Should oral glucose tolerance testing be mandatory following acute myocardial infarction?

Abstract

A high prevalence of newly detected diabetes mellitus (DM) and impaired glucose tolerance (IGT) has been reported in patients with acute myocardial infarction (AMI) and no previous diagnosis of DM. However, the prevalence of newly detected DM is grossly underestimated by using fasting plasma glucose (FPG). We determined the prevalence of DM and IGT in patients post-AMI from our local mixed ethnicity population, and evaluated the usefulness of oral glucose tolerance testing in such patients. All non-diabetic subjects admitted with AMI underwent a standardised oral glucose tolerance test (OGTT) with 75 g glucose load predischarge in our institution. Fasting and 2-h postchallenge plasma glucose levels were recorded, in addition to admission plasma glucose, serum cholesterol, triglycerides, HDL cholesterol and haemoglobin A1(C)levels. We studied 61 patients [38 (62%) male; mean (SD) age, 64 (12.5) years], of whom 70% were white European and 30% South Asians. Mean (SD) plasma glucose concentration on admission was 6.9 (1.7; range, 5.8-8.1) mmol/l. Newly diagnosed DM and IGT were detected in 31% (95% CI 10-52) and 33% (95% CI 12-53) of patients respectively. Of those with newly detected diabetes only 32% (95% CI 0-69) had FPG > 6.1 mmol/l. The 12 month major adverse cardiac event rate was 4.5%, 15% and 32% in those with normal glucose tolerance, IGT and DM respectively. Previously undiagnosed DM and IGT in patients with AMI is common. The false reassurance of a normal FPG denies a significant proportion of undiagnosed diabetics the chance of early treatment. The importance of OGTT in the diagnostic work up of this vulnerable high-risk group cannot be over-emphasised.

Screening for overt diabetes by oral glucose tolerance test: Stratification by fasting blood glucose and patients' age improve practicability of guidelines in cardiological routine

“…Depending on the underlying study population the prevalences for prediabetes, i.e. IFG and/or IGT and T2DM vary from 33-47% to 19-33%, respectively, in patients with acute myocardial infarction [4,[12][13][14], while in patients with acute coronary syndrome [15][16][17] the percentages are 37-46% for prediabetes and 10-37% for T2DM. 36-37% prediabetes and 22-27% T2DM have been newly diagnosed in patients with coronary artery disease [10,18], while in patients scheduled for coronary angiography [3,19,20] about 36-40% have been diagnosed with prediabetes and 16-23% with T2DM.…”

Abnormal Glucose Metabolism in Acute Myocardial Infarction

“…After adjustment for differences in LV function, as well as other relevant characteristics, newly detected, as well as known diabetes were independent predictors of both all-cause mortality (hazard ratios [ (1,2), and patients with DM who suffer an acute myocardial infarction (AMI) have a worse outcome than nondiabetic patients do (1,3). The use of an oral glucose tolerance test (OGTT) has therefore been advocated (7)(8)(9). Thus, the severity of abnormal glucose metabolism appears to represent a continuum that translates into a gradual increase in the risk of cardiac morbidity.…”

Importance of Investigating Mild Hyperglycaemia Using Oral Glucose Tolerance Test in the Setting of Acute Coronary Syndrome: Prospective Investigational Study

“…The OGTT has been found to be effective and reliable in evaluating glycaemic status compared with FBG, which may miss up to 70% of cases (Jessani et al 2007). Another study found that 2-hour post prandial blood glucose during admission, as opposed to FBG, predicted DS (SrinivasShankar et al 2008).…”

“…Research has emphasised the benefits of OGTT over FBG in terms of both reliability and sensitivity (Wallender et al 2008). In fact, FBG may miss DS in up to 70% of patients (Jessani et al 2007, Henareh et al 2004. Data suggest that IGT, but not IFG, is a risk factor for cardiovascular diseases, although IFG is associated with an increased risk of progression to IGT (Tominaga et al 1999).…”