Masao Iwagami

1. Sleep epidemiology studies using InSomnograf®

　While most epidemiological studies of sleep have examined the association between sleep duration or subjective sleep quality (e.g., "Are you satisfied with your sleep?") and diseases, objective sleep quality can now be measured at home with InSomnograf®, recently developed by S'UIMIN Inc., a start-up company from the University of Tsukuba. Using this home brain wave measurement service, we are examining the relationship between objective sleep quality and diseases by recruiting participants from health checkup and community-based cohort study settings. We are also investigating the influence of genetic and environmental factors on objective sleep quality, as well as the interplay of these factors (gene-environment interactions).

2. Real-world data studies of narcolepsy

　Narcolepsy may be associated with the onset of various diseases such as cardiovascular disease (Sleep. 2023;zsad161. doi: 10.1093/sleep/zsad161.). However, most studies have been conducted in Europe and the United States, and the association is less clear in Asian populations including Japanese. Therefore, using medical claims data in Japan, we are examining what conditions people with narcolepsy are susceptible to, whether the risk of developing these conditions differs depending on the narcolepsy medication, and whether there is any room for intervention (e.g., early detection of lifestyle-related diseases through health checkups).

3. Pharmacoepidemiological studies of sleeping drugs

　Sleeping drugs generally carry a variety of risks, such as falls and fractures due to drowsiness. Meanwhile, benefits have also been suggested, such as improved quality of life (QOL) by being able to sleep and the recently suggested possibility that orexin receptor antagonists may prevent Alzheimer's disease (Ann Neurol. 2023;94:27-40). Thus, we are conducting pharmacoepidemiological studies, including meta-analyses of randomized controlled trials and retrospective cohort studies, to quantify the risk-benefit balance of sleeping drugs and compare it among different sleeping drugs.

Link	Department of Health Services Research, Institute of Medicine, University of Tsukuba Health Services Research and Development Center, University of Tsukuba