Author Contributions: Dr Travison had full access to all of 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: S. Bhasin, Storer, Basaria.
Acquisition of data: S. Bhasin, Storer, Lakshman, Mazer, Knapp, Hanka, Mohammed, Daou, Miciek, Ulloor, Zhang, Brooks, Orwoll, Hede-Brierley, Eder, Elmi, G. Bhasin, Collins, Basaria.
Analysis and interpretation of data: S. Bhasin, Travison, Lakshman, Kaushik, Ngyuen, Davda, Jara, Aakil, Anderson, Hanka, Mohammed, Singh, Basaria.
Drafting of the manuscript: S. Bhasin, Travison, Lakshman, Kaushik, Anderson, Miciek, Ulloor, Brooks, Orwoll, Elmi, Basaria.
Critical revision of the manuscript for important intellectual content: S. Bhasin, Travison, Storer, Mazer, Ngyuen, Davda, Jara, Aakil, Knapp, Hanka, Mohammed, Daou, Zhang, Hede-Brierley, G. Bhasin, Collins, Basaria.
Statistical analysis: S. Bhasin, Travison, Lakshman, Kaushik, Ngyuen, Davda.
Obtained funding: S. Bhasin.
Administrative, technical, or material support: S. Bhasin, Storer, Lakshman, Jara, Anderson, Knapp, Hanka, Mohammed, Daou, Ulloor, Zhang, Hede-Brierley, Elmi, G. Bhasin, Collins, Singh, Basaria.
Study supervision: S. Bhasin, Storer, Eder, Collins, Basaria.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr S. Bhasin reported board membership for Novartis, working as a consultant to GlaxoSmithKline, having grants pending with Solvay Pharmaceuticals, Merck & Co, and Ligand Pharmaceuticals Inc, receiving reimbursement for travel expenses from GlaxoSmithKline, Novartis, Lilly and Co, and Ligand Pharmaceuticals, and receiving compensation for serving as the chair for 2 Endocrine Society expert panels. No other author reported disclosures.
Funding/Support: This study was supported by grant 1RO1HD043348 from the National Institute of Child Health and Human Development. Additional support was provided by Boston University Clinical and Translational Science Institute grant 1UL1RR025771, by the Boston Claude D. Pepper Older Americans Independence Center, and by grant 5P30AG031679 from the National Institute on Aging. Glaxo SmithKline Inc provided dutasteride and placebo and ENDO Pharmaceuticals provided testosterone enanthate.
Role of the Sponsors: The sponsors 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.
Independent Statistical Analyses: Dr Travison performed the statistical analyses of the data with the assistance of Ms Davda.
Data and Safety Monitoring Board: Steven Grinspoon, MD, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (chair), and Peter J. Snyder, MD, University of Pennsylvania, Philadelphia.
Additional Contributions: We thank the staff of the General Clinical Research Unit of Boston University's Clinical and Translational Science Institute for their help with these studies, and the study participants for their commitment and generosity.