1Department of Public Health, Tohoku University School of Medicine, Sendai, Japan
2Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan
3Environmental Health Science, Tohoku University School of Medicine, Sendai, Japan
4Department of Medicine, Ohasama Hospital, Iwate, Japan
5Correspondence and requests for reprints to Takayoshi Ohkubo, MD, Department of Public Health, Tohoku University School of Medicine, Sendai, 980–8575, Japan.
Tel: +81 22 717 8123; fax: +81 22 717 8125
Sponsorship: This work was supported by research grants from the Miyagi Prefectural Kidney Association, from the Takeda Medical Research Foundation, from the Japan Heart Foundation for Research on Hypertension and Vascular Metabolism, from the National Center for Cardiovascular Disease (grant 4C-3, 5C-2), from the Ministry of Health and Welfare (Evaluation of the Effect of Drug Treatment on Hypertension and Other Chronic Disease Conditions in the Elderly, 1994–96, Kosei-Kagaku Kenkyuhi, 1996–97 and the Health Services for the Elderly, 1996), and from the Ministry of Education, Science, and Culture (grant 07670420) of Japan.
Received 12 December 1997 Revised 12 January 1998 Accepted 16 February 1998
