Elsevier

The Lancet

Volume 359, Issue 9324, 22 June 2002, Pages 2140-2144
The Lancet

Articles
Glucose metabolism in patients with acute myocardial infarction and no previous diagnosis of diabetes mellitus: a prospective study

https://doi.org/10.1016/S0140-6736(02)09089-XGet rights and content

Summary

Background

Glycometabolic state at hospital admission is an important risk marker for long-term mortality in patients with acute myocardial infarction, whether or not they have known diabetes mellitus. Our aim was to ascertain the prevalence of impaired glucose metabolism in patients without diagnosed diabetes but with myocardial infarction, and to assess whether such abnormalities can be identified in the early course of a myocardial infarction.

Methods

We did a prospective study, in which we enrolled 181 consecutive patients admitted to the coronary care units of two hospitals in Sweden with acute myocardial infarction, no diagnosis of diabetes, and a blood glucose concentration of less than 11·1 mmol/L. We recorded glucose concentrations during the hospital stay, and did standardised oral glucose tolerance tests with 75 g of glucose at discharge and again 3 months later.

Findings

The mean age of our cohort was 63.5 years (SD 9) and the mean blood glucose concentration at admission was 6·5 mmol/L (1·4). The mean 2-h postload blood glucose concentration was 9.2 mmol/L (2·9) at hospital discharge, and 9·0 mmol/L (3.0) 3 months later. 58 of 164 (35%, 95% CI 28–43) and 58 of 144 (40%, 32–48) individuals had impaired glucose tolerance at discharge and after 3 months, respectively, and 51 of 164 (31%, 24–38) and 36 of 144 (25%, 18–32) had previously undiagnosed diabetes mellitus. Independent predictors of abnormal glucose tolerance at 3 months were concentrations of HbA1c at admission (p=0·024) and fasting blood glucose concentrations on day 4 (p=0·044).

Interpretation

Previously undiagnosed diabetes and impaired glucose tolerance are common in patients with an acute myocardial infarction. These abnormalities can be detected early in the postinfarction period. Our results suggest that fasting and postchallenge hyperglycaemia in the early phase of an acute myocardial infarction could be used as early markers of high-risk individuals.

Introduction

Individuals with diabetes who have myocardial infarction are more likely to die than those without diabetes.1, 2, 3, 4, 5 Furthermore, results of several large cohort studies6, 7, 8 indicate that people with prediabetic conditions, such as impaired glucose tolerance, have a raised risk of cardiovascular disease, and the findings of a systematic overview9 suggest that a blood glucose concentration even below the threshold for diabetes mellitus is associated with coronary artery disease. There is also a relation between plasma glucose concentrations at time of admission to hospital for acute myocardial infarction and risk of death. This association exists in patients with10, 11 and without12, 13 diagnosed diabetes, and has recently been emphasised in a meta-analysis.14 The amount by which a patient's plasma glucose concentration increases during the early phase of an acute myocardial infarction is associated with the degree of left ventricular failure15— ie, catecholamines and cortisol, produced in response to infarct extension and myocardial dysfunction, result in an increase in the concentration of glucose in the blood.12 However, observations made in the Diabetes Insulin Glucose in Acute Myocardial Infarction (DIGAMI) study suggest that the glycometabolic state at admission, as indicated by blood glucose and HbA1c concentrations, is also a long-term risk marker in patients with diabetes mellitus and acute myocardial infarction.16 Furthermore, a similar relation has recently been suggested for patients without diabetes.17

Our aim was to ascertain the prevalence of glucose abnormalities in an unselected population without a diagnosis of diabetes who had an acute myocardial infarction. A second objective was to explore whether or not established abnormal glucose metabolism can be identified in the early phase of an acute myocardial infarction, thereby permitting early initiation of appropriate preventive measures.

Section snippets

Patients

We enrolled patients admitted to the coronary care units of the Karolinska and Västerås Hospitals, Sweden, for suspected acute myocardial infarction between Nov 1, 1998, and Dec 15, 2000. All individuals enrolled had a baseline capillary blood glucose concentration of less than 11·1 mmol/L. We did not recruit individuals admitted during weekends and holiday seasons, and excluded all individuals who had known diabetes mellitus or who lived outside the catchment area, or who had serum creatinine

Results

We enrolled 181 patients, of whom 164 and 144, respectively, did an oral glucose tolerance test before hospital discharge and again 3 months later. The reasons for not doing the test at 3 months were death (six), overt diabetes (four), acute bypass surgery (three), concomitant disease (ten; pneumonia, severe heart failure, cancer), and unwillingness (14). Table 1 shows baseline characteristics of all patients.

The mean 2-h postload blood glucose concentration measured with the oral glucose

Discussion

Our findings indicate a high prevalence of abnormal glucose metabolism in patients with acute myocardial infarction. Furthermore, our findings suggest that this metabolic abnormality can be detected before hospital discharge. The high prevalence of glucose abnormalities was evident despite the exclusion of patients with previously diagnosed diabetes or with blood glucose concentrations of more than 11 mmol/L at hospital admission. Thus, the true prevalence of diabetes mellitus among people with

References (30)

  • Glucose tolerance and mortality: comparison of WHO and American Diabetes Association diagnostic criteria

    Lancet

    (1999)
  • M Coutinho et al.

    The relationship between glucose and incident cardiovascular events: a metaregression analysis of published data from 20 studies of 95,783 individuals followed for 12.4 years

    Diabetes Care

    (1999)
  • J O Sullivan et al.

    Inhospital prognosis of patients with fasting hyperglycemia after first myocardial infarction

    Diabetes Care

    (1991)
  • S Fava et al.

    The prognostic value of blood glucose in diabetic patients with acute myocardial infarction

    Diabet Med

    (1996)
  • G Oswald et al.

    Determinants and importance of stress hyperglycaemia in non-diabetic patients with myocardial infarction

    BMJ

    (1986)
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