The association of adult kidney size with childhood vesicoureteral reflux.

backgroundWe used ultrasound to measure kidney volumes in adults with a history of childhood vesicoureteral reflux (VUR) and assessed whether total renal volume, small kidney size or the thickness of the upper pole correlated with renal function or hypertension.

methodsThe kidneys of 123 adults were studied by ultrasound, calculating their volumes using an ellipsoid formula normalised to body surface area (Vol(N)). The thickness of the upper pole parenchyma and the number of small kidneys (<80% of normal volume) were recorded. Blood pressure measurements and laboratory tests were also performed.

resultsKidneys with a history of VUR were 12% smaller than those without known VUR (p < 0.05), and those with prior dilating VUR were 16% smaller than those with non-dilating VUR (p < 0.05). There was a moderate correlation (r = 0.42, p < 0.05) between total Vol(N) and GFR values in the total patient series. Thirteen percent of the patients had a moderate decrease in kidney function. The occurrence of hypertension and proteinuria was not affected by either kidney size or a thin upper pole.

conclusionsTotal Vol(N) in ultrasound in early adulthood could probably predict possible renal deterioration in later life. The occurrence of one small kidney was a common finding and seemed not to affect the prevalence of proteinuria or hypertension.