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Reference ranges for muscle carnitine concentration in children
Gertrud Angsten1, Gitten Cederblad, Staffan Meurling
1Department of Paediatric Surgery, University Children's Hospital, S-751 85 Uppsala, Sweden. Gertrud.Angsten@surgsci.uu.se
Insights
Muscle carnitine levels in children vary by age and gestational age. This study establishes crucial reference intervals for skeletal muscle carnitine concentrations in pediatric patients.
Area of Science:
- Biochemistry
- Pediatric Medicine
- Nutritional Science
Background:
- Carnitine is essential for energy metabolism.
- Establishing reference intervals for carnitine is vital for clinical diagnosis in children.
- Skeletal muscle carnitine levels are a key indicator of carnitine status.
Purpose of the Study:
- To determine muscle and plasma carnitine concentrations in children.
- To establish reference intervals for skeletal muscle carnitine in pediatric populations.
- To investigate the influence of age and gestational age on carnitine levels.
Main Methods:
- Study included 50 children aged 0-14 years undergoing elective surgery.
- Participants were categorized into six age groups, from neonates to 14-year-olds.
- Muscle and plasma samples were collected at the start of surgery.
Main Results:
- Gestational age significantly impacted newborn muscle carnitine (r(s) = 0.692, P < 0.01).
- Muscle carnitine was low in the first year, then stabilized across older age groups.
- Median muscle carnitine in neonates was 5.9 µmol/g dry weight; free/total ratio was 62%.
Conclusions:
- Newborn muscle carnitine concentrations are linked to gestational age.
- Carnitine accumulates in skeletal muscle during the first year of life.
- Provided reference intervals aid in the clinical assessment of pediatric carnitine status.
Background:
We investigated muscle and plasma carnitine concentrations in children to establish reference intervals for use following biopsy of skeletal muscle.
Methods:
The study comprised 50 children from newborns up to 14 years of age, all undergoing elective surgery. They were divided into six age groups, the youngest 0-2 days and the oldest 11-14 years. The samples were taken at the beginning of surgery.
Results:
Gestational age was a major determinant of the total muscle carnitine concentration in newborns (Spearman's r(s) = 0.692, P < 0.01). This concentration was low during the first year, but subsequently did not differ between age groups. In neonates the median value (range) for total carnitine concentration in skeletal muscle was 5.9 (2.2-15.9) micro mol/g dry weight and the free to total carnitine ratio was 62 (31-81)%. In children 1-12 months old the corresponding figures were 6.0 (3.5-7.9) micro mol/g dry weight and 51 (28-71)% and in those 1-14 years they were 12.1 (6.6-17.4) micro mol/g dry weight and 76 (42-92)%.
Conclusion:
This study shows that muscle carnitine concentrations in newborns are dependent on gestational age. The data suggest that there is an accretion of carnitine in skeletal muscle during the first year of life. Reference intervals are given.
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