Differences in respiratory metabolism during treatment of hypoglycemia in infants of diabetic mothers and small-for-gestational-age infants

We investigated oxygen consumption and carbon dioxide production during treatment of hypoglycemia in infants of diabetic mothers (IDM) (n = 11) and small-for-gestational-age (SGA) infants (n = 6). Healthy newborn infants served as controls (n = 16). The infants in both groups received normal enteral feedings and they were treated with intravenous glucose at a rate adjusted to increase plasma glucose concentration above 45 mg/dL. Oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured using indirect calorimetry and respiratory quotient (RQ) was calculated. Measurements were performed immediately after the correction of hypoglycemia (6-10 hr), and 24, 72, and 120 hr later. After initiation of treatment, and 24 hr later mean VCO, and RQ were significantly higher in the IDM and the SGA infants than in healthy infants. 72 and 120 hr after the first measurement, the IDM did not differ from the healthy controls, whereas in the SGA infants mean VCO2 and VO2 were still significantly increased. In the SCA infants, the hypermetabolism was sustained during whole study period. Our results indicate that the metabolic defect resulting in hypoglycemia is different between the SGA and IDM infants. However, the treatment with supplemental glucose is necessary to both groups.