低出生体重儿婴儿期生长速度与胰岛素敏感性的关系

Relationship between growth velocity and insulin sensitivity in low birth weight infants during infancy

【目的】探讨低出生体重儿婴儿期生长速度与胰岛素敏感性的关系。【方法】将全部入选对象分为低出生体重儿组(low birth weight,LBW)和正常对照组(normal control,NC),并随访1年。766例新生儿纳入研究,共计628例完成1年随访。分别在生后42d、4、6、8、10个月和12个月共计随访6次,进行体格测量,并在6个月和12个月随访当日测定血清胰岛素(fasting insulin,FI)和血糖水平。计算出生体格Ponderal指数,随访中计算体质指数(body mass index,BMI)以及内稳态模式评估值(homeostasis model assessment,HOMA)评价胰岛素敏感性。【结果】LBW组与NC组相比,LBW组婴儿在12个月内的每一个监测点生长发育水平始终低于NC组,但是由体重和身长的Z-score变化可以看到,虽然两组间在12个月时差异仍然显著,但是Z-score值在不断减小;最后,由1年内Z-score的变化即ΔZ-score可见,在婴儿期,LBW组婴儿体重及身长均快速增长,其增长速度显著高于NC组婴儿,但是,在12个月时仍未能追上NC组婴儿。6月龄时,两组间胰岛素敏感性无差异,12个月龄时,LBW组FI和HOMA值较高,提示此阶段胰岛素敏感性相对差。【结论】低出生体重儿在12个月内生长发育速度快于正常体重儿,在12个月时体重、身长和BMI值仍低于正常体重儿;低出生体重儿在婴儿期末已经表现出胰岛素敏感性相对差。

[Objective] To investigate the relationship between growth velocity and insulin sensitivity in low birth weight （LBW） infants during infancy. [Methods] LBW infants as LBW group and normal weight infants as control （normal control, NC） were recruited into the study and follow up one year. Seven hundred and sixty six subjects met the in- clusion criteria and 628 infants finished the follow-up. Body weight,length, fasting glucose and fasting insulin （FI） levels were measured at 6 months and 12 months of age. Homeostasis model assessment （HOMA）,ponderal index （PI） and body mass index （BMI） were calculated. Insulin sensitivity was evaluated by FI and HOMA. [Results] During infancy,al- though LBW infants had gained more weight and length, they had been lighter and smaller than NC infants. Body weight, body length and BMI of LBW group were significantly lower than NC group at each measurement. In LBW group, the chan- ges of weight Z-score and height Z-score during infancy were larger than NC group. At 12 months,the FI and HOMA （loga- rithmically transformed） were significantly higher in LBW group. [Conclusions] In current study,although LBW infants have gained more weight and length, they have been lighter and smaller during infancy. Until the end of infancy, fasting insulin and HOMA suggest that LBW infants have relatively impaired insulin sensitivity.