Higher-Order Organization Links Circulating Metabolites to Glucocorticoid Action in Human Adipose Tissue
Glucocorticoids (GCs) are regulators of metabolism, yet how physiological GC exposure remodels adipose metabolism and its relationship with circulating biomarkers remains poorly understood. In a randomised cross-over study of individuals with primary adrenal insufficiency, near-physiological GC exposure was compared to withdrawal using integrated serum metabolomics, abdominal subcutaneous microdialysis metabolomics, and adipose tissue transcriptomics. GC exposure induced coordinated changes in adipose lipid and amino-acid metabolism. Pathway-level entropy analysis revealed GC-state-dependent transcriptional reorganisation, with concentrated organisation during exposure and diffuse organisation during withdrawal. Integrative hypergraph and topological analyses revealed GC-state-dependent reorganisation of circulating metabolite-adipose tissue relationships, with greater higher-order coordination during exposure. The circulating phenylalanine/kynurenine ratio discriminated GC state, showed the strongest shared connectivity to GC-regulated adipose networks, persisted at midnight and in an independent dose-response study, and exhibited circadian rhythmicity. These findings reveal dynamic GC regulation of adipose metabolism and identify a circulating biomarker with potential to guide personalised GC therapy.