Association of impaired fasting glucose and coronary artery calcification as a marker of subclinical atherosclerosis in a population-based cohort--results of the Heinz Nixdorf Recall Study

Aims/hypothesis Atherosclerosis and cardiovascular diseases are often present at the time of diagnosis of type 2 diabetes mellitus. Whether subclinical atherosclerosis can be detected in the pre-diabetic (borderline fasting hyperglycemia) state is not clear. This study investigated the association of impaired fasting glucose (IFG) and coronary artery calcification (CAC), a marker of subclinical atherosclerosis, among participants without a history of coronary heart disease or manifest diabetes mellitus. Methods Study participants (aged 45-75 years) of the population-based Heinz Nixdorf Recall Study were categorised into those with normal fasting glucose (glucose <6.1 mmol/l) and those with IFG (glucose >=6.1 to <7.0 mmol/l), excluding participants with a history of CHD or diabetes mellitus. CAC was assessed by electron-beam computed tomography, and risk factors were assessed by extended interviews, anthropometric measurements and laboratory tests. Various CAC cut-off points were used in multiple logistic and ordinal logistic regression models to estimate ORs and 95% CIs. Results Of the 2,184 participants, more men had IFG than did women (37% vs 22%). Participants with IFG showed a higher prevalence of CAC > 0 (men OR 1.90, 95% CI 1.33-2.70; women 1.63, 1.23-2.15). Risk factor adjustment weakened this association in both sexes (men 1.63, 1.12-1.36; women 1.26, 0.93-1.70). When the age- and sex-specific 75th percentile was used as the cut-off point for CAC, the association further decreased in men (1.10, 0.81-1.50), but became stronger in women (1.41, 1.02-1.94). Conclusions/interpretation These data support the hypothesis that CAC is already present in the pre-diabetic state and that IFG has a modest and independent impact on the atherosclerotic process. Biological sex appears to modify the association between IFG and CAC.