Associations of Total Testosterone and Sex Hormone–Binding Globulin Levels With Insulin Sensitivity in Middle-Aged Finnish Men
- Ulla M. Rajala, MD, PHD12,
- Sirkka M. Keinänen-Kiukaanniemi, MD, PHD123,
- Paivi K. Hirsso, MD12,
- Jari J. Jokelainen, MSC12,
- Mauri A. Laakso, MD12,
- Liisa A. Hiltunen, MD, PHD123,
- Aimo O. Ruokonen, MD, PHD4,
- Pirjo K. Härkönen, MNSC5 and
- Markku J. Timonen, MD, PHD1
- 1Department of Public Health Science and General Practice, University of Oulu, Oulu, Finland
- 2Unit of General Practice, Oulu University Hospital, Oulu, Finland
- 3Oulu Health Center, Oulu, Finland
- 4Unit of Clinical Chemistry, Oulu University Hospital, Oulu, Finland
- 5Oulu Deaconess Institute, Sports Medicine, Oulu, Finland
- Address correspondence to Ulla Rajala, MD, University of Oulu, Public Health Science and General Practice, Box 5000, FIN-90014, Finland. E-mail: ulla.rajala{at}oulu.fi
While sex hormone–binding globulin (SHBG) production in the liver is mainly regulated by sex steroids and thyroxine, insulin is suggested to be another important regulator, and a low SHBG level is a marker of insulin resistance (1) and, consequently, a predictor of type 2 diabetes (2). The role of testosterone, another risk marker of type 2 diabetes, has been insufficiently clarified (2). Further, only one earlier study (3) has found evidence suggesting that, compared with total testosterone, high SHBG may be a more powerful correlate of insulin sensitivity, mediating the link between total testosterone and insulin sensitivity. We investigated the contribution of SHBG to the association between total …
