Effect of theophylline on glucose production and lipolysis in preterm infants (<= 32 weeks)

Apnea occurs commonly in preterm infants. Theophylline is used as prophylax is and treatment. Apart from improving ventilatory function, theophylline m ay also have metabolic effects, including an effect on glucose metabolism a nd lipolysis. No data are available on the effect of theophylline on glucos e production and lipolysis in preterm infants at start of medication. Ten p reterm infants with gestational ages of less than or equal to 32 wk. postna tal ages of 16-84 h, and birth weights >900 g were recruited. Hepatic gluco se production and lipolysis were measured by use of gas chromatography/mass spectrometry after constant rate infusion of [6,6-H-2]glucose and [2-C-13] glycerol tracers. Plasma glucose levels increased after theophylline admini stration (mean +/- SD, 4.0 +/- 1.9 mmol/L before and 4.7 +/- 2.1 mmol/L aft er start of therapy), whereas the rate of glucose production decreased (6.0 +/- 2.5 mg.kg(-1).min(-1) and 4.3 +/- 1.9 mg.kg(-1).min(-1), respectively) . The plasma glycerol concentration did not show any change after theophyll ine administration (154 +/- 257 mu mol/L before and 217 +/- 258 mu mol/L af ter), and the same was true for the rate of glycerol production (5.9 +/- 2. 6 mu mol.kg(-1).min(-1) before and 6.7 +/- 3.0 mu mol.kg(-1).min(-1) after) . The fraction of glycerol converted into glucose did not change significan tly, although the percentage of glucose derived from glycerol increased aft er theophylline administration. The results are in line with the lack of ad verse metabolic effects at start of theophylline treatment in the preterm i nfant.