Endocrine and Other Considerations



The relationship between calcium, phosphate, and parathyroid hormone has already been con­sidered. Glucose intolerance is common in pa­tients with end-stage renal disease. A patient with pre-existing diabetes mellitus may experience marked changes in insulin and carbohydrate re­quirements as renal function deteriorates. If an­orexia limits the intake of carbohydrates, hypo­glycemia may ensue if the insulin dose is not adjusted. In addition, some uremic patients have impaired gluconeogenesis. On the other hand, the following factors may result in hyperglycemia. Uremic patients have defects in the tissue uptake and metabolism of glucose and in the number and action of insulin receptors. Carbohydrate intake as a percentage of total calories is increased by the dietary regimen. The plasma concentration of glu­cagon is also elevated in patients with renal fail­ure. Finally, advanced renal disease limits the uri­nary excretion of glucose when hyperglycemia is present. In the diabetic patient with advanced renal failure, frequent monitoring of blood sugar concentrations, adjustments in the doses of in­sulin, and alterations in the diet are required. There is no clinical method to assess the relative influence of all of the multiple factors that affect glucose metabolism in the ESRD patient. Mea­surements of glycosylated hemoglobin concentrations as an index of glucose control are not valid in patients with advanced renal disease.

Administration of androgens may be of value as a stimulus to the production of red blood cells in men. In females, anabolic steroids with low an­drogenic activity are used for stimulation of the bone marrow. A variety of abnormalities in thy­roid function tests have been described in patients with advanced renal failure. These tests need to be carefully correlated with the clinical assess­ment of the patient prior to administration of thy­roid hormone replacement. Despite laboratory tests that, if considered by themselves, might sug­gest hypothyroidism, the incidence of hypothy­roidism is probably not significantly increased in patients with end-stage renal disease.

Anemia is very common in patients with ESRD, and the average patient on dialysis has hematocrit readings of 20 to 30 per cent. Folate is provided to all patients on dialysis, since it is removed by dialysis. Iron supplements are given if iron defi­ciency is documented. Iron should not routinely be provided, since excess iron administration may result in the development of hemochromatosis. Blood transfusions may be indicated in patients who are unable to maintain their red cell mass and are symptomatic from the anemia. Transfusions are also given prior to surgery to improve toler­ance to the stress of anesthesia and surgical ma­nipulations. Treatable causes of gastrointestinal bleeding should also be addressed.

Vitamin supplements are indicated in most ESRD patients. Water-soluble vitamins are re­moved by dialysis and supplements are clearly indicated in patients on dialysis.