E.B. is a 51-year-old man who presents to the ER with a 2-week history of polyuria, polydipsia, polyphagia, weight loss, fatigue, and blurred vision. A random glucose test performed 1 day before presentation was 352 mg/dl. The patient denied any symptoms of numbness, tingling in hands or feet, dysuria, chest pain, cough, or fevers. He had no prior history of diabetes and no family history of diabetes.
Admission non-fasting serum glucose 248 mg/dl (N=<180 mg/dl), HbA1c 9.6% (N=4-6.1%). Electrolytes, BUN, and creatinine were normal.
Physical examination revealed a weight of 180 pounds, height 5'5.5" (IBW 140-145). The rest of the examination was unremarkable, i.e., no signs of retinopathy or neuropathy. The patient was taught self-monitoring of blood glucose and begun on 5 mg glyburide once a day. He was instructed in a diet (1800 cal ADA). Blood glucose levels ranged from 80 to 120 mg/dl within 2 weeks of starting glyburide, his symptoms disappeared, and weight remained constant. During the next two months, blood glucose levels decreased to 80 mg/dl, and glyburide was stopped. The patient did not return until one year later; fasting serum glucose was 190 mg/dl, and HbA1c 8%. He again had polyuria and nocturia. Weight was unchanged from the time of presentation. The physician put him on 5 mg/day of glyburide. His blood sugar one month later remained at 180 mg/dl. At this point, his physician decided to put him on insulin alone, 20 units/day at bedtime. Two weeks later, his fasting plasma glucose was 120 mg/dl.