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Question 22#

A 19-year-old man with insulin-dependent diabetes mellitus is taking 30 units of NPH insulin each morning and 15 units at night. Because of persistent morning glycosuria with some ketonuria, the evening dose is increased to 20 units. This worsens the morning glycosuria, and now moderate ketones are noted in urine. The patient complains of sweats and headaches at night. Which of the following is the most appropriate next step in management?

A. Measure blood glucose levels at bedtime
B. Increase the evening dose of NPH insulin further
C. Add regular insulin to NPH at a ratio of 2/3 NPH to 1/3 regular
D. Obtain blood sugar levels between 2:00 and 5:00 AM
E. Add lispro via a calculated scale to each meal; continue NPH

Correct Answer is D

Comment:

Episodic hypoglycemia at night is followed by rebound hyperglycemia. This condition, called the Somogyi effect, develops in response to excessive insulin administration. An adrenergic response to hypoglycemia results in increased glycogenolysis, gluconeogenesis, and diminished glucose uptake by peripheral tissues; hence the prebreakfast blood sugars are often elevated. Checking the blood sugars at 2 and 5 AM will demonstrate the hypoglycemia and allow the proper treatment changes—less long-acting insulin at bedtime, not more—to be made. Nocturnal hypoglycemia is a common problem with intermediate-acting insulin such as NPH. The nearly peakless long-acting insulins glargine and detemir rarely lead to the Somogyi effect. If early morning hypoglycemia is documented, discontinuing the NPH and converting the patient to a basal-bolus regimen would be indicated.