Background: Estimation of urinary parameters in preterm infants is a useful method for identifying metabolic derangements. Objectives: A prospective, longitudinal, hospital-based study was designed to examine the variability and the associations in renal excretion of calcium (Ca), magnesium (Mg), phosphate (P) and sodium (Na) in formula-fed preterm infants during the first month of life. Patients: Thirty-four infants <32 weeks gestational age, clinically stable, not receiving nephrotoxic drugs. Methods: Measurements of serum and 8-hour urinary mineral and creatinine (Cr) concentrations were made in all infants during three periods (at 7–10, 14–17 and 21–26 days postnatally). The urinary parameters, FENa, FEP, UCa/UCr, UMg/UCr were calculated. 24- hour urinary excretion was estimated by extrapolation of the 8-hour values. Results: The 24-hour excretion values (median and range) (mmol/kg) during the three study periods were, respectively, for Ca: 0.027 (0.015–0.15), 0.030 (0.007–0.12), 0.031 (0.008–0.12), for P: 0.26 (0.07–0.83), 0.29 (0.06–0.67), 0.41 (0.22–0.70), for Mg: 0.025 (0.007–0.14), 0.025 (0.008–0.16), 0.027 (0.010–0.10) and for Na: 2.85 (0.8–15), 1.45 (0.3–17), 1.56 (0.6–4.3). Na excretion declined while the excretion of the other minerals remained stable. A positive correlation was observed between excretion of Ca, Mg and Na (Ca vs. Na r = 0.63, p < 0.0001; Ca vs. Mg r = 0.65, p < 0.0001; Na vs. Mg r = 0.38, p = 0.012) as well as between the renal parameters FENa, FEP, UCa/UCr, UMg/UCr and the respective 24-hour excretion values (r = 0.80, 0.86, 0.84, 0.81) Conclusions: Urinary excretion of Ca, P, and Mg in preterm formula-fed infants is stable during the first month of life while urinary Ca, Na and Mg are closely correlated during the same period.

Twenty-five children with radiologically confirmed primary peptic ulcers were investigated. All patients suffered from duodenal ulcer and there was an unexpected female preponderance. The frequency of introverted personalities was greater in the patients than in the controls. Five patients suffered from psychiatric disorders, three had histories of suicidal attempts and three reported homosexual experiences. Six patients had nicknames. Eight patients had been operated on for appendicitis. The above parameters were negative in all control cases. The patients had lower mean IQ, worse adaptation to school, more anxious and overprotective parents, higher frequency of faddiness in food and lower frequency of nail-biting than the controls. The onset of symptoms was preceded by psychotraumatic events in eight cases. The findings suggest that the manifestation of the genetic background of duodenal ulcer is strongly influenced by environmental factors and factors associated with the personality of the patients.

In preterm neonates on total parenteral nutrition, urinary oxalate -to-creatinine ratio (a potent lithogenic factor) was lower and urinary citrate -to-creatinine ratio (a lithoprotective factor) also lower than in formula fed neonates. The type of feeding (total parenteral nutrition or special preterm milk formula) seems to affect urinary oxalate and citrate but not calcium and magnesium in non-furosemide treated preterm infants during the first 3 weeks of life.