Objectives: Our objective was to examine fasting glucose and insulin levels in patients surviving 3 months after a first AMI in relation to long-term prognosis.
Design: A total of 1167 consecutive patients between 45 and 70 years with a first nonfatal AMI underwent a standardized clinical examination and were followed for a mean of 8 years for total and cardiac mortality and hospitalization for nonfatal cardiovascular disease. Impaired fasting glucose (IFG) was defined as fasting glucose between 5.6 and 7 mmol L(-1) and a level >or=7 mmol L(-1) as newly detected diabetes. Patients with a fasting glucose level <5.6 mmol L(-1) and without a history of diabetes were classified as normoglycemic (NG). An estimate of insulin resistance was calculated using the homeostasis model assessment (HOMA).
Results: We recorded 219 deaths, 121 deaths from cardiac causes, during the follow-up period. After adjustment for several potential confounders, hazard ratios for total mortality were 1.36 (95% confidence interval 0.93-1.99, P=0.11), 2.27 (1.26-4.09, P=0.006) and 2.15 (1.43-3.21, P<0.001) for patients with IFG, newly detected diabetes and history of diabetes when compared to the NG group. Cardiac mortality, risk of hospitalization for recurrent nonfatal AMI, stroke or heart failure generally showed a similar pattern to that of total mortality. Insulin level and HOMA values were also associated with increased risk for recurrent events.
Conclusions: We confirmed that both known and newly detected diabetes is a strong prognostic factor in AMI. In addition, our findings suggest that glucose levels below the diabetes cut off value might also predict poor long-term prognosis when assessed in a metabolically stable phase.