Short summary

Patients with type 2 diabetes mellitus (T2DM) have an increased risk for cardiovascular disease and patients with dysglycemia without diabetes also have an increased risk. We want to investigate patients referred for coronary CT angiography with suspicion of cardiovascular disease.

The aims of the study are to investigate:

1) The correlation between coronary plaque burden and morphology according to glycemic status evaluated by an oral glucose tolerance test in patients without known diabetes.

and to investigate

2) The correlation between echocardiography systolic and diastolic function according to glycemic status evaluated by an oral glucose tolerance test in patients without known T2DM.

Rationale

Cardiovascular disease (CVD) is still one of the leading courses of death in the Western Society. Mortality during first-time admission for AMI was 9.2 and 13.3% for men and women respectively. Atherosclerosis is a stepwise process that may be initiated already in young years and is correlated to the traditional risk factors; smoking, obesity, hypercholesterolemia, diabetes and hypertension. Over time atherosclerotic lesions progress into symptomatic plaque which is manifested as either stabile angina pectoris or the acute coronary syndrome (ACS), where ACS is further subdivided into unstable angina pectoris, ST-elevations myocardial infarction or non-ST-elevations myocardial infarction. Despite extensive research, risk estimation based on traditional risk factors predicts risk in the general population but may not give an adequate individual risk, and can thereby under- or overestimate the risk of future cardiovascular event and therefore lead to either over- or undertreatment of a not ignorable part of the population.

T2DM/dysglycemia and atherosclerosis

The prevalence of T2DM is rising rapidly. To date the prevalence of T2DM in Denmark is estimated to 340.000 people with probably an equal amount with undiagnosed T2DM. T2DM is known to be strongly associated with an increased risk of CVD, and studies have reported T2DM patients to have twice the mortality of healthy controls, mostly due to CVD early in life. Accordingly, Xu et al. reported newly diagnosed T2DM to have twice the prevalence of significant coronary stenosis compared to those with normal glycemic status.

It is generally accepted that there is a progressive development from normal glycemic status to dysglycemia to T2DM. Dysglycemia is further subdivided into impaired glycemic tolerance (IGT) and impaired fasting glucose (IFG). IGT and IFG are diagnosed with an oral glucose tolerance test (OGTT) or a fasting glucose concentration, respectively (see more detailed definition below). A Danish study reported that the prevalence of IGT and IFG was 34.1%, and that the prevalence of dysglycemia or undiagnosed diabetes was 43.8% among 60-year-old men (9). Dysglycemia is related to an increased risk of developing CVD. Accordingly, studies have reported a significant relationship between increased blood glucose concentrations assessed by OGTT and increased CVD risk. Thus, it is possible that there is a linear relationship between stepwise dysregulated glycemic status and increased coronary plaque burden, but the relationship has not been fully explored.

Description of the cohort

Men and women referred for coronary CT-angiography with symptoms that give suspicion of cardiovascular disease.

Data and biological material

In relation to the oral glucose tolerance test blood samples are collected and will be analyzed later and correlated to coronary artery plaque burden and plaque morphology. Information from patients and their files will be collected to obtain information about cardiovascular risk factors, previous diseases, medication, and objective findings.

Collaborating researchers and departments

Cardiovascular Research Unit, OUH Svendborg Sygehus

• Professor Kenneth Egstrup
• Associated professor Jess Lambrechtsen, PhD

Department of Clinical Biochemistry, OUH Svendborg Sygehus

• Biochemist, Trine Rennebod Larsen, PhD