Intraday glucose fluctuation is common in preterm infants receiving intermittent tube feeding

Background: We previously reported on three preterm infants with blood glucose abnormalities after reaching full enteral feeding. Recently, it has been shown that clinically stable preterm infants may have large fluctuations in blood glucose after the establishment of enteral nutrition. We hypothesized that intraday glucose fluctuation is a common finding in preterm infants, but improves at term post-conceptual age. This report describes a case series. Methods: From June 2010 to July 2012, 13 preterm infants (29.5 +/- 2.1 post-conceptual weeks, 1144 +/- 319 g) were enrolled in this study. Continuous glucose monitoring (CGM) was conducted on average at 33.5 +/- 1.4 post-conceptual weeks, when they received gastric tube feeding every 3 h in the absence of i.v. glucose supply. Results: Eight infants (62%) had large intraday glucose fluctuation with repeated hyperglycemic (>150 mg/dL) and hypoglycemic (<50 mg/dL) events. In five infants, follow-up CGM at 36-38 weeks post-conceptual age showed more stable glycemic changes without any abnormal glucose levels. Conclusions: On CGM, in some preterm infants intermittent tube feeding resulted in large intraday glucose fluctuation at 31-35 post-conceptual weeks, but the pattern disappeared before discharge (36-38 post-conceptual weeks).