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Selenium and glutathione peroxidase levels in cystic fibrosis
Insights
Children with cystic fibrosis have lower blood selenium levels than healthy children, but their glutathione peroxidase levels are normal. This suggests selenium deficiency does not cause cystic fibrosis.
Area of Science:
- Biochemistry
- Pediatrics
- Nutritional Science
Background:
- Cystic fibrosis (CF) is a genetic disorder affecting multiple organs.
- Selenium is an essential trace element involved in antioxidant defense via glutathione peroxidase.
- Previous hypotheses suggested a link between selenium deficiency and CF.
Purpose of the Study:
- To investigate whole blood selenium and glutathione peroxidase levels in children with cystic fibrosis.
- To determine if selenium deficiency is a contributing factor to cystic fibrosis.
Main Methods:
- Whole blood samples were collected from 20 pediatric patients with cystic fibrosis (aged 6 months to 15 years).
- Selenium concentrations were measured using established methods.
- Activity of the selenoenzyme glutathione peroxidase was determined and compared to reference ranges.
Main Results:
- Mean whole blood selenium concentration in CF patients was 0.122 +/- 0.025 microgram/gm, lower than healthy controls (0.223 +/- 0.007 microgram/gm).
- Selenium levels in CF children were comparable to dietetically treated phenylketonuria patients and higher than healthy New Zealand children.
- Glutathione peroxidase levels in CF patients (0.042 +/- 0.007 units/mg Hb) were within the normal range (0.035 +/- 0.003 units/mg Hb).
Conclusions:
- The findings do not support the hypothesis that selenium deficiency is responsible for cystic fibrosis.
- While selenium levels are reduced in children with CF, antioxidant enzyme function appears preserved.
Abstract:
Whole blood selenium and glutathione peroxidase levels were measured in 20 infants and children (aged 6 months to 15 years) with cystic fibrosis. The whole blood selenium concentration in cystic fibrosis was 0.122 +/- 0.025 microgram/gm. Although the levels of selenium in cystic fibrosis children were below the levels found in a study of healthy children (0.223 +/- 0.007 microgram/gm), they are comparable to those found in children with phenylketonuria treated dietetically and exceed the blood selenium level of healthy children in New Zealand. Levels of the selenoenzyme glutathione peroxidase in children with cystic fibrosis (0.042 +/- 0.007 units/mg Hb) were in the normal range (0.035 +/- 0.003 units/mg of Hb). These results do not support the hypothesis that deficiency of selenium is reponsible for cystic fibrosis.