Introduction: Body temperature determinants include head-brain thermal homeostatic mechanisms and, in the human newborn (NWB), birth gestational age (GA). Estimated birth brain weight (BRW) ratio to birth body weight (BW)(BBR) resulted associated with GA and blood serum Insulin-like Growth Factor (IGF)-II(IG2) ratio to blood serum IGF Binding Protein-3 (IB3)(IG2 through chronologically-corresponding IB3, IG2/IB3R) in our previous NWB observations. Here we evaluate BRW, BW, BBR and axillary temperature (TEMP) relations to IG2/IB3R in NWBs.
Methods: NWBs with any among total parenteral nutrition, blood transfusion, therapeutic hypothermia, life-threatening disease, diabetes mellitus (DM), non-DM endocrine diagnosis, malformation, and mother with DM were excluded. 78 included NWBs presented complete data availability for 1) same-day records at one of the first 5 postnatal days(x), 5 days after x(y) and 10 days after x(z), of postnatal age (PNA, unit:day), TEMP (unit: °C), caloric intake (kcal/kg/24hrs, or kcal/kg/postnatal life hrs for PNA<1 day; K), and IG2-IB3 RIA measurements (unit:uM/dl), and for 2) gender (SEX), GA (unit:complete week; range=2842), GA<=36(PTB), BW (unit:g; range=12004150), head circumference (HC; unit:cm; range=27.036.0), BW<=10.th centile for GA(SGA)(numerosity; male SEX, 43; PTB, 46; SGA, 20), BRW (unit:g) and BBR (calculations according to Lindley-McLennan; BRW=0.037 × HC2.57; BBR=100 x (BRW/BW)). IG2/IB3R was calculated at x, y and z. Arithmetical means were calculated over x-y-x((x+y+z)/3) for TEMP(TEMPM), K(KM) and IG2/IB3R(IG2/IB3RM). IG2/IB3RM van der Waerden normal score (IG2/IB3RM-NS) resulted near-normally distributed. Spearman Correlation and Multiple Linear Regression (MLR) were used (MLR computations; male SEX, SGA; condition absent=0, condition present=1).
Results: TEMPM range: 36.0737.00 °C. Spearman Correlation as rho/significance; BRW vs. TEMPM: 0.306/P=0.006; BRW vs. IG2/IB3RM: −0.391/P<0.001); BW vs. TEMPM: 0.204/P=0.073; BW vs. IG2/IB3RM: −0.511/P<0.001; BBR vs. TEMPM: −0.059/P=0.606; BBR vs. IG2/IB3RM: 0.468/P<0.001. BRW MLR partial correlation with outcome IG2/IB3RM-NS(pc) was significant in MLR with predictors SEX+SGA+BRW+PNA at x(PNAx)+KM(pc coefficient=−0.300, t=−2.669, P=0.009) but not in MLR with predictors SEX+SGA+BRW+PNAx+KM+TEMPM(R2 always significant).
Conclusions: TEMPM could be involved in BRW-IG2/IB3RM-NS relationships in not-life-threatened NWBs.
27 - 29 Sep 2018
European Society for Paediatric Endocrinology