ABSTRACT
Twenty four hours urine specimens have been analysed with regard to cortisol, sodium, potassium, calcium and phosphate in 48 Full-term and premature newborns. The mean values of 24 hours urinary cortisol in 10 uncomplicated premature newborns [12.45 +/- 5.8 ug/kg], in 16 complicated premature newborns [24.35 +/- 15.55 ug/kg] and in 12 complicated full-term [14.9 +/- 10.91 ug/kg] were found to be significantly higher than that in 10 uncomplicated full-tern newborns [6.68 +/- 2.76 ug/kg]. Significant negative correlations between cortisol excretion and gestational age were found in the group of normal full-term [r = -0.73, P < 0.02] and in the group of uncomplicated premature newborns [r = 0.81, P < 0.01]. Significantly higher levels of 24 hours sodium, potassium, calcium and phosphate urinary excretion were observed in uncomplicated preterm [2.43 +/- 1.14 m Eq/kg, 1.31 +/- 0.31, 1.65 +/- 0.23 mg/kg and 28.97 +/- 5.4 mg/kg respectively] compared to normal full-term [0.88 +/- 0.17 mEq/kg P < 0.01, 1.01 +/- 0.19 mEq/kg P 0.05, 0.64 +/- 0.1 mg/kg P < 0.01 and 7.27 +/- 1.07 mg/kg P < 0.01 respectively]. Complicated premature newborns excrete significantly higher level of sodium, calcium and phosphate [2.99 +/- 1.30 mEq/kg, 3.02 +/- 1.62 mg/kg and 36.70 +/- 19.15 mg/kg respectively] than the group of normal full-term newborns P < 0.01 for each. Complicated full-term newborns excrete significantly more sodium [2.11 +/- 1.60 mEq/kg] and phosphate [36.65 +/- 7.88 mg/kg] than normal full-term neonates P < 0.05 and P < 0.01 respectively. Significant negative correlations were found between either sodium or phosphate excretion and gestational age in the group of uncomplicated premature newborns [r = 0.78 P < 0.01 and r = -0.80 P < 0.01 respectively]. The results were discussed in the light of the available data