Maha Al Fify1, Ben Nichols2, Lefkothea Arailoudi Alexiadou2, Fiona Stefanowicz3, Janis Armstrong2, Richard K Russell4, Adrian Raudaschl2, Naina Pinto2, Andrew Duncan5, Anthony Catchpole3, Peter Galloway6, Dinesh Talwar3, Konstantinos Gerasimidis7. 1. Human Nutrition, School of Medicine, Dentistry and Nursing, University of Glasgow, New Lister Building, Glasgow Royal Infirmary, Glasgow, UK; Clinical Nutrition Department, Faculty of Applied Medical Science, Jazan University, Saudi Arabia. 2. Human Nutrition, School of Medicine, Dentistry and Nursing, University of Glasgow, New Lister Building, Glasgow Royal Infirmary, Glasgow, UK. 3. Scottish Trace Element and Micronutrient Diagnostic and Research Laboratory, Department of Clinical Biochemistry, MacEwen Building, Glasgow Royal Infirmary, Castle Street, Glasgow, UK. 4. Department of Paediatric Gastroenterology and Nutrition, Royal Hospital for Children & Young People, Edinburgh, UK. 5. Department of Health, University of Edinburgh, Edinburgh Royal Infirmary, Little France, Edinburgh, UK. 6. Department of Metabolic Medicine, Glasgow Royal Infirmary Hospital, Glasgow, UK. 7. Human Nutrition, School of Medicine, Dentistry and Nursing, University of Glasgow, New Lister Building, Glasgow Royal Infirmary, Glasgow, UK. Electronic address: Konstantinos.gerasimidis@glasgow.ac.uk.
Abstract
BACKGROUND & AIMS: Interpretation of blood micronutrient levels requires age-appropriate reference intervals. This study developed age-dependent micronutrient centiles for healthy children (HC) and explored their utility in sick children. METHODS: 244 blood samples were collected from normal HC who underwent tests for acute illness. Age-dependent, centile charts were fitted for zinc, copper, magnesium and selenium in plasma and erythrocytes (RBC), and for vitamins B1, B2 and B6 in RBC. For 34 children with Crohn's disease (CrD) and 55 with coeliac disease (CoeD), Z-scores for the levels of these micronutrients were computed, using the new charts. Associations were explored between plasma and RBC micronutrient Z-scores, and in CrD with CRP and serum albumin. RESULTS: In HC, plasma zinc and selenium increased and plasma copper, magnesium and RBC vitamins B1, B2 and B6 decreased with age. In HC and in CrD, plasma and RBC Z-scores for copper, selenium and magnesium (all p < 0.001) were positively correlated, but not for zinc. In CrD, albumin was related with plasma zinc (rho = 0.62; p < 0.001) and selenium Z-scores (rho = 0.65; p < 0.001) and plasma copper Z-score with CRP (rho = 0.45; p = 0.02). A higher proportion of CrD children had low levels for B2 (21% vs 0%; p = 0.01) and B6 (18% vs 0%; p = 0.02) using the new centile charts than the local laboratory references. CONCLUSION: Age-dependent micronutrient centile charts enable tracking of micronutrient status, Z-score calculation and may prevent misdiagnosis and inappropriate treatment of deficiencies. In systemic inflammatory conditions, RBC measurements of certain micronutrients may be more reliable to use than measurements in plasma.
BACKGROUND & AIMS: Interpretation of blood micronutrient levels requires age-appropriate reference intervals. This study developed age-dependent micronutrient centiles for healthy children (HC) and explored their utility in sick children. METHODS: 244 blood samples were collected from normal HC who underwent tests for acute illness. Age-dependent, centile charts were fitted for zinc, copper, magnesium and selenium in plasma and erythrocytes (RBC), and for vitamins B1, B2 and B6 in RBC. For 34 children with Crohn's disease (CrD) and 55 with coeliac disease (CoeD), Z-scores for the levels of these micronutrients were computed, using the new charts. Associations were explored between plasma and RBC micronutrient Z-scores, and in CrD with CRP and serum albumin. RESULTS: In HC, plasma zinc and selenium increased and plasma copper, magnesium and RBC vitamins B1, B2 and B6 decreased with age. In HC and in CrD, plasma and RBC Z-scores for copper, selenium and magnesium (all p < 0.001) were positively correlated, but not for zinc. In CrD, albumin was related with plasma zinc (rho = 0.62; p < 0.001) and selenium Z-scores (rho = 0.65; p < 0.001) and plasma copper Z-score with CRP (rho = 0.45; p = 0.02). A higher proportion of CrD children had low levels for B2 (21% vs 0%; p = 0.01) and B6 (18% vs 0%; p = 0.02) using the new centile charts than the local laboratory references. CONCLUSION: Age-dependent micronutrient centile charts enable tracking of micronutrient status, Z-score calculation and may prevent misdiagnosis and inappropriate treatment of deficiencies. In systemic inflammatory conditions, RBC measurements of certain micronutrients may be more reliable to use than measurements in plasma.