Impaired fasting glucose in combination with silent myocardial ischaemia is associated with poor prognosis in healthy individuals

AIM: As both impaired fasting glucose and silent myocardial ischaemia are risk factors for cardiovascular disease and death, we hypothesized that these risk factors in combination would identify those subjects at the highest risk of adverse events. METHODS: Healthy individuals without diabetes (n=596, 55-75 years) were examined for silent myocardial infarction (≥ 1 mm ST-interval during ≥ 1 min) by ambulant 48-h continuous electrocardiogram monitoring and impaired fasting glucose (fasting plasma glucose 5.6-6.9 mmol/l). RESULTS: After 6.3 years, 77 subjects met the endpoint of myocardial infarction and/or death. The prevalence of silent myocardial ischaemia at inclusion was 12.3% in subjects with impaired fasting glucose and 11.7% in subjects with normal fasting glucose, P=0.69. Subjects with impaired fasting glucose/silent myocardial ischaemia more often met the endpoint (36%) than subjects with impaired fasting glucose/no silent myocardial ischaemia (15%), subjects with normal fasting glucose/silent myocardial ischaemia (12%), and subjects with normal fasting glucose/no silent myocardial ischaemia (10%), respectively, (P<0.001). In a Cox model including these four study groups of interest, gender, age, smoking habits, blood pressure and total cholesterol, only subjects with impaired fasting glucose/silent myocardial ischaemia exhibited an increased risk of death or myocardial infarction (hazard ratio 2.5, P=0.016). CONCLUSION: The combination of impaired fasting glucose and silent myocardial ischaemia was associated with the poorest prognosis in middle-aged and older subjects without previously known glucose metabolic aberration and heart disease.