Vitamin D Deficiency Prevalence in Late Neonatal Hypocalcemia: A Multicenter Study

OBJECTIVE

Late neonatal hypocalcemia (LNH) is a common metabolic problem associated with hypoparathyroidism, high phosphate intake and vitamin D deficiency, often presenting with seizures. In this cross-sectional study, we aimed to evaluate the role of vitamin D deficiency in LNH in Turkey and to describe the characteristics of affected newborns.

METHODS

Conducted with a cross-sectional design and with the participation of 61 neonatal centers from December 2015 to December 2016, the study included term neonates with LNH (n=96) and their mothers (n=93). Data were registered on the FAVOR Web Registry System. Serum samples of newborns and mothers were analyzed for calcium, phosphate, magnesium, albumin, alkaline phosphatase, intact parathyroid hormone (iPTH) and 25 hydroxyvitamin D [25(OH)D] levels.

RESULTS

The median (range) onset time of hypocalcemia was 5.0 (4.0-8.0) days of age, with a male preponderance (60.4%). The median (range) serum 25(OH)D levels of the neonates and their mothers were 6.3 (4.1-9.05) and 5.2 (4.7-8.8) ng/mL, respectively. The prevalence of vitamin D deficiency (<12 ng/mL) was high in both the neonates (86.5%) and mothers (93%). Serum 25(OH)D levels of the infants and mothers showed a strong correlation (p<0.001). While the majority (93.7%) of the neonates had normal/high phosphorus levels, iPTH levels were low or inappropriately normal in 54.2% of the patients.

CONCLUSION

Vitamin D deficiency prevalence was found to be high in LNH. Efforts to provide vitamin D supplementation during pregnancy should be encouraged. Evaluation of vitamin D status should be included in the workup of LNH.

Impulse oscillometry reference values and correlation with predictors in Turkish preschool children

Er İ, Günlemez A, Baydemir C, Kılıçbay F, Ersu R, Uyan ZS. Impulse oscillometry reference values and correlation with predictors in Turkish preschool children. Turk J Pediatr 2019; 61: 560-567. Impulse oscillometry (IOS) is a noninvasive, rapid technique requiring passive cooperation that allows for evaluation of lung function through the measurement of airway resistance and reactance. There are no available reference values for Turkish children. This study is aimed to determine the reference values of IOS parameters and to study their correlation with height, weight, body mass index, and age as predictors in healthy Turkish preschool children. Healthy children between 3-7 years of age who were selected according to ERS/ATS criteria and followed at Kocaeli University outpatient clinic performed IOS. The correlation between the anthropometric predictor variables and resistance and reactance at 5-20 hertz (R5-R20 and X5-X20), the respiratory impedance at 5 hertz (Z5), resistance area (AX) and resonance frequency (Fres) were assessed by regression analysis and stepwise method. 151 children (93 female) with the mean age of 67.9±16.2 months participated in the study. Multilinear regression analysis for IOS values of all children revealed that resistance was significantly correlated with height and reactance was significantly correlated with age (p < 0.05). For girls, height had a negative effect on R5-20, Z5, AX values, while age had a positive effect on X5-20 and a negative effect on Fres (p < 0.05). For boys, weight had a negative effect on R5- 20, Z5 values, while age had a positive effect on X15-20 and a negative effect on AX, Fres (p < 0,05). This study provided reference values of IOS in healthy Turkish children that would be a useful guide for diagnosing and following respiratory diseases in preschool children.

Evaluation of pulmonary functions in preschool children born late-preterm

AIM

The aim of this study was to evaluate the pulmonary functions of preschool children born late-preterm.

MATERIAL AND METHODS

Children aged between 3-7 years who were born at 340/7-366/7 weeks' gestation represented the target sample. Patients with a diagnosis of congenital cardiac, pulmonary and/or muscle diseases were excluded. Respiratory symptoms were evaluated using the modified asthma predictive index and International Study of Asthma and Allergies in Childhood criteria for children aged under and over 6 years, respectively. Skin prick tests were performed. Age-matched healthy controls were chosen according to the criteria proposed by the American Thoracic Society. Lung functions were evaluated using impulse oscillometry study in both groups. Data were recorded in the SPSS program.

RESULTS

A total of 139 late-preterms and 75 healthy controls participated in the study. The mean gestational week of the late-preterms was 35.3±0.9 weeks. The main admission diagnosis to neonatal intensive care unit was respiratory distress. In the postdischarge period, 54.1% were hospitalized for pulmonary infections at least once, and 57.8% were passive smoking currently. Aeroallergen sensitivity was detected as 25.8% in the late-preterm group; 34.5% and 15.1% were diagnosed as having asthma and non-asthmatic atopy, respectively. Impulse oscillometry study parameters of R5, R10, and Z5 were higher and X10 and X15 were lower in late-preterms than in controls (p<0.05). Late-preterms with and without respiratory distress in the postnatal period revealed no statistical differences for any parameters.

CONCLUSIONS

Our findings suggest that presence of increased peripheral airway resistance in late-preterms as compared to term-born controls.

Metabolic bone disease of prematurity: report of four cases

Osteopenia of prematurity has become a common problem recently because of improved survival rates of infants with very low birth weight (VLBW). The incidence of neonatal osteopenia is inversely correlated with gestational age and birth weight. Herein, we present four cases of preterm osteopenia that were referred to the pediatric endocrinology outpatient clinic with diverse clinical and laboratory findings and we discuss the clinical course of these infants with regard to bone disease after discharge from the neonatal intensive care unit (NICU). This report highlights the importance of enteral calcium, phosphorus and vitamin D support at adequate doses following discharge from NICU for preterm infants with VLBW who are at risk of metabolic bone disease.