Prevalence of coronary atherosclerosis in individuals with pre-diabetes and diabetes compared to normoglycemic individuals

Patients with type 2 diabetes have a two- to four-fold higher risk of death and cardiovascular events than the general population. Understanding the characteristics of atherosclerosis in people with different stages of dysglycaemia compared to normoglycaemic individuals may be useful for tailored prevention strategies in the future.

To characterise the prevalence of coronary artery atherosclerosis in individuals with prediabetes, previously undetected diabetes and previously known diabetes compared with normoglycaemic individuals in a large population-based cohort.

Data were obtained from the Swedish CArdiopulumonary bioImage Study (SCAPIS), a population-based cohort of participants aged 50–64 years. The 25,553 study participants were categorised according to their glycaemic status: normoglycaemic (glucose: <6.1 mmol/L and HbA1c <6.0% (<42 mmol/mol)), pre-diabetes (6.1–6.9 mmol/L and/or elevated HbA1c 6.0–6.5% (42–47mmol/mol)), previously undetected diabetes (glucose ≥7.0 mmol/L and/or HbA1c >6.5% (≥48 mmol/mol)) or known diabetes. Plaque burden (number of diseased coronary segments) was determined by coronary computed tomography angiography (CCTA) in all 18 coronary artery segments. Total coronary artery atherosclerotic burden was assessed by segment involvement score (SIS) ≥4 and any coronary atherosclerosis. Imaging and analyses were performed using a calcium scoring protocol. The calcium content in each coronary artery was measured and summed to obtain an overall coronary artery calcification score (CACS).

Study participants with dysclycaemia were defined as pre-diabetes (n=3,989, 16%), undetected diabetes (n=648, 2.5%) or known diabetes (n=1,033, 6.5%). The prevalence of CCTA-detected atherosclerosis among study participants, stratified by glycaemic status into four groups, is shown in Figure 1. The distribution of CACS categories by glycaemic status is shown in Figure 2. The association between CACS and glycaemic status, with normoglycemia as reference, was further explored in an adjusted (age, sex and site) ordinal regression: pre-diabetes 1.33 (95% CI 1.25–1.42), undetected diabetes 1.82 (95% CI 1.59–2.09), known diabetes 2.88 (95% CI 2.59–3.20). In a sensitivity analysis excluding people with previous myocardial infarction, coronary artery bypass grafting, percutaneous coronary intervention or with stent (n=693), the results were virtually unchanged, pre-diabetes 1.31 (95% CI 1.23–1.40), undetected diabetes 1.80 (95% CI 1.57–2.07), known diabetes 2.73 (95% CI 2.45–3.05).

The prevalence of coronary atherosclerosis increased substantially with increasing dysglycaemia. Our data suggest that more aggressive screening and/or treatment of individuals with prediabetes and diabetes to prevent cardiovascular disease should be discussed in the future.

Type of funding sources: Foundation. Main funding source(s): The main funding body of The Swedish CArdioPulmonary bioImage Study (SCAPIS) is the Swedish Heart- and Lung Foundation.