Linda Gallo

BACKGROUND. Prenatal alcohol exposure (PAE) around conception in preclinical models results in placental insufficiency, likely contributing to offspring abnormalities. Altered placental DNA methylation (DNAm) and gene expression suggest epigenetic mechanisms, perhaps involving impacts on methyl donor levels. PAE around conception in women is common but placental effects are rarely examined. This cohort study investigated associations between PAE around conception and intake/plasma measures of the methyl donors folate and choline, feto-placental blood flow, and placental growth measures, gene expression, and DNAm.

METHODS. Pregnant participants delivered at Mater Mothers’ Hospital, Brisbane, Queensland, Australia (n = 411). Dietary intake of choline and folate were calculated and plasma concentrations measured using mass spectrometry (MS) and clinical immunoanalyzer, respectively. Cerebroplacental ratio (CPR) was calculated using Doppler measurements. Placentas were weighed/measured at delivery and samples used to quantify methyl donors (MS), global DNAm (ELISA), and gene expression (quantitative PCR). Data were compared between control/abstinent and PAE groups, by fetal sex.

RESULTS. A CPR <5th-centile, indicating fetal brain sparing because of placental insufficiency, was found in 2% of controls and 18% of the PAE group, mostly male fetuses (63%). Compared with controls, male PAE placentas had reduced mean thickness and placental growth factor mRNA and DNAm, whereas female PAE placentas had increased S-adenosylmethionine and a trend toward increased DNAm.

CONCLUSION. PAE around conception is associated with reduced CPR and altered placental growth measures, particularly in males, with potential implications for future health.

Background
Achieving an in-range glycated haemoglobin (HbA1c) is essential for managing diabetes mellitus (DM). However, this parameter provides an estimate of long-term blood glucose control rather than daily glycaemic variations. Glycaemic variability can be more predictive than HbA1c in terms of identifying those at risk for diabetes complications, including risk of severe respiratory virus infections and is usually measured via a continuous glucose monitor (CGM). For individuals for whom a CGM is not available, serum 1,5 anhydroglucitol (1,5-AG) level has shown potential as an alternative method for monitoring glycaemic variability. Despite this, at present 1,5-AG is not routinely used in the clinical assessment of DM. Here, we aim to determine whether assessing 1,5-AG, in addition to HbA1c, is of any potential clinical utility to the management of DM for patients.

Methods
Using machine learning and data derived from 78 patients with type I DM (for whom CGM data is available) we show that the combination of 1,5-AG and HbA1c improves the prediction of a patient’s glycemia risk index (GRI) compared to HbA1c alone.

Results
The GRI is an essential tool in the management of DM as it reflects both clinical priorities and patient centred outcomes. The inclusion of 1,5-AG in this prediction was particularly important for individuals who had very high or very low GRI. Furthermore, in the context of glycaemic variability and susceptibility to severe respiratory virus infections, we show that reduced 1,5-AG in the plasma is associated with reduced ex vivo CD4 + T cell cytokine responses to influenza virus in individuals with a matched HbA1c.

Conclusions
Taken together, these data argue for an increased monitoring of 1,5-AG in the clinic for individuals without a CGM to provide additional insights for diabetes management.

The ‘Developmental Origins of Health and Disease’ (DOHaD) hypothesis postulates that exposures during critical periods of development and growth, including maternal hyperglycemia, can have significant consequences for short- and long-term health in offspring. The influence of fetal status on maternal (patho)physiology is less well understood but gaining attention. Fetal sex specifically may be an independent risk factor for a range of adverse pregnancy outcomes, including increased gestational diabetes mellitus (GDM) frequency with male fetuses in multi-ethnic populations. Fetal sex has been thought to modulate maternal glucose metabolism, including insulin dynamics, through complex genetic and hormonal interactions. Mechanisms have not been fully elucidated, however, but may relate to sexual dimorphism in maternal-fetal-placental interactions. We review current evidence on the potential influence of fetal sex on maternal glucose and insulin dynamics, and fetal outcomes.

Diabetes mellitus significantly increases the risk of severe respiratory virus disease like influenza and COVID-19. Early evidence suggests that this susceptibility to respiratory viral disease is driven by glycemic variability, rather than average blood glucose levels. Here, we use blood samples and constant glucose monitoring (CGM) data obtained from people living with type 1 diabetes (T1D) to determine the effects of glycemic variability on the ex vivo T cell response to influenza virus. We show that high glycemic variability in participants living with T1D is associated with a reduced proportion of CD8+CD107a−IFNγ−MIP1β−TNF+ T cells in response to stimulation with influenza virus and an influenza virus peptide pool. Thus, this study provides evidence that glycemic variability affects the ex vivo T cell response to respiratory viruses. These data suggest that monitoring glycemic variability may have important implications in understanding the antiviral immune response in people with diabetes.

In high-income nations, multiple micronutrient (MMN) supplementation during pregnancy is a common practice. We aimed to describe maternal characteristics associated with supplement use and daily dose of supplemental nutrients consumed in pregnancy, and whether guideline alignment and nutrient status are related to supplement use. The Queensland Family Cohort is a prospective, Australian observational longitudinal study. Maternal characteristics, nutrient intake from food and supplements, and biochemical nutrient status were assessed in the second trimester (n = 127). Supplement use was reported by 89% of participants, of whom 91% reported taking an MMN supplement. Participants who received private obstetric care, had private health insurance and had greater alignment to meat/vegetarian alternatives recommendations were more likely to report MMN supplement use. Private obstetric care and general practitioner shared care were associated with higher daily dose of supplemental nutrients consumed compared with midwifery group practice. There was high reliance on supplements to meet nutrient reference values for folate, iodine and iron, but only plasma folate concentrations were higher in MMN supplement versus nonsupplement users. Exceeding the upper level of intake for folic acid and iron was more likely among combined MMN and individual supplement/s users, and associated with higher plasma concentrations of the respective nutrients. Given the low alignment with food group recommendations and potential risks associated with high MMN supplement use, whole food diets should be emphasized. This study confirms the need to define effective strategies for optimizing nutrient intake in pregnancy, especially among those most vulnerable where MMN supplement use may be appropriate.

Diabetes mellitus is on the rise globally and is a known susceptibility factor for severe influenza virus infections. However, the mechanisms by which diabetes increases the severity of an influenza virus infection are yet to be fully defined. Diabetes mellitus is hallmarked by high glucose concentrations in the blood. We hypothesized that these high glucose concentrations affect the functionality of CD8+ T cells, which play a key role eliminating virus-infected cells and have been shown to decrease influenza disease severity. To study the effect of hyperglycemia on CD8+ T cell function, we stimulated peripheral blood mononuclear cells (PBMCs) from donors with and without diabetes with influenza A virus, anti-CD3/anti-CD28-coated beads, PMA and ionomycin (PMA/I), or an influenza viral peptide pool. After stimulation, cells were assessed for functionality [as defined by expression of IFN-γ, TNF-α, macrophage inflammatory protein (MIP)-1β, and lysosomal-associated membrane protein-1 (CD107a)] using flow cytometry. Our results showed that increasing HbA1c correlated with a reduction in TNF-α production by CD8+ T cells in response to influenza stimulation in a TCR-specific manner. This was not associated with any changes to CD8+ T cell subsets. We conclude that hyperglycemia impairs CD8+ T cell function to influenza virus infection, which may be linked with the increased risk of severe influenza in patients with diabetes.

Objective
Diabetes mellitus significantly increases the risk of severe respiratory virus disease like influenza and COVID-19. Early evidence suggests that this susceptibility to respiratory viral disease is driven by glycaemic variability, rather than average blood glucose levels. In healthy individuals, blood glucose levels remain relatively stable throughout the day. However, in individuals living with diabetes, blood glucose spikes are more frequent and higher in magnitude. Continuous glucose monitoring (CGM) provides a unique opportunity to detect these hyper and hypoglycaemic events, even in the presence of an in range HbA1c.

Research design and methods
Here, we use blood samples and CGM data obtained from people living with Type 1 diabetes (T1D) to determine the effects of glycaemic variability on the T-cell response to influenza virus. Low glycaemic variability was defined as a coefficient of variation (CV) <33% (n = 13) whilst high glycaemic variability was defined as a CV >33% (n = 19).

Results
We show that high glycaemic variability in participants living with T1D is associated with a reduced proportion of CD8+CD107α-IFNγ-MIP1β-TNF+ T-cells in response to stimulation with influenza virus and an influenza peptide pool. High glycaemic variability in this patient population is primarily driven by hypoglycaemic events and was also associated with an increase in the proportion of naïve CD8+ T cells and a decrease in terminally differentiated CD8+ T cells (TEMRA).

Conclusions
Together, this study provides the first evidence that glycaemic variability affects the T- cell response to respiratory viruses. These data suggest that monitoring glycaemic variability may have important implications in understanding the antiviral immune response in people with diabetes.

Objective:
Class III obesity (body mass index [BMI] ≥ 40 kg m−2) significantly impairs the immune response to SARS-CoV-2 vaccination. However, the effect of an elevated BMI (≥ 25 kg m−2) on humoral immunity to SARS-CoV-2 infection and COVID-19 vaccination remains unclear.

Methods:
We collected blood samples from people who recovered from SARS-CoV-2 infection approximately 3 and 13 months of post-infection (noting that these individuals were not exposed to SARS-CoV-2 or vaccinated in the interim). We also collected blood samples from people approximately 5 months of post-second dose COVID-19 vaccination (the majority of whom did not have a prior SARS-CoV-2 infection). We measured their humoral responses to SARS-CoV-2, grouping individuals based on a BMI greater or less than 25 kg m−2.

Results:
Here, we show that an increased BMI (≥ 25 kg m−2), when accounting for age and sex differences, is associated with reduced antibody responses after SARS-CoV-2 infection. At 3 months of post-infection, an elevated BMI was associated with reduced antibody titres. At 13 months of post-infection, an elevated BMI was associated with reduced antibody avidity and a reduced percentage of spike-positive B cells. In contrast, no significant association was noted between a BMI ≥ 25 kg m−2 and humoral immunity to SARS-CoV-2 at 5 months of post-secondary vaccination.

Conclusions:
Taken together, these data showed that elevated BMI is associated with an impaired humoral immune response to SARS-CoV-2 infection. The impairment of infection-induced immunity in individuals with a BMI ≥ 25 kg m−2 suggests an added impetus for vaccination rather than relying on infection-induced immunity.

Preterm birth (PTB) is the leading cause of infant mortality worldwide. Changes in PTB rates, ranging from -90% to +30%, were reported in many countries following early COVID-19 pandemic response measures ('lockdowns'). It is unclear whether this variation reflects real differences in lockdown impacts, or perhaps differences in stillbirth rates and/or study designs. Here we present interrupted time series and meta-analyses using harmonized data from 52 million births in 26 countries, 18 of which had representative population-based data, with overall PTB rates ranging from 6% to 12% and stillbirth ranging from 2.5 to 10.5 per 1,000 births. We show small reductions in PTB in the first (odds ratio 0.96, 95% confidence interval 0.95-0.98, P value <0.0001), second (0.96, 0.92-0.99, 0.03) and third (0.97, 0.94-1.00, 0.09) months of lockdown, but not in the fourth month of lockdown (0.99, 0.96-1.01, 0.34), although there were some between-country differences after the first month. For high-income countries in this study, we did not observe an association between lockdown and stillbirths in the second (1.00, 0.88-1.14, 0.98), third (0.99, 0.88-1.12, 0.89) and fourth (1.01, 0.87-1.18, 0.86) months of lockdown, although we have imprecise estimates due to stillbirths being a relatively rare event. We did, however, find evidence of increased risk of stillbirth in the first month of lockdown in high-income countries (1.14, 1.02-1.29, 0.02) and, in Brazil, we found evidence for an association between lockdown and stillbirth in the second (1.09, 1.03-1.15, 0.002), third (1.10, 1.03-1.17, 0.003) and fourth (1.12, 1.05-1.19, <0.001) months of lockdown. With an estimated 14.8 million PTB annually worldwide, the modest reductions observed during early pandemic lockdowns translate into large numbers of PTB averted globally and warrant further research into causal pathways.