Butler MP, et al. - Researchers investigated if all-cause mortality could be predicted by respiratory event duration, a heritable sleep apnea trait reflective of arousal threshold. They used Cox proportional hazards and estimated mortality risk as a function of event duration in a prospective community-based cohort (the Sleep Heart Health Study). They also computed gender-specific hazard ratios. Participants (n=5,712) were followed-up for 11 years, during which, 1,290 deaths were reported. In men and women, mortality prediction was enabled by short respiratory event duration, a marker for low arousal threshold. A tendency to increased ventilatory instability and/or having augmented autonomic nervous system responses, that increase the probability of adverse health outcomes, could be seen among individuals with shorter respiratory events. These findings emphasized the significance of evaluating physiological variation in obstructive sleep apnea.