Cord blood level of insulin-like growth factor-1 and IGF binding protein-3 in monochorionic twins

Identification of PDXDC1 as a novel pleiotropic susceptibility locus shared between lumbar spine bone mineral density and birth weight

An increasing number of epidemiological studies have suggested that birth weight (BW) may be a determinant of bone health later in life, although the underlying genetic mechanism remains unclear. Here, we applied a pleiotropic conditional false discovery rate (cFDR) approach to the genome-wide association study (GWAS) summary statistics for lumbar spine bone mineral density (LS BMD) and BW, aiming to identify novel susceptibility variants shared between these two traits. We detected 5 novel potential pleiotropic loci which are located at or near 7 different genes (NTAN1, PDXDC1, CACNA1G, JAG1, FAT1P1, CCDC170, ESR1), among which PDXDC1 and FAT1P1 have not previously been linked to these phenotypes. To partially validate the findings, we demonstrated that the expression of PDXDC1 was dramatically reduced in ovariectomized (OVX) mice in comparison with sham-operated (SHAM) mice in both the growth plate and trabecula bone. Furthermore, immunohistochemistry assay with serial sections showed that both osteoclasts and osteoblasts express PDXDC1, supporting its potential role in bone metabolism. In conclusion, our study provides insights into some shared genetic mechanisms for BMD and BW as well as a novel potential therapeutic target for the prevention of OP in the early stages of the disease development. KEY MESSAGES : We investigated pleiotropy-informed enrichment between LS BMD and BW. We identified genetic variants related to both LS BMD and BW by utilizing a cFDR approach. PDXDC1 is a novel pleiotropic gene which may be related to both LS BMD and BW. Elevated expression of PDXDC1 is related to higher BMD and lower ratio n-6/n-3 PUFA indicating a bone protective effect of PDXDC1.

Prenatal vanadium exposure, cytokine expression, and fetal growth: A gender-specific analysis in Shanghai MCPC study

Increasing evidence supports that maternal exposure to vanadium (V) is associated with adverse birth outcomes including preterm birth and low birth weight. However, the effect of V exposure on intrauterine fetal growth and the underlying biological mechanism are still unclear. The present study includes 227 mother-infant pairs from the Shanghai Maternal-Child Pairs Cohort to assess the gender-specific effect of intrauterine V exposure on fetal growth and related cytokines. Maternal blood samples were collected to measure V concentration and biomarkers of growth. We used multiple linear regression to evaluate the gender-specific effect of prenatal V exposure on birth parameter and growth-related cytokines. Mixed-effect models were applied to assess the non-linear association between gestational V exposure and intrauterine fetal growth. Covariates adjusted in the regression models as potential confounders including maternal age, pre-pregnancy body mass index, gestational weeks, parity, socio-demographic status, etc. Results showed that prenatal V exposure was negatively associated with birth weight (β = -64.73) in female newborns and body length (β = -0.10) in male. During the fetal period, maternal V exposure was associated with decreased biparietal diameter (β = -0.91), head circumference (β = -2.96), femur length (β = -0.72) and humerus length (β = -0.64) in male. Trimester-specific analyses showed that serum V concentration in the second trimester was associated with significant reductions in intrauterine growth parameters. Besides, prenatal V exposure could down-regulate the expression of growth hormone (GH) in both maternal blood (β = -0.23) and umbilical cord blood (β = -1.66) in male fetuses, and the expression of brain derived neurotrophic factor (BDNF) in cord blood in females (β = -0.52). Our results suggest that prenatal V exposure has a gender-specific effect on fetal growth and the second trimester may be a sensitive window. The disruption of grow-related cytokines may potentially be the biological mechanism of these effects.

Placental Growth Factor and Endothelial Cell-Specific Molecule 1 Levels in Discordant and Concordant Twins and Their Effects on Fetal Growth

OBJECTIVE

We explored whether fetal twin growth was related to the levels of placental growth factor (PGF) and endothelial cell-specific molecule 1 (ESM-1) and sought correlations between cord blood PGF and ESM1 levels and birth weight discordance.

METHODS

This was a prospective study. We evaluated 79 pairs of twins, thus 158 infants. Twenty-nine (37%) twins were naturally conceived; the remaining 50 (63%) resulted from assisted reproduction.

RESULTS

Nine (11%) sets of twins were monochorionic. Eighteen of the 79 twin sets (22%) were discordant. We found a positive correlation between PGF and ESM-1 levels (r = 0.51, p = 0.001) and between discordance and PGF level (r = 0.430, p = 0.001).

CONCLUSION

The growth discordance may not be attributable to the different PGF levels, but the difference in PGF level may be a consequence.

Analysis of the value and correlation of IGF-1 with GH and IGFBP-3 in the diagnosis of dwarfism

Correlation between the value of insulin-like growth factor-1 (IGF-1) in the diagnosis of dwarfism and the levels of growth hormone (GH) and insulin-like growth factor binding protein-3 (IGFBP-3) was investigated. From April 2014 to June 2017, 122 children with dwarfism who were treated in The Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University and The First Affiliated Hospital of Xinxiang Medical University were selected as the experimental group, and 51 normal children as the control group. The basic information was recorded in detail; serum GH and IGFBP-3 levels were measured using an arginine stimulation test and an insulin hypoglycemia stimulation test, respectively. According to the peak of GH in the experimental group, there were 65 cases of growth hormone deficiency (GHD) and 57 cases of idiopathic short stature (ISS). The expression levels of IGF-1 of the serum in the experimental and control group were detected by chemiluminescence immunoassay (CLIA). The correlation between IGF-1 and GH, IGF-1 and IGFBP-3 was analyzed. The expression level of serum IGF-1 in GHD group was significantly lower than that in the ISS group (P<0.05). The expression level of serum IGF-1 in GHD group was significantly lower than that in the control group (P<0.05). The expression level of serum IGF-1 in ISS group was significantly lower than that in the control group (P<0.05). The results of partial correlation studies showed that IGF-1 is positively correlated with GH and IGFBP-3. Detection of GH and IGFBP-3 are important for the early diagnosis and comprehensive evaluation of children with dwarfism, and also in the detection of IGF-1 can reflect the therapeutic effect of dwarfism on recombinant human growth hormone (rhGH) treatment, which is worthy of application in clinics.

Effects of dietary advice on insulin-like growth factors among healthy newborns

OBJECTIVES

In fetal life, insulin, insulin-like growth factor (IGF) 1, IGF 2 and IGF-binding protein (IGFBP) 3 are essential growth factors. The purpose of this study is to investigate the effects of dietary intervention on insulin-like growth factors in the cord blood of neonates.

METHODS

The study involved 52 pregnant women who were followed up in Gazi University Medical School Hospital at Ankara, Turkey. They were randomly divided into two groups: The experimental group was involved in nutrition education. We measured IGF 1, IGF 2 and IGFBP 3 concentrations in cord blood from 52 neonates.

RESULTS

In the experimental group, cord serum levels of IGF 1, IGF 2 were observed to be higher than that of control group.

CONCLUSION

Dietary advice had positive effects on the cord serum IGF 1 and IGF 2 concentrations. Dietary advice during pregnancy proved to be effective in fetal development.