01 Research Summary

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.


02 Major achievement

Iwagami M, Seol J, Hiei T, Tani A, Chiba S, Kanbayashi T, Kondo H, Tanaka T, Yanagisawa M. Association between electroencephalogram-based sleep characteristics and physical health in the general adult population. Sci Rep. 2023;13(1):21545. doi: 10.1038/s41598-023-47979-9.

Iwagami M, Qizilbash N, Gregson J, Douglas I, Johnson M, Pearce N, Evans S, Pocock S. Blood cholesterol and risk of dementia in more than 1·8 million people over two decades: a retrospective cohort study. Lancet Healthy Longev. 2021;2(8):e498-e506. doi: 10.1016/S2666-7568(21)00150-1.

Mahalingasivam V, Su G, Iwagami M, Davids MR, Wetmore JB, Nitsch D. COVID-19 and kidney disease: insights from epidemiology to inform clinical practice. Nat Rev Nephrol. 2022;18(8):485-498. doi: 10.1038/s41581-022-00570-3.

03 Education/Academic background and major awards

Education/Academic background

2008 Graduated from the University of Tokyo Faculty of Medicine
2008-2010 Junior residency, The University of Tokyo Hospital
2010-2012 Senior residency, Department of Nephrology, Immunology, and Vascular Medicine, Shonan Kamakura General Hospital
2012-2013 Master of Public Health, School of Public Health, The University of Tokyo
2013 Research Assistant Professor, Department of Hemodialysis and Apheresis, The University of Tokyo Hospital
2013-2014 Master of Epidemiology, London School of Hygiene and Tropical Medicine, University of London
2014-2018 Ph.D. London School of Hygiene and Tropical Medicine, University of London
2018-Present Honorary Assistant Professor, London School of Hygiene and Tropical Medicine, University of London
2018-2022 Assistant Professor, Institute of Medicine, University of Tsukuba
2022-Present Associate Professor, Institute of Medicine, University of Tsukuba


2018 Young Investigators Travel Grants, International Society of Nephrology Frontiers 2018, International Society of Nephrology
2020 Spotlight Poster Winner, International Society of Pharmacoepidemiology (ICPE), International Society of Pharmacoepidemiology
2020 Outstanding Young Faculty Award, University of Tsukuba
2020 Outstanding Faculty Award (Research Field) , Institute of Medicine, University of Tsukuba
2021 Reviewer-of-the Year Award, Kidney International, International Society of Nephrology
2021 Outstanding Faculty Award (Research Field) , Institute of Medicine, University of Tsukuba
2022 Outstanding Faculty Award (Research Field) , Institute of Medicine, University of Tsukuba
2023 Outstanding Reviewer Award, Journal of Epidemiology, Japanese Society of Epidemiology