The role of interleukin-6 and C-reactive protein in non-thyroidal illness in premature infants followed in neonatal intensive care unit

Abstract

Objective: To investigate the role of interleukin-6 (IL-6) and C-reactive protein (CRP) in non-thyroidal illness (NTI) in premature infants. Methods: Serum levels of IL-6 and CRP, thyroid-stimulating hormone (TSH), total thyroxine (T4), free T4 (fT4), total triiodothyronine (T3), and free T3 (fT3) were determined at the 1 st, 2 nd and 4th weeks of postnatal life in 148 premature infants born before 33 weeks of gestation. Results: At the 1 st week, serum T3 was negatively correlated with IL-6 (r= -0.33, p= 0.001) and CRP (r= -0.17, p= 0.03). Serum T3 was negatively and more strongly correlated with IL-6 (r= -0.49, p= 0.001) and CRP (r=- 0.33, p= 0.03) at the 2 nd week, at which time sepsis frequency and low T3 rates were the highest. At the 4 th week, mortality rate was higher among infants with lower T3 levels. Conclusions: High IL-6 and CRP values related to neonatal sepsis might have a significant role in the pathogenesis of NTI in premature infants. ©Journal of Clinical Research in Pediatric Endocrinology, Published byGalenos Publishing.