Recommended Nordic paediatric reference intervals for 21 common biochemical properties

Abstract

Paediatric reference intervals based on samples from healthy children are difficult to establish and consequently data are often from hospitalized children. Furthermore, biases may present in published data due to differences in the analytical methods employed. Blood samples from 1429 healthy Danish children were collected for establishing reference intervals for 21 common biochemical properties (Alanine transaminase, Albumin, Alkaline phosphatase, Aspartate transaminase, Bilirubin, Calcium, Cholesterol, Creatinine, Creatine kinase, HDL-Cholesterol, Iron, Lactate dehydrogenase, LDL- Cholesterol, Magnesium, Phosphate, Potassium, Protein, Sodium, Transferrin, Triglycerides and Urate). Samples were analyzed on a Roche-Modular-P/ISE-system. The NORIP reference material (NFKK Reference Serum X) was included in all the analytical runs. Reference values were recalculated according to the target values of X for the properties and statistical calculations carried out as performed in the NORIP study. Thus commutable (regarding analytical method) reference intervals for 20 properties were established and for LDL-Cholesterol reference intervals were reported for the specific analytical method employed. The data were compared to previous studies and to those obtained from the youngest age group in the NORIP study. Marked age differences were observed for most of the properties. Several properties also showed gender-related differences, mainly at the onset of puberty. Data are presented as suggested intervals for combined age groups, but can be accessed via the NORIP home page if more detailed division according to age or gender is desired.

Trial registration: ClinicalTrials.gov identifier: NCT01411527.

Key Words::

• Reference material
• reference limit
• reference individual
• Nordic Reference Interval Project 2000
• Paediatrics

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Corrigendum

Acknowledgements

We are grateful to all the participating children from Brønshøj Skole, Hanssted Skole, Hyltebjerg Skole, Kongevejens Skole, Rødkilde Skole, Sankt Annæ Gymnasium, Vibenshus Skole and Øster Farimagsgade Skole. The expert technical assistance of laboratory technologists Jane Lancaster and Annette Jans is gratefully acknowledged.

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.

The COPENHAGEN Puberty Study received financial support from the Kirsten and Freddy Johansen Foundation, Aase and Ejnar Danielsen Foundation, The Ministry of Science, Technology and Innovation, Denmark, the European Commission (FP7) and Anti-Doping Denmark. NFKK Reference Serum X was kindly donated from The Danish Institute for External Quality Assurance for Laboratories in Health Care (DEKS). Reagents and calibrators for the analyses performed on the Modular^® ANALYTICS P/ISE-platforms were generously donated by Roche Diagnostics, Denmark.