Resting and postprandial inflammasome and metabolic biomarkers in chronic spinal cord injury

Abstract Study Design Prospective case series with body mass index (BMI)-matched case-controls. Objectives To compare resting and postprandial inflammasome biomarkers and metabolic measurements in people with and without chronic spinal cord injury (SCI). Setting A tertiary academic rehabilitation center in an urban, metropolitan setting in the southeastern United States. Methods Blood samples were collected from 5 individuals with chronic SCI and 5 BMI-matched controls without chronic SCI at baseline and at 80 and 400 min following the consumption of a 600-kcal liquid meal comprised of 35% fat, 50% carbohydrate, and 15% protein. Inflammasome biomarkers included apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), interleukin-18 (IL-18), caspase-1 (CASP-1), and triggering receptor expressed on myeloid cells-2 (TREM-2). Metabolic biomarkers included glucose, insulin, triglyceride (TG), non-esterified fatty acid (NEFA), and glycerol. Results Individuals with chronic SCI showed higher mean baseline concentrations of all inflammatory markers. There were greater mean postprandial decreases of ASC and CASP-1, with values remaining below baseline at 400 min. IL-18 remained near baseline. TREM-2 declined modestly in both groups. There were relative differences in glycemic and lipemic postprandial responses between groups at 80 min. Conclusions In this case series, individuals with chronic SCI exhibited higher mean baseline inflammasome biomarker levels and different postprandial trajectories compared to controls. These preliminary hypothesis-generating observations warrant adequately powered studies to clarify the role of inflammasome-related mechanisms in inflammatory and metabolic dysregulation of chronic SCI.