Thyroid Function Tests in Children with Cystic Fibrosis: Is Thyroid Dysfunction more Common than Estimated in These Patients?

Abstract

Objective: Cystic fibrosis (CF) is a life-limiting, multisystemic, autosomal recessive genetic disorder that is characterized by digestive and respiratory dysfunction contributing to growth deficit, chronic respiratory infections, progressive lung tissue damage, and premature death. CF patients have several important endocrine abnormalities including exocrine pancreatic insufficiency, poor linear growth, bone diseases, hypogonadism and thyroid dysfunction. In the present study, we aimed to investigate the prevalence of thyroid dysfunction in children with CF and evaluate the general characteristics of these patients in Turkey. Material and Methods:The study was conducted between January 2015 and June 2015. A total of 42 patients (20 male, 22 female) with CF were included in the study. Demographic information; clinical, laboratory and radiological findings; medication use, and genetic analyses were assessed from the medical records. The serum fT4, fT3 and TSH levels were measured by chemiluminescence immunoassay using a DxI800 autoanalyzer (Beckman Coulter Inc., CA, USA). results: The mean age at the time of diagnosis of CF was 35.5±53.2 (2-194) months in the study population. Eight of the 42 (19%) patients whose TSH, fT4 and fT3 levels were measured had abnormal TSH and fT4 levels (two overt hypothyroidism and six subclinical hypothyroidism). Five (62.5%) of the subjects with thyroid dysfunction were receiving thyroid hormone replacement therapy. conclusion: Our study presents the first evaluation of the patients with CF for thyroid dysfunction in Turkey. In our study population, we detected eight (19 %) CF patients with thyroid dysfunction and five (62.5%) of them were receiving L-thyroxine treatment. In our opinion, regular evaluation of thyroid function tests in patients with CF may be necessary to prevent problems associated with hypothyroidism. Key Words: Children, Cystic fibrosis, L-thyroxine, Thyroid dysfunction ÖzEt Amaç: Kistik fibrozis progresif akciğer hasarı, kronik solunum yolu enfeksiyonları, büyüme geriliği ve erken ölüme neden olan sindirim ve solunum disfonksiyonu ile karakterize multistemik, hayatı kısıtlayan, otozomal resesif genetik bir hastalıktır. Kistik fibrozis ekzokrin panreatik yetmezlik, büyüme geriliği, kemik hastalıkları, hipogonodism ve tiroid hastalıklarını kapsayan bazı önemli endokrin anormalliklere neden olabilmektedir. Bu çalışmada amaç, kistik fibrozisli çocuklarda tiroid disfonksiyonu prevelansını araştırmak ve bu hastaların genel karakteristiklerini belirlemektir. Gereç ve Yöntemler: Çalışma, Ocak 2015-Haziran 2015 tarihleri arasında yapılmıştır. Toplam 42 kistik fibrozisli hasta (20 erkek, 22 kız) çalışmaya alınmıştır. Demografik, klinik, laboratuvar ve radyolojik bulgular, ilaç kullanımı, genetik analizler dosya kayıtlarından elde edilmiştir. Serum fT4, fT3 ve TSH düzeyleri kemilüminesans immunoassay yöntemiyle DxI800 autoanalyzer (Beckman Coulter Inc, CA, USA) kullanılarak ölçülmüştür. bulgular: Çalışma populasyonunda tanı anındaki ortalama yaş 2.9±4.4 (yıl)'di. T...