Intrarenal Arterial Resistance in Children and Adolescents with Type 1 Diabetes Mellitus: Relation to Microvascular Diabetic Complications

Abstract

Constant increase in the incidence of Type 1 DM has made it necessary to have new markers for early detection of diabetic nephropathy. One of the markers that could be helpful in detecting functional alterations in renal hemodynamics is the assessment of renal resistive index (RI) by using the renal Doppler. The present study was conducted on 100 children and adolescents with Type 1 DM. They were further subdivided into two subgroups ; group 1 including 50 normo-albuminuric diabetic patients, while group 2 included 50 diabetic patients with increased urinary albumin excretion (UAE) > 30mg /24 hours (N=50).They were 37(37 %) males and 63 females (63 %); their mean age was 13.6 ± 2.53 years (range 10-19) and mean disease duration was 8.867±2.260 years (range 5-13). Fifty age and sex matched healthy individuals served as a control group . They were 27 males (54%) and 23 females (46% ); their mean age was 13.48 ± 2.29 years (range 10-18) In a comparison between patients and controls, patients had a significant increase in serum triglycerides and mean renal resistive index (RI) compared to controls with the best cut off point of RI detected at a value= (0.53) . While micro-albuminuric patients had a significant difference in serum HDL, systolic blood pressure and mean renal RI than non-albuminuric patients.The best cut off level between the two groups was detected at a value = (0.58). The only predictor for increased RI at this cut off value was HBA1c (odds ratio=0.633, C.I= [0.466 - 0.859] ). Progressive increase in RI was significantly associated with increased disease duration more than 10 years, increased serum HBA1c more than 7.5 % and early pubertal stages (Tanner stage 2 ,3 ) (p<0.005). It was not significantly related to sex, weight, height, blood pressure or serum lipid profile (p<0.005). Diabetic micro-vascular complications (nephropathy and sensory neuropathy) were more prevalent among pts with RI more than 0.58 (p<0.001). Significant increase in RI was detected among pts with neuropathy ( p < 0.05). These results may suggest the use of renal resistive index (RI) as a useful complementary test for the evaluation of functional alterations in renal hemodynamics in early stages of diabetic nephropathy and possible concurrent microvascular diabetic complications.