Yet, in the male, there is no such clear-cut event and thus no specific developmental stage appears to exist. Witness putative fathers ages over 70 years. Nevertheless, there are clear signs of hormonal changes that signify aging in the male. Other hormonal changes may be subtler and may involve such concepts as hemodynamic shear stress, which may regulate endothelial function and gene expression and give rise to atherosclerosis via enhancing the inflammatory components of the body. Izumo S. Hemodynamic Shear Stress and Its Role in Artherosclerosis.
Atherosclerosis is the leading cause of death in the developed world.
The hormonal changes lead to a range of symptoms that include general decrease in libido and sexual activity. There is a decrease in general well being, muscle mass and strength, as well as an increase of incidence of impotency. A tendency for cognitive performance to decline takes place and there are more incidents of forgetting and increase in sleep disturbances. There are great individual differences in these processes among men, which creates a more gradual, less defined stage of aging in males. Many of these changes are subtle and do not show up until hormonal changes get further away from the normative range of these hormones levels and indications are that they usually start manifesting themselves in the fiftieth year of the male life span.