ABSTRACT
Birth chest circumference(CC) shows often, like birth gestational age(GA), tight direct relations to birth body weight(BW). However distinct connections of hypoxia/undernutrition with different body structures might be suspected based on brain-, heartand adrenal-sparing following intrauterine growth restriction and, postnatally, on higher chest size for body mass observed at high altitude. Growth retarded fetuses gestated by hypoxic rats may present increments of blood serum Insulin-like Growth Factor Binding Protein(IB) 2, but not of IB3. Relevance of human newborn(NWB) CC/BW ratio(i.e., CC through BW, CC/BWR) to relationships between BW<=10.th centile for GA(SGA), and IB2/ IB3 ratio(IB2/IB3R) was evaluated. NWBs with any among total parenteral nutrition, parenteral nutrition other than dextrose, blood component transfusion, postnatal corticosteroid-, catecholamine- or methylxantine-based treatments, life-threatening disease, diabetes mellitus(DM) or other endocrine diagnosis, malformation, and mother with DM were excluded. 78 included NWBs, all studied before covid-19 pandemic and from conception to study end near sea-level, had complete data 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), IB2 and IB3 radioimmunoassay(unit=uM/dl), and for 2) gender(SEX), GA(unit: complete week;extremes=28-42), GA<=36 present(PTB, n=46), CC(25th-75th centiles=27-32cm), BW(25th-75th centiles=1926-2942g), and SGA(n=20)(computations;male SEX(n=43), SGA;condition absent=0, condition present=1). SPSS-27 software was used to generate GA-unrelated CC/BWR standardized residuals(CC/BWRsr)(i.e., Linear regression procedure- Save pushbutton/ Standardized residual checkbox-Continue pushbutton/ regress CC/BWR on only GA). IB2/IB3R(i.e., IB2 through IB3) calculated at x-y-z time-poins, was averaged(i.e., (x+y+z)/3;IB2/IB3RM). IB2/IB3RM normal scores according to Van der Waerden(IB2/IB3RM-NS) were normally distributed. SGA evidenced significantly higher CC/BWR, CC/BWRsr and IB2/IB3RM than non-SGA(Mann-Whitney Test). Spearman rank correlations between the following variable pairs are reported(Rho;significance): GA vs CC/BWR(-.706, p<.0001), GA vs CC/BWRsr (-.024;p=.8315), GA vs IB2/IB3R(-,409;p=.0002), CC/BWRsr vs IB2/IB3R(.346;p=.0019). Partial correlation(pc) coefficient(pcc) of SGA pc with outcome IB2/IB3RM-NS in multiple linear regression(MLR) was significant (t=4.194, p<.0001, pcc=.565) with SEX-GA-SGA-PNAx as predictors, but non-significant with SEX-GA-SGA-CC/BWRsr-PNAx as predictors(MLR R2, .447- .492, always significant). CC/BWRsr could be involved in direct relationships between SGA and IB2/IB3RM-NS after controls including GA in not-life-threatened NWBs.
ABSTRACT
Birth chest circumference(CC) shows often, like birth gestational age(GA), tight direct relations to birth body weight(BW). However distinct connections of hypoxia/undernutrition with different body structures might be suspected based on brain-, heartand adrenal-sparing following intrauterine growth restriction and, postnatally, on higher chest size for body mass observed at high altitude. Low BW and hypoxia may be associated with circulating Insulin-like Growth Factor-I(IG1) lower levels. Relevance of human newborn(NWB) CC/BW ratio(i.e., CC through BW, CC/ BWR) to relationships between BW<=10.th centile for GA(SGA), and blood serum IG1(IG1s) was evaluated. NWBs with any among total parenteral nutrition, parenteral nutrition other than dextrose, blood component transfusion, postnatal corticosteroid-, catecholamine- or methylxantine-based treatments, life-threatening disease, diabetes mellitus(DM) or other endocrine diagnosis, malformation, and mother with DM were excluded. 78 included NWBs, all studied before covid-19 pandemic and from conception to study end near sea-level, had complete data 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) and IG1s radioimmunoassay(unit=uM/dl), and for 2) gender (SEX), GA(unit:complete week;extremes=28-42), GA<=36 present(PTB, n=46), CC(25th-75th centiles=27-32cm), BW(25th-75th centiles=1926-2942g), BW standard deviation scores(BW-SDS), and SGA(n=20)(computations;male SEX(n=43), SGA;condition absent=0, condition present=1). SPSS-27 software was used to generate GA-unrelated CC/BWR standardized residuals(CC/ BWRsr)(i.e., Linear regression procedure-Save pushbutton/ Standardized residual checkbox-Continue pushbutton/ regress CC/BWR on only GA). IG1s at x-y-z time-points was averaged (i.e., (x+y+z)/3;IG1sM). IG1sM normal score according to Van der Waerden(IG1sM-NS) resulted normally distributed. Mann- Whitney Test: PTB did not differ significantly from non-PTB for CC/BWRsr;SGA showed significantly lower IG1sM than non- SGA. Spearman rank correlations between the following variable pairs are reported(Rho;significance): BW-SDS vs CC/BWR(-.361;p=.0012), BW-SDS vs CC/BWRsr(-.766;p<.0001), CC/BWR vs IG1sM(-.659, p<.0001), CC/BWRsr vs IG1sM(-.271, p=.0166). Partial correlation(pc) coefficient(pcc) of SGA pc with outcome IG1sM-NS in Multiple linear regression (MLR) was significant(t=-3.349, p<.0013, pcc=-.365) with SEX-GA-SGAPNAx as predictors, but was non-significant with SEX-GASGA- CC/BWRsr-PNAx as predictors (MLR R2, .486-.513, always significant). CC/BWRsr could be involved in inverse relationships between SGA and IG1sM-NS after controls including GA in NWBs free of life-threatenig disease.