Correlation between the resistive index values of renal and orbital arteries.

BACKGROUND

Resistive index (RI) is an indirect measurement of blood flow resistance that can be used to evaluate vascular damage.

AIMS

The purpose of this study is to evaluate the association between RI values of orbital and intrarenal arteries by means of Doppler ultrasonography (US).

METHODS

We evaluated 103 diabetic patients. As a control group, 30 subjects were examined. The patients were divided into two groups. Group 1 consisted of patients with urinary albumin excretion (UAE) <300 mg/day and estimated glomerular filtration rate (eGFR) levels >90 ml/min (n = 50); Group 2 had a UAE >300 mg/day and/or eGFR levels between 89 and 60 ml/min (n = 53). The association between RI values obtained with Doppler US of the ophthalmic artery, central retinal artery, posterior ciliary artery and intrarenal arteries were calculated.

RESULTS

Both orbital and intrarenal arterial RI values in Group 1 and Group 2 were higher than the control group (p = 0.001); furthermore, values were higher in Group 2 than in Group 1 (p = 0.0004/0.029/0.036, p = 0.016, respectively). A positive correlation was found between orbital and intrarenal arterial RI values in Group 2 (r = 0.475, 0.285, 0.363, p < 0.01, respectively).

CONCLUSION

Both orbital and renal arterial RI values were shown to be higher than the control group. Further, a trend towards higher RI values was observed with renal disease. RI may be useful as one of the markers for early diagnosis and follow-up of diabetic nephropathy and retinopathy.