How does aging affect the bodys ability to make testosterone?
Not only does the amount of testosterone produced decline with age, the morning spike of testosterone seen in young men is blunted in older men. The pituitary glands of older men also may produce less luteinizing hormone (LH), which decreases testosterone production. Testosterone in aging men is more likely to bind to sex hormone binding globulin (SHBG), which reduces the amount of bioavailable or freely circulating testosterone that is available to the body. However, aging also is frequently associated with increasing obesity, and obesity is associated with decreased SHBG levels. Thus, measurement of non-SHBG bound testosterone may be needed in aging, obese men.
