FACTORS RELATING TO URINARY PROTEIN EXCRETION IN CHILDREN WITH AUTOSOMAL-DOMINANT POLYCYSTIC KIDNEY-DISEASE

Adults with autosomal dominant polycystic kidney disease (ADPKD) who h ave overt proteinuria (>300 mg/d) have higher mean arterial pressures, lower creatinine clearances, larger renal volumes, and a more aggress ive course of renal disease than ADPKD patients without proteinuria. T his study examines the relationship between proteinuria and microalbum inuria and similar factors in ADPKD children. A total of 189 children from 81 ADPKD families was included in the analysis. The ADPKD childre n (n = 103) had significantly greater urine protein excretion rates th an the non-ADPKD children (n = 86) (3.9 +/- 0.3 versus 2.8 +/- 0.2 mg/ m(2) per h, P < 0.001). Children with severe renal cystic disease (>10 cysts; n = 54) had greater protein excretion than those with moderate disease (less than or equal to 10 cysts; n = 49) (4.4 +/- 0.5 versus 3.3 +/- 0.2 mg/m(2) per h, P < 0.05), The ADPKD children had significa ntly greater albumin excretion rates than the non-ADPKD children (32 /- 6 versus 10 +/- 2 mg/m(2) per 24 h, P < 0.001), and a higher percen tage of ADPKD children had significant microalbuminuria (>15 mg/m(2) p er 24 h in boys and >23 mg/m(2) per 24 h in girls) than their unaffect ed siblings (30% versus 10%, P < 0.05). Thirty percent of ADPKD childr en had albuminuria and 23% had overt proteinuria. For all ADPKD childr en, there was no correlation between proteinuria and hypertension. How ever, there was a significant correlation between urinary protein excr etion and diastolic BP among children diagnosed after the first year o f life (r = 0.23, P < 0.05). Therefore, proteinuria and albuminuria oc cur early in the course of ADPKD and may be markers of more severe ren al disease.