Associations between Maternal Diet, Human Milk Macronutrients, and Breast-Fed Infant Growth during the First Month of Life in the SMILE Iwamizawa in Japan

PsyNBIOsis: Investigating the Association between Maternal Gestational Diabetes, Mental Health, Diet and Childhood Obesity Risk: Protocol for a Prospective, Longitudinal, Observational Study

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with poorer maternal mental health (depression and anxiety). Maternal mental health and GDM are likely to influence diet, which in turn impacts the course of GDM. Maternal diet may also be directly or indirectly associated with changes in infant anthropometry. The aims of this study are to (1) examine the associations between maternal GDM, mental health and diet, and (2) evaluate the associations between these maternal factors, breastmilk composition and infant anthropometry.

METHODS

This prospective, observational, longitudinal cohort study compares a cohort of women with and without GDM. Maternal mental health and diet are assessed using validated questionnaires. Breastmilk composition is measured with the Human Milk Analyzer, and infant body composition is measured with air displacement plethysmography.

SIGNIFICANCE AND IMPACT

Once data have been collected, PsyNBIOsis will provide evidence for the associations between maternal mental health, GDM status and diet, and their impact on breastmilk composition and early infant growth. The results may inform the Developmental Origins of Health and Disease framework and provide data on which to build cost-effective interventions to prevent both the development of mental health issues in mothers and adverse growth patterns in infants.

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.