Prevalence and Mortality of Acute Myocardial Infarction in Patients with Diabetes

The purpose of this study was to investigate if insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM) predispose to the development of acute myocardial infarction (AMI) and modify the prognosis. The study includes 832 AMI patients consecutively hospitalized over a 3-yr period. The prevalence of diabetes mellitus among the AMI patients was 9.7% and is significantly higher than in an age-matched population, where it is 6.1% (P < 0.001). The prevalence of diabetes was higher for women than for men (14.9% versus 7.6%). The risk of AMI was found to be twice as high among IDDM than among nondiabetic patients (P < 0.001). Men with NIDDM were not found to have a significantly higher risk of AMI (P > 0.1), but the risk of AMI in women with NIDDM was approximately doubled (P < 0.01). During the first month following AMI the mortality rate for nondiabetic patients was 20.2% compared with 42.0% for diabetic patients (P < 0.001). Insulin treatment in NIDDM was associated with a reduced mortality rate compared with treatment with oral agents (P < 0.05). The mortality rate was significantly higher in patients with poor metabolic control compared with patients in good control, whether before AMI or at the time of hospitalization. Diabetic patients had a higher risk of developing cardiogenic shock and conduction disorders than nondiabetic patients. We conclude that diabetes mellitus disposes to AMI and that the mortality rate of AMI is significantly increased among diabetic patients. Poor metabolic regulation of the diabetes may aggravate the prognosis for AMI.