1. Department of Aging Medicine and Geriatrics (S.S., J.-i.M., K.H.), Institute on Aging and Adaptation, Shinshu University, Matsumoto 390-8621, Japan
2. Graduate School of Medicine, and Department of Otorhinolaryngology (N.S., S.U.), Shinshu University School of Medicine, Matsumoto 390-8621, Japan