The connection between CRI and growth failure
The kidneys have a number of important functions. When they fail, many different things can go wrong. In CRI, the kidneys slowly lose their ability to function normally. This means that they concentrate urine, conserve salt and water, and lose the ability to excrete wastes. Their role in the growth process is also compromised, which can lead to growth failure.
One of the reasons for this growth failure centers on vitamin D, a nutrient that is activated by the kidneys. Activated vitamin D helps the body absorb calcium from foods, and also helps the bones absorb the right amount of calcium that will enable them to grow. When the kidneys are impaired, they are unable to activate vitamin D, and the bones cannot get enough calcium. Consequently, the growth process is interrupted. It's easy to see how poor nutrition can also contribute to growth failure in young people with CRI.
Often, the signs and symptoms of chronic renal insufficiency aren't evident until after serious damage has already occurred. As CRI progresses, the kidneys may fail to the point where either kidney dialysis (a medical procedure used to remove waste products from the bloodstream) or kidney transplantation becomes necessary to keep the patient alive.
Although a kidney transplant can return a child's growth rate to normal, by that time growth potential may already have been lost. That is why therapy with growth hormone prior to kidney transplantation is an important component of the treatment strategy for chronic renal insufficiency.
References
Guyton AC, Hall JE. Textbook of Medical Physiology. 9th ed. Philadelphia, PA: WB Saunders; 1996.Wilson JD, Foster DW, Kronenberg HM, Larsen PR, eds. Williams Textbook of Endocrinology. 9th ed. Philadelphia, PA: WB Saunders; 1998.
