Abstract
BACKGROUND: Calcium (Ca), phosphorus (P), and magnesium (Mg) are essential elements for keeping the body homeostasis. We aimed to investigate the changing trend of serum levels of Ca/P/Mg in neonates. METHODS: We enrolled 82 premature newborns, 173 neonatal sepsis, 50 neonatal hypoglycemia, 254 neonatal jaundice, 43 neonatal haemolytic disease, and 59 healthy controls in our retrospective study. Serum levels of Ca/P/Mg were collected and expressed in quarters. We analysed the association between neonatal disorders and Ca/P/Mg levels (fourth quarter vs. first quarter) using binary logistic regression analysis. Smooth curve analysis was performed to analyze the non-linear association between birthweight/procalcitonin (PCT) and Ca/P levels. Threshold effect analysis was also performed to yield the turning point of birthweight/PCT in their associations with Ca/P levels. RESULTS: Binary logistic regression analyses showed that neonatal haemolytic disease, hypoglycemia, sepsis, jaundice, and prematurity were all significantly associated with the fourth quarter of Ca level (P<10(-4); P<10(-4); P<10(-4); P=0.001; and P<10(-4), respectively). Neonatal hypoglycemia and prematurity were significantly associated with the fourth quarter of P level (P=0.004; and P=0.003, respectively). Neonatal haemolytic disease, hypoglycemia, sepsis, jaundice and prematurity were not associated with Mg level. Birthweight was significantly associated with Ca level before and after the turning point of 3,220 grams. PCT was significantly associated with Ca level before and after the turning point of 16.8 µg/L. Birthweight was significantly associated with P level before the turning point of 2,990 gram. PCT was significantly associated with P level before the turning points of 3.5 and 34.21 µg/L. CONCLUSIONS: Neonatal disorders demonstrated a decreasing trend of serum Ca/P level. A significantly non-linear association was observed between birthweight/PCT and serum Ca/P levels.