Type 2 diabetes patients have a greater likelihood of having an acute myocardial infarction if they are treated with insulin glargine than if they are treated with human neutral protamine hagedorn insulin, according to findings from a large retrospective study.
The results are hypothesis generating and should be interpreted cautiously, noted the study's lead author Dr. George G. Rhoads of the University of Medicine and Dentistry of New Jersey School of Public Health in Piscataway and his associates.
However, they do “raise the possibility that specific insulin formulations or regimens might confer different levels of risk of [acute myocardial infarction] in patients with type 2 diabetes mellitus, and that this effect might be independent of the intensity of glucose control,” the investigators wrote (Am. J. Cardiol. 2009;104:910-6 [doi:10. 1016/j.amjcard.2009.05.030]).
The investigators culled data from the Integrated Health Care Information System, a large administrative database.
All the inpatient claims analyzed were for acute myocardial infarctions (AMIs) among patients who were taking oral antidiabetic agents after initiation of either NPH, a basal insulin (5,461 patients), or insulin glargine, a newer, long-acting synthetic insulin analog (14,730 patients). Their mean age was 56 years.
In the neutral protamine hagedorn (NPH) group, significantly more patients were women and the rates of baseline comorbidities, medical claims for hypoglycemia, and medical service use for diabetes were higher, but the rates of hypertension, hyperlipidemia, and statin use were lower. The average adjusted hemoglobin A1c was about 8% in the two groups.
During a mean 2-year follow-up period after initiating insulin treatment, the risk of an AMI was 56% greater in NPH insulin group, when compared with the insulin glargine group.
The study was sponsored by Sanofi-Aventis, the manufacturer of insulin glargine. An independent statistical analysis was conducted by a University of Medicine and Dentistry of New Jersey statistician. Dr. Rhoads has served as a consultant to Sanofi-Aventis; other authors have served as a speaker, adviser, and consultant for the company.