Niveles de zinc en suero en recién nacidos pretérmino a la edad a término y factores asociados a hipozinquemia

Resumen

Introduction: Preterm newborns have decreased zinc deposits, so they are a risk poblation of hypozinchemia. There are few published studies about zinc levels in the preterm and hypozinchemia factors associated. Objective: The aim of the study was to analyze zinc levels of preterm infants and how much of them have hypozinquemia. To determine somatometric, nutritional or clinical factors that may be associated with serum zinc levels in preterm. Material and methods: Prospective descriptive and analytical observational study at the General University Hospital of Elche. The study included all preterm gestational age between 24 and 34 weeks, born during a period of 13 months ( October 1, 2016 to October 31, 2017). The variables have been collected from medical histories and at the age for term analyzed zinc in blood and the other analytical variables. As a control group of zinc values in serum of 20 full-term infants were included. For the statistical analysis, EPIDAT has been used for the sample calculation and the Statistical Package for the Social Sciences program 22 for the descriptive and comparative analysis including the multivariate study. Results: In the period of study, 110 preterm infants were born, 92 met inclusion criteria and throughout the study there were 9 losses. Of the total of 83 subjects analyzed 44 (53%) were women and 39 (47%) males with mean gestation week 31 (29-33), mean birth weight of 1523 (535.42) g. Levels of zinc in plasma when they reached the age at term were 29 (17.3-45.6) mcg / dL and those of the control group 66 (56.15, 71.75) mcg / dL. From the total of preterms studied 74.7% had hypozinemia. The analisis of the factors associated with zinc levels demostrated relation with birth weight (r 0.269 p 0.014), to be small for gestational age (p 0.011), to have received recombinant human erythropoietin (p 0.02) and to have diagnosis of bronchopulmonary dysplasia (p 0.005). From the analysis of nutritional variables, a negative relation was found in the grams / day of weight gained (r -0.208 p 0.05) and a direct relation with z-score of length at discharge (r 0.22 p 0.04). ). Neither the analytical variables studied (albumin, alkaline phosphatase and vitamin D) nor the kind of enteral alimentation or amount of non-pharmacologically zinc ingested, showed relation with zinc levels. The multivariate analysis demostrated relation between bronchopulmonary dysplasia and protein intake Odds Ratio 2.1 CI 95% (1,001-4,415). Conclusions: High percentage of zinc deficit has been found in the population of preterm newborns studied. Neither the amount of non-pharmacologically ingested zinc nor the type of food have been shown to be related to serum zinc levels. A direct relation with the nutritional status at the time of preterm birth has been determined. The factors that have been shown to be directly related to plasma zinc levels in the multivariate study was the diagnosis of bronchopulmonary dysplasia with a direct relation and protein intake whit a negative relation. Preterm with less weight at birth, high protein intake and with bronchopulmonary dysplasia diagnosis, are at high risk of presenting hypozinquemia, so in this group it would be recommended to increase the zinc apports to the maximum levels and to control zinc levels and possible symthoms associated with this deficit.