High-normal fasting blood glucose in non-diabetic range is associated with increased coronary artery calcium burden in asymptomatic men

Objective : The objective of the study is to evaluate whether high fasting blood glucose (FBG) in the non-diabetic range (<126 mg/dl) is associated with subclinical coronary atherosclerosis as determined by coronary artery calcium (CAC) independent of clustering of metabolic syndrome (MS) risk factors. Methods & results : Previously non-diabetic, 458 asymptomatic non-diabetic Brazilian men (mean age: 46 ± 7 years, range: 29–65) underwent clinical consultation including FBG measurements and electron-beam tomography (EBT). The mean FBG of the study population was 88 ± 10 mg/dl. Overall, 190 (42%) of men had CAC > 0. The prevalence of CAC was significantly higher among men with high-normal FBG (4th quartile: 94–125 mg/dl) versus normal FBG group (lower three quartiles: 66–93 mg/dl) (62% versus 35%, p < 0.0001). In age adjusted analyses the odds ratio (OR) for any CAC among men with high-normal FBG versus normal FBG was 2.19 (95% CI: 1.33–3.58). On further adjustment for risk factors the relationship was slightly attenuated, however remained statistically significant (OR = 1.78, 95% CI 1.05–3.00, p = 0.03). In sub-stratified analyses high-normal FBG was associated with CAC among men without MS (OR: 1.99, 95% CI: 1.04–3.78) and with MS (OR: 2.12, 95% CI: 0.95–4.80). Similar relations with high-normal FBG were observed among individuals classified low risk (OR: 2.34, 95% CI: 1.14–4.83) as well intermediate high-risk men (OR: 1.95, 95% CI: 0.99–3.86) by Framingham risk score (FRS), respectively. Conclusions : Fasting blood glucose in the upper normal range appears to be associated with the presence of CAC in apparently non-diabetic Brazilian men.