Education of the patient and family is a critical component of care. The patient should be informed about the kind of diabetes he or she has and the rationale for controlling the glucose levels (see Box: Benefits of Tight Glycemic Control in Diabetes). Self-monitoring of glucose levels should be emphasized, especially if the patient is on insulin or oral secretagogues that can cause hypoglycemia. The patient on insulin therapy should understand the action profile of the insulins. He or she should know how to determine if the basal insulin dose is correct and how to adjust the rapidly acting insulin dose for carbohydrate content of meals. Insulin adjustments for exercise and infections should be discussed. The patient and family members also should be informed about the signs and symptoms of hypoglycemia.
The American Diabetes Association criteria for acceptable control include an HbA1c of less than 7% (53 mmol/mol) and pre-meal glucose levels of 90–130 mg/dL (5–7.2 mmol/L) and less than 180 mg/dL (10 mmol/L) one hour and 150 mg/dL (8.3 mmol/L) two hours after meals. While the HbA1c target is appropriate for individuals treated with lifestyle interventions and euglycemic therapy, it may need to be modified for individuals treated with insulin or insulin secretagogues due to their increased risk of hypoglycemia. Less stringent blood glucose control also is appropriate for children as well as patients with a history of severe hypoglycemia, limited life expectancy, and significant microvascular and macrovascular disease. For the elderly frail patient an HbA1c greater than 8% may be appropriate.
Treatment must be individualized on the basis of the type of diabetes and specific needs of each patient.
A. Type 1 Diabetes
For most type 1 patients, at least 3 or 4 insulin injections a day are necessary for safe and effective control of glucose levels. A combination of rapidly acting insulin analogs and long-acting insulin analogs allow for more physiologic insulin replacement. Generally, for an adult with type 1 diabetes, the total daily insulin requirement in units is equal to the weight in pounds divided by four, or 0.55 times the person’s weight in kilograms. Approximately 40% of the total daily insulin dosage covers the background or basal insulin requirements, and the remainder covers meal and snack requirement and high blood sugar corrections. This is an approximate calculation and should be individualized. Examples of