Published Online: November 11, 2013. doi:10.1001/jamainternmed.2013.12188.
Study concept and design: All authors.
Acquisition of data: Willard.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: Willard.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Willard, Leung.
Administrative, technical, or material support: Leung.
Study supervision: Leung, Pearce.
Funding/Support: This work was supported by National Institutes of Health (NIH) grant 7K23HD068552 to Dr Leung.
Role of the Sponsor: The NIH had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Previous Presentation: This work was previously presented as a poster abstract at the American Association of Clinical Endocrinologists Annual Meeting; May 3, 2013; Phoenix, Arizona.