Pediatric reference intervals for 19 biologic variables in healthy children

Area of Science:

• Clinical Chemistry
• Pediatric Laboratory Medicine
• Biostatistics

Background:

• Establishing accurate reference intervals is crucial for interpreting pediatric laboratory test results.
• Existing reference intervals may not adequately account for age and sex variations in children.
• Common laboratory equipment was utilized to ensure broad applicability.

Purpose of the Study:

• To define age- and sex-specific reference intervals for 19 biologic variables in serum from healthy children.
• To provide updated and precise reference ranges for pediatric clinical chemistry.
• To identify trends and differences in biologic variables across pediatric age groups and sexes.

Main Methods:

• Serum samples from healthy children aged 1 to 22 years were analyzed.
• Age- and sex-specific reference intervals were determined using polynomial regression for age-dependent variables.
• Parametric and nonparametric percentile methods (2.5th and 97.5th) were employed to define intervals.

Main Results:

• No significant age or sex differences were observed for sodium, total protein, glucose, direct bilirubin, and albumin.
• Potassium, chloride, and urea levels showed age-independent differences compared to adults.
• Creatinine, uric acid, bicarbonate, and immunoglobulins demonstrated age-related trends, with some sex-specific variations noted for certain analytes.

Conclusions:

• This study provides comprehensive, age- and sex-specific reference intervals for 19 serum biologic variables in children.
• The findings highlight significant age-related changes in several pediatric serum analytes.
• These established intervals are vital for accurate diagnosis and monitoring in pediatric healthcare.