Obesity is associated with higher levels of circulating cytokines involved in the development of cardiovascular disease in people living with HIV.

Background: Obesity is increasingly described in people living with HIV (PLWH), but its impact on immune activation and inflammation in HIV is still poorly characterised. We aimed to analyse the difference in circulating cytokines involved in pathways associated with co-morbidities in PLWH according to the presence or absence of obesity.

Methods: Age and sex matched PLWH with and without obesity (BMI ≥30 kg/m2) from a multicentre, prospective cohort were recruited with a 1:2 ratio. Twenty-three biomarkers covering pathways associated with systemic inflammation (hsCRP, IL-2, IL-6, TNFR1, TNFR2, TNF-α, IFN-γ, IL-18), coagulation (vWF, D-dimer, sCD40L), endothelial function (E-selectin, P-selectin, sICAM-1, sVCAM-1), atherosclerosis (MPO, Lp-PLA2), immune regulation (IL-1RA), innate immune activation (MIP-1, MCP-1, sCD163, sCD14) and microbial translocation (LBP) were measured in the two groups. Between-group difference in biomarkers were assessed using Mann-Whitney test. Associations between obesity and biomarkers were assessed using logistic regression adjusted for age, gender, ethnicity, smoking status, and antiretroviral therapy (ART).

Results: Ninety-nine ART-treated PLWH were included in the analysis (33 with obesity, 66 without obesity). PLWH with obesity had higher levels of hsCRP, IL-6, vWF, D-dimer, E-selectin, MPO, IL-1RA, and LBP. Six markers (hsCRP, IL-6, vWF, E-selectin, MPO, IL-1RA), reflecting systemic inflammation, coagulation and atherosclerosis pathways were associated with increased odds of obesity in the adjusted logistic regression model: hsCRP (aOR 2.7, 95% CI [1.7, 4.29]), IL-6 (3.77 [1.43, 9.93]), vWF (5.33 [1.51, 18.75]), E-selectin (6.28 [1.36, 29.04]), MPO (6.85 [1.87, 25.04]), IL-1RA (6.45 [2.28, 18.2]). No association was observed between obesity and markers of innate immune activation and gut microbial translocation.

Conclusions: Obesity in PLWH was associated with activation of systemic inflammatory, endothelial, atherosclerosis and coagulation pathways, rather than those associated with innate immune activation and gut microbial translocation. These pathways point towards an unfavourable cardiovascular profile in PLWH with obesity, which will have to be further explored in future studies on long-term outcomes.