Interactive diabetes case 18: A 61-year-old man with type 2 diabetes and a recent change in diet (medical nutrition therapy)
- Lloyd Axelrod, MD
Lloyd Axelrod, MD
- Associate Professor of Medicine
- Harvard Medical School
A patient calls for an early appointment on the advice of a clinician in a nearby emergency department after being treated for hypoglycemia.
The patient, whom you have followed for several years, is a 61-year-old man with a 17-year history of type 2 diabetes. He has been treated with insulin for the last eight years. He checks his fingerstick glucose level only three times per week, and only before breakfast. At his most recent office visit seven weeks ago, the fasting glucose values in his diary were in the range of 95 to 154 mg/dL (5.3 to 8.6 mmol/L) and the glycated hemoglobin (A1C) was 7.3 percent.
He was treated with NPH insulin 44 units before breakfast, regular insulin 14 units before supper and NPH insulin 16 units at bedtime. He was also taking lisinopril 30 mg every morning, atorvastatin 20 mg at bedtime, and aspirin 81 mg a day. He usually avoided concentrated sweets but did not count carbohydrates or follow a specified diabetes nutritional regimen. The patient had been referred to a nutritionist, but had not kept the appointment. At his last visit, his body mass index was 34 kg/m2 and he was noted to have nonproliferative retinopathy, distal sensory neuropathy, and modest microalbuminuria.
Yesterday, the patient became confused and combative. His wife called 911. The emergency medical technician noted a fingerstick glucose level of 29 mg/dL (1.6 mmol/L), gave 25 cc of D5W (5 percent dextrose in water) intravenously and transported him to the emergency department. His mental status returned rapidly to normal. The doctor on duty learned from the patient that he had been having insulin reactions for about 10 days at various times of day. The clinician advised him to reduce all insulin doses by half, and advised him to call you. You agree to see him the next day.
At the office visit, you review the patient's interval history. His daughter had urged him to follow the South Beach Diet to lose weight, and given him the book by that name. He immediately started Phase 1 of the diet, in which he eliminated bread, rice, potatoes, pasta, baked goods, and fruit. He did not adjust his insulin regimen. The insulin reactions began two days later. You explain to the patient the relationship between his very-low-carbohydrate diet and the marked fall in insulin requirement he has experienced. He is motivated to improve his diet, but requests your advice.