Plasma noradrenaline and adrenaline in infants of diabetic mothers at birth and at two hours of age

Tactile-kinesthetic stimulation effects on sympathetic and adrenocortical function in preterm infants

The purpose of our study was to investigate the neuroendocrine response in preterm infants to a pattern of tactile-kinesthetic stimulation that facilitates their growth and development. Preterm infants (mean gestational age 30 weeks, mean birth weight 1176 gm) received normal nursery care or tactile-kinesthetic stimulation for three 15-minute periods at the start of three consecutive hours each day for 10 days. On day 1 and day 10 of the study, a 24-hour urine sample was collected for norepinephrine, epinephrine, dopamine, cortisol, and creatinine assay and a blood sample was taken by heel stick for cortisol and growth hormone assay. Urine norepinephrine and epinephrine values increased significantly only in the stimulated babies. Urine dopamine and cortisol values increased in both groups, and serum growth hormone decreased in both groups. Individual differences in urine norepinephrine, epinephrine, dopamine, and cortisol values were highly stable across the 10 days despite a 10-fold range of values among the infants. The results of this study suggest that tactile-kinesthetic stimulation of preterm infants has fairly specific effects on maturation and/or activity of the sympathetic nervous system. In addition, this study has defined catecholamine and cortisol secretion across gestational age in normal preterm infants. Finally, these data suggest that highly stable individual levels of catecholamine and cortisol secretion are established by birth in humans.

Changes in catecholamine-induced lipolysis in isolated human fat cells during the first year of life

Catecholamine-induced lipolysis in isolated human adipocytes during the first year of life was investigated. During this period fat cell size increased markedly. Basal and catecholamine-induced glycerol release were positively correlated with age when lipolysis was expressed per cell. However, when lipolysis was expressed per unit of cell surface area (micrometer squared), this correlation was observed only for noradrenaline. Basal lipolysis and the effect of the pure beta-agonist, isoprenaline, were identical in infants and adults. From 0 to 2 mo of age noradrenaline had very little lipolytic effect. The addition of the alpha-2-adrenoceptor antagonist, yohimbine, to noradrenaline equalized lipolysis per micrometer squared in infants and adults and the alpha-2-adrenoceptor sensitivity was significantly enhanced in infants. In both groups the lipolytic adrenoceptor was of the beta-1 type. In conclusion, adipocytes from infants have a poor lipolytic response to noradrenaline partly because of the small fat cells but mainly because of an enhanced alpha-2-adrenoceptor activity.

Fetal distress during labour in diabetic pregnancy

The frequency of fetal distress in labour was studied in 46 diabetic women and in 46 non-diabetic matched controls. Fetal distress was assessed by electronic fetal heart rate (FHR) monitoring and fetal scalp blood pH determinations in late first stage of labour. Ominous FHR and/or low pH (less than 7.26) was more common in the diabetic group than in the control group (17.4% and 10.9%, respectively) but the difference was not statistically significant. The frequency of caesarean section and low Apgar score at 1 min was significantly higher in the diabetic group (P less than 0.05). There was no correlation between maternal blood glucose regulation and the occurrence of fetal distress in the diabetic group. The results suggest that fetal distress may be slightly more common in labour in diabetic women compared with controls managed in a similar way. Careful FHR monitoring and liberal use of fetal scalp blood pH determinations is recommended.

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.

Sympatho-adrenal activity and metabolic adjustment during the first 12 hours after birth in infants of diabetic mothers

Plasma adrenaline and noradrenaline concentrations at birth were the same in infants of diabetic mothers and controls after both vaginal and abdominal delivery. The infants delivered vaginally had significantly higher noradrenaline concentrations than those delivered by caesarean section. During the first 12 postnatal hours, the concentration of noradrenaline decreased to levels similar to those found in newborn infants with minor respiratory problems. No hypoglycemic values were recorded in infants of diabetic mothers at birth nor during the first twelve hours after birth. The C-peptide concentrations at birth were significantly lower in infants of diabetic mothers delivered vaginally as compared to those delivered by caesarean section. The FFA concentrations increased after birth possibly as a result of the lipolytic action of catecholamines released during labour and delivery. We have not been able to confirm the increased sympatho-adrenal activity previously reported in infants of diabetic mothers. We suggest that the difference is due to better metabolic control in the diabetic mothers during pregnancy and delivery in this study.