.

RECENT FINDINGS

Recent studies have reported that increased inflammation and oxidative stress, frequently observed in Long COVID, may contribute to NO dysfunction, ultimately leading to decreased vascular reactivity. These mechanisms have also been reported in people living with HIV. In regions like Africa, where HIV infection is still a major public health challenge with a prevalence of approximately 26 million people in 2022. Specifically, endothelial dysfunction has been reported as a major mechanism that appears to contribute to cardiovascular diseases and the intersection with Long COVID mechanisms is of particular concern. Further, it is well established that this population is more likely to develop Long COVID following infection with SARS-CoV-2. Therefore, concomitant infection with SARS-CoV-2 may lead to accelerated cardiovascular disease. We outline the details of the worsening health problems caused by Long COVID, which exacerbate pre-existing conditions such as endothelial dysfunction. The overlapping mechanisms of HIV and SARS-CoV-2, particularly the prolonged inflammatory response and chronic hypoxia, may increase susceptibility to Long COVID. Addressing these overlapping health issues is critical as it provides clinical entry points for interventions that could improve and enhance outcomes and quality of life for those affected by both HIV and Long COVID in the region.

Hypertension among people living with human immunodeficiency virus in sub-Saharan Africa: a systematic review and meta-analysis

We performed a systematic review and meta-analysis of hypertension in people living with human immunodeficiency virus (HIV) in sub-Saharan Africa (SSA). We searched the PubMed, Google Scholar, African Index Medicus, and Embase databases to identify studies published from January 1, 2010, to December 31, 2021. We used a random-effects model to estimate the pooled prevalence of hypertension and mean SBP/DBP level on a sex-specific basis. We included 48 studies reporting data on a pooled sample of 193,843 people living with HIV (PLW-HIV) in SSA. The pooled mean SBP/DBP level was 120 (95% CI 113-128)/77 (95%CI 72-82) mmHg, while the overall pooled prevalence of hypertension was 21.9% (95% CI 19.9-23.9%). Further meta-regression analyses suggested that the prevalence of hypertension was 1.33 times greater in males, 1.23 times greater in individuals receiving antiretroviral therapy (ART) and 1.45 times greater in those individuals with a CD4-count ≥ 200. This meta-analysis of the contemporary pattern of BP levels among PLW-HIV in SSA, suggests that around one in five of such individuals also have hypertension. Given the further context of greater access to ART and subsequently greater longevity, study findings support calls to integrate cardiovascular management into routine HIV care.

Association between HIV and Prevalent Hypertension and Diabetes Mellitus in South Africa: Analysis of a Nationally Representative Cross-Sectional Survey

OBJECTIVES

Cardiovascular disease (CVD) burden is increasing among persons living with HIV (PLWH) in sub-Saharan Africa. It is unclear whether this reflects absolute increase in HIV-related CVD risk or unmasking by improved survival. Therefore, we examined whether HIV is associated with adverse cardiometabolic profiles among South African adults.

METHODS

We analyzed a nationally representative dataset (n=6420), estimating the weighted prevalence of hypertension, diabetes, and 10-year predicted risk of incident fatal/nonfatal CVD (if aged ≥40 years). Associations between HIV and cardiometabolic indices were assessed using log-binomial regression models adjusted for sociodemographic factors.

RESULTS

HIV population prevalence was 18.9%, with a median age of 36 years. Hypertension (44.2% vs 45.4%), diabetes (18.6% vs 20.4%), and overweight/obesity (body mass index ≥25 kg/m²: 54.9% vs 52.0%) prevalence did not substantially differ by HIV status, although PLWH had a lower 10-year predicted CVD risk (median: 5.1% vs 13.5%). In adjusted models, females who are HIV-negative had a 5 mm Hg higher median systolic blood pressure (128 vs 123 mmHg) than female PLWH.

CONCLUSIONS

PLWH in South Africa have better cardiometabolic disease profiles than the general population, and social determinants, rather than HIV, may have a greater influence on cardiometabolic risk. Designating PLWH a CVD high-risk group in South Africa is likely unwarranted.

Linear and non-linear analysis of heart rate variability in HIV-positive patients on two different antiretroviral therapy regimens

Background

Cardiac autonomic dysfunction in HIV+ patients on different antiretroviral therapy (ART) regimens has been described. We aimed to characterize parameters of heart rate variability (HRV) and correlate with different classes of ART in HIV+ patients in three experimental conditions: rest, cold face, and tilt tests.

Methods

Cross-sectional study with three groups of age- and gender-matched individuals: group 1, 44 HIV+ patients undergoing combination therapy, with two nucleoside reverse transcriptase inhibitors (NRTI) and one non-nucleoside reverse transcriptase inhibitor (NNRTI); group 2, 42 HIV+ patients using two NRTI and protease inhibitors (PI’s); and group 3, 35 healthy volunteers with negative HIV serology (control group). Autonomic function at rest and during cold face- and tilt-tests was assessed through computerized analysis of HRV, via quantification of time- and frequency domains by linear and non-linear parameters in the three groups.

Results

Anthropometric and clinical parameters were similar between both HIV groups, except CD4+ T lymphocytes, which were significantly lower in group 2 (p = 0.039). At baseline, time-domain linear HRV parameters, RMSSD and pNN50, and the correlation dimension, a non-linear HRV parameter (p < 0.001; p = 0.018; p = 0.019, respectively), as well as response of RMSSD to cold face test were also lower in the HIV+ group than in the control individuals (p < 0.001), while no differences among groups were detected in HRV parameters during the tilt test.

Conclusions

Despite ART regimens, HIV+ patients presented lower cardiac vagal modulation than controls, whereas no difference was observed among the HIV groups, suggesting that higher cardiovascular risk linked to PIs may be associated with factors other than autonomic dysfunction.

Peripheral Neuronopathy Associated With Ebola Virus Infection in Rhesus Macaques: A Possible Cause of Neurological Signs and Symptoms in Human Ebola Patients

Neurological signs and symptoms are the most common complications of Ebola virus disease. However, the mechanisms underlying the neurologic manifestations in Ebola patients are not known. In this study, peripheral ganglia were collected from 12 rhesus macaques that succumbed to Ebola virus (EBOV) disease from 5 to 8 days post exposure. Ganglionitis, characterized by neuronal degeneration, necrosis, and mononuclear leukocyte infiltrates, was observed in the dorsal root, autonomic, and enteric ganglia. By immunohistochemistry, RNAscope in situ hybridization, transmission electron microscopy, and confocal microscopy, we confirmed that CD68+ macrophages are the target cells for EBOV in affected ganglia. Further, we demonstrated that EBOV can induce satellite cell and neuronal apoptosis and microglial activation in infected ganglia. Our results demonstrate that EBOV can infect peripheral ganglia and results in ganglionopathy in rhesus macaques, which may contribute to the neurological signs and symptoms observed in acute and convalescent Ebola virus disease in human patients.

Blood pressure trajectories and the mediated effects of body mass index and HIV-related inflammation in a mixed cohort of people with and without HIV in rural Uganda

We sought to describe changes in blood pressure and estimate the effect of HIV on blood pressure (BP) over 4 years of observation in a cohort of 155 HIV-infected adults (≥40 years) on antiretroviral therapy (ART) and 154 sex- and age-quartile-matched, population-based, HIV-uninfected controls for four years in rural Uganda, we compared changes in blood pressure (BP) by HIV serostatus and tested whether body mass index and inflammation (high-sensitivity C-reactive protein and interleukin-6) and immune activation (sCD14 and sCD163) mediated the effects of HIV on BP using hierarchical multivariate and two-stage parametric regression models. Overall HIV-uninfected participants had higher mean BP than HIV-infected counterparts (differences in trend P < 0.0001 for diastolic BP and P = 0.164 for systolic BP). After initial declines in BP in both groups between years 1 and 2, BP moderately increased in both groups through year 4, with greater change over time observed in the HIV-uninfected group. Body mass index mediated 72% (95%CI 57, 97) of the association between HIV and systolic BP. We found a minimal mediating effect of sCD14 on the relationship between HIV and SBP (9%, 95% CI 5%, 21%), but found no association between other HIV-related biomarkers. Over four years of observation, HIV-infected people in rural Uganda have lower BP than HIV-uninfected counterparts despite having higher levels of inflammation. BMI, rather than measures of HIV-associated inflammation, explained a majority of the difference in BP observed.

HIV-related cardiovascular disease and drug interactions

HIV infection is a global public health issue that is frequently associated with cardiovascular involvement. These HIV-associated cardiovascular manifestations are often clinically occult or attributed incorrectly to other non-cardiac disease processes. A heightened awareness and routine screening for cardiovascular involvement in HIV-infected patients leads to earlier detection and the hope for a reduction in associated morbidity and mortality. Left ventricular dysfunction, an independent predictor of mortality in HIV-infected patients, is the result of many causes in this population and may result in dilated cardiomyopathy and congestive heart failure in about 10% of patients. Other HIV-associated cardiovascular problems include infective endocarditis, cardiovascular malignancy, pulmonary arterial hypertension, vasculitis, pericardial effusion, premature atherosclerosis, and arrhythmias. HIV-associated cardiovascular emergencies include congestive heart failure, pulmonary edema, supraventricular and ventricular arrhythmias, endocarditis, and tamponade. Anti-infective and immunomodulatory therapies may be particularly helpful in this population to reduce associated cardiovascular disease. Highly active antiretroviral therapy may result in lipodystrophy, hyperlipidemia, truncal adiposity, and insulin resistance that can be improved by physical activity and training programs. Cardiovascular complications of therapeutic drugs in HIV-infected patients include torsade de pointes, congestive heart failure, dyslipidemia, accelerated atherosclerosis, and myocardial infarction. In summary, cardiovascular complications are important contributors to morbidity and mortality in HIV-infected patients that can be detected early in many cases and treated effectively.