Hormones. Hormonal decline is a central feature of the degenerative process known as aging, responsible for diminished energy levels, lack of sexual vitality, and a steady upward creep in the fat/muscle ratio. Hormonal therapy has become increasingly popular in recent years not only as a means to improve quality of life, mental acuity, and physical vigor, but also because research shows that many diseases that hospitalize and kill millions of people each year are related to unfavorable shifts in hormone levels.
For example, an elevation in baseline insulin levels associated with insulin resistance causes a rise in triglyceride levels and the ratio of LDL to HDL cholesterol, which increases the risk of heart disease. In women, declining estrogen and growth hormone levels contribute to bone loss and increase the risk of osteoporosis. In both sexes, loss of muscle mass and functional strength is largely a consequence of hormonal alterations occurring with advancing age; and in men, falling testosterone and rising estrogen levels have been linked to heart disease.
Type 2 diabetes is a disease of insulin receptor dysfunction, but may in some instances be related to shifts in other hormonal systems. For example, hypothyroidism and elevated cortisol levels occurring in response to chronic stress can cause an increase in bodyfat and insulin resistance. Insulin resistance promotes heart disease, and this illustrates how potentially reversible hormonal changes can lead to degeneration and illness.
Hormonal decline makes you less active which perpetuates the problem. Also, because the entire hormonal system is interconnected, a change in one hormone affects other hormones. This dynamic of hormonal synergy underlies what is sometimes referred to as the "downward spiral of aging" - leading from the robust tight-bodied vigor of youth to the feeble frailty of old age. Conversely, hormonal synergy can work to your advantage if the change is positive, making hormonal enhancement a powerful tool for improving health and performance.