Proteinuria and glomerular hypertrophy in extremely low-birthweight children

Of late, there is an increased awareness of the frequent occurrence of hypertension or proteinuria in adults born at low birthweight.

We retrospectively studied five children born with extremely low birthweight (ELBW) who were first diagnosed with proteinuria in a school urinary screening program.

These children were born at 23-25 weeks of gestation, and their birthweight was 532-732 g. Proteinuria was identified in all the subjects in a school urinary screening program when they were 6-15 years old. Renal biopsy showed diffuse increase in glomerular size, consistent with glomerular hypertrophy. There were no findings of mesangial proliferation or glomerular sclerosis. All the subjects had a marked decrease in proteinuria after angiotensin receptor blocker (ARB) treatment.

Reduced number of glomeruli associated with prematurity was speculated to have caused compensatory glomerular hyperfiltration, hypertrophy, and hypertension in children born with ELBW when they developed proteinuria. ARB could have been effective for proteinuria by reducing glomerular hypertension. Physicians should be aware of proteinuria in children born with ELBW because there is an increasing number of ELBW survivors as a result of advances in medical technology.