Basal–bolus regimens reduce severe nocturnal hypoglycemia in Type 1 diabetes patients
MedWire News: Researchers report a low incidence of severe nocturnal hypoglycemia in patients with Type 1 diabetes treated with insulin glargine in combination with either regular human insulin or insulin lispro.
Long-acting insulin analogs such as insulin glargine may help reduce the high risk for nocturnal hypoglycemia associated with neutral protamine Hagedorn (NPH) insulin, a basal insulin commonly used by patients with Type 1 diabetes.
Paolo Brunetti (University of Perugia, Italy) and co-workers investigated the effects of combining regular human insulin or insulin lispro with insulin glargine on the incidence of severe nocturnal hypoglycemia.
They explain that regular human insulin has a longer duration of action compared with insulin lispro, and would therefore be expected to induce a higher risk for nocturnal hypoglycemia.
Patients with Type 1 diabetes using NPH insulin or insulin glargine were switched to, or continued on, insulin glargine for 8 weeks. The authors then randomly assigned 395 patients to insulin lispro or regular human insulin at each meal for 16 weeks; patients continued to receive insulin glargine at dinner time.
Seven-point self-monitored blood glucose profiles were taken. Hypoglycemia was assessed throughout the study and categorized according to blood glucose levels as mild (60-72 mg/dl), symptomatic (42–59 mg/dl), or severe (less than 41 mg/dl).
As reported in the journal Nutrition, Metabolism & Cardiovascular Diseases, a low rate of severe nocturnal hypoglycemia was observed, with three (1.55%) patients in the regular human insulin group and two (1.11%) in the insulin lispro group experiencing the event. The primary endpoint of the study, non-inferiority of regular human insulin compared with insulin lispro, was therefore demonstrated.
There was also no difference in the incidence of overall hypoglycemia with 2.85 episodes per patient a month reported for both groups.
Glycated hemoglobin (HbA1c) levels were significantly reduced with both insulin glargine combinations with no significant difference between the groups. However, mean levels of fasting plasma glucose were slightly lower in the regular human insulin group than in the insulin lispro group at the end of the study.
The authors reported a trend for lower post-prandial blood glucose levels in the lispro group compared with the regular human insulin group, but the latter tended to have lower pre-prandial blood glucose levels compared with the lispro group, suggesting that meal time doses of both bolus insulins should be managed with care.
The authors acknowledge that further studies with larger sample sizes are necessary to verify their findings. But they conclude: “Insulin glargine in combination with a short-acting analog or regular human insulin is associated with a similar and low rate of nocturnal hypoglycemia and glycemic control.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2009
By Jenny Grice