Heightened levels of plasma growth differentiation factor 15 in men living with HIV

CROI 2024: Metabolic and Other Complications of HIV Infection

Comorbid conditions have a major impact on the health, quality of life, and survival of people with HIV (PWH), particularly as they age. The 2024 Conference on Retroviruses and Opportunistic Infections (CROI) featured many excellent reports related to specific comorbidities, most notably cardiovascular disease, cancer, fatty liver disease, and hypertension. Major themes included hypertension management strategies used in low- and middle-income countries, important insights from the REPRIEVE (Randomized Trial to Prevent Vascular Events in HIV) study that focused on cardiometabolic outcomes, studies investigating metabolic-associated fatty liver disease, and the use of glucagon-like peptide-1 receptor agonists in PWH. This review focuses on the abstracts presented at CROI 2024 that discussed these areas, highlighting those with the most clinical impact.

Adipose Tissue Dysfunction and Energy Balance Paradigms in People Living With HIV

Over the past 4 decades, the clinical care of people living with HIV (PLWH) evolved from treatment of acute opportunistic infections to the management of chronic, noncommunicable comorbidities. Concurrently, our understanding of adipose tissue function matured to acknowledge its important endocrine contributions to energy balance. PLWH experience changes in the mass and composition of adipose tissue depots before and after initiating antiretroviral therapy, including regional loss (lipoatrophy), gain (lipohypertrophy), or mixed lipodystrophy. These conditions may coexist with generalized obesity in PLWH and reflect disturbances of energy balance regulation caused by HIV persistence and antiretroviral therapy drugs. Adipocyte hypertrophy characterizes visceral and subcutaneous adipose tissue depot expansion, as well as ectopic lipid deposition that occurs diffusely in the liver, skeletal muscle, and heart. PLWH with excess visceral adipose tissue exhibit adipokine dysregulation coupled with increased insulin resistance, heightening their risk for cardiovascular disease above that of the HIV-negative population. However, conventional therapies are ineffective for the management of cardiometabolic risk in this patient population. Although the knowledge of complex cardiometabolic comorbidities in PLWH continues to expand, significant knowledge gaps remain. Ongoing studies aimed at understanding interorgan communication and energy balance provide insights into metabolic observations in PLWH and reveal potential therapeutic targets. Our review focuses on current knowledge and recent advances in HIV-associated adipose tissue dysfunction, highlights emerging adipokine paradigms, and describes critical mechanistic and clinical insights.

Energy balance and body composition after switch between integrase strand transfer inhibitors and doravirine among people with HIV

BACKGROUND

Integrase strand transfer inhibitors (INSTIs) are associated with excessive weight gain among a subset of persons with HIV (PWH), due to unclear mechanisms. We assessed energy intake (EI) and expenditure (EE) following switch off and onto INSTIs.

METHODS

PWH with >10% weight gain on an INSTI-based regimen switched INSTI to doravirine for 12 weeks, then back to INSTI for 12 weeks while keeping their remaining regimen stable. Twenty-four-hour EE, EI and weight were measured on INSTI, following switch to doravirine, and upon INSTI restart. Mixed models analysed changes over time.

RESULTS

Among 18 participants, unadjusted 24 h EE decreased by 83 (95% CI -181 to 14) kcal following switch to doravirine, and by 2 (-105 to 100) kcal after INSTI restart; energy balance (EE-EI) increased by 266 (-126 to 658) kcal from Week 0 to Week 12, and decreased by 3 (-429 to 423) kcal from Week 12 to Week 24. Trends toward weight loss occurred following switch to doravirine [mean -1.25 (-3.18 to 0.69) kg] and when back on INSTI [-0.47 (-2.45 to 1.52) kg]. Trunk fat decreased on doravirine [-474 (-1398 to 449) g], with some regain following INSTI restart [199 (-747 to 1145) g]. Fat-free mass decreased on doravirine [-491 (-1399 to 417) g] and increased slightly after INSTI restart [178 (-753 to 1108) g].

CONCLUSIONS

Among PWH with >10% weight gain on an INSTI, switch to doravirine was associated with a trend towards decreases in 24 h EE, weight, trunk fat mass and fat-free mass. Observed changes were not significant, but suggest a mild weight-suppressive effect of doravirine among PWH.

Growth differentiation factor-15 as a biomarker of atherosclerotic coronary plaque: Value in people living with and without HIV

Background

Increased rates of cardiovascular diseases (CVD) and larger subclinical high-risk coronary plaques in coronary CT angiography have been observed in people living with HIV (PLWH) treated with antiretroviral therapy (ART) compared to HIV-uninfected people. Growth differentiation factor-15 (GDF-15) is a cytokine emerging as an optimal marker for CVD in the general population.

Methods

We cross-sectionally analyzed plasma of 95 PLWH on ART and 52 controls. We measured GDF-15, fibroblast growth factor-21 (FGF-21), glucagon-like peptide-2 (GLP-2), soluble urokinase plasminogen activator receptor (suPAR), CRP, and anti-CMV and anti-EBV IgG levels. All participants had no clinical CVD and underwent coronary CT angiography with the 3D reconstruction of coronary artery atherosclerotic plaques. Total plaque volume (TPV) and low attenuation plaque volume (LAPV, defined as density <30 Hounsfield Units) were calculated (mm3).

Results

In both PLWH and controls, GDF-15 levels were increased in participants with presence of coronary plaque vs. without (p = 0.04 and p < 0.001, respectively) and correlated with TPV (r = 0.27, p = 0.009 and r = 0.62, p < 0.001, respectively) and LAPV (r = 0.28, p = 0.008, r = 0.60, p < 0.001, respectively). However, in a multivariate model, GDF-15 was independently associated with LAPV in controls only (adjusted OR 35.1, p = 0.04) and not in PLWH, mainly due to confounding by smoking. Other markers were not independently associated with plaque volume, except for anti-EBV IgGs in controls (adjusted OR 3.51, p = 0.02).

Conclusion

In PLWH, GDF-15 and smoking seemed to synergistically contribute to coronary plaque volume. Conversely, increased GDF-15 levels were associated with the presence of coronary artery plaques in people without HIV, independently of CV risk factors.