Temporal trends in the initiation of glucose-lowering medications after a first-time myocardial infarction - a nationwide study between 1997 and 2006

Background: Type 2 diabetes is a well-established risk factor for cardiovascular disease and is common among patients with acute myocardial infarction (MI). The extent to which patients with first-time MI develop diabetes requiring glucose-lowering medications (GLM) is largely unknown. The aim of the study was to investigate temporal trends in the initiation of GLM among patients discharged after first-time MI. Methods: All Danish residents aged >= 30 years without prior diabetes hospitalized with first-time MI between 1997 and 2006 were identified by individual-level-linkage of nationwide registers. Initiation of GLM during follow-up was assessed by claimed prescriptions from pharmacies. Temporal trends in initiation of GLM were assessed by incidence rate calculations in the MI population as in the general population. Multivariable Cox proportional-hazard models were used to investigate the likelihood of initiating GLM within a year post-MI. Results: The population comprised 66,788 patients. Among these patients 3962 patients initiated GLM, of whom 1567 started within one year post-MI. An increase in incidence rates of GLM initiation in the MI population from 19.6 per 1000 person years in 1997 to approximately 27.6 in 2001 was demonstrated. After 2001 the incidence rates stabilized. A similar trend was observed in the general population where the incidence rates increased from 2.8 in 1997 to 4.0 in 2004 and then stabilized. Conclusion: Our study demonstrated an increase in incidence rates of GLM initiation within the first year post-MI. A similar trend was observed in the general population suggesting that the increase in GLM among MI patients was primarily the effect of a general increased awareness of diabetes. From a public heath perspective, this study underscores a continuous need for diagnostic and therapeutic improvement in the care of MI patients that develop diabetes.