Trace metals in cystic fibrosis

Area of Science:

• Pediatric Nutrition
• Gastroenterology
• Clinical Biochemistry

Background:

• Cystic fibrosis (CF) is a genetic disorder affecting multiple organs, particularly the pancreas.
• Malabsorption and nutrient deficiencies are common complications in CF patients due to exocrine pancreatic insufficiency.

Purpose of the Study:

• To investigate serum and urinary zinc and copper levels, plasma selenium, and red blood cell glutathione peroxidase activity in children with cystic fibrosis.
• To assess the risk of micronutrient deficiencies, specifically zinc and selenium, in pediatric CF patients.

Main Methods:

• Measured serum zinc and copper, 24-hour urinary zinc and copper excretion, plasma selenium, and RBC glutathione peroxidase activity in 13 CF patients (ages 6-15).
• Compared patient values to a control group.
• Analyzed correlations between nutrient levels and clinical parameters like fecal fat excretion.

Main Results:

• Serum zinc levels were comparable to controls, but 4 children exhibited elevated urinary copper excretion.
• Plasma selenium levels were significantly reduced in CF patients compared to controls (p < 0.05).
• A significant positive correlation was found between selenium concentration and RBC glutathione peroxidase activity (p < 0.01), and a negative correlation between plasma selenium and fecal fat excretion (p < 0.05).

Conclusions:

• Cystic fibrosis children with severe exocrine pancreatic dysfunction are at increased risk of subclinical or overt zinc and/or selenium deficiency.
• Systematic consideration of appropriate zinc and selenium supplementation is warranted for these patients.