Hyperthyrotropinemia in newly diagnosed cystic fibrosis patients with pancreatic insufficiency reversed by enzyme therapy
Patients with cystic fibrosis (CF) commonly present with an elevated TSH concentration, suggesting subclinical hypothyroidism. Its relation to concomitant pancreatic insufficiency and its natural course upon initiation of enzyme replacement have not been adequately studied. Herein, we investigated the thyroid function in newly diagnosed infants with CF and monitored the course of thyroid function response to pancreatic enzyme substitution treatment. Fourteen, newly diagnosed infants with CF and pancreatic insufficiency, were followed every 6–8 weeks for 6 months ensuing onset of pancreatic enzyme substitution therapy. All infants had normal TSH values on neonatal screening. Ten out of 14 (71%) had hyperthyrotropinemia and normal freeT4 values at presentation. No patient received thyroxine. Upon follow-up, after 6 months, TSH values normalized in 90% of infants with CF and hyperthyrotropinemia. Serum selenium levels were negatively correlated with TSH levels.
What is Known:
• Newly diagnosed infants with cystic fibrosis often present with a state of hyperthyrotropinemia suggesting subclinical hypothyroidism.
What is New:
• Pancreatic enzyme substitution and improvement of nutrition restores normal TSH levels without the need of thyroxine therapy.
KeywordsSubclinical hypothyroidism Pancreatic enzyme therapy Cystic fibrosis Hyperthyrotropinemia Thyroid
AG wrote the manuscript and processed the data; AK and MN retrieved the data; TK did lab work, and CK and SD designed the study.
Compliance with ethical standards
Informed written consent was obtained from the parents of the participating individuals and the study wasapproved from the local Ethical Committee.
Conflict of interest
The authors declare that they have no conflict of interest.
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