Continuous, complete and comparable NT-proBNP reference ranges in healthy children

Area of Science:

• Biochemistry
• Pediatric Cardiology
• Biomarker Research

Background:

• N-terminal pro-B-type natriuretic peptide (NT-proBNP) is crucial for adult heart failure diagnosis and risk assessment.
• Pediatric NT-proBNP reference intervals (RIs) are age-dependent, lack coverage for all ages, and are right-skewed.
• Current pediatric RIs prevent common Z-score formation and cross-age interpretation.

Purpose of the Study:

• To develop a novel, age-independent interpretive method for NT-proBNP in children.
• To establish continuous reference limits for NT-proBNP across pediatric age groups.
• To introduce a Zlog formula for simplified cross-age NT-proBNP interpretation.

Main Methods:

• Applied new evaluation techniques to existing and new NT-proBNP data.
• Utilized linear regression analysis to assess power-like behavior of NT-proBNP limits with age.
• Derived functions for continuous RIs and calculated daily reference limits.
• Deduced a Zlog formula for NT-proBNP interpretation.

Main Results:

• Demonstrated power-like behavior of NT-proBNP concentration from birth to 18 years.
• Established an age-specific Zlog formula for NT-proBNP: ZlogNT-proBNP = (log x + 0.512*log t - 3.417) / (1.489 + 0.014*log t) * 3.92.
• Validated the formula's utility with two clinical examples.

Conclusions:

• Continuous NT-proBNP RIs from 0 to 18 years can be obtained using derived upper and lower limit formulas.
• The NT-proBNP-specific Zlog value serves as a cross-age Z-score equivalent, simplifying pediatric practice.
• This approach enhances the identification of clinical worsening, offering earlier and clearer insights than absolute values.