As men age, changes in testosterone production and secretion patterns often occur. A decline in testosterone concentration is associated with increasing age after the fifth decade. Levels of bioavailable testosterone also appear to decline rapidly with advancing age. Clinical Manifestations of Testosterone Deficiency Clinical manifestations of testosterone deficiency depend on the age at onset and duration of deficiency. Lethargy, depression, and other negative mood and energy parameters have also been reported in some testosterone-deficient men.
Erectile dysfunction is a significant health concern that affects millions of men.
The effect of testosterone on sexual function and behavior appears to be quite complex and is not yet fully understood. Androgen replacement therapy is indicated in these men, with the goal of maintaining serum testosterone levels within the physiologic range. Primary and secondary hypogonadism have been linked to muscle weakness and osteoporosis in some patients. Spinal, trabecular, and radial cortical bone density may be significantly reduced in testosterone-deficient males. Spinal trabecular bone density compared with age in 23 men with idiopathic hypogonadotropic hypo-gonadism.