Reference Ranges for Testosterone in Men Generated Using Liquid Chromatography TandemMass Spectrometry in a Community-Based Sample of Healthy Nonobese YoungMen in the FraminghamHeart Study and Applied to Three Geographically Distinct Cohorts

Context:Reference ranges are essential for partitioning testosterone levels into lowor normal and making the diagnosis of androgen deficiency. We established reference ranges for total testos-terone (TT) and free testosterone (FT) in a community-based sample of men. Methods: TT was measured using liquid chromatography tandemmass spectrometry in nonobese healthymen, 19–40 yr old, in the FraminghamHeart StudyGeneration 3; FTwas calculated. Values below the 2.5th percentile of reference sample were deemed low.We determined the association of low TT and FT with physical dysfunction, sexual symptoms [EuropeanMale Aging Study (EMAS) only], and diabetesmellitus in three cohorts: FraminghamHeart Study generations 2 and 3, EMAS, and the Osteoporotic Fractures in Men Study