Subcutaneous Continuous Glucose Monitor
R.F. is a 48-year-old white man with type 1 diabetes since age 24. He was initially seen at the Utah Diabetes Center in Salt Lake City on 15 September 2006. The patient had been treated with NPH insulin, 2 units at bedtime; ultralente insulin, 3 units twice a day; and lispro insulin, 2-3 units at each meal. The patient corrected elevated blood glucose levels with 1 unit of lispro for blood glucose readings > 200 mg/dl and about 2 units of lispro for blood glucose readings > 300 mg/dl. His hemoglobin A1c (A1C) was 9.2%, and he described losing control of his diabetes progressively through the years.
The patient often developed nocturnal hypoglycemia, most likely as a result of the combination of NPH and ultralente insulins taken at bedtime, and his blood glucose levels often dropped by 50-80 mg/dl through the night. The fear of nocturnal hypoglycemia and the patient’s inability to control postprandial blood glucose levels were very frustrating to him. He had no evidence of microvascular complications. His blood pressure and lipids have always been within the normal range.
R.F.’s basal insulin regimen was changed to detemir insulin twice daily, and he was also given an insulin-to-carbohydrate ratio to determine lispro doses at mealtimes and a correction scale to aggressively correct hyperglycemia. He also received intensive diabetes education. By 7 April 2007, his A1C was 7.8%, and he had gained much more confidence as his blood glucose levels remained stable through the nights.
The patient then decided to purchase a continuous glucose monitor (CGM) system (Medtronic MiniMed Guardian REAL-Time Continuous Glucose Monitoring System). The patient was instructed on the use of the sensor system by the diabetes education team at the Utah Diabetes Center. He continued to monitor his blood glucose levels four to six times per day. He found that he was able to aggressively dose insulin at meals based on anticipated carbohydrate intake and to correct even mild hyperglycemia throughout the day. His A1C had improved to 5.5% when measured on 11 October 2007. More …..
