The Use of Basal Insulins in Type 1 Diabetes
According to recent media publications, the Food and Drug Administration has approved the use of Levemir (insulin detemir) for Type 1 diabetes in children ages 2 to 5 years. According to Novo Nordisk, Levemir, although approved for use in older children and adults for both Type 1 and Type 2 diabetes, is now the first FDA approved basal insulin analog for younger children. Currently there are only two types of basal insulin on the market for application in multiple daily injections (MDI): Levemir (insulin detemir) and Lantus (insulin glargine). Both are excellent basal insulins and have distinct roles in the management of type 1 and type 2 diabetes. Keep in mind that diabetes care providers often use these medications “off-label.” Therefore, although Glargine is approved for use in children older than 6 years of age, many diabetes teams are comfortable with both Levemir and Lantus in the younger age groups. Both Levemir and Lantus are relatively peakless insulins, lasting approximately 12 to 16 hours and 24 hours, respectively. As such, it is generally our practice at Children’s National Medical Center to use Levemir twice daily and Lantus once daily as a basal insulin in our patients using MDI in combination with rapid acting insulin analogs as bolus insulin to cover carbohydrates and lower blood sugars.
A recent paper by Cengiz et. al in Endocrine Practice’s November-December 2011 issue discussed the use of Levemir in a different “basal” role. In situations that may preclude the administration of insulin in the school setting, patients are treated with conventional split mixed insulin. The other “basal” insulin, NPH, is an intermediate acting insulin that peaks in 6 to 10 hours and is used in combination with either regular insulin (fast acting) or analog insulin (rapid acting). The dosing is usually NPH/Regular or rapid acting insulin at breakfast, Regular or rapid acting insulin at dinner and NPH at dinner or bedtime. There is a greater risk of hypoglycemia when using basal insulin that peaks especially in active children and adolescents. A very real fear is the threat of hypoglycemia overnight, especially in those children and adolescents that receive NPH in the evening.
Dr. Cengiz conducted a study in which he gave NPH/rapid acting insulin at breakfast and rapid acting insulin and Levemir at dinner and noted a decreased incidence of hypoglycemia overnight. This is one of the first papers to provide evidenced-based information on this type of insulin regimen. The authors’ goal was to initially start newly diagnosed patients on this form of insulin therapy and rapidly transition to insulin pump therapy. It is our experience at Children’s National to match the insulin regimen based on the individual family’s wishes and lifestyle. We therefore have had positive experiences substituting Levemir instead of NPH as the evening basal insulin. However, it should be realized that Levemir cannot be mixed with rapid acting insulin and if given at dinner two injections, rapid acting insulin and Levemir, would be required. Another scheme is to use Levemir at bedtime, which is a practice that I have employed since Levemir became available and approved for use by the FDA. My previous experience with NPH at bedtime confirmed a decreased risk of hypoglycemia overnight as the NPH peaks around 5 am in which counter-regulatory hormones are produced resulting in higher blood sugars. Thus, thepeak ofNPH would theoretically coincide with the rise of blood sugars secondary to the “Dawn Phenomena.” If one decides to use Levemir in place of NPH at bedtime, there is even a further risk reduction of hypoglycemia due to the lack of a pronounced peak. However, Levemir doses will need to be adjusted based on the blood sugar rise in the early morning hours.
The take-home message is “creativity.” The key to successful diabetes management is to use an insulin regime where the person with diabetes (and family) will be most successful in the improvement of blood sugars and quality of life. Thus, there is a dance between the patient/family and the diabetes team to ensure the best management possible based on the varying action profiles of the available insulins.