Weight Gain After HIV Therapy Initiation: Pathophysiology and Implications

Changes in hepatic steatosis before and after direct acting antiviral treatment in people living with HIV and Hepatitis C coinfection

BACKGROUND

Both HIV and hepatitis C virus (HCV) infection increase the risk of hepatic steatosis (HS), which in turn contributes to the severity and progression of liver disease. Direct acting antivirals (DAAs) can cure HCV but whether they reduce HS is unclear.

METHODS

HS was assessed using the controlled attenuation parameter (CAP) and the hepatic steatosis index (HSI) in participants coinfected with HIV-HCV from the Canadian Coinfection Cohort. Changes in HS, before, during and after successful DAA treatment, were estimated using generalized additive mixed models, adjusted for covariates measured prior to treatment (age, sex, duration of HCV infection, body mass index, diabetes, prior exposure to dideoxynucleosides and hazardous drinking).

RESULTS

431 participants with at least one measure of CAP or HSI before treatment were included. CAP steadily increased over time: adjusted annual slope 3.3 dB/m (95% credible interval (CrI) 1.6, 4.9) before, and 3.9 dB/m (95% CrI: 1.9, 5.9) after DAA treatment, irrespective of pre-treatment CAP. In contrast, HSI changed little over time: annual slope 0.2 (95% CrI: -0.1, 0.5) before and 0.2 (95% CrI -0.1, 0.5) after, but demonstrated a marked reduction during treatment -4.5 (95% CrI -5.9, -3.1).

CONCLUSIONS

When assessed by CAP, HS was unaffected by DAA treatment and steadily increased over time. In contrast, HSI did not appear to reflect changes in HS, with the decrease during treatment likely related to resolution of hepatic inflammation. Ongoing HS may pose a risk for liver disease in coinfected people cured of HCV.

Changes in bodyweight after initiating antiretroviral therapy close to HIV-1 seroconversion: an international cohort collaboration

BACKGROUND

Understanding the reasons for and consequences of bodyweight change in people living with HIV initiating antiretroviral therapy (ART) is crucial to optimising long-term health and wellbeing. We aimed to examine bodyweight trends and associated factors among individuals with well estimated dates of HIV-1 seroconversion.

METHODS

In this cohort study, we pooled retrospective data from clinical records of participants in CASCADE aged 16 years and older recruited from clinics in France, Greece, the Netherlands, Spain, Sweden, the UK, and Canada. All participants had well estimated dates of HIV-1 seroconversion, seroconverted between Jan 1, 2007, and Dec 31, 2022 (HIV-1 positive antibody test within 12 months of an HIV-1 negative antibody test, or other laboratory evidence of seroconversion), initiated ART within 1 year of seroconversion, and were previously ART-naive. Participants were followed up to the time of data pooling (May 31, 2023). We modelled bodyweight changes after ART initiation by ART class, BMI categories, and other demographic characteristics using linear mixed models.

FINDINGS

Of 15 755 potentially eligible participants, 5698 met inclusion criteria. Of those, 5148 (90·3%) were assigned male at birth, 517 (9·1%) were assigned female at birth, and 33 (0·6%) had sex not known. 2778 (48·8%) participants initiated integrase strand transfer inhibitor (INSTI)-based ART regimens, 1809 (31·7%) initiated protease inhibitor-based regimens, and 1111 (19·5%) initiated non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens. The majority of participants were men who have sex with men (MSM; 4519 [79·3%]). Median age at seroconversion was 33·7 years (IQR 26·9-43·2). Bodyweight changes differed significantly by ART class within all baseline BMI categories (BMI <18·5 kg/m2 p=0·026, BMI 18·5-24·9 kg/m2 p<0·0001, BMI 25·0-29·9 kg/m2 p=0·0021, and BMI ≥30·0 kg/m2 p=0·0033; ART class and BMI interaction p=0·011). Participants with BMI less than 30 kg/m2 on regimens including both INSTI and tenofovir alafenamide gained 4·76 kg (95% CI 4·05-5·46) or more at 3 years. Of those with baseline BMI 18·5-24·9 kg/m2, 31·3% (95% CI 29·5-33·1) on INSTI-based regimens, 25·3% (23·0-27·7) on protease inhibitor-based regimens, 20·4% (18·8-22·9) on NNRTI-based regimens, 37·4% (33·9-40·9) on tenofovir alafenamide-based regimens, and 38·4% (34·6-42·1) on tenofovir alafenamide and INSTI-based regimens had gained more than 10% of their baseline bodyweight at 3 years. The greatest 3-year bodyweight gains by individuals on INSTI-based regimens and with BMI 18·5-24·9 kg/m2 were in women (5·63 kg [95% CI 4·92-6·35]), and people originating from sub-Saharan African (5·76 kg [5·06-6·46]), compared with MSM (3·82 kg [3·50-4·13]).

INTERPRETATION

Our findings suggest a direct effect of INSTIs and tenofovir alafenamide on bodyweight gain, rather than a return to health effect. Given the known risk for cardiometabolic disease, bodyweight management needs to be part of the overall care of individuals prescribed these drugs.

FUNDING

ViiV Healthcare UK, Janssen Pharmaceutica, and Merck Sharp & Dohme.

The impact of sex on HIV immunopathogenesis and therapeutic interventions

Globally, the majority of people living with HIV are women or girls, but they have been a minority of participants in clinical trials and observational studies of HIV. Despite this underrepresentation, differences in the pathogenesis of HIV have been observed between men and women, with contributions from both gender- and sex-based factors. These include differences in the risk of HIV acquisition, in viral load set point and immune activation in responses to viremia, and differences in HIV reservoir maintenance. These differences obligate adequate study in both males and females in order to optimize treatments, but also provide a powerful leverage point for delineating the mechanisms of HIV pathogenesis. The shifts in exposure to sex steroid hormones across a lifespan introduce additional complexity, which again can be used to focus on either genetic or hormonal influences as the driver of an outcome. In this Review, we discuss consistent and reproducible differences by sex across the spectrum of HIV, from acquisition through pathogenesis, treatment, and cure, and explore potential mechanisms and gaps in knowledge.

Low CD4 counts predict excessive weight gains during first-line treatment for HIV

BACKGROUND

Weight gain is common after antiretroviral initiation, especially among females, those of black race and lower baseline CD4, although this may potentially be due to lower baseline weight. Use of tenofovir disoproxil fumarate or efavirenz can suppress weight gain.

METHODS

Data were pooled from the ADVANCE (n = 1053), NAMSAL (n = 613) and WHRI001 (n = 536) trials investigating first-line regimen. Week 96 weight and body mass index (BMI) was stratified by baseline CD4. Multivariable models of weight change and incident obesity (BMI ≥30 kg/m2) were adjusted for baseline CD4, age, sex, tenofovir disoproxil fumarate, efavirenz, baseline BMI and trial.

RESULTS

Participants across all treatment arms experienced weight gain from baseline to week 96, with baseline CD4 count, baseline HIV RNA, tenofovir alafenamide and dolutegravir use, and female sex significant predictors. Mean unadjusted weight change was highest with CD4 < 100 (+8.6 kg; SD = 8.2) and lowest with CD4 ≥ 350 (+3.0 kg; SD = 6.5). This weight gain in CD4 < 100 was highest for participants on tenofovir alafenamide-inclusive treatment, such that absolute weight at week 96 was highest in the CD4 < 100 group. Although not statistically significant, obesity rate (BMI ≥ 30 kg/m2) in those taking TAF/FTC + DTG with CD4 < 100 overtook that seen in CD4 ≥ 350, despite lower baseline obesity prevalence. The unadjusted findings were corroborated in multivariable longitudinal models.

CONCLUSIONS

Participants with low CD4 may demonstrate significant 'overshoot' weight gain, in addition to 'return to health', with a trend towards increased risk of obesity when initiated on TAF/FTC + DTG. Use of tenofovir disoproxil fumarate and efavirenz were associated with smaller weight gains. Effective weight management strategies are needed, especially for individuals with low baseline CD4.

Safety and Efficacy of Antiviral Drugs and Vaccines in Pregnant Women: Insights from Physiologically Based Pharmacokinetic Modeling and Integration of Viral Infection Dynamics

Addressing the complexities of managing viral infections during pregnancy is essential for informed medical decision-making. This comprehensive review delves into the management of key viral infections impacting pregnant women, namely Human Immunodeficiency Virus (HIV), Hepatitis B Virus/Hepatitis C Virus (HBV/HCV), Influenza, Cytomegalovirus (CMV), and SARS-CoV-2 (COVID-19). We evaluate the safety and efficacy profiles of antiviral treatments for each infection, while also exploring innovative avenues such as gene vaccines and their potential in mitigating viral threats during pregnancy. Additionally, the review examines strategies to overcome challenges, encompassing prophylactic and therapeutic vaccine research, regulatory considerations, and safety protocols. Utilizing advanced methodologies, including PBPK modeling, machine learning, artificial intelligence, and causal inference, we can amplify our comprehension and decision-making capabilities in this intricate domain. This narrative review aims to shed light on diverse approaches and ongoing advancements, this review aims to foster progress in antiviral therapy for pregnant women, improving maternal and fetal health outcomes.

Gestational weight gain and adverse birth outcomes in South African women with HIV on antiretroviral therapy and without HIV: a prospective cohort study

INTRODUCTION

Outside of pregnancy, evidence shows that persons with HIV initiating or switching to dolutegravir (DTG)-based antiretroviral therapy (ART) experience greater weight gain compared to those on other ART classes. However, there are few data on the impact of DTG-based ART on gestational weight gain (GWG) in sub-Saharan Africa where HIV is most common. According to the National Academy of Medicine (NAM), GWG below and above NAM guidelines is associated with adverse birth outcomes. Therefore, the objective of this study was to describe GWG by HIV status and ART regimen, and examine the associations with adverse birth outcomes.

METHODS

We enrolled pregnant women with HIV (WHIV) and without HIV (≥18 years) in a peri-urban primary healthcare facility in Cape Town, South Africa between 2019 and 2022. GWG was study-measured at 24-28 (baseline) and 33-38 weeks gestation and converted to GWG rate (kg/week) in accordance with NAM guidelines. GWG z-scores were generated using the INTEGROWTH-21 and US standards to account for differing lengths of gestation. Birth outcome data were obtained from medical records. Associations of GWG z-score with adverse birth outcomes were assessed using multivariable linear or log-binomial regression.

RESULTS

Among 292 participants (48% WHIV), median age was 29 years (IQR, 25-33), median pre-pregnancy body mass index (BMI) was 31 kg/m2 (IQR, 26-36) and 20% were primiparous at baseline. The median weekly rate of GWG was 0.30 kg/week (IQR, 0.12-0.50), 35% had GWG below NAM standards (59% WHIV) and 48% had GWG above NAM standards (36% WHIV). WHIV gained weight more slowly (0.25 vs. 0.37 kg/week, p<0.01) than women without HIV. Weekly rate of GWG did not differ by ART regimen (DTG-based ART 0.25 vs. efavirenz-based ART 0.27 kg/week, p = 0.80). In multivariable analyses, GWG z-score was positively associated with continuous birth weight (mean difference = 68.53 95% CI 8.96, 128.10) and categorical high birth weight of >4000 g (RR = 2.18 95% CI 1.18, 4.01).

CONCLUSIONS

Despite slower GWG among WHIV, nearly half of all women gained weight faster than recommended by the NAM. GWG was positively associated with infant birth weight. Interventions to support healthy GWG in sub-Saharan Africa are urgently needed.

Exercise to Prevent Accelerated Vascular Aging in People Living With HIV

Given advances in antiretroviral therapy, the mortality rate for HIV infection has dropped considerably over recent decades. However, people living with HIV (PLWH) experience longer life spans coupled with persistent immune activation despite viral suppression and potential toxicity from long-term antiretroviral therapy use. Consequently, PLWH face a cardiovascular disease (CVD) risk more than twice that of the general population, making it the leading cause of death among this group. Here, we briefly review the epidemiology of CVD in PLWH highlighting disparities at the intersections of sex and gender, age, race/ethnicity, and the contributions of social determinants of health and psychosocial stress to increased CVD risk among individuals with marginalized identities. We then overview the pathophysiology of HIV and discuss the primary factors implicated as contributors to CVD risk among PLWH on antiretroviral therapy. Subsequently, we highlight the functional evidence of premature vascular dysfunction as an early pathophysiological determinant of CVD risk among PLWH, discuss several mechanisms underlying premature vascular dysfunction in PLWH, and synthesize current research on the pathophysiological mechanisms underlying accelerated vascular aging in PLWH, focusing on immune activation, chronic inflammation, and oxidative stress. We consider understudied aspects such as HIV-related changes to the gut microbiome and psychosocial stress, which may serve as mechanisms through which exercise can abrogate accelerated vascular aging. Emphasizing the significance of exercise, we review various modalities and their impacts on vascular health, proposing a holistic approach to managing CVD risks in PLWH. The discussion extends to critical future study areas related to vascular aging, CVD, and the efficacy of exercise interventions, with a call for more inclusive research that considers the diversity of the PLWH population.

Expanding the human gut microbiome atlas of Africa

Population studies are crucial in understanding the complex interplay between the gut microbiome and geographical, lifestyle, genetic, and environmental factors. However, populations from low- and middle-income countries, which represent ~84% of the world population, have been excluded from large-scale gut microbiome research. Here, we present the AWI-Gen 2 Microbiome Project, a cross-sectional gut microbiome study sampling 1,803 women from Burkina Faso, Ghana, Kenya, and South Africa. By intensively engaging with communities that range from rural and horticultural to urban informal settlements and post-industrial, we capture population diversity that represents a far greater breadth of the world's population. Using shotgun metagenomic sequencing, we find that study site explains substantially more microbial variation than disease status. We identify taxa with strong geographic and lifestyle associations, including loss of Treponema and Cryptobacteroides species and gain of Bifidobacterium species in urban populations. We uncover a wealth of prokaryotic and viral novelty, including 1,005 new bacterial metagenome-assembled genomes, and identify phylogeography signatures in Treponema succinifaciens. Finally, we find a microbiome signature of HIV infection that is defined by several taxa not previously associated with HIV, including Dysosmobacter welbionis and Enterocloster sp. This study represents the largest population-representative survey of gut metagenomes of African individuals to date, and paired with extensive clinical biomarkers, demographic data, and lifestyle information, provides extensive opportunity for microbiome-related discovery and research.

Recent data on the role of antiretroviral therapy in weight gain and obesity in persons living with HIV

PURPOSE OF REVIEW

Antiretroviral therapy (ART) has long been implicated in fat alterations and weight variations leading to cardiometabolic consequences. Recent largely prescribed antiretrovirals (ARVs) from the integrase-strand-transfer-inhibitor (INSTI) class have been associated with excessive weight gain/obesity in a minority of persons with HIV (PWH). As well, in the nucleoside reverse transcriptase inhibitors (NRTI) class, tenofovir-alafenamide (TAF), often replacing tenofovir-disoproxil-fumarate (TDF), has been associated with weight gain, a worrying concern in the present worldwide obesogenic environment. The respective role of the different ARV, the risk factors and the mechanisms remain questionable.

RECENT FINDINGS

The INSTIs dolutegravir (DTG) and bictegravir (BIC) and TAF have a proper effect on weight gain, while efavirenz (EFV) and TDF inhibit it. These effects are reported in ART-naïve PWH, in addition to weight gain resulting from the return to health process, and in ART-controlled PWH. Also, INSTIs induce weight gain in adolescents and excessive weight gain during pregnancy. The effects of INSTIs and TAF are additive. Their trajectory differs. Most of the weight gain is observed during the initial 12-month period.The main risk factors are low CD4+ and high viral load (VL) in ART-naïve PWH, Black race or originating from some African countries and female gender. The role of age and BMI differs between studies. The reversibility of the effect of INSTI and TAF appears limited.Regarding the mechanisms, the INSTIs can directly alter adipose tissue in particular through inhibition of fat beiging, resulting in fat fibrosis and hypertrophy. Macrophage infiltration is decreased. The mechanisms explaining the opposite effects of TDF and TAF remain elusive.

SUMMARY

The specific impact of DTG, BIC and TAF on weight gain/obesity in PWH is confirmed in different populations independently of the weight limiting effect of EFV and TDF. ART-linked excessive weight gain is uncommon. African origin and female sex are risk factors that need to be considered. The mechanisms are better understood for INSTIs but unknown for TDF/TAF. The reversibility of weight gain/obesity when stopping INSTI or TAF remains limited.

Intersections between HIV and obesity in emerging economies

PURPOSE OF REVIEW

HIV epidemics are increasing in many emerging economy countries, whilst the very process of 'economic emergence' is obesogenic. Annual deaths related to obesity and overweight are now four times more than for HIV globally. We describe the intersections between HIV and obesity in emerging economies, and highlight potential mitigation options, including antiobesity medications (AOMs), which are safe and effective, but inaccessibly priced.

RECENT FINDINGS

We summarize what is known about weight-change in HIV and review strategies including public health policies and clinical interventions for emerging economy countries to fight obesity. We also illustrate the landscape from a selection of 'emerging economy' countries with available data from UNAIDS, World Bank and World Obesity Federation to visualize the developing challenges faced. AOM course prices are high in many countries, but could be manufactured and sold profitably for much less. We present lessons from the early HIV/AIDS movements on how to improve access and pricing for AOMs for people with HIV with obesity in emerging economy countries.

SUMMARY

We illustrate the complex intersectional issues that 'emerging economy countries' may experience, with a 'double burden' of increasing HIV and obesity epidemics, and explore potential mitigation options, focussing on AOM access and pricing.

Sociodemographic and Clinical Predictors of Weight Gain During the First Year of Antiretroviral Therapy among Adults Living With HIV in Urban Tanzania

Antiretroviral therapy (ART) has improved the survival of people living with HIV (PLHIV) but this success has been accompanied by an increase in noncommunicable diseases. We conducted a prospective cohort study of 4000 adult PLHIV who were initiating ART in Dar es Salaam, Tanzania, to assess weight gain during the first year of treatment and associated sociodemographic and clinical factors. Anthropometric data were collected at ART initiation and monthly follow-up visits. The mean weight gain during the first year of treatment was 2.6 ± 0.3 kg, and the prevalence of overweight or obesity increased from 26.3% at baseline to 40.7%. Female sex, greater household wealth, lower CD4-T-cell counts, higher WHO HIV disease stage, and pulmonary tuberculosis were associated with a greater increase in body mass index (P < .05). Weight gain following ART initiation was common but was greater among females and PLHIV with advanced HIV or comorbidities.