THE EFFECT OF FEEDING ON OXYGEN CONSUMPTION, RQ AND PLASMA LEVELS OF GLUCOSE, FFA, AND D-β-HYDROXYBUTYRATE IN NEWBORN INFANTS OF DIABETIC MOTHERS AND SMALL FOR GESTATIONAL AGE INFANTS

Abstract. Eight infants of strictly controlled diabetic mothers (IDM), 8 infants of gestational diabetic mothers (IGDM) and 6 small for gestational age infants (SGA) were studied before the first feeding and during an early feeding regimen. In IDMs and IGDMs continuous monitoring from 2 hours up to 7 1/2 hours after birth before feeding revealed no consistent changes of Vo₂ and RQ. The groups of infants were studied on 4 different occasions: (I) 2 to 16 hours, (II) 1 to 2 days, (III) 3 to 4 days, and (IV) 7 to 11 days. Prefeeding Vo₂-values were not significantly different between each of the groups, but mean RQ was higher in IGDMs than in IDMs. Age of the infant and prefeeding RQ were inversely correlated (r=-0.537, p<0.02). With increasing age and milk intake Vo₂ increased significantly in all groups. RQ decreased during the first 24 to 48 hours in all groups and rose thereafter with highest values at 7 to 11 days. Plasma levels of glucose, FFA, and D-β-hydroxybutyrate were not significantly different between each of the groups. The highest values for D-β-hydroxybutyrate were found at 1–2 days when the lowest RQ values were also recorded. D-β-hydroxybutyrate concentrations and RQ values (r= -0.648, p<0.001) were inversely correlated suggesting increasing oxidation of fat. Feeding resulted in a marked rise in RQ to values around unity, which preceded a distinct increase in Vo₂ that reached a maximum at 1 to 1 1/2 hours after the feed, then slowly returned to pretest values. The rise in Vo₂ was accompanied by an increase in rectal temperature (0.4 to 1.5°C). Vo₂, RQ, and plasma levels of glucose, FFA, and D-β-hydroxybutyrate, were almost identical for each of the groups. We suggest: 1) That differences in feeding practice is the most likely explanation for the discrepancy between reported values for Vo₂, RQ, and circulating substrates in normal and low birth weight newborns. 2) That the rise in Vo₂ during the neonatal period, caused by feeding, reflects the cost of growth.     

METABOLIC OBSERVATIONS IN INFANTS OF STRICTLY CONTROLLED DIABETIC MOTHERS

Abstract. Thirty-five infants of strictly controlled diabetic mothers (IDM), 12 infants of gestational diabetic mothers (IGDM) and 29 control infants were studied to assess the influence of maternal blood glucose level during pregnancy on infant metabolic measurements. At 2 hours after birth the disapperance rate k_t of intravenously injected glucose was determined. Plasma concentration of glucose, insulin, FFA, glycerol and β-hydroxybutyrate were followed in umbilical arterial blood. The 2 hour mean k_t value of IDMs (1.27) was higher (p<0.05) than in IGDMs (1.14) and controls (0.80), but the group mean values were no different at 3 to 5 days although the k_t values were higher. In 10 IDms, k_t values were determined both at 2 hours (1.24) and at 3 days (1.39) without significant differences. Pretest FFA but not glycerol values correlated inversely to k_t values in IDMs and IGDMs. A late insulin peak at 60 min was found in both controls and IGDMs. Insulin responses were unrelated to k_t values. No relation was found between pregnancy glucose value (5 daily determinations during 4 and 2 weeks prior to delivery in DM and GDM respectively) or maternal glucose at delivery and k_t values of IDMs and IGDMs. According to the FFA and glycerol values at 2 hours after birth, 3 sub-groups of IDMs and IGDMs were arbitrarily formed. IDMs and IGDMs of group 1 had glucose, k_ts, FFA, glycerol and β-hydroxybutyrate values no different from controls, whereas sub-groups 2 and 3 showed increasing metabolic deviations. Clinical data and pregnancy glucose levels could not separate the 3 sub-groups. However, the day-to-day variation in maternal glucose was greater in sub-group 3. Mean values of daily maternal blood glucose differences at 10 o'clock correlated to 2-hour k_ts in IDMs. We conclude that strict metabolic control during pregnancy will normalize metabolic adjustment of the infant, thus supporting the maternal hyperglycemia-fetal hyper-insulinism theory.     

Plasma Noradrenaline and Adrenaline in Newborn Infants of Diabetic Mothers: Relation to Plasma Lipids

ABSTRACT. No significant differences in plasma noradrenaline and adrenaline concentrations were found between 14 infants of diabetic mothers (IDMs) and 7 infants of non-diabetic mothers at birth or at 2 hours of age, although the mean values were higher in the IDMs. The mean blood glucose concentration declined from birth to 2 hours of age and it was lower at 2 hours of age in the IDMs although only one IDM became hypoglycaemic. Plasma non-antibody bound insulin concentrations were approximately 12 fold higher at birth and at 2 hours of age in the IDMs than in the control infants. Similar increases in plasma free fatty acids and free glycerol concentrations from birth to 2 hours of age were observed in the 2 groups. At 2 hours of age positive correlations were found between plasma noradrenaline and free fatty acids ( r =0.85, p < 0.01) and free glycerol ( r =0.65, p < 0.05) and between plasma adrenaline and free glycerol ( r =0.71, p < 0.05) and the rise in free glycerol from birth to 2 hours of age ( r =0.65, p < 0.05) in the IDMs. At birth positive correlations between plasma free fatty acids and plasma noradrenaline ( r =0.69, p < 0.02) and plasma adrenaline ( r =0.88, p < 0.01) were found in the IDMs. No correlations were found in the control infants. These findings indicate that the catecholamines counteracts the inhibitory effect of insulin on lipolysis in IDMs.     

Plasma noradrenaline and adrenaline in newborn infants of diabetic mothers: relation to plasma lipids

No significant differences in plasma noradrenaline and adrenaline concentrations were found between 14 infants of diabetic mothers (IDMs) and 7 infants of non-diabetic mothers at birth or at 2 hours of age, although the mean values were higher in the IDMs. The mean blood glucose concentration declined from birth to 2 hours of age and it was lower at 2 hours of age in the IDMs although only one IDM became hypoglycaemic. Plasma non-antibody bound insulin concentrations were approximately 12 fold higher at birth and at 2 hours of age in the IDMs than in the control infants. Similar increases in plasma free fatty acids and free glycerol concentrations from birth to 2 hours of age were observed in the 2 groups. At 2 hours of age positive correlations were found between plasma noradrenaline and free fatty acids (r = 0.85, p less than 0.01) and free glycerol (r = 0.65, p less than 0.05) and between plasma adrenaline and free glycerol (r = 0.71, p less than 0.05) and the rise in free glycerol from birth to 2 hours of age (r = 0.65, p less than 0.05) in the IDMs. At birth positive correlations between plasma free fatty acids and plasma noradrenaline (r = 0.69, p less than 0.02) and plasma adrenaline (r = 0.88, p less than 0.01) were found in the IDMs. No correlations were found in the control infants. These findings indicate that the catecholamines counteracts the inhibitory effect of insulin on lipolysis in IDMs.     

INFLUENCE OF ENVIRONMENTAL TEMPERATURE AND ACIDOSIS ON LIPID MOBILIZATION IN THE HUMAN INFANT DURING THE FIRST TWO HOURS AFTER BIRTH

Arterial concentrations of glycerol, FFA, glucose, lactate and β-hydroxybutyrate were serially measured during the first two hours after birth in normal fullterm infants in a thermo-controlled environment. Blood gas tensions, acid-base balance, pulmonary gas exchange, motor activity and heart rate were also determined: a detailed report of these data will be published separately. In 22 infants the glycerol concentrations showed a rapid immediate increase after birth wheras the rises in FFA concentrations were delayed until between 30 and 120 minutes, indicating a prompt increase in lipolysis and a suppression of lipid mobilization during the first half hour after birth. This suppression might be explained by a high rate of reesterification or oxidation of FFA within adipose tissue. The influence of environmental temperature (2 8.7-3 4.8 ^oC) and degree of acidosis on the pattern of changes in FFA and glycerol were only marginal. No inhibition of lipolysis and lipid mobilization was shown in an infant who developed postnatal asphyxia.
At 120 min after birth, when acidosis had been eliminated, an inverse correlation was found between the rise in FFA from birth to 120 min and the respiratory exchange ratio (co₂/o₂).
The glucose concentrations were related neither to the FFA nor to the glycerol concentrations. The rate of elimination of lactate and β-hydroxybutyrate was not influenced by environmental temperature or acidosis. Minute amounts of administered heparin caused an increased rise in FFA and glycerol concentrations which were associated with the appearance of lipoprotein lipase activity.     

FREE FATTY ACIDS, GLYCEROL AND TRIGLYCERIDES DURING THE FIRST 24 HOURS IN INFANTS WITH A BIRTH WEIGHT ≤2 700 GRAMS

ABSTRACT. Christensen, N. C. (Departments of Obstetrics and Paediatrics, Odense University Hospital, Odense, Denmark). Free fatty acids, glycerol and triglycerides during the first 24 hours in infants with a birth weight <2 700 grams. Acta Paediatr Scand 70:485,.–The influence of birth weight and gestational age on the concentrations of free fatty acids, glycerol and triglycerides during the first 24 hours of life were studied in 86 healthy newborn infants with BW ≤2700 g. Very low FFA values were found in the first 6 hours in infants with GA ≤34 weeks, whereas FFA increased from the second hour in infants with higher GA. All infants had peak values at 12 h. Significant correlations were found between FFA and GA, most pronounced in the second hour after birth. No differences were seen between AGA and SGA infants of similar GA. High glycerol concentrations were found from the second hour in all infants irrespective of GA and BW. Triglyceride concentrations 24 hours after birth were not influenced by GA or BW. The finding of intact lipolysis but low FFA releases in the first hours in infants with GA ≤34 weeks could not be explained by differences in rectal temperature, blood glucose or caloric intake.     

Influence of the maternal plasma glucose concentration at delivery on the risk of hypoglycaemia in infants of insulin-dependent diabetic mothers

Plasma glucose concentrations at birth and at two hours of age were measured in 53 infants of insulin-dependent mothers (IDMs). The plasma glucose concentrations at delivery were measured in the mothers of 17 IDMs and in the remaining 36 mothers, glucose was estimated by interpolation from concentrations achieved just before and after delivery. Clinical and laboratory data from the two groups were otherwise similar, so the groups were combined for further analyses. The maternal plasma glucose at delivery correlated positively with the glucose concentration of the IDMs at birth (rho = 0.82, p less than 0.001) and negatively with the glucose concentration at two hours of age (rho = -0.46, p less than 0.001). Maternal plasma glucose concentration was higher in mothers delivered by caesarean section than in vaginally delivered mothers (p less than 0.05). Eleven IDMs became hypoglycaemic at two hours of life (plasma glucose less than or equal to 1.7 mmol/l). These infants had higher cord plasma glucose concentrations at birth than those who remained normoglycaemic; the maternal glucose concentration was also higher. None of the IDMs became hypoglycaemic if the maternal glucose concentration at delivery was less than 7.1 mmol/l. In 28 IDMs the simultaneous plasma concentrations of non-antibody bound immunoreactive insulin (IRI) were recorded. Cord plasma IRI correlated with glucose and IRI at two hours of age (rho = -0.73, p less than 0.001 and rho = 0.77, p less than 0.001, respectively). Cord plasma IRI was higher in IDMs who became hypoglycaemic than in the remaining infants.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of the Maternal Plasma Glucose Concentration at Delivery on the Risk of Hypoglycaemia in Infants of Insulin-Dependent Diabetic Mothers

Plasma glucose concentrations at birth and at two hours of age were measured in 53 infants of insulin-dependent mothers (IDMs). The plasma glucose concentrations at delivery were measured in the mothers of 17 IDMs and in the remaining 36 mothers, glucose was estimated by interpolation from concentrations achieved just before and after delivery. Clinical and laboratory data from the two groups were otherwise similar, so the groups were combined for further analyses. The maternal plasma glucose at delivery correlated positively with the glucose concentration of the IDMs at birth (Q=0.82, p <0.001) and negatively with the glucose concentration at two hours of age (Q= -0.46, p <0.001). Maternal plasma glucose concentration was higher in mothers delivered by caesarean section than in vaginally delivered mothers ( p <0.05). Eleven IDMs became hypoglycaemic at two hours of life (plasma glucose ≥1.7 mmol/1). These infants had higher cord plasma glucose concentrations at birth than those who remained normoglycaemic; the maternal glucose concentration was also higher. None of the IDMs became hypoglycaemic if the maternal glucose concentration at delivery was less than 7.1 mmol/l. In 28 IDMs the simultaneous plasma concentrations of non-antibodybound immunoreactive insulin (IRI) were recorded. Cord plasma IRI correlated with glucose and IRI at two hours of age (Q=-0.73, p <0.001 and Q=0.77, p <0.001, respectively). Cord plasma IRI was higher in IDMs who became hypoglycaemic than in the remaining infants. The results suggest that among the factors which may be responsible for neonatal hypoglycaemia in IDMs a major factor may be the maternal plasma glucose concentration at the time of delivery.     

DIETARY EFFECTS IN THE EARLY RECOVERY PHASE OF KWASHIORKOR Plasma levels of triglycerides, FFA, d-β-hydroxybutyrate, glycerol, postheparin lipoprotein lipase (LPL), glucose and insulin

Abstract. The fatty liver often found in untreated kwashiorkor has been associated with highly variable concentrations of circulating lipids. The effect on lipid metabolism of two isocaloric diets—one synthetic monomolecular (Vivonex) and one standard (Casilan)—which both initiated satisfactory clinical improvement was studied in 21 Ethiopian children with kwashiorkor during the first weeks of rehabilitation. Before treatment mean fasting values of all biochemical parameters were within normal ranges except for moderately elevated triglycerides—an unexpected finding—and low insulin. Individual values varied greatly; triglyceride between 0.39 and 3.49 mmol/l. FFA correlated both to glycerol, d -β-hydroxybutyrate and triglyceride values. During treatment insulin, glucose and glycerol remained essentially unchanged and were similar in both dietary groups. In the Vivonex group only there was an initial marked, parallel fall of FFA and d -β-hydroxybutyrate suggesting greater availability of carbohydrate and enhanced glucose utilization. This pattern of response seemed to occur without comparable inhibition of lipolysis. Triglycerides—like serum albumin—increased faster in the Casilan group. The highest mean triglyceride value was reached by day 8 in the Casilan group and by day 15 in the Vivonex group. Ten minutes following heparin injection triglycerides declined, FFA and glycerol increased indicating release of in vivo active lipase. LPL activity assayed in vitro was similar and unaffected by 2 weeks of dietary treatment in both groups. LPL activity was inversely correlated to triglycerides providing—beside the type of diet—another possible explanation for the wide variations seen in circulatory triglycerides.     

INTRAVENOUS GLUCOSE TOLERANCE, PLASMA INSULIN, FREE FATTY ACIDS AND β-HYDROXYBUTYRATE IN UNDERWEIGHT NEWBORN INFANTS

Blood glucose, plasma insulin, FFA and β-hydroxybutyrate values during intravenous glucose tolerance were reported in 20 small for gestational age (SGA) and 15 appropriate for gestational age (AGA) low birthweight infants. The babies were divided into three groups according to their age when tested; <24 hours, 24–48 hours and >48 hours. Both the SGA and AGA infants cleared glucose more rapidly with increasing age. The change was more marked in the SGA babies. The clearance rates were similar to those reported in normal full-sized infants. The insulin values before the glucose load were similar in all groups and comparable to those reported in normal newborn infants. The insulin response to glucose was variable. There were no significant differences with increasing age or between the two groups of infants. The insulin curve of the individual infant followed one of three patterns. Most commonly seen was a double-peak curve. The infants who showed a single-peak insulin response had a better but not significantly different glucose tolerance than that of the other babies. Infants with no appreciable insulin response still removed glucose from plasma at a rate similar to those with a double-peak insulin curve. It is concluded that insulin as measured in peripheral plasma could not explain the rate of removal of glucose from the plasma of the newborn low birthweight infant. Infants of low birthweight had higher plasma FFA values as compared to that reported in normal full term infants. The FFA values in SGA infants were higher than those in AGA babies. In both groups of infants, the jS-hydroxybutyrate values were comparable to those reported in normal full-term babies. Thus there was an unexpected discrepancy between the high FFA and relatively low β-hydroxybutyrate levels in plasma. The fall in plasma FFA and β-hydroxybutyrate after glucose was minimal but similar in both groups of infants. The findings are compatible with a decreased sensitivity to insulin in the infants studied.     

Five-hour Oral Glucose Tolerance Test in Obese Children

Concentrations of blood glucose, plasma free fatty acids, and plasma glycerol during a 5-hour oral glucose tolerance test on 46 obese children are reported.Seven children had unequivocally impaired glucose tolerance. However in the group as a whole, there was a delay in return of blood glucose to baseline levels after oral glucose, 27 children (60%) having a blood glucose concentration greater than 110 mg/100 ml at 2 hours. It was concluded that some degree of glucose intolerance is common in childhood obesity. No relation was seen among the following: impairment of glucose tolerance and age, degree or duration of obesity, or family history of diabetes.Fasting plasma free fatty acids and glycerol concentrations were high (mean ± 1SD, 1030 ± 221 μEq/litre FFA and 121 ± 44 μmol/l. glycerol). For all children, concentrations of FFA and glycerol decreased during the first hour after glucose, though minimal levels were not reached until 90-120 minutes (mean ± 1SD, 395 ± 170 μEq/litre FFA, 77 ± 24 μmol/l. glycerol). For those children (27) who had raised blood glucose at 2 hours, there was a positive correlation between fasting plasma glycerol concentration and glucose tolerance sum, suggesting that impaired glucose tolerance was associated with increased basal lipolysis.     

METABOLIC EVENTS IN INFANTS OF DIABETIC MOTHERS DURING FIRST 24 HOURS AFTER BIRTH II.

ABSTRACT. Changes in plasma glycerol (FG), free fatty acids (FFA) and triglyceride (TG) were studied in 24 normo- and 8 hypoglycemic infants of diabetic mothers (IDM). In both groups a normal rise in plasma FG 2 hours after birth was found indicating unimpaired lipolysis. The rise in plasma FFA, however, was only about 50% of normal in normoglycemic IDM and about 25% of normal in hypoglycemic IDM. The rise in plasma TG was normal in normoglycemic and about 70% of normal in hypoglycemic IDM. The 2 hour rise in plasma FFA correlated with the 2 hour concentration of insulin and glucose, whereas the rise in plasma FG and TG did not. Maternal plasma FFA correlated with fetal FFA retention (unbilical vein minus artery (V-A) FFA concentrations). No correlations were found between maternal plasma FFA values and birth-weights nor between umbilical V-A FFA concentrations and birth-weights.     

THE EFFECT OF MODERATE HYPOCAPNIA ON THE CEREBRAL ARTERIO-VENOUS DIFFERENCE OF ACETOACETATE, d-β-HYDROXYBUTYRATE AND OXYGEN IN CHILDREN

Cerebral arterio-venous differences of aceto-acetate, D-β-hydroxybutyrate, glucose, glycerol, FFA, lactate, pyruvate and oxygen were determined during normo- and hypocapnia in children anaesthetized in connection with surgical operations or X-ray procedures. Cerebral flow equivalent values were used to calculate the relative changes in uptake or production of substrates during hypocapnia. The uptake of ketone bodies was proportional to the cerebral blood flow and to the arterial concentration. In comparison with reported values in adults the estimated uptake of ketone bodies at a given arterial concentration was about four times higher in children. During hypocapnia, but not during normocapnia children had a significant lactate production. The vasodilating effect of carbon dioxide on the cerebral blood vessels seems to be the same in children and adults.     

URINARY CYCLIC AMP IN INFANTS ADMITTED TO A NEONATAL INTENSIVE CARE UNIT

ABSTRACT. The urinary excretion of cyclic AMP was studied during the first 3 days of life in 46 randomly selected infants admitted to a neonatal intensive care unit. The data were compared with those of normal newborn infants. Urinary cyclic AMP concentrations were significantly correlated with gestational age (all patients), and with birth weight (all patients except infants of diabetic mothers (IDMs)). The urinary cyclic AMP/creatinine ratio increased from day 1 to day 3 in normal newborns and in IDMs, and tended to increase also in small-for-gestational age (SGA), low birth weight (LBW), and sick, term infants, although the changes in the latter groups were not statistically significant. Four infants studied with parallel determinations showed increased cyclic AMP/creatinine ratio from day 1 to day 3 both in plasma and urine. All urinary cyclic AMP/creatinine ratios were lower than the corresponding ratios found in plasma. In LBW infants, there was an inverse relationship between urinary cyclic AMP and serum calcium. In IDMs a positive correlation was observed between urinary cyclic AMP and blood glucose concentration. In conclusion, the excretion of cyclic AMP in sick newborn infants is influenced by the following factors: gestational age, postnatal age, birth weight, and derangements of serum calcium and blood glucose concentrations.     

Urinary cyclic AMP in infants admitted to a neonatal intensive care unit.

The urinary excretion of cyclic AMP was studied during the first 3 days of life in 46 randomly selected infants admitted to a neonatal intensive care unit. The data were compared with those of normal newborn infants. Urinary cyclic AMP concentrations were significantly correlated with gestational age (all patients), and with birth weight (all patients except infants of diabetic mothers (IDMs)). The urinary cyclic AMP/creatine ratio increased from day 1 to day 3 in normal newborns and in IDMs, and tended to increase also in small-for-gestational age (SGA), low birth weight (LBW), and sick, term infants, although the changes in the latter groups were not statistically significant. Four infants studied with parallel determinations showed increased cyclic AMP/creatinine ratio from day 1 to day 3 both in plasma and urine. All urinary cyclic AMP/creatine ratios were lower than the corresponding ratios found in plasma. In LBW infants, there was an inverse relationship between urinary cyclic AMP and serum calcium. In IDMs a positive correlation was observed between urinary cyclic AMP and blood glucose concentration. In conclusion, the excretion of cyclic AMP in sick newborn infants is influenced by the following factors: gestational age, postnatal age, birth weight, and derangements of serum calcium and blood glucose concentrations.     

INTERRELATION BETWEEN FATTY ACID OXIDATION AND CONTROL OF GLUCONEOGENIC SUBSTRATES IN SMALL-FOR-GESTATIONAL-AGE (SGA) INFANTS WITH HYPOGLYCEMIA AND WITH NORMOGLYCEMIA

ABSTRACT. Twelve SGA infants were studied from 4 hours after birth (day 1), before and for 4 hours after injection of 0.5 g of fat/kg b. w. (Intralipid®, IL). Eight infants were restudied after 24 hours (day 2). A positive correlation was found between initial samples of FTA and glucose on day 1 (n= 11, r 0.71, p < 0.02) and between FFA and β-hydroxybutyrate (n= 12, r 0.62, p < 0.05), suggesting low FFA mobilization and oxidation in SGA infants with low blood glucose. After IL infants with low blood glucose had a more pronounced defect of intravascular lipolysis. Four infants had initial hypoglycemia (HG), with blood glucose 0.4-1.3 mmol/l, and 8 were normoglycemic (NG). In the NG group initial levels of lactate and alanine were within normal limits, and no changes occurred after IL. An early peak of glycerol was seen. In the HG group initial lactate and alanine levels were higher than in the NG group, while glycerol did not differ. After injection of IL, glucose increased at 60 and 120 min in the HG group. A close correlation was found between mean levels of lactate and alanine and a negative correlation between lactate and glucose, while no correlation was found between glycerol and glucose levels. The infants with the lowest initial glucose and the highest lactate levels had the steepest rise in glucose and the fastest decrease in lactate per unit increase in β-hydroxybutyrate after IL. On day 2 the initial levels of lactate and alanine were lower than on day 1 and all infants were normoglycemic. A glucose peak corresponding to the glycerol peak was seen after IL, but lactate and alanine levels did not change. These data were consistent with reduced lipolytic capacity, low fatty acid oxidation and reduced gluconeogenesis in SGA infants on day 1, especially in those with HG. The glucose and β-hydroxybutyrate levels were rapidly increasing and lactate levels decreasing after IL, suggesting improving gluconeogenesis concomitantly with increasing fatty acid oxidation.     

Dietary effects in the early recovery phase of kwashiorkor. Plasma levels of triglycerides, FFA, D-beta-hydroxybutyrate, glycerol, postheparin lipoprotein lipase (LPL), glucose and insulin.

The fatty liver often found in untreated kwashiorkor has been associated with highly variable concentration of circulating lipids. The effect on lipid metabolism of two isocaloric diets--one synthetic monomolecular (Vivonex) and one standard (Casilan)--which both initiated satisfactory clinical improvement was studied in 21 Ethiopian children with kwashiorkor during the first weeks of rehabilitation. Before treatment mean fasting values of all biochemical parameters were within normal ranges except for moderately elevated triglycerides--an unexpected finding-and low insulin. Individual values varied greatly; triglyceride between 0.39 and 3.49 mmol/1. FFA correlated both to glycerol, D-beta-hydroxybutyrate and triglyceride values. During treatment insulin, glucose and glycerol remained essentially unchanged and were similar in both dietary groups. In the Vivonex group only there was an initial marked, parallel fall of FFA and D-beta-hydroxybutyrate suggesting greater availability of carbohydrate and enhanced glucose utilization. This pattern of response seemed to occur without comparable inhibition of lipolysis. Triglycerides--like serum albumin--increased faster in the Casilan group. The highest mean triglyceride value was reached by day 8 in the Casilan group and by day 15 in the Vivonex group. Ten minutes following heparin injection triglycerides declined, FFA and glycerol increased indicating release of in vivo active lipase. LPL activity assayed in vitro was similar and unaffected by 2 weeks of dietary treatment in both groups. LPL activity was inversely correlated to triglycerides providing--beside the type of diet--another possible explanation for the wide variations seen in circulatory triglycerides.     

Low birthweight infants and total parenteral nutrition immediately after birth. II. Randomised study of biochemical tolerance of intravenous glucose,amino acids,and lipid.

This randomised study aimed to compare the biochemical tolerance of three parenteral regimens administered during the first 48 hours of life. Twenty nine infants were randomised to either: (a) glucose 10%; (b) glucose 10%/amino acids; (c) glucose 10%/amino acids/lipid. Blood samples for plasma amino acid profiles, cholesterol, and triglyceride concentrations were taken on arrival in the neonatal unit and again between 36 and 48 hours of life. Arterial or capillary blood gas analysis and blood glucose estimates were performed routinely during the first 48 hours of life. There was a sharp decline in plasma amino acid concentrations in the group following (a) compared with the two groups following (b) and (c) regimens. In all groups plasma triglyceride and cholesterol were not significantly different before and after 48 hours of lipid infusion. Peak mean (SE) bilirubin concentrations (203 (12) v 181 (19) v 220 (20) mumol/l) and the need for phototherapy (nine v eight v five infants) were similar for each of the groups. Hypoglycaemia occurred most frequently during the (b) regimen and least commonly in the (c) group. There are potential health gains from giving parenteral nutrition to low birthweight infants immediately after birth, and this study indicates that restriction of nutritional intake immediately after birth in preterm infants may cause significant metabolic disturbance. This can be prevented by starting a regimen of intravenous amino acids and lipid immediately after birth.     

Hypoglycemia in the newborn growth-retarded rat: delayed phosphoenolpyruvate carboxykinase induction despite increased glucagon availability

We have characterized the sequential changes in plasma glucose, insulin and glucagon concentrations, and hepatic glycogen and phosphoenolpyruvate carboxykinase (PEPCK) during the first 240 min of life in rat pups growth retarded [small for gestational age (SGA)] due to bilateral maternal uterine artery ligation. Pups of sham and nonoperated (normal) mothers served as controls. SGA pups were smaller, had reduced liver mass, and demonstrated a pattern of hypoglycemia. They had significantly reduced plasma glucose concentrations at birth, 20, and 240 min but had normal values at 60 and 120 min. SGA pups had significantly reduced hepatic glycogen stores at birth. Plasma glucagon concentrations in SGA pups increased significantly at 20 and 60 min while insulin concentrations decreased equally in all groups. Hepatic PEPCK activity increased greatly in the sham and normal pups. SGA pups did not induce PEPCK during the first 240 min of life; however, pharmacologic doses of glucagon at birth accelerated PEPCK induction in SGA pups and prevented hypoglycemia. These data indicate that newborn SGA pups develop hypoglycemia because of limited hepatic glycogen stores and retarded gluconeogenesis. The delay in PEPCK induction in SGA pups may result from an inadequate although increased glucagon release at birth or diminished sensitivity to available glucagon.     

CONCENTRATIONS OF TRIGLYCERIDES, FREE FATTY ACIDS AND GLYCEROL IN CORD BLOOD OF NEWBORN INFANTS WITH A BIRTH WEIGHT OF ≤2700 GRAMS

Abstract Concentrations of triglycerides, free fatty acids (FFA) and glycerol were measured in umbilical venous blood from 99 infants with a birth weight of between 1100–2700 g and a gestational age of 27–41 weeks. Thirty infants were small for gestational age (SGA), 58 were appropriate (AGA) and 11 were of uncertain gestational age. In AGA infants with a gestational age of ≥35 weeks, FFA values were lower than in those with a gestational age of>35 weeks; otherwise concentrations of triglycerides, FFA and glycerol were independent of birth weight and gestational age in AGA infants. In SGA infants, higher FFA values were found compared with both AGA and term infants of normal birth weight. Triglyceride values were higher in SGA than in AGA infants. In SGA infants, a significant positive correlation was found between gestational age and concentrations of both FFA and triglycerides. No differences in FFA, glycerol and triglyceride concentrations were seen between asphyxiated and non-asphyxiated AGA infants.