1. Second Department of Internal Medicine, Faculty of Medicine, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113, Japan.
2. Department of Biochemistry Isotopes, Tokyo Metropolitan Institute of Gerontology 35-2, Sakae-cho, Itabashi-ku, Tokyo 173, Japan.
3. Department of Pathology, Tokyo Metropolitan Institute of Gerontology 35-2, Sakae-cho, Itabashi-ku, Tokyo 173, Japan.
4. Endocrinology and Metabolism Section of Tokyo Metropolitan Geriatric Hospital 35-2, Sakae-cho, ltabashi-ku, Tokyo 173, Japan.