Breast-Milk Rubidium and Other Trace Elements are Associated with Neurocognitive Development in Infants at Age of 8 Months

Breastmilk mineral composition among well-educated mothers from Central Poland - Associations with maternal dietary intake, dietary patterns and infant psychomotor development

BACKGROUND

Maternal dietary habits could affect breastmilk mineral composition, which may influence infant development. Mineral dietary intake or supplementation slightly affects its breastmilk concentration. However, the intake of selected food groups or dietary patterns that reflect diet complexity could have a greater impact. Hence, the aim of the study was to assess breastmilk mineral composition at one, three, and six months of lactation among mothers living in urban area of Central Poland, as well as the evaluate maternal dietary determinants and associations with infant anthropometric and psychomotor development.

METHODS

The study was conducted among 43 healthy and exclusively breastfeeding mothers. In the first, third, and sixth months of lactation, we collected breastmilk samples and assessed the concentration of Ca, P, Zn, Fe, Se, Ni, As, Pb, and Cd using the ICP-MS method. Maternal dietary habits were evaluated by a food frequency questionnaire in the first month of lactation, whereas in the third and sixth by the three-day food record. Based on the collected data adherence to the Polish-adapted Mediterranean (Pl-aMED; 1 month) and the DASH diet (Mellen's Index; 3 and 6 months) was assessed. In the third and sixth months of lactation infant anthropometric parameters and the sixth month of lactation psychomotor development were evaluated.

RESULTS

Breastmilk Se, Ni, As, Pb, and Cd levels were under the LOQ in all the breastmilk samples at all study visits. Median breastmilk mineral concentrations of Ca, P, Zn, and Fe in the first, third, and sixth months of lactation varied from 381.9 to 332.7 mg/L, 161.6 to 139.1 mg/L, 2.2 to 0.8 mg/L, and 0.26 to 0.17 mg/L, respectively. Maternal dietary intake and supplementation did not affect breastmilk Ca, P, Zn, and Fe. Pl-aMED scores were associated with breastmilk Ca (β = 0.489, 95% CI 0.180 - 0.799, p = 0.003) and Zn (β = 0.499, 95% CI 0.199 - 0.798, p = 0.002) in the first month of lactation, whereas no association with the DASH diet were observed in the third and sixth month of lactation. Breastmilk Fe in the third month was associated with infant motor development (β = 0.420, 95% CI 0.113 - 0.727, p = 0.009) in the sixth month of life, but no other associations with anthropometric or psychomotor development were observed. Moreover, we estimated that few infants meet their adequate intake (AI) requirements for P, Zn, and Fe.

CONCLUSION

Our study showed that maternal adherence to Pl-aMED is a significant predictor of breastmilk Ca and Zn in the first month of lactation, which may be especially important considering that more than 75% of infants had inadequate Zn intake. Moreover, we found that breastmilk Fe positively influenced infant motor development, despite the majority of infants having inadequate intake. On the other hand, no infant had deficiency symptoms, which emphasizes the necessity to evaluate of AI norms for infants.

Exposure to metal mixtures and young children's growth and development: A biomonitoring-based study in Eastern China

Exposure to metal mixtures may affect children's health but the conclusions are controversial. We aimed to investigate the associations of metal mixture exposure with children's physical and behavioral development. 15 metals were detected in the urine samples of 278 preschoolers aged 3-6 years from eastern China. Multiple linear models and restricted cubic splines were used to evaluate dose-response relationships between single metal and children's physical and behavioral development. The Bayesian Kernel Machine Regression (BKMR) models, the weighted quantile sum (WQS) models and Quantile G-Computation were applied to evaluate the joint effects of metal mixtures. The results showed that arsenic (As) was negatively associated with z score of height for age (HAZ) in individual-metal models [β (95%CI): - 0.22 (-0.38, -0.06), P = 0.006]. Concerning children's behavioral development, multiple-metal models demonstrated a negative association with strontium (Sr) [β (95%CI): - 0.82 (-1.38, -0.26), P = 0.004], and a positive association with tin (Sn) [β (95%CI): 0.69 (0.16, 1.21), P = 0.010]. Notably, these associations remained significant or suggestive even after adjustments for multiple tests, sensitivity analyses, and application of different statistical models, including BKMR, WQS, and Quantile G-Computation. Furthermore, the study identified a negative joint effect of the metal mixture on HAZ, as demonstrated by BKMR and Quantile G-Computation models, with As playing an irreplaceable role in this observed impact. In summary, exposure to As appears to have adverse effects on HAZ, while exposure to Sn may hinder children's behavioral development. Conversely, exposure to Sr may have a protective effect on children's behavioral development. Additionally, the combined impact of metal mixtures is implicated in potentially impairing children's physical development, particularly in terms of HAZ.

Amniotic fluid rubidium concentration association with newborn birthweight: a maternal-neonatal pilot study

BACKGROUND

Although most biological systems, including human tissues, contain rubidium, its biogeochemical functions and possible role in neonatal birthweight are largely unknown. An animal study indicated a correlation between rubidium deficiency in the maternal diet and lower newborn birthweight.

OBJECTIVE

This pilot study measured rubidium concentrations in amniotic fluid during the second trimester of (low-risk) pregnancy and investigated potential correlations between rubidium levels and third-trimester newborn birthweight-small for gestational age, appropriate for gestational age, and large for gestational age-and between preterm birth and term birth in uncomplicated pregnancies.

STUDY DESIGN

This prospective, single-center study investigated a possible relationship between rubidium concentration in second-trimester amniotic fluid and third-trimester birthweight percentile. Amniotic fluid (at a median gestational age of 19 weeks) was sampled to determine rubidium concentration. Maternal and newborn characteristics were obtained from participant and delivery records.

RESULTS

After screening 173 pregnant women, 99 amniotic fluid samples were evaluated. Midpregnancy median rubidium concentrations were significantly lower among newborns that were classified as small for gestational age than among newborns that were classified as appropriate for gestational age (106 vs 136 μg/L; P<.01). Based on a logistic regression random forest model, amniotic fluid rubidium was identified as a significant contributing factor to appropriate-for-gestational-age birthweight with 54% of the total contribution.

CONCLUSION

Amniotic fluid rubidium concentration seems to be a strong predictor of appropriate-for-gestational-age birthweight and a potential marker for newborn birthweight classifications. In particular, low rubidium concentrations in amniotic fluid during midpregnancy are linked to third-trimester lower birthweight percentile. These findings could potentially serve as a valuable tool for early identification of pregnancy outcomes. Further investigation is necessary to fully explore the effect of rubidium on fetal development.

Microspatial distribution of trace elements in feline dental hard tissues: early life exposure to essential and toxic elements

Introduction

Trace elements play a key role in dental tissue development, as dental hard tissues accumulate both essential and toxic trace elements during mineralization. Characterization of the spatial accumulation pattern of trace elements may provide insight into exposure to toxic elements over time and to the nature of disease processes affecting the hard dental tissues. Here, we present the first report of the use of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to map the microspatial distribution of multiple trace elements, essential and toxic, across feline dental hard tissues.

Methods

Eleven teeth were extracted from 8 cats. Nine teeth were from 7 cats diagnosed with idiopathic tooth resorption on intraoral radiographs prior to extraction. Two teeth were included from a cadaver that had no signs of tooth resorption on intraoral radiographs. The normal dental tissue was analyzed from each sample using LA-ICP-MS to map the microspatial distribution of essential and toxic trace elements across feline enamel, dentin, and cementum.

Results

Results showed a higher accumulation of barium and strontium in coronal dentin as compared to root dentin. The timing of the accumulation mirrors nursing timelines seen in teeth from human and non-human primates, consistent with barium and strontium being sourced from maternal milk. Results also showed a higher uptake of lead in the coronal dentin, suggesting this lead exposure was likely passed from mother to offspring.

Discussion

This work characterizes a baseline for elemental distribution in feline teeth linked to early life exposure to toxic elements such as lead and provides a framework for future studies investigating long-term environmental exposures to trace elements, essential and toxic, and their involvement in feline systemic and dental diseases.

Sex-specific associations of early postnatal blood copper levels with neurodevelopment at 2 years of age

Copper (Cu) is an essential trace element; however, it can be harmful in excess. Previous studies have shown that prenatal Cu levels may affect childhood neurodevelopment; however, studies focused on early postnatal Cu levels are limited. We studied 843 children born in Wuhan City and investigated the associations between early life Cu levels and neurodevelopment in 2-year-old children. Blood samples collected from children at 12 and 24 months of age were used to analyze Cu levels. Neurodevelopment was scored using the Bayley Scale of Children at 24 months of age. We found that a higher Cu level at 12 months of age was positively associated with mental development index (MDI) in boys (β = 6.75, 95 %CI: 1.12, 12.38). Further non-linear analysis showed an inverted U-shape association between Cu level at 20 months and PDI in boys, indicating that Cu levels may have an optimal concentration for neurodevelopment (p for overall association = 0.01, p for non-linear association < 0.01). In addition, all meaningful results mentioned above were observed only in boys, and a statistically significant sex-related modifying effect was observed (p < 0.05). In conclusion, this study repeated measures early life Cu levels and suggested sex-specific associations between early life Cu levels and neurodevelopment in 2-year-old children.