[Effects of age, renal diseases and diabetes mellitus on the renal size reduction accompanied by the decrease of...

Renal size reduction accompanied by the decrease of renal function was evaluated by ultrasonography in 30 normal controls, 45 patients with chronic renal diseases (CRD) and 22 patients with diabetic nephropathy (DN). In controls, significant positive correlation was observed between sectional areas of right kidney and creatinine clearance (Ccr) (r = 0.794, p < 0.001), suggesting that the decrease of renal function due to aging was accompanied by the renal size reduction. Significant correlation was also found between the size and Ccr in CRD (r = 0.814, p < 0.001) and DN (r = 0.640, p < 0.01). No significant difference was observed between controls and CRD in the reduction rate of renal size per unit change of Ccr, which suggested that the renal size reduction accompanied by the decrease in Ccr was the same in controls and CRD. In contrast, in DN, renal size reduction accompanied by the decrease in Ccr was smaller than controls or CRD. When renal sizes were compared in patients, whose Ccr were equal or less than 20 ml/min, renal sizes were significantly larger in DN than CRD (p < 0.001). The duration of illness from the onset of proteinuria was longer in CRD than DN (13.5 years and 4.7 years, respectively). The difference of renal sizes, however, can not be fully explained by the differences in the length of illness, since the renal size was larger in DN than CRD even when we compared the patients with the similar length of illness. In conclusion, renal size decreased with the reduction in the renal function in controls, CRD and DN.(ABSTRACT TRUNCATED AT 250 WORDS)