[Insulin glargine--a systematic review of clinical studies. No documented advantages with Lantus compared to NPH insulin].

The prescription of insulin glargine has increased in Sweden and during 2003 the cost in the county of Skåne equalled all intermediate-acting insulins (ATC-code A10AC01). To investigate the evidence behind claimed advantages of insulin glargine over existing therapy, we carried out a systematic review. We analysed the available documentation presented after registration of the drug by the drug regulatory authorities FDA and EMEA. Data presented at the authorithies' Internet sites was approached. All published studies not included in the registration file were also included in the analysis. Data on glycemic control, expressed as HbA1c, and hypoglycemia was registered. Most studies included a comparison with NPH insulin, incorporating both type 1 and type 2-diabetes. In six pivotal studies there were no significant difference between the two insulin treatments regarding HbA1c, nor was there any substancial evidence concerning differences regarding hypoglycemia. According to FDA, no claim of superiority of insulin glargine could be expressed as all studies had an open design. Studies not included at registration did not add any new evidence. The claimed advantages of insulin glargine does not seem to be substantiated by available evidence.