Interactive diabetes case 10: A 45-year-old patient with variable glucose values and hypoglycemia unawareness on insulin therapy – B2

ANSWER — 

Correct.

On this regimen, hyperglycemia remains infrequent. The pattern of hypoglycemic reactions becomes more predictable, with more consistent symptoms accompanying low glucose values before lunch and occasionally before supper. You reduce the dose of NPH insulin before breakfast to 12 units at the next visit and to 8 units at the subsequent visit, with elimination of hypoglycemia before lunch and supper. However, the values at these times were in the high 100s and low 200s, so the patient reverted to NPH 12 units before breakfast with good results. However, she is now having hypoglycemia before breakfast. You reduce the dose of NPH insulin at bedtime to 6 units. The patient tries this for two weeks, finds that glucose values were too high before breakfast, and reverts to a bedtime dose of 10 units. Glucose values are variable, often exceeding 200 mg/dL (11.1 mmol/L) before meals and at bedtime. Nevertheless, she is now having occasional hypoglycemic reactions before breakfast, lunch, and dinner but not at bedtime. The overall frequency of reactions is reduced. The patient continues to count carbohydrates and to follow her diet. Hypoglycemia unawareness recurs. The glycated hemoglobin (A1C) is 6.40 percent.

What is your assessment and plan?

●You conclude that the recurrence of hypoglycemia unawareness despite the reduced frequency of reported insulin reactions suggests that not all insulin reactions are being detected. You order continuous monitoring of glucose values in interstitial fluid using a commercial monitoring system designed for short-term retrospective analysis. You do not change the insulin regimen. (See "Interactive diabetes case 10: A 45-year-old patient with variable glucose values and hypoglycemia unawareness on insulin therapy – C1".)

●You note that both the morning and bedtime doses of NPH insulin have been reduced below their present levels with ensuing hyperglycemia and that the total daily dose of basal (NPH) insulin of 22 units is exactly half of what it was when the patient was referred to you (44 units). You conclude that glycemic management is excellent with an A1C level below 7.0 percent, that the frequency of reactions has been reduced, and that the insulin regimen cannot be improved upon. You advise the patient to increase the carbohydrate content of her meals and to increase preprandial insulin doses accordingly. (See "Interactive diabetes case 10: A 45-year-old patient with variable glucose values and hypoglycemia unawareness on insulin therapy – C2".)

●You note that both the morning and bedtime doses of NPH insulin have been reduced below their present levels with ensuing hyperglycemia, and that the total daily dose of basal (NPH) insulin of 22 units is exactly half of what it was when the patient was referred to you (44 units). You add metformin 1000 mg twice a day with breakfast and supper to decrease hepatic glucose output and reduce the peak glucose values. (See "Interactive diabetes case 10: A 45-year-old patient with variable glucose values and hypoglycemia unawareness on insulin therapy – C3".)