A patient who has been on long-term corticosteroid therapy has had surgery to correct an abdominal hernia. The nurse keeps in mind that which potential effect of this medication may have the most impact on the patient's recovery?

Choice A reason: This is correct because hemoglobin A1C level reflects the average blood glucose level over the past 2 to 3 months. It is a reliable indicator of the patient's glycemic control and adherence to the antidiabetic therapy. The goal for most patients with type 2 diabetes is to keep the hemoglobin A1C level below 7%.

Choice B reason: This is incorrect because serum insulin level is not a good measure of the patient's adherence to the antidiabetic therapy, as it may vary depending on the type, dose, and timing of the insulin or oral antidiabetic agents. Serum insulin level may also be affected by other factors, such as stress, infection, or exercise.

Choice C reason: This is incorrect because fingerstick fasting blood glucose level only reflects the blood glucose level at a single point in time. It does not provide information about the patient's long-term glycemic control or adherence to the antidiabetic therapy. Fingerstick fasting blood glucose level may also be influenced by the patient's diet, activity, or medication intake before the test.

Choice D reason: This is incorrect because hemoglobin level is not related to the patient's adherence to the antidiabetic therapy, as it measures the amount of oxygen-carrying protein in the red blood cells. Hemoglobin level may be affected by conditions such as anemia, dehydration, or blood loss.

Choice A reason: Hyperkalemia is not the correct answer. Hyperkalemia is a high level of potassium in the blood. Corticosteroids do not cause hyperkalemia, but rather hypokalemia. Hyperkalemia may be caused by other factors such as renal failure, acidosis, or potassium-sparing diuretics.

Choice B reason: Hypokalemia is the correct answer. Hypokalemia is a low level of potassium in the blood. Corticosteroids can cause hypokalemia by increasing the excretion of potassium and sodium in the urine. Hypokalemia can cause muscle weakness, cramps, arrhythmias, and digoxin toxicity.

Choice C reason: Hypermagnesemia is not the correct answer. Hypermagnesemia is a high level of magnesium in the blood. Corticosteroids do not affect magnesium levels. Hypermagnesemia may be caused by other factors such as renal failure, excessive antacid use, or magnesium-containing laxatives.

Choice D reason: Hypomagnesemia is not the correct answer. Hypomagnesemia is a low level of magnesium in the blood. Corticosteroids do not affect magnesium levels. Hypomagnesemia may be caused by other factors such as malnutrition, alcoholism, or diuretic use.