Jessica's hyperglycemia caused her renal carrier proteins to become saturated, resulting in glycosuria (glucose in the urine). The elimination of glucose in the urine and its consequent osmotic effects caused the urinary excretion of an excessive amount of water, resulting in dehydration. This raised the plasma osmolality, stimulating the thirst center in the hypothalamus. (Hyperglycemia and excessive thirst and urination are cardinal signs of diabetes mellitus.) Further, the loss of plasma water (increased plasma osmolal-ity) caused an increase in the concentration of plasma solutes, including K+. The resulting hyperkalemia affected the membrane potential of myocardial cells of the heart, producing electrical abnormalities that were revealed in Jessica's electrocardiogram.
Was this article helpful?