Associations among nonrestorative sleep status, sleep apnea syndrome, and major adverse cardiac and cerebrovascular events: Health check-up and claims data in Japan

Study Objectives Nonrestorative sleep (NRS) refers to the subjective experience of feeling unrefreshed upon awakening that is not attributed to a lack of sleep. NRS may lead to the development of various lifestyle-related diseases, including cardiovascular disease. We investigated the relationships among NRS status, major adverse cardiac and cerebrovascular events (MACCEs), and newly diagnosed sleep apnea syndrome (SAS) status among health check-up participants via the health insurance claims database. Methods We followed 86009 participants who underwent health check-ups in 2014 and answered a sleep-related question for up to 6 years via health insurance claims and a health check-up database. MACCEs were defined as the initial recording of a diagnostic code for MACCEs that required hospitalization. Cox proportional hazards models were constructed to determine whether NRS status was significantly associated with MACCE risk. Results The mean age of the participants was 50.7±15.8 years; 58.8% were male, and 32.9% had NRS status. Even after adjusting for other factors, NRS status was a significant risk factor for MACCE development (hazard ratio: 1.14, 95% CI: 1.07–1.23). A total of 75.9% of the participants who had both MACCEs and newly diagnosed SAS during the follow-up period had heart disease. Conclusions NRS status is an important indicator of sleep hygiene, and improving NRS might reduce the risk of MACCE development. Further screening tests (e.g., home sleep apnea testing) and consequent appropriate treatment may reduce MACCE risk and maintain their health status in people with NRS identified during checkups.