The Effect of Non-nutritive Sucking on Expression of BMAL1 and CRY1 in Peripheral Blood Mononuclear Cells of Preterm Neonates: A Preliminary Study

Objectives: To determine whether non-nutritive sucking (NNS) has an effect on circadian rhythm of circadian genes in peripheral blood mononuclear cells (PBMC) in preterm neonates. Methods: Ten premature neonates, gestational age from 30 to 31 weeks, were recruited. Infants with birth asphyxia, respiratory distress syndrome, apnoea, malformation, infection or haemolytic diseases were excluded. All infants were provided with fifteen minutes of NNS every three hours before a tube feed over a period of two weeks. At 7am and 7pm on the 1st day, 7th day and 14th day of hospitalisation, peripheral venous blood was obtained from the premature babies and real-time reverse transcription polymerase chain reaction was used to determine the expressions of BMAL1 and CRY1. Results: In this study, preterm infants treated with NNS, the expressions of BMAL1 and CRY1 in peripheral blood mononuclear cells did not have a statistical difference between 7am and 7pm on the 1st day, 7th day or 14th day of hospitalisation. Conclusions: The study results suggested that NNS did not affect BMAL1 and CRY1 gene expressions in PBMC of preterm neonates.