What Causes Growth Hormone Deficiency?

Growth hormone controls human growth and development and related metabolic activities. It is more necessary, and more of it is secreted, during the active growth years. After full growth has been reached, the level of growth hormone naturally declines.

Pituitary Gland Abnormalities

Human growth hormone is released by the pituitary gland. Hormonal deficiency is caused by problems within the pituitary gland. Growth hormone deficiency may be complete (no hormone is produced) or partial (some hormone is produced, but not enough for normal growth). Hypopituitrism may be congenital or acquired.

Congenital hypopitruitism is present at birth and is usually detected within the first year. Acquired hypopituitrism appears after birth and is caused by head injury, infection or brain tumor.

Growth hormone deficiency is difficult to diagnose because growth hormone is secreted in spurts, rather than at a steady level. Once it is diagnosed, however, the condition is treated with injections of human growth hormone.

Aging

There is some controversy over growth hormone deficiency in aging. Growth hormone levels naturally decline as we age, but we do not know if aging in itself is a natural process of the result of cumulative toxic exposures. We do not know if growth hormone deficiency causes aging, or if it is the result of aging. What we do know is that some of the results of aging—bone demineralization, loss of muscle mass, cardiovascular disease—are processes that are regulated by growth hormone.

Some people believe that aging can be delayed, prevented or even reversed by correcting the growth hormone deficiency that accompanies it.

In one study of elderly men, half were given growth hormone injections and half were not. The men who received the injections increased their muscle mass, lost weight and had a better sense of well-being. Is this age reversal?

As we learn more about the aging process and what causes it, we may discover that some "normal" changes—like the decline in growth hormone—aren't normal at all. We may discover that restoring hormonal levels to what they were at our peak prevents age-related health problems.

This has personal significance, of course, but it also has societal significance. The diseases of aging cost us billions of dollars every year. Preventing these diseases could give us longer and healthier lives and decrease the cost of healthcare for everybody.

Human growth hormone is one area of aging research that shows some promise, and many people are discovering that human growth hormone replacement therapy makes them feel younger, more vital and healthier.