Renal disease and anemia in the elderly.

As individuals age, the incidence of both renal insufficiency and anemia increases. Some of the changes in renal function can be traced to age-related alterations in the renal vasculature that may dissociate renal blood flow from glomerular filtration. In addition, there appear to be paradoxical changes in renal production of erythropoietin (Epo), in that Epo levels actually increase over time with aging, suggesting that the erythroid marrow may become less sensitive to Epo stimulation. These factors, together with the confounding effects of possible nutritional deficits and the disproportionate effect of early-stage diabetes mellitus on renal endocrine function and Epo production, all can contribute to anemia in the elderly. As anemia is an independent predictor of poor outcomes with many diseases and at any age, recognizing and correcting the underlying cause of the anemia is an important aspect of medically managing the elderly patient.