Effect of abnormal fasting plasma glucose level on all-cause mortality in older patients with acute myocardial infarction: results from the Beijing Elderly Acute Myocardial Infarction Study (BEAMIS)

OBJECTIVE: To assess whether the relationship between abnormal fasting plasma glucose (FPG) levels and patient outcomes holds for both older men and older women with acute myocardial infarction (AMI).PATIENTS AND METHODS: From April 1, 2004, to October 31, 2006, a total of 2016 consecutive older patients (age ≥65 years) presenting with AMI were screened. Of these patients, 1854 were consecutively enrolled in the study. Patients were categorized into 4 groups: the hypoglycemic group (FPG, ≤90.0 mg/dL [to convert to mmol/L, multiply by 0.0555]; n=443, 23.9%), the euglycemic group (FPG, 90.1-126.0 mg/dL; n=812, 43.8%), the mildly hyperglycemic group (FPG, 126.1-162.0 mg/dL; n=308, 16.6%), and the severely hyperglycemic group (FPG, ≥162.1 mg/dL; n=291, 15.7%). The primary outcomes were rates of in-hospital and 3-year mortality.RESULTS: Female patients were older and had a higher incidence of diabetes mellitus but lower rates of smoking and use of invasive therapy. Men tended to have a higher frequency of hypoglycemia, whereas women tended to have a higher frequency of hyperglycemia. No significant difference was found in in-hospital (10.9% vs 9.1%; P=.36) or 3-year (24.5% vs 24.5%; P=.99) mortality between male and female patients, and FPG-associated mortality did not vary significantly by sex.CONCLUSION: An increased FPG level was associated with a relatively higher risk of in-hospital mortality in men but not in women. Nonetheless, increased and decreased FPG levels at admission could predict higher mortality rates regardless of sex. There was a striking U-shaped relationship between FPG levels and in-hospital and 3-year mortality. The effect of abnormal FPG level on outcomes among older patients with AMI did not vary significantly by sex.AMI = acute myocardial infarction; BEAMIS = the Beijing Elderly Acute Myocardial Infarction Study; CABG = coronary artery bypass grafting; CI = confidence interval; DM = diabetes mellitus; FPG = fasting plasma glucose; PCI = percutaneous coronary interventionMany primary and secondary prevention strategies for acute myocardial infarction (AMI) shown to be efficacious in randomized controlled trials have been implemented by physicians and health care systems, resulting in improved control of cardiovascular risk factors in several populations.^1-5 Although better management of risk factors is an important quality benchmark, reductions in the incidence of myocardial infarction and mortality are better measures of quality. Previous studies of mortality associated with AMI have often focused on selected subgroups in populations with limited diversity with respect to coexisting conditions, and most have not examined differences due to sex, although management and outcomes differ markedly.^6-9 Several studies have reported that acute hyperglycemia in patients with AMI is related to a higher incidence of mortality.^10-16 No studies have evaluated the relationship between abnormal fasting plasma glucose (FPG) levels and outcomes separately for men and women. The aim of this study, therefore, was to assess whether the relationship between FPG levels and all-cause mortality is different for men and women among older patients with AMI by analyzing data from BEAMIS (the Beijing Elderly Acute Myocardial Infarction Study).