Intermediate and long-acting insulins: a review of NPH insulin, insulin glargine and insulin detemir

OBJECTIVE: To review intermediate- and long-acting insulins with specific emphasis on the newer insulin analogs. METHODS: A MEDLINE search, in English, was conducted with a cut-off of June 30, 2006, using the terms 'NPH insulin', 'insulin analogs', 'insulin glargine', 'insulin detemir' and 'long-acting insulins'. All clinical trials from within the search period were included. RESULTS: The insulin analogs, insulin glargine and insulin detemir, were introduced in an attempt to improve glycemic control among patients with diabetes, without increasing the risk of hypoglycemia. This review indicates that both insulin analogs demonstrate better glycemic control than NPH insulin, based on measurements of HbA1c, fasting glucose and intra-subject variability in blood glucose. This was accomplished with similar or reduced risk of hypoglycemia. Also, insulin detemir appears to be associated with less body weight increase than NPH insulin or insulin glargine. CONCLUSION: The newer long-acting insulin analogs, insulin detemir and glargine, appear to provide better glycemic control than NPH insulin without increasing the risk of hypoglycemia.