This patient should measure his postprandial glucose level. The hemoglobin A_1c measurement is not always reliable in the setting of chronic kidney disease; thus fingerstick blood glucose measurements should be closely evaluated to help guide therapy. This patient's slightly elevated fasting and premeal blood glucose values may be indicative of postprandial hyperglycemia that could be detected with postprandial glucose measurements and used to guide therapy. For patients trying to achieve hemoglobin A_1c levels less than 7.0%, fasting and premeal glucose targets usually are set at approximately 80 to 130 mg/dL (4.4-7.2 mmol/L). This patient's slightly out of range fasting and premeal glucose measurements seem at odds with the recent drop in his hemoglobin A_1c level to 6.2%. Specific scenarios unique to end-stage kidney disease can affect the accuracy of the hemoglobin A_1c measurement. Hemoglobin A_1c can be falsely elevated in the setting of chronic kidney disease due to carbamylated hemoglobin secondary to uremia interfering with some of the assays. Hemoglobin A_1c can be falsely decreased in the setting of a reduced erythrocyte lifespan, iron deficiency, blood transfusions, and increased erythropoiesis with erythropoietin use. In this patient, the fingerstick blood glucose measurements do not correlate with the most recent hemoglobin A_1c after initiation of erythropoietin. The hemoglobin A_1c value is falsely decreased after erythropoietin therapy as a result of a change in the proportion of young and old erythrocytes and a change in the rate of glycation.

The patient's fingerstick blood glucose values are elevated, which further increases risk for microvascular and macrovascular damage. The current regimen should be adjusted to decrease hyperglycemia.

Decreasing the insulin detemir dose would increase hyperglycemia based on daily blood glucose data provided by the patient.

Discontinuation of the preprandial insulin glulisine based on the falsely decreased hemoglobin A_1c level would increase the hyperglycemia noted in the fingerstick blood glucose values.