Acute blood biomarker responses to consensual sexual choking/strangulation in young adult women: a randomized crossover study

Abstract

Introduction: Sexual strangulation, commonly referred to as "choking", has become increasingly common among young adults, yet its neurobiological consequences remain poorly understood. Preclinical and clinical evidence suggests strangulation may trigger axonal injury, neuroinflammation, and blood-brain barrier dysfunction. Blood biomarkers of neural injury and inflammation provide a sensitive means to detect subtle effects. Aim: To examine whether consensual sexual choking/strangulation acutely alters blood biomarkers of neural injury and inflammation compared to non-choking sexual activity in young adult women. Methods: In a randomized crossover study, 29 women (mean age 21.5 ± 2.7) completed three laboratory visits: baseline (≥24 h abstinence), post-choking sex, and post-non-choking sex. Blood was collected within 24 h of sexual events. Neural injury biomarkers (NfL, tau, GFAP, UCH-L1, S100B) and inflammatory markers (IL-1ra, TNF-R1, CCL-2, VEGF-A, VCAM-1) were analyzed using Quanterix and Luminex multiplex immunoassays. Mixed-effects regression models tested exposure-by-time interactions, adjusting for age and brain trauma history. Results: Neurofilament light (NfL) significantly increased after choking-involved sex but remained unchanged after non-choking, which resulted in a statistically significant exposure-by-time interaction [β = -0.21, 95% CI (-0.38, -0.03), p = 0.021]. Other neural biomarkers did not differ by exposure. Among inflammatory markers, CCL-2 and VEGF-A demonstrated a similar pattern as NfL, with acute increases after choking-involved sex, but not following non-choking sex, yielding in exposure-by-time interaction effects (CCL-2: β = -14.60, 95% CI [-25.70, -3.43, p = 0.011; VEGF-A: β = -9.29 (-19.71, 1.13), p = 0.079]. IL-1ra, TNF-R1, and VCAM-1 remained stable. Discussion: Consensual sexual strangulation elicited acute increases in NfL and CCL-2, with VEGF-A showing a similar pattern, suggesting transient axonal stress and hypoxia-related inflammatory signaling. These findings indicate that sexual choking/strangulation, even in consensual contexts, may have subtle, yet detectable cellular burden. Future studies with larger samples, refined temporal sampling, and multimodal outcomes are needed to clarify short- and long-term implications.