Prevalence and atherosclerosis risk in different types of non-diabetic hyperglycemia. Is mild hyperglycemia an underestimated evil?

So far little is known about the importance of different types of non-diabe tic hyperglycemia for the development of macrovascular disease. The aim of this work was to examine the intima-media thickness (IMT) of the common car otid artery (CCA), a well-accepted marker of atherosclerosis, as well as va rious risk factors for atherosclerosis in non-diabetic subjects with isolat ed fasting (IFH: n=67), isolated postchallenge (IPH; n=82) and combined hyp erglycemia (CH; n=88) in comparison to normoglycemic (NG; n=265) controls. Subjects were participants of the RIAD study (Risk Factors in IGT for Ather osclerosis and Diabetes). IMT in the IPH (IMTmean: 0.89+/-0.02 mm; IMTmax: 1.01 +/-0.02 mm; mean+/-SEM) and CH group (IMTmean: 0.9+/-0.02 mm; IMTmax: 1.03+/-0.02 mm) was significantly increased vs. the NG (IMTmean: 0.82+/-0.0 1 mm. IMTmax: 0.94+/-0.01 mm) and IFH group (IMTmean: 0.81+/-0.02 mm: IMTma x: 0.90+/-0.03 mm). IMT of the IFH group was similar to the normoglycemic c ontrols. Subjects in the first and second tertile for postchallenge plasma glucose have similar carotid IMT irrespective of the level of fasting plasm a glucose. The individuals of the third tertile for 2 h plasma glucose, whe ther in the first, second or third tertile of fasting plasma glucose, showe d the same carotid IMT, which was significantly higher than all other group s, except for the one with lowest tertile for fasting and postchallenge pla sma glucose. Except for total cholesterol and von Willebrand factor the lev els of all other risk parameters were significantly higher in the hyperglyc emic groups in comparison to the normoglycemic controls. Among the hypergly cemic subjects the CH group was at the highest risk for atherosclerosis wit h significantly increased levels of plasma triglycerides, fibrinogen, PAI-I , albuminuria, HDL-triglycerides, free fatty acids, insulin and proinsulin, and significantly reduced HDL-cholesterol in comparison to the normoglycem ic controls. In summary, postchallenge hyperglycemia within the non-diabeti c range is associated with atherosclerosis, as measured by the increased in tima-media thickness of the common carotid artery. Furthermore, cardiovascu lar risk factors are significantly raised in all types of non-diabetic hype rglycemia.