1. Department of Public Health; Juntendo University Graduate School of Medicine; Bunkyo Tokyo Japan
2. RESM Shin Yokohama Clinic; Yokohama Kanagawa Japan
3. Tokorozawa Sleep and Respiratory Clinic; Tokorozawa Saitama Japan
4. Department of Bioscience; Graduate School of Agriculture; Ehime University; Matsuyama Ehime Japan
5. Department of Epidemiologic Research; Toho University; Ohta-ku Tokyo Japan
6. Department of Child Health; University of Missouri School of Medicine; Columbia Missouri