Mean resistive index Serum nitric oxide (mmol/l) r P-value r P-value Serum nitric oxide  (mmol/l) 0.536 0.002*   Age (years) -0.132 0.488 -0.031 0.873 Duration (years) 0.608 0.000* 0.505 0.004* Mean PPBG (mg/dl) 0.682 0.000* 0.616 0.000* Mean HbA1C   (%) 0.062 0.025* 0.452 0.012* Urinary  nitric oxide (mmol/l) 0.577 <0.001* 0.795 <0.001* BMI (kg/m2) -0.046 0.810 -0.044 0.818

Table 3: Correlation between mean resistive index and serum nitric oxide with studied variables in diabetic patients.