ABSTRACT
Objective To analyze serum 25(OH)D level and the influence factors in preterm infants. Methods The data of serum 25(OH)D level in preterm infants born from July 2012 to June 2014 were retrospectively analyzed along with gestational age, gender, parity, delivery mode, birth season, birth weight, age of the mother and pregnancy complications. Results Totally 325 cases were included and their average gestational age was 33.41±2.29 week, the ratio of male to female was 1.32?1 and average serum 25(OH)D level was 37.34±16.17 nmol/L. The incidence of vitamin D deficiency and insufficiency in preterm infants was 37.8% and 41.8% respectively. Serum 25 (OH) D levels in preterm infants born in summer and autumn were higher than those born in winter and spring, and there was statistical difference (P<0.05). Logistic regression analysis showed that birth season and the mother's age may be the risk factors that influence serum 25 (OH) D levels in preterm infants. Conclusion The incidence of vitamin D deficiency and insufficiency in preterm infants is high, and the factors affecting the level of vitamin D need to be further studied.
ABSTRACT
Objective To compare the bone status between Shanghai and Caucasian infants at birth by quantitative ultrasound (QUS) and evaluate its clinical application. Methods An ultrasound bone sonometer, Omnisense (Sunlight Medical Ltd, Israel), was used to measure the bone speed of sound (SOS) of tibia in 157 Shanghai infants, and then compared with those of Caucasian. Results No significant difference of SOS was found between male [n=88, (2968?115) m/s] and female infants [n = 69, (2956?105) m/s](P=0. 524). The SOS of premature infants [(2935?96) m/s] was lower than that of full-term infants [2984?116) m/s] (P = 0. 005). Comparing with Caucasian infants, the tibial SOS was lower in Shanghai infants. The differences of SOS, which were defined as Z-Score, in Shanghai infants were more remarkable in female infants (-0. 81?0.92 Z-Score) than that of male (-0. 55?0. 97 Z-Score), and in full-term infants ( -0. 80?1. 03 Z-Score)than in premature infants (-0. 50?0. 83 Z-Score) , and in infants with normal birth weight than in infants with lower birth weight. Conclusions QUS is suitable for evaluating bone status in infants. Shanghai infants have lower bone strength than Caucasian's and the difference becomes more significant in the last trimester.