Background

HIV is associated with atherosclerosis and low high-density lipoprotein (HDL). With inflammation, HDL becomes dysfunctional. We previously showed that proinflammatory HDL has high HDL redox activity (HRA). In this study, we compare HRA in HIV-infected versus non-HIV-infected subjects and relate HRA to indices of macrophage activation and cardiovascular disease risk.

Methods

102 HIV-infected subjects and 41 matched non-HIV controls without clinical cardiovascular disease underwent coronary CT angiography (CTA) and testing for immune/inflammatory biomarkers. The effect of purified HDL from each study subject on the oxidation rate of dihydrorhodamine-123 (DOR) was normalized to the DOR of pooled HDL from healthy subjects. The normalized ratio DOR subject/DOR pooled was used as a measure of HRA, with higher HRA suggesting dysfunctional HDL.

Results

HRA was higher in HIV-infected versus non-HIV subjects (1.4 ±0.01 versus 1.3 ±0.01, P=0.03). In multivariate modelling for HRA among all subjects, HIV status remained positively related to HRA (P=0.02), even after controlling for traditional cardiovascular risk factors, comorbid conditions and immune activation. Among HIV-infected subjects, HRA correlated inversely with HDL (rho=-0.32, P=0.002) and log adiponectin (r=-0.28, P=0.006), and correlated positively with log sCD163 (r=0.24, P=0.02) - a monocyte/macrophage activation marker - and with the percentage of non-calcified coronary atherosclerotic plaque (r=0.29, P=0.03). sCD163 remained significantly associated with HRA in multivariate modelling among HIV-infected subjects (P=0.03).

Conclusions

These data demonstrate increased HRA among HIV-infected subjects versus matched non-HIV subjects with comparable HDL levels. In HIV-infected subjects, HRA relates to macrophage activation and to non-calcified coronary atherosclerotic plaque, which may be rupture-prone. Further studies are needed in HIV-infected patients to elucidate the interplay between immune activation, HDL function and CVD risk.

Clinical trial registration number

NCT 00455793.

Metabolic complications relating to complex effects of viral and immune-mediated mechanisms are now a focus of clinical care among persons living with human immunodeficiency virus (PLHIV), and obesity is emerging as a critical problem. To address knowledge gaps, the US National Institutes of Health sponsored a symposium in May 2018 entitled "Obesity and Fat Metabolism in HIV-infected Individuals." Mechanisms relating to adipose dysfunction and fibrosis, immune function, inflammation, and gastrointestinal integrity were highlighted as contributors to obesity among PLHIV. Fibrotic subcutaneous adipose tissue is metabolically dysfunctional and loses its capacity to expand, leading to fat redistribution, including visceral obesity and ectopic fat accumulation, promoting insulin resistance. Viral proteins, including viral protein R and negative regulatory factor, have effects on adipogenic pathways and cellular metabolism in resident macrophages and T cells. HIV also affects immune cell trafficking into the adipose compartments, with effects on adipogenesis, lipolysis, and ectopic fat accumulation. Key cellular metabolic functions are likely to be affected in PLHIV by gut-derived cytokines and altered microbiota. There are limited strategies to reduce obesity specifically in PLHIV. Enhancing our understanding of critical pathogenic mechanisms will enable the development of novel therapeutics that may normalize adipose tissue function and distribution, reduce inflammation, and improve insulin sensitivity in PLHIV.

Background

Emerging data demonstrate that the use of integrase inhibitor (INSTI)-based antiretroviral treatment (ART) is associated with increased weight, but the cardiometabolic health consequences of increased weight remains poorly understood.

Methods

This analysis examined INSTI use (>6 months) at entry among REPRIEVE participants enrolled in High Income and Latin America/Caribbean Global Burden of Disease regions. Primary analyses used linear and logistic regression; secondary analyses used quantile regression to examine differences across the full data distribution. Characteristics of those with and without INSTI use were balanced using inverse probability of treatment weighting.

Results

Among 4500 REPRIEVE participants, 1848 were on an INSTI-based regimen at entry for an average of 2.1 ± 1.8 years. Integrase inhibitor use (vs no INSTI use) was associated with higher odds of obesity (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.4-1.9) and higher mean body mass index ([BMI] +1.5kg/m2; 95% CI, 1.0-1.9) and waist circumference (+3.6cm; 95% CI, 2.6-4.6). Differences in weight related to INSTI use were greater in the upper tails of the distribution (+3.1kg/m2 [95% CI, 1.9-4.4] at the 90th centile vs +0.7kg/m2 [95% CI, 0.2-1.2] at the 50th centile) and among women and nonwhite participants, with sex and race having an additive effect on BMI. Conversely, INSTI use was not associated with differences in glucose, low-density lipoprotein cholesterol, or higher odds of metabolic syndrome or hypertension.

Conclusions

Differences in weight and waist circumference associated with INSTI use are (1) not uniform across people with human immunodeficiency virus, (2) greatest among women and nonwhites, and (3) concentrated at the upper tails of weight distribution. These data identify at-risk subgroups for whom long-term cardiovascular disease outcomes should be carefully assessed.

Background

Patterns of antiretroviral therapy (ART) use and immunologic correlates vary globally, and contemporary trends are not well described.

Methods

The REPRIEVE trial (Randomized Trial to Prevent Vascular Events in HIV) enrolled persons with human immunodeficiency virus (HIV) who were aged 40-75 years, receiving ART, and had low-to-moderate cardiovascular disease risk. ART use was summarized within Global Burden of Disease (GBD) super-regions, with adjusted linear and logistic regression analyses examining associations with immune parameters and key demographics.

Results

A total of 7770 participants were enrolled, with a median age of 50 years (interquartile range, 45-55 years); 31% were female, 43% were black or African American, 15% were Asian, 56% had a body mass index >25 (calculated as weight in kilograms divided by height in meters squared), and 49% were current or former smokers. The median CD4 T-cell count was 620/µL (interquartile range, 447-826/ µ L), and the median duration of prior ART use, 9.5 years (5.3-14.8) years. The most common ART regimens were nucleoside/nucleotide reverse-transcriptase inhibitor (NRTI) plus nonnucleoside reverse-transcriptase inhibitor (43%), NRTI plus integrase strand transfer inhibitor (25%), and NRTI plus protease inhibitor (19%). Entry ART varied by GBD region, with shifts during the trial enrollment period. In adjusted analyses, entry CD4 cell count and CD4/CD8 ratio were associated with GBD region, sex, entry regimen, duration of ART, and nadir CD4 cell count; CD4 and CD8 cell counts were also associated with body mass index and smoking status.

Conclusions

There were substantial variations in ART use by geographic region and over time, likely reflecting the local availability of specific medications, changes in treatment guidelines and provider/patient preferences. The analyses of CD4 cell counts and CD4/CD8 ratios may provide valuable insights regarding immune correlates and outcomes in people living with HIV.

Clinical trials registration

NCT02344290.