602 HYPERKALEMIA IN A CHILD WITH SICKLE CELL ANEMIA AND DIABETES MELLITUS

Abstract

An 18 year old black girl with sickle cell anemia (SCA) who has diabetes mellitus, a high renal threshold for glucose, and unexplained hyperkalemia is reported. The patient was diagnosed to have SCA at 2-8/12 years of age and diabetes mellitus at 11 years of age. During her recent admissions for painful crises her renal threshold for glucose was found to be increased to 350 mg/dl and on several occasions her serum potassium levels were elevated (5.5-8.5 mEq/liter). Ketones were not found in the blood or urine and her blood gases were normal. In an attempt to explain the hyperkalemia and high renal threshold for glucose, sodium and potassium balance and renal function studies were done, as well as an evaluation of her renin aldosterone axis (RAA). The following results were found: (a) normal plasma renin activity and aldosterone at the time of hyperkalemia and under controlled circumstances, (b) slightly positive sodium balance, (c) positive potassium balance, as long as the hyperglycemia was not well controlled, and (d) glomerular, proximal and distal tubular dysfunction. These results can best be explained by lack of insulin and a mild degree of renal insufficiency. This renal insufficiency is mainly secondary to SCA but is aggravated by her diabetes as shown by renal biopsy.