Early detection of microalbuminuria and hypertension in children of very low birthweight

Objective. We retrospectively investigated a cohort of very low birthweight infants (VLBWI) by comparing two methods for assessment of albuminuria: nephelometry (standard) and high performance liquid chromatography (HPLC), measuring urinary immunoreactive and non-immunoreactive albumin to evaluate if the latter is more sensitive in identifying childhood onset of albuminuria and hypertension in VLBWI individuals. Methods. Spot urine samples of a total of 109 subjects (5.3±2.2 years old) who were VLBWI were investigated by HPLC and nephelometry. Twenty-eight subjects were small for gestational age (SGA) and 81 were appropriate for gestational age (AGA). Blood Pressure (BP) was also recorded. Results. Twelve children (11%) with albuminuria 20 mg/g Cr by nephelometry versus 48 (44.5%) by HPLC (p <0.001) were identified. The mean±SD of values in the range of normoalbuminuria was 2.9±5.81 by nephelometry versus 22.6±14 for HPLC (p <0.001). The values were not statistically different in the two birthweight categories (90th percentile) versus normal BP children. Conclusions. Microalbuminuria by HPLC was more marked in VLBWI than in adults and the difference between values using the two methods was significative.