The steering committee, composed of the principal investigator at each clinical site and at the data coordinating center and the project scientist from the sponsor (NIDDK), designed and implemented the study. The data coordinating center accumulated data in a central database during the study and performed data analyses according to a prespecified plan developed by the biostatisticians at the data coordinating center and approved by the steering committee and the data and safety monitoring board. The study investigators, who had access to all data analyses and wrote the manuscript, attest to the veracity and completeness of the data and the fidelity of the study to the protocol. The decision to submit the manuscript for publication was made by the steering committee, with no restrictions imposed by the sponsor. The data were analyzed by two members of the writing group. The drugs used in the study were donated by pharmaceutical manufacturers (listed at the end of the article), which had no role in the study design, data accrual, data analysis, or manuscript preparation.