Ambulatory blood pressure profiles in a subset of HIV-positive patients pre and post antiretroviral therapy

24-hour ambulatory blood pressure monitoring and hypertension related risk among HIV-positive and HIV-negative individuals: cross sectional study findings from rural Uganda

Hypertension is diagnosed and treated based on blood pressure (BP) readings obtained in the clinic setting. Positive HIV status is associated with a higher prevalence of abnormal diurnal BP patterns, diagnosed with ambulatory BP monitoring rather than the conventional method of BP measurement. Little is known about ambulatory BP profiles in people living with HIV (PLHIV) in low-income countries, especially within sub-Saharan Africa. In this study, we compared 24-h ambulatory BP profiles of 140 HIV-positive individuals vs. profiles in 166 HIV negative individuals living in rural Uganda. HIV was well-controlled, with all HIV seropositive participants reporting use of anti-retroviral therapy, and ~123 (88%) having undetectable viral load. Most participants reported ART use duration of less than 10 years. Compared to HIV negative participants, HIV positive participants had lower median 24-h systolic BP (110.4 mmHg (IQR: 105.7, 118.7) vs 117.7 mmHg (IQR: 110.8, 129.8), p < 0.001), and 24-h diastolic BP (69.2 mmHg (IQR: 65.0, 74.9) vs. 71.9 mmHg (IQR: 67.2, 78.1), p = 0.004). Adjusted results showed greater percentage systolic nocturnal dipping among PLHIV compared to HIV negative individuals (difference = 2.70 (IQR: 0.94, 4.47), p < 0.05). Results of the adjusted Poisson regression suggested lower prevalence of 24-h and night hypertension among HIV positives compared to HIV negative, but were not statistically significant. Our data suggest that continuous 24-h BP measurements are lower in PLHIV on ART compared to HIV negative individuals.

Diurnal Variation of Plasma Extracellular Vesicle Is Disrupted in People Living with HIV

BACKGROUND

Several types of extracellular vesicles (EVs) secreted by various immune and non-immune cells are present in the human plasma. We previously demonstrated that EV abundance and microRNA content change in pathological conditions, such as HIV infection. Here, we investigated daily variations of large and small EVs, in terms of abundance and microRNA contents in people living with HIV (PLWH) receiving antiretroviral therapy (HIV+ART) and uninfected controls (HIV-).

METHODS

Venous blood samples from n = 10 HIV+ART and n = 10 HIV- participants were collected at 10:00 and 22:00 the same day. Large and small plasma EVs were purified, counted, and the mature miRNAs miR-29a, miR-29b, miR-92, miR-155, and miR-223 copies were measured by RT-PCR.

RESULTS

Large EVs were significantly bigger in the plasma collected at 10:00 versus 22:00 in both groups. There was a significant day-night increase in the quantity of 5 miRNAs in HIV- large EVs. In HIV+ART, only miR-155 daily variation has been observed in large EVs. Finally, EV-miRNA content permits to distinguish HIV- to HIV+ART in multivariate analysis.

CONCLUSION

These results point that plasma EV amount and microRNA contents are under daily variation in HIV- people. This new dynamic measure is disrupted in PLWH despite viral-suppressive ART. This study highlights a significant difference concerning EV abundance and their content measured at 22:00 between both groups. Therefore, the time of blood collection must be considered in the future for the EV as biomarkers.

HIV-positive demonstrate more salt sensitivity and nocturnal non-dipping blood pressure than HIV-negative individuals

Background

High dietary salt and a lack of reduced blood pressure (BP) at night (non-dipping) are risk factors for the development of hypertension which may result in end-organ damage and death. The effect of high dietary salt on BP in black people of sub-Saharan Africa living with HIV is not well established. The goal of this study was to explore the associations between salt sensitivity and nocturnal blood pressure dipping according to HIV and hypertension status in a cohort of adult Zambian population.

Methods

We conducted an interventional study among 43 HIV-positive and 42 HIV-negative adults matched for age and sex. Study participants were instructed to consume a low (4 g) dietary salt intake for a week followed by high (9 g) dietary salt intake for a week. Salt resistance and salt sensitivity were defined by a mean arterial pressure difference of ≤5 mmHg and ≥ 8 mmHg, respectively, between the last day of low and high dietary salt intervention. Nocturnal dipping was defined as a 10–15% decrease in night-time blood pressure measured with an ambulatory blood pressure monitor.

Results

The median age was 40 years for both the HIV-positive and the HIV-negative group with 1:1 male to female ratio. HIV positive individuals with hypertension exhibited a higher BP sensitivity to salt (95%) and non-dipping BP (86%) prevalence compared with the HIV negative hypertensive (71 and 67%), HIV positive (10 and 24%) and HIV-negative normotensive (29 and 52%) groups, respectively (p < 0.05). Salt sensitivity was associated with non-dipping BP and hypertension in both the HIV-positive and HIV-negative groups even after adjustment in multivariate logistic regression (< 0.001).

Conclusions

The results of the present study suggest that high dietary salt intake raises blood pressure and worsens nocturnal BP dipping to a greater extent in hypertensive than normotensive individuals and that hypertensive individuals have higher dietary salt intake than their normotensive counterparts. Regarding HIV status, BP of HIV-positive hypertensive patients may be more sensitive to salt intake and demonstrate more non-dipping pattern compared to HIV-negative hypertensive group. However, further studies with a larger sample size are required to validate this.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40885-020-00160-0.

Pharmacological activation of the circadian component REV-ERB inhibits HIV-1 replication

Human immunodeficiency virus 1 (HIV-1) is a life-threatening pathogen that still lacks a curative therapy or vaccine. Despite the reduction in AIDS-related deaths achieved by current antiretroviral therapies, drawbacks including drug resistance and the failure to eradicate infection highlight the need to identify new pathways to target the infection. Circadian rhythms are endogenous 24-h oscillations which regulate physiological processes including immune responses to infection, and there is an emerging role for the circadian components in regulating viral replication. The molecular clock consists of transcriptional/translational feedback loops that generate rhythms. In mammals, BMAL1 and CLOCK activate rhythmic transcription of genes including the nuclear receptor REV-ERBα, which represses BMAL1 and plays an essential role in sustaining a functional clock. We investigated whether REV-ERB activity regulates HIV-1 replication and found REV-ERB agonists inhibited HIV-1 promoter activity in cell lines, primary human CD4 T cells and macrophages, whilst antagonism or genetic disruption of REV-ERB increased promoter activity. The REV-ERB agonist SR9009 inhibited promoter activity of diverse HIV-subtypes and HIV-1 replication in primary T cells. This study shows a role for REV-ERB synthetic agonists to inhibit HIV-1 LTR promoter activity and viral replication, supporting a role for circadian clock components in regulating HIV-1 replication.

Interplay between circadian clock and viral infection

The circadian clock underpins most physiological conditions and provides a temporal dimension to our understanding of body and tissue homeostasis. Disruptions of circadian rhythms have been associated with many diseases, including metabolic disorders and cancer. Recent literature highlights a role for the circadian clock to regulate innate and adaptive immune functions that may prime the host response to infectious organisms. Viruses are obligate parasites that rely on host cell synthesis machinery for their own replication, survival and dissemination. Here, we review key findings on how circadian rhythms impact viral infection and how viruses modulate molecular clocks to facilitate their own replication. This emerging area of viral-clock biology research provides a fertile ground for discovering novel anti-viral targets and optimizing immune-based therapies.

High prevalence of "non-dipping" blood pressure and vascular stiffness in HIV-infected South Africans on antiretrovirals

BACKGROUND

HIV-infected individuals are at increased risk of tissue inflammation and accelerated vascular aging ('inflamm-aging'). Abnormal diurnal blood pressure (BP) rhythms such as non-dipping may contribute to an increased risk of cardiovascular and cerebrovascular events in HIV infected individuals. However, little data exists on ambulatory blood pressure (ABP) and measures of vascular stiffness in the black African HIV infected population.

METHODS

This is a cross-sectional analysis of otherwise well, HIV infected outpatients on ART for >5 years. Study assessments included: 24hr ABP monitoring, pulse wave velocity (PWV) and central aortic systolic pressure (CASP) using a AtCor Medical Sphygmocor device, fasting lipogram, oral glucose tolerance test, high-sensitivity C-reactive protein (hsCRP) and anthropometric data. Patients completed a questionnaire of autonomic symptoms. CD4+ counts and viral loads were obtained from the National Laboratory results system.

RESULTS

Sixty seven black participants were included in the analysis of whom 91% (n = 61) were female with a mean age of 42.2 ± 8.6 years. The median duration on ART was 7.5 years (IQR = 6-10), 84% were virally supressed and the median CD4 count was 529.5cells/mm3 (IQR = 372.0-686.5). The majority (67%) were classified as overweight and 76% had an increased waist circumference, yet only 88% of participants were normotensive. A hsCRP level in the high cardiovascular risk category was found in 68% of participants. The prevalence of non-dipping BP was 65%. Interestingly, there was no association on multivariable analysis between dipping status and traditional risk factors for non-dipping BP, such as: obesity, autonomic dysfunction and older age.

CONCLUSION

This relatively young cross-sectional sample of predominantly normotensive, but overweight black women on effective ART >5 years showed: a high prevalence of non-dipping BP, inflammation and vascular stiffness. Causality cannot be inferred but cardiovascular risk reduction should be emphasized in these patients.

Immune markers, diurnal blood pressure profile and cardiac function in virologically suppressed HIV-infected patients

PURPOSE

Non-dipping nocturnal blood pressure (BP) pattern has been reported prevalent among HIV-infected patients and is associated with adverse cardiovascular outcomes. The aims of this observational study were to identify predictors of nocturnal BP decline, and to explore whether diurnal BP profile is associated with alterations in cardiac structure and function.

MATERIALS AND METHODS

A total of 108 treated HIV-infected patients with suppressed viremia underwent ambulatory BP measurement, 51 of these patients also underwent echocardiography.

RESULTS

Non-dipping nocturnal BP pattern was present in 51% of the patients. Decreased nocturnal decline in systolic BP (SBP) correlated with lower CD4 count (r_sp = 0.21, p = 0.032) and lower CD4/CD8 ratio (r_sp = 0.26, p = 0.008). In multivariate linear regression analyses, lower BMI (p = 0.015) and CD4/CD8 ratio <0.4 (p = 0.010) remained independent predictors of nocturnal decline in SBP. Nocturnal decline in SBP correlated with impaired diastolic function, e' (r = 0.28, p = 0.049) as did nadir CD4 count (r_sp = 0.38, p = 0.006). In multivariate linear regression analyses, nadir CD4 count <100 cells/μL (p = 0.037) and age (p < 0.001) remained independent predictors of e'.

CONCLUSIONS

Compromised immune status may contribute to attenuated diurnal BP profile as well as impaired diastolic function in well-treated HIV infection.

Race and sex differences in ambulatory blood pressure measures among HIV+ adults

Ambulatory blood pressure monitoring (ABPM) can identify phenotypes that cannot be measured in the clinic. Determining race and sex disparities in ABPM measures among HIV+ individuals may improve strategies to diagnose and treat hypertension in this high-risk population. We compared ABPM measures between 24 African-American and 25 white HIV+ adults (36 men and 13 women). Awake systolic blood pressure (SBP) and diastolic blood pressure (DBP) were similar in African-Americans and whites. After multivariable adjustment, sleep SBP and DBP were 9.7 mm Hg (95% confidence interval [95% CI]: 4.7, 14.8) and 8.4 mm Hg (95% CI: 4.3, 12.5) higher, respectively, among African-Americans compared with whites. After multivariable adjustment, SBP and DBP dipping ratios were 5.2% (95% CI: 1.7%, 8.7%) and 6.1% (95% CI 2.0%, 10.3%) smaller among African-Americans compared with whites. After multivariable adjustment, awake and sleep SBP and DBP were higher in men compared to women. There was no difference in SBP or DBP dipping ratios comparing men and women. The prevalence of awake masked hypertension was 42% in men versus 17% in women, and the prevalence of sleep masked hypertension was 57% among African-Americans versus 18% among whites. These data suggest that ABPM measures differ by race and sex in HIV+ adults.

Human Immunodeficiency Virus and Heart Failure in Low- and Middle-Income Countries

Successful combination therapy for human immunodeficiency virus (HIV) has transformed this disease from a short-lived infection with high mortality to a chronic disease associated with increasing life expectancy. This is true for high- as well as low- and middle-income countries. As a result of this increased life expectancy, people living with HIV are now at risk of developing other chronic diseases associated with aging. Heart failure has been common among people living with HIV in the eras of pre- and post- availability of antiretroviral therapy; however, our current understanding of the pathogenesis and approaches to management have not been systematically addressed. HIV may cause heart failure through direct (e.g., viral replication, mitochondrial dysfunction, cardiac autoimmunity, autonomic dysfunction) and indirect (e.g., opportunistic infections, antiretroviral therapy, alcohol abuse, micronutrient deficiency, tobacco use) pathways. In low- and middle-income countries, 2 large observational studies have recently reported clinical characteristics and outcomes in these patients. HIV-associated heart failure remains a common cardiac diagnosis in people living with heart failure, yet a unifying set of diagnostic criteria is lacking. Treatment patterns for heart failure fall short of society guidelines. Although there may be promise in cardiac glycosides for treating heart failure in people living with HIV, clinical studies are needed to validate in vitro findings. Owing to the burden of HIV in low- and middle-income countries and the concurrent rise of traditional cardiovascular risk factors, strategic and concerted efforts in this area are likely to impact the care of people living with HIV around the globe.

Ambulatory Blood Pressure Monitoring in Individuals with HIV: A Systematic Review and Meta-Analysis

INTRODUCTION

Abnormal diurnal blood pressure (BP) rhythms may contribute to the high cardiovascular disease risk in HIV-positive (HIV+) individuals. To synthesize the current literature on ambulatory BP monitoring (ABPM) in HIV+ individuals, a systematic literature review and meta-analysis were performed.

METHODS

Medical databases were searched through November 11, 2015 for studies that reported ABPM results in HIV+ individuals. Data were extracted by 2 reviewers and pooled differences between HIV+ and HIV-negative (HIV-) individuals in clinic BP and ABPM measures were calculated using random-effects inverse variance weighted models.

RESULTS

Of 597 abstracts reviewed, 8 studies with HIV+ cohorts met the inclusion criteria. The 420 HIV+ and 714 HIV- individuals in 7 studies with HIV- comparison groups were pooled for analyses. The pooled absolute nocturnal systolic and diastolic BP declines were 3.16% (95% confidence interval [CI]: 1.13%, 5.20%) and 2.92% (95% CI: 1.64%, 4.19%) less, respectively, in HIV+ versus HIV- individuals. The pooled odds ratio for non-dipping systolic BP (nocturnal systolic BP decline <10%) in HIV+ versus HIV- individuals was 2.72 (95% CI: 1.92, 3.85). Differences in mean clinic, 24-hour, daytime, or nighttime BP were not statistically significant. I2 and heterogeneity chi-squared statistics indicated the presence of high heterogeneity for all outcomes except percent DBP dipping and non-dipping SBP pattern.

CONCLUSIONS

An abnormal diurnal BP pattern may be more common among HIV+ versus HIV- individuals. However, results were heterogeneous for most BP measures, suggesting more research in this area is needed.

Mechanisms Influencing Circadian Blood Pressure Patterns Among Individuals with HIV

HIV+ individuals have an increased risk for cardiovascular disease (CVD), but the mechanisms behind this association are poorly understood. While hypertension is a well-established CVD risk factor, clinic-based blood pressure (BP) assessment by itself cannot identify several important BP patterns, including white coat hypertension, masked hypertension, nighttime hypertension, and nighttime BP dipping. These BP patterns can be identified over a 24-h period by ambulatory BP monitoring (ABPM). In this review, we provide an overview of the potential value of conducting ABPM in HIV+ individuals. ABPM phenotypes associated with increased CVD risk include masked hypertension (i.e., elevated out-of-clinic BP despite non-elevated clinic BP), nighttime hypertension, and a non-dipping BP pattern (i.e., a drop in BP of <10 % from daytime to nighttime). These adverse ABPM phenotypes may be highly relevant in the setting of HIV infection, given that increased levels of inflammatory biomarkers, high psychosocial burden, high prevalence of sleep disturbance, and autonomic dysfunction have been commonly reported in HIV+ persons. Additionally, although antiretroviral therapy (ART) is associated with lower AIDS-related morbidity and CVD risk, the mitochondrial toxicity, oxidative stress, lipodystrophy, and insulin resistance associated with long-term ART use potentially lead to adverse ABPM phenotypes. Existing data on ABPM phenotypes in the setting of HIV are limited, but suggest an increased prevalence of a non-dipping BP pattern. In conclusion, identifying ABPM phenotypes may provide crucial information regarding the mechanisms underlying the excess CVD risk in HIV+ individuals.

Cardiac Disease and HIV in Africa: A Case for Physical Exercise

AIDS-related deaths and new HIV infections have declined globally, but continue to be a major problem in Africa. Prior to the advent of antiretroviral treatment (ART) HIV patients died of immunodeficiency and associated opportunistic infections; Highly Active Antiretroviral Therapy (HAART) has resulted in increased survival of these patients and has transformed this illness into a chronic condition. Cardiovascular, respiratory, neurological and muscular problems interfere with exercise in HIV-infected patients. Particularly cardiovascular disease may be associated with direct damage by the virus, by antiretroviral therapy and by malnutrition and chronic lung disease, resulting in physical and psychological impairment. Recent studies have shown the benefits of exercise training to improvement of physiologic and functional parameters, with the gains being specific to the type of exercise performed. Exercise should be recommended to all HIV patients as an effective prevention and treatment for metabolic and cardiovascular syndromes associated with HIV and HAART exposure in sub-Saharan Africa.