The Low Birth Weight Infant and Parenteral Nutrition

Copper Concentration in the Blood Serum of Low Birth Weight Newborns

Until now in the information resources data on the reference values of the concentration of this essential trace element in biological fluids in low birth weight (LBW) newborns are absent. The purpose of our study was to study the copper content in serum in various categories of LBW children during the neonatal period. This prospective study included 173 newborns with LBW, including babies with intrauterine growth retardation (IUGR). The dynamic monitoring of copper concentration in the blood serum, as well as the analysis of these parameters depending on the birth weight has been performed. Quantitative determination of serum copper was carried out by the method of emission spectral analysis. When analyzing the level of copper in the blood serum on the 10th and 25th days of life, a lower content of this element was noted in extremely LBW children with (8.10±1.16 and 6.99±0.41, on the 10th and 25th days of life, respectively) and without IUGR (7.49±1.07 and 7.19±0.91, respectively). On the 25th day of life, serum copper levels were reduced in all groups of children (P<0.001). All LBW newborns and especially in children with IUGR has a deficiency of this micronutrient throughout the observation period. In newborns with ELBW or VLBW, there is a deficiency of serum copper throughout the neonatal period.

Short-term exposure to exogenous lipids in premature infants and long-term changes in aortic and cardiac function

OBJECTIVE

Intravenous lipid use is associated with an acute hyperlipidemia, but long-term consequences have not been studied. We investigated whether elevated lipids in humans during the critical period of preterm neonatal life have a long-term impact on aortic and myocardial function relevant to adult disease.

METHODS AND RESULTS

We followed up 102 subjects born prematurely and now aged 23 to 28 years. Eighteen received intravenous lipids as neonates and were matched to controls with equivalent perinatal characteristics. Global and regional aortic stiffness and left ventricular function were assessed by cardiovascular magnetic resonance. Those who received intravenous lipids had greater aortic stiffness in early adulthood (P=0.0002), with greater stiffness in the abdominal aorta (P=0.012). The relationship was graded according to the elevation in neonatal cholesterol induced by intravenous lipids (P<0.0001) but not other metabolic parameters altered by the infusion. Peak systolic circumferential strain was also reduced in the lipid group (P=0.006), which, again, was proportional to neonatal cholesterol level (P<0.01).

CONCLUSIONS

Aortic and myocardial function in young adulthood is associated with intralipid exposure during neonatal life for preterm infants, in a graded manner related to the rise in cholesterol. Circulating cholesterol during critical developmental periods may have long-term impacts on the human cardiovascular system.

Low birthweight infants and total parenteral nutrition immediately after birth. I. Energy expenditure and respiratory quotient of ventilated and non-ventilated infants

The aim of this study was to determine the energy expenditure and respiratory quotient (RQ) of ventilated and non-ventilated low birthweight infants during the first five days of life, in order to determine optimal feeding regimens. Eighty six infants, of birthweight less than 1750 g, were grouped according to whether they were artificially ventilated or breathing air spontaneously, and whether they were parenterally or enterally fed at the time of study. Energy expenditure and respiratory quotient were measured during days 1-5 and the relation of energy expenditure to several explanatory variables was investigated using multiple regression analysis. The energy expenditure of ventilated infants was less than that of spontaneously breathing infants; the differences were significant on days 1-3. The respiratory quotient (mean (SE)) was greater in intravenously fed infants compared with milk-fed--0.99 (0.03) v 0.92 (0.01) (P < 0.05), with 42% of studies of infants receiving total parenteral nutrition (TPN) producing an RQ of > 1.0 compared with 16.6% of milk-fed infants (P < 0.01). There was a significant correlation between glucose intake and RQ (r = 0.39, P < 0.001). The activity scores were measured during 75 studies and scores were significantly higher in spontaneously breathing milk-fed infants compared with ventilated parenterally fed infants. Factors independently related to energy expenditure were: postnatal age (P < 0.01); milk feeds (P < 0.01); and physical activity (P < 0.05). A mix of carbohydrate and fat from day 1 may not only meet energy needs but may also reduce respiratory quotient.