Background: A causal relationship has been established between hyperglycemia and cardiovascular diseases, but no threshold has been retained to determine a 'glycemia-associated' cardiovascular risk. Carotid intima-media thickness (CIMT) is an independent predictor for cardiovascular events. High blood pressure is a major determinant of CIMT.
Objectives: To determine the influence of fasting glycemia on CIMT in hypertensive patients with either normal fasting glucose, impaired fasting glucose (IFG) or type 2 diabetes (DM-2).
Methods: We included 158 essential hypertensive patients with either normal fasting glucose (n=74), IFG (n=24) or DM-2 (n=60) in a cross-sectional study. Common carotid IMT was measured with a high resolution echotracking system.
Results: CIMT of DM-2 patients was significantly higher than that of IFG and normal fasting glucose patients (809 +/- 180, 697 +/- 151 and 689 +/- 134 microm, respectively; analysis of variance (ANOVA) P <0.0001). In multivariate analysis in normal fasting glucose patients, local pulse pressure and age were the major determinants of CIMT, whereas glycemia was not. In IFG and DM-2 patients, fasting glycemia was strongly associated with CIMT, explaining 21 and 18% of its variance, respectively. Particularly, in IFG patients, an increase in 1 mmol/l glycemia was associated with a 165 microm increase in CIMT. In hyperglycemic patients, with either IFG or DM-2, age was an important determinant of CIMT, whereas local pulse pressure was not.
Conclusion: These data suggest that glycemia is a major independent determinant of CIMT in hypertensive hyperglycemic patients, not only in DM-2 patients but also at the earlier stage of IFG, offsetting the mechanical role of local pulse pressure.