Accepted for Publication: April 25, 2011.
Author Contributions: Dr Watanabe had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Saito, Watanabe, Takagi, Tajima, Nakamura, and Ito. Acquisition of data: Nishida, Izumi, Omura, Takagi, Fukunaga, and Nakamura. Analysis and interpretation of data: Saito, Watanabe, Bandai, and Nakamura. Drafting of the manuscript: Saito, Watanabe, Bandai, and Nakamura. Critical revision of the manuscript for important intellectual content: Nishida, Izumi, Omura, Takagi, Fukunaga, Bandai, Tajima, Nakamura, and Ito. Statistical analysis: Watanabe, Izumi, and Nakamura. Obtaining funding: Saito and Ito. Administrative, technical, and material support: Izumi, Nishida, Omura, Takagi, and Nakamura. Supervision: Bandai and Tajima.
Financial Disclosure: None reported.
Funding/Support: This study was supported by the All Japan Federation of Social Insurance Associations (the Zensharen).
Previous Presentation: This study was presented at the 53rd Meeting of the Japan Diabetes Society; May 27, 2010; Okayama, Japan.
Additional Contributions: Shoichiro Nagasaka, MD, PhD, Jichi Medical University, provided useful advice. We thank all staff members in local study centers and the administrative office for their collaboration.