Impact of obese body mass index on inflammasome blood biomarkers and neurocognitive performance following traumatic brain injury with Glasgow coma scale 13 to 15

Activation of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a moderating factor between obesity and cognitive impairment in animals, but this has never been tested in humans following mild traumatic brain injury (mTBI). This is a retrospective cohort analysis of subjects enrolled at a single level 1 trauma center (n = 172). Participants completed Trail Making Test Part A and B (TMT-A and B) at six- and twelve-months, Blood samples were obtained within 24 h of mTBI and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), caspase-1, interleukin-18 (IL-18), and IL-1β were assayed. Obese participants (BMI = 30-34.9) were associated with higher IL-18 (p = 0.03) and IL-1β (p = 0.05) and severely obese participants (BMI > 35.0) were associated with higher IL-1β (p = 0.005) than healthy weight participants. IL-1β was associated with TMT-A at six- (p = 0.01) and twelve-months (p = 0.03) and TMT-B at twelve-months (p = 0.046). The interaction of severely obese BMI and IL-1β was associated with TMT-B at six- (p = 0.049) and twelve-months (p = 0.02). ASC (p = 0.03) and the interaction of ASC with severely obese BMI was associated with TMTB at six- (p = 0.02) and twelve-months (p = 0.02). Obesity may augment acute inflammasome response to mTBI and influence worse long-term cognitive outcomes up to one-year post-injury.