Endothelial dysfunction in type 2 diabetic patients with normal coronary arteries. A peripheral arterial tonometry study

Aim: to evaluate endothelial function (EF) in diabetic and non-diabetic patients without CAD by peripheral artery tonometry (PAT) technique. Methods: a cohort of 94 patients (55 men and 39 postmenopausal women; mean age 63±9 years) undergoing coronary angiography was divided into 2 groups: 58 patients with DM and (group 1) and 36 patients without DM. Endothelial dysfunction (ED) was assessed by digital pulse amplitude, using a fingertip peripheral arterial tonometry (PAT). As a measure of ED, reactive hyperemia index (RHI) was calculated as the ratio of the digital pulse volume during reactive hyperemia following 5 min ischemia and its basal value. Results: prevalence of cardiovascular risk factors was similar between the two groups. RHI values were significantly lower in diabetic patients compared to non-diabetics (1.72±0.34 vs 2.00±0.44; p<0.005) and they correlated with levels of glycosylated hemoglobin (p=0.05; r=-0.266). Conclusion: despite similar level of other risk factors, EF was much more impaired in diabetic patients than in non-diabetics. These evidences further support the impact of DM on cardiovascular risk.