P29: Snore Vibro-acoustic Platelet Activation: A Thrombotic Risk Factor in Obstructive Sleep Apnea

Abstract

Background: Obstructive sleep apnea (OSA) is a common disease state with prevalence in the U.S. of near 25%. of the population, characterized by snoring and apnea. Beyond intermittent hypoxemia, OSA imparts increased risk of myocardial infarction (MI) and stroke (CVA), both driven by thrombosis and thromboembolism. Central in thrombosis is platelet activation, traditionally felt to driven by biochemical agonists. We explored the possibility that mechanical vibration generated by OSA snore is also a driver of platelet activation. We hypothesized that OSA snore frequency components induce vibration capable of platelet activation. Here we characterized 1. the frequency content of OSA snore and 2. the effect of specific frequencies ranges on platelet activation, and 3. the optoacoustic vibration pattern generated by snore frequency components. Methods: Snore from OSA patients was recorded in a sleep lab. A snore emulator device (speaker platform) was constructed allowing exposure of human gel filtered platelets to snore via placement on a stage transmitting sound and associated vibration, at clinical sound intensity. Snore was analyzed as to sound frequency content. Gel filtered platelet were exposed to snore sound bandwidths (100 – 1000 Hz.) for 40 min (identical intensities) with activation assessed by thrombin generation (PAS assay). Snore vibration was characterized via assessment of optoacoustic fluid wave patterns generated. Results: OSA snore vibration led to definitive platelet activation. Notably, low frequency snore bandwidths induced greater degrees of activation than high frequency exposure - 53.26% activation at 300 hz vs. 13.44% at 900 hz. (Fig. 1a). Low frequency bandwidths induced noticeably greater fluid oscillation than high frequency bandwidth exposure. (Fig. 1b). Conclusion: OSA snore is capable of inducing vibrations which impart adequate mechanical energy to fluid to induce platelet activation. Within snore, specific frequency bandwidths, i.e. low frequencies, appear to be more activating than others. Correlating with platelet activation is detectable visual fluid disturbance which may be characterized via opto-acoustic patterns. Modulation of sound and vibration associated with OSA snore may offer opportunity as a means of limiting thrombotic consequences and adverse events associated with OSA.