The patients who were non-obese (BMI<30kg/m2), non dyslipidemic (total cholesterol <200mg/dl, Triglyceride<150mg/dl), and free of cardiovascular events (negative medical history, negative ECG findings) were investigated for enrollment. CKD stage 1 patients older than 18 years of age and willing to participate to the study were screened. From the 375 patients with established type 2 diabetes mellitus+hypertension, 174 had proteinuria and/or hypertension (24 h protein excretion 1-2 g/day, systolic blood pressures ≥140mmHg and/or diastolic blood pressures ≥ 90 mmHg, respectively). All cases were first referrals and at the time of the study all were off treatment. Patients with history of coronary artery disease, smokers and those taking statins or renin-angiotensin blockers were excluded because of the effect of these factors on endothelial dysfunction. Of 174 screened patients 107 met the study criteria and were included in this study. The duration of proteinuria and diabetic nephropathy after initial diagnosis was not known.