Maternal Serum Albumin Redox State Is Associated with Infant Birth Weight in Japanese Pregnant Women

Serum albumin redox state as an indicator of dietary protein intake among community-dwelling older adults

BACKGROUND AND AIMS

Serum markers capable of detecting mild levels of undernutrition, such as insufficient dietary protein intake (IDPI), have not been established among community-dwelling older adults. Although the serum albumin redox state, expressed as the ratio of reduced albumin (Alb) to total Alb (the reduced albumin ratio), has the potential to overcome this challenge, empirical epidemiological data are lacking. This study aimed to investigate the association between a serum reduced Alb ratio and dietary protein intake among community-dwelling older adults.

METHODS

This study analyzed cross-sectional data from 1,005 community dwelling population (572 males and 433 females) aged 70-84 years who participated in the Itabashi Longitudinal Study on Aging. Exclusion criteria included participants with incomplete data, individuals with a history of kidney disease and high C-reactive protein (CRP) levels. The dietary protein intake was estimated using validated food frequency questionnaires. The IDPI was defined as not meeting the level recommended by the Dietary Reference Intakes for Japanese (Men ≥60 g/day, Women ≥50 g/day).

RESULTS

IDPI was observed in 14.1% of the study population. Logistic regression analyses adjusted for sex, age, body weight and malnutrition showed that a serum reduced Alb ratio was significantly associated with IDPI (odds ratio = 0.962, 95% confidence interval = 0.926-0.999), whereas serum albumin concentration was not (odds ratio = 0.549, 95% confidence interval = 0.285-1.061).

CONCLUSIONS

A serum reduced Alb ratio would be a useful indicator of protein insufficiency among community-dwelling older adults.

Nutritional status of Vietnamese infants assessed by Fenton growth chart and related factors: A cross-sectional study

Importance

Nutritional status of infants, measured by birth weight and length, is an essential factor in neonatal development. Malnutrition in newborns may lead to a higher risk of mortality, neurological and cognitive impairment, and poor language development.

Objective

This study aims to assess the nutritional status of infants and related factors regarding maternal anthropometric characteristics and medical history.

Methods

A cross-sectional study was conducted at the National Hospital of Obstetrics and Gynecology, Vietnam from May 2021 to May 2022 on 340 infants and mothers. Low birth weight was defined following the Intergrowth-21 standards. Stunting was evaluated using the Fenton growth chart when the length was below the 10% percentile line of the gestational week. Multivariate regression models were applied to identify factors associated with the nutritional status of infants.

Results

We found that 12.4% and 14.1% of infants in our study fell into stunted and underweight categories, respectively. Infants of mothers over 35 years old, having a height lower than 150 cm or experiencing anemia during pregnancy were more likely to be stunted or have low birth weight. Serum albumin deficiency during pregnancy was strongly associated with the infant being underweight (odds ratio [OR]  =  2.8, 95% confidence interval [95%CI] 1.1-7.3). Newborns were more likely to be stunted if their mothers had a history of preterm birth (OR = 3.3, 95%CI 1.1-10.2).

Interpretation

Maternal nutritional status is closely related to infant malnutrition, particularly in preterm infants. Improving the understanding of mothers regarding prenatal care, reproductive healthcare, adequate nutritional diet, and multi-micronutrient supplements during pregnancy is therefore important.

A Methodological Basis for Estimating Human Mercaptalbumin in Serum and Plasma Using a Thiol-Binding Resin

Human serum albumin is categorized into human mercaptalbumin (HMA) and human non-mercaptalbumin (HNA), according to the redox state of the cysteine residue at position 34. The ratio of HMA to total albumin (%HMA) is a novel biomarker of oxidative stress as well as protein nutritional status, but measuring %HMA normally requires an expensive analyzer such as HPLC and LC-MS, and can hardly be conducted in many clinical sites. To address this issue, we aimed to develop a methodological basis for estimating %HMA without these analyzers. An analytical method was investigated consisting of three steps, i.e., 1) removal of HMA from serum or plasma by using a thiol-binding resin (i.e., thereby obtaining a HNA fraction), 2) determination of both total albumin and HNA concentrations by a colorimetric assay or ELISA, and 3) calculation of %HMA. Proof-of-concept experiments, using serum and plasma samples of 4 adult volunteers, showed that the estimated value of %HMA obtained by this analytical method was significantly correlated with the theoretical value of %HMA determined by HPLC. The subsequent validation experiment, using 86 serum samples of pregnant women in the Japanese participants of SMILE Iwamizawa, also confirmed the significant association between the estimated and theoretical values of %HMA. This analytical method can be a basis to determine %HMA without using HPLC or LC-MS, contributing to the universalization of %HMA measurement as a clinical test.

Adverse maternofoetal outcomes associated with ionised calcaemia, total calcaemia, albuminaemia, and calcium supplementation in pregnancy: Analysis from a resource-limited setting

Introduction

Disorders of total calcium (tCa) in pregnancy have been associated with adverse maternofoetal outcomes. However, studies evaluating this from the viewpoint of ionised calcaemia are practically inexistent. This study estimates the prevalence of some adverse maternal and foetal outcomes and the potential effect of ionised calcium (iCa), tCa, albumin and calcium supplementation on some maternofoetal outcomes.

Methods

A cross-sectional study was conducted among 1074 pregnant women in late pregnancy from four health facilities in the Nkongsamba Health District. Data were collected by interview, analysis of maternal blood samples and measurement of maternal and foetal parameters. Total calcaemia and albuminaemia were measured by atomic absorption spectrophotometry, while iCa and pH were measured using ion-selective potentiometry. Associations were measured using the odds ratio in simple and multiple logistic regression.

Results

The prevalence of low birth weight, macrosomia, and hypertension in pregnancy was 6.27 [4.97–7.89]%, 4.78 [3.65–7.89]%, 10.24 [8.57–12.20]%, respectively. Following multiple logistic regression, women with iCa levels ≤ 1.31mmol/L had significantly increased odds of hypertension in pregnancy (AOR = 2.47 [1.63–3.74], p-value = 0.000), having babies with low birth weight (AOR = 2.02[1.33–3.61], p-value = 0.002), low birth length (AOR = 2.00 [1.34–2.99], p-value = 0.001), low brachial circumference (AOR = 1.41[1.10–1.81], p-value = 0.007), first minute Apgar score < 7 (AOR = 3.08[1.70–5.59], p-value = 0.000) and fifth minute Apgar score < 7 (AOR = 2.86[1.32–6.16], p-value = 0.007). Ionised calcaemia had no significant association with maternal body mass index immediately after birth and the head circumference of the baby. Total calcaemia was found to have no significant association with any of the selected outcomes, while women with total albuminaemia ≤ 30mg/L had significantly higher odds of having babies with low birth weight (AOR = 3.40[1.96–5.91], p-value = 0.000), and Apgar scores < 7 at the first (AOR = 2.07[1.16–3.70], p-value = 0.013). Calcium supplementation showed no significant association with any of the selected outcomes except for the first (OR = 0.42[0.24–0.72], p-value = 0.002) and fifth minute Apgar score (OR = 0.25[0.12–0.50], p-value = 0.000).

Conclusion

The prevalence of low birth weight, macrosomia, and hypertension in pregnancy was 6.27 [4.97–7.89]%, 4.78 [3.65–7.89]%, 10.24 [8.57–12.20]%, respectively. Maternal iCa levels ≤ 1.31mmol/L significantly increase the odds of having babies with low birth weight, low birth length, low brachial circumference at birth, low Apgar scores at the first and fifth minutes and maternal hypertension in pregnancy. Low maternal albuminaemia is significantly associated with low birth weight, and Apgar score < 7 at the first minute. None f the selected maternofoetal outcomes directly depend on total calcaemia, given that none of the associations was statistically significant. Even though iCa levels remain relatively normal in normal pregnancies, it remains the strongest predictor of foetal outcomes. Calcium supplementation significantly improves the Apgar scores at the first and fifth minute. Routine pregnancy follow-up should include evaluating maternal calcaemic states, particularly the ionised fraction, to detect the low-normal concentrations likely to impact maternal and foetal outcomes. Normal iCa levels for pregnant women need revisiting.