Even with modern antiretroviral therapy bringing HIV viral loads to undetectable levels, metabolic disease remains a stubborn and underappreciated threat in this population. New findings from JCI Insight offer a molecular explanation — one that reframes subcutaneous fat not merely as an energy depot but as an active site of immune-driven fibrotic remodeling with direct consequences for glucose regulation.
In a cohort of 46 people with HIV (PWH) and 74 HIV-negative controls — with individuals diagnosed with type 2 diabetes excluded — researchers quantified subcutaneous adipose tissue (SAT) fibrosis via hydroxyproline content and profiled fibrosis-related gene expression. PWH exhibited substantially greater SAT fibrosis, a difference particularly pronounced in non-obese individuals, challenging the assumption that metabolic risk in this population is primarily driven by weight gain. SAT fibrosis correlated independently with insulin resistance regardless of legacy antiretroviral exposure or current integrase strand transfer inhibitor use. Mechanistically, fibrotic SAT in PWH showed upregulation of COL14A1, the inflammasome regulator NLRP3, and the chemokine CCL4, alongside suppression of thermogenic and insulin-signaling pathways. Circulating endotrophin — a collagen VI cleavage product marking extracellular matrix remodeling — was elevated in PWH and independently tracked SAT fibrosis.
This work is notable for several reasons. First, it disentangles HIV-associated fibrosis from obesity-related fibrosis at the transcriptional level, suggesting a mechanistically distinct process — likely immune-mediated — rather than a mere amplification of common metabolic dysregulation. Second, the identification of endotrophin as a correlating plasma biomarker opens a potential non-invasive monitoring avenue. Limitations include the modest cohort size, cross-sectional design precluding causal inference, and the need for replication in larger, more diverse HIV populations. Still, the inflammasome and ECM remodeling signatures identified here align with emerging evidence linking chronic immune activation in treated HIV to organ-level fibrosis beyond the liver and lung. This study is incremental but directionally important, pointing toward fat tissue immune biology as a tractable therapeutic target in HIV-associated metabolic disease.