A prospective cohort study of 6,441 adults aged 40 years or older found that sleep-disordered breathing (SDB), characterized by apneas and hypopneas during sleep, is associated with increased all-cause mortality. The study used the apnea-hypopnea index (AHI) to assess SDB severity, with higher AHI values indicating more severe SDB. Participants with mild, moderate, and severe SDB had hazard ratios of 0.93, 1.17, and 1.46, respectively, for all-cause mortality compared to those without SDB. The risk was most significant in men aged 40–70 years, with a hazard ratio of 2.09 for severe SDB. Sleep-related intermittent hypoxemia, but not sleep fragmentation, was independently associated with mortality. Coronary artery disease-related mortality also showed a similar association with SDB. The study found that SDB is independently linked to all-cause and cardiovascular disease-related mortality, particularly in men with severe SDB. The findings suggest that SDB may increase mortality risk through mechanisms such as intermittent hypoxemia and cardiovascular disease. The study highlights the importance of identifying and treating SDB, especially in men aged 40–70 years, to reduce mortality risk. Limitations include reliance on a single night's sleep study for SDB diagnosis and potential confounding factors. The study underscores the need for further research to confirm the association between SDB and mortality in women and to explore the effectiveness of treatment in reducing mortality risk.A prospective cohort study of 6,441 adults aged 40 years or older found that sleep-disordered breathing (SDB), characterized by apneas and hypopneas during sleep, is associated with increased all-cause mortality. The study used the apnea-hypopnea index (AHI) to assess SDB severity, with higher AHI values indicating more severe SDB. Participants with mild, moderate, and severe SDB had hazard ratios of 0.93, 1.17, and 1.46, respectively, for all-cause mortality compared to those without SDB. The risk was most significant in men aged 40–70 years, with a hazard ratio of 2.09 for severe SDB. Sleep-related intermittent hypoxemia, but not sleep fragmentation, was independently associated with mortality. Coronary artery disease-related mortality also showed a similar association with SDB. The study found that SDB is independently linked to all-cause and cardiovascular disease-related mortality, particularly in men with severe SDB. The findings suggest that SDB may increase mortality risk through mechanisms such as intermittent hypoxemia and cardiovascular disease. The study highlights the importance of identifying and treating SDB, especially in men aged 40–70 years, to reduce mortality risk. Limitations include reliance on a single night's sleep study for SDB diagnosis and potential confounding factors. The study underscores the need for further research to confirm the association between SDB and mortality in women and to explore the effectiveness of treatment in reducing mortality risk.