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.