Vulnerability and Burden of All-Cause Mortality Associated with Particulate Air Pollution during COVID-19 Pandemic: A Nationwide Observed Study in Italy

Probiotics Alleviate Chemotherapy-Associated Intestinal Mucosal Injury via the TLR4-NFκB Signaling Pathway

Introduction

Temozolomide (TMZ) induces intestinal mucosa injury that cannot be fully counteracted by supportive treatment. Probiotics regulate gut microbial composition and the host immune system and may alleviate this side effect. We aimed to investigate the potential and mechanism of Lactobacillus rhamnosus GG (LGG) in relieving intestinal mucosal injury induced by TMZ.

Methods

Glioblastoma mice were divided into four groups: CON (control), LGG (10⁹ CFU/mL, treated for 7 days), TMZ (50 mg/kg·d, treated for 5 days), LGG+TMZ (LGG for 7 days and TMZ subsequently for 5 days). Body weight, food intake, and fecal pH were recorded. Intestinal tissue samples were collected 1 day after the end of TMZ treatment. Degree of damage to intestine, expression of IL1β, IL6, TNFα, and IL10 in jejunum were determined. Levels of tight-junction proteins (ZO1, occludin), TLR4, IKKβ, IκBα, and P65 with their phosphorylation in jejunum were measured.

Results

Decreases in body weight, food intake, spleen index in the TMZ group were mitigated in the LGG+TMZ group, and the degree of intestinal shortening and damage to jejunum villus were also alleviated. The expression of tight-junction proteins in the LGG+TMZ group was significantly greater than that in the TMZ group. IκBα in intestinal tissue significantly decreased in the TMZ group, phos-IKKβ and phos-P65 increased compared to the CON group, and LGG reversed such changes in IκBα and phos-P65 in the LGG+TMZ group. Intestinal inflammatory cytokines were significantly increased in the TMZ group, but lower in the LGG+TMZ group. Moreover, expression of TLR4 in LGG group was significantly lower than that in the CON group. LGG inhibited the rise of TLR4 after TMZ in the LGG+TMZ group compared to the TMZ group.

Conclusion

LGG inhibits the activation of the TLR4-NFκB pathway and alleviates intestinal mucosal inflammation induced by TMZ, thereby protect the jejunum villi and mucosal physical barrier.

A new method to separate the impacts of interday and intraday temperature variability on mortality

BACKGROUND

Temperature variability (TV) is associated with increased mortality risks. However, the independent impacts of interday and intraday are still unknown.

METHODS

We proposed a new method to decompose TV into interday TV and intraday TV through algebra derivation. Intraday TV was defined as the weighted average standard deviation (SD) of minimum temperature and maximum temperature on each day. Interday TV was defined as the weighted SD of daily mean temperatures during the exposure period. We then performed an illustrative analysis using data on daily mortality and temperature in France in 2019-2021.

RESULTS

The novel interday and intraday TV indices were good proxies for existing indicators, inlcluding diurnal temperature range (DTR) and temperature change between neighbouring days (TCN). In the illustrative analyses, interday and intraday TVs showed differentiated mortality risks. Mortality burden related to TV was mainly explained by the intraday component, accounting for an attributable fraction (AF) of 1.81% (95% CI: 0.64%, 2.97%) of total mortality, more than twice the AF of interday TV (0.86%, 95% CI: 0.47%, 1.24%).

CONCLUSIONS

This study proposed a novel method for identifying and isolating the different components of temperature variability and offered a comprehensive way to investigate their health impacts.

Bayesian profile regression to study the ecologic associations of correlated environmental exposures with excess mortality risk during the first year of the Covid-19 epidemic in lombardy, Italy

Many countries, including Italy, have experienced significant social and spatial inequalities in mortality during the Covid-19 pandemic. This study applies a multiple exposures framework to investigate how joint place-based factors influence spatial inequalities of excess mortality during the first year of the Covid -19 pandemic in the Lombardy region of Italy. For the Lombardy region, we integrated municipality-level data on all-cause mortality between 2015 and 2020 with 13 spatial covariates, including 5-year average concentrations of six air pollutants, the average temperature in 2020, and multiple socio-demographic factors, and health facilities per capita. Using the clustering algorithm Bayesian profile regression, we fit spatial covariates jointly to identify clusters of municipalities with similar exposure profiles and estimated associations between clusters and excess mortality in 2020. Cluster analysis resulted in 13 clusters. Controlling for spatial autocorrelation of excess mortality and health-protective agency, two clusters had significantly elevated excess mortality than the rest of Lombardy. Municipalities in these highest-risk clusters are in Bergamo, Brescia, and Cremona provinces. The highest risk cluster (C11) had the highest long-term particulate matter air pollution levels (PM2.5 and PM10) and significantly elevated NO2 and CO air pollutants, temperature, proportion ≤18 years, and male-to-female ratio. This cluster is significantly lower for income and ≥65 years. The other high-risk cluster, Cluster 10 (C10), is elevated significantly for ozone but significantly lower for other air pollutants. Covariates with elevated levels for C10 include proportion 65 years or older and a male-to-female ratio. Cluster 10 is significantly lower for income, temperature, per capita health facilities, ≤18 years, and population density. Our results suggest that joint built, natural, and socio-demographic factors influenced spatial inequalities of excess mortality in Lombardy in 2020. Studies must apply a multiple exposures framework to guide policy decisions addressing the complex and multi-dimensional nature of spatial inequalities of Covid-19-related mortality.

High-altitude exposure decreases bone mineral density and its relationship with gut microbiota: Results from the China multi-ethnic cohort (CMEC) study

BACKGROUND

Geographic altitude is a potent environmental factor for human microbiota and bone mineral density. However, little evidence exists in population-based studies with altitude diversity ranges across more than 3000 m. This study assessed the associations between a wide range of altitudes and bone mineral density, as well as the potential mediating role of microbiota in this relationship.

METHODS

A total of 99,556 participants from the China Multi-Ethnic Cohort (CMEC) study were enrolled. The altitude of each participant was extracted from global Shuttle Radar Topography Mission (SRTM) 4 data. Bone mineral density was measured by calcaneus quantitative ultrasound index (QUI). Stool samples were collected for 16S rRNA gene sequencing (n = 1384). The metabolites of gut microbiota, seven kinds of short-chain fatty acids (SCFAs), were detected by gas chromatography-mass spectrometry (GC-MS, n = 128). After screening, 73,974 participants were selected for the "altitude-QUI" analysis and they were placed into the low-altitude (LA) and high-altitude (HA) groups. Additionally, a subgroup (n = 1384) was further selected for the "altitude-microbiota-QUI" analysis. Multivariate linear regression models and mediation analyses were conducted among participants.

RESULTS

A significant negative association between high-altitude and QUI was obtained (mean difference = -0.373 standard deviation [SD], 95% confidence interval [CI]: -0.389, -0.358, n = 73,974). The same negative association was also observed in the population with microbiota data (mean difference = -0.185 SD, 95%CI: -0.360, -0.010, n = 1384), and a significant mediating effect of Catenibacteriumon on the association between altitude and QUI (proportion mediated = 25.2%, P = 0.038) was also noticed. Additionally, the acetic acid, butyric acid, and total amount of seven SCFAs of the low-altitude group were significantly higher than that of the high-altitude group (P < 0.05).

CONCLUSION

High-altitude exposure may decrease bone mineral density in adults, thus increasing the risk of osteoporosis. The modulation of gut microbiota may be a potential strategy for alleviating the decrease of bone mineral density.

Short-term exposure to ozone and economic burden of premature mortality in Italy: A nationwide observation study

Italy is among the countries with the highest ozone concentration in Europe. However, the mortality burden of ozone and related economic loss has not been fully characterized. This study aimed to estimate the ozone-mortality association in Italy and evaluate attributable mortality burden and related economic loss in 2015-2019. We collected daily all-cause mortality data stratified by age and sex from 2015 to 2019 in 107 provinces of Italy. A two-stage time-series framework was applied to estimate the association between daily maximum eight-hour average ozone and mortality as well as economic loss. An overall increase in the risk of mortality (RR=1.0043, 95% CI: 1.0029, 1.0057) was associated with every 10 µg/m³ increase in ozone. Generally, a total of 70,060 deaths and $65 billion economic loss were attributed to ozone exposure, corresponding to 3.11% of mortality and about 0.5% of the national GDP during the study period, respectively. The highest ozone-related mortality burden (30,910 deaths) and economic loss ($29.24 billion) were observed in the hot season. This nationwide study suggested considerable mortality burden and economic loss were associated with exposure to ozone. More actions and policies should be proposed to reduce ozone levels and help the public protect their health.

Effects of environmental parameters and their interactions on the spreading of SARS-CoV-2 in North Italy under different social restrictions. A new approach based on multivariate analysis

In 2020 North Italy suffered the SARS-CoV-2-related pandemic with a high number of deaths and hospitalization. The effect of atmospheric parameters on the amount of hospital admissions (temperature, solar radiation, particulate matter, relative humidity and wind speed) is studied through about 8 months (May-December). Two periods are considered depending on different conditions: a) low incidence of COVID-19 and very few regulations concerning personal mobility and protection ("free/summer period"); b) increasing incidence of disease, social restrictions and use of personal protections ("confined/autumn period"). The "hospitalized people in medical area wards/100000 residents" was used as a reliable measure of COVID-19 spreading and load on the sanitary system. We developed a chemometric approach (multiple linear regression analysis) using the daily incidence of hospitalizations as a function of the single independent variables and of their products (interactions). Eight administrative domains were considered (altogether 26 million inhabitants) to account for relatively homogeneous territorial and social conditions. The obtained models very significantly match the daily variation of hospitalizations, during the two periods. Under the confined/autumn period, the effect of non-pharmacologic measures (social distances, personal protection, etc.) possibly attenuates the virus diffusion despite environmental factors. On the contrary, in the free/summer conditions the effects of atmospheric parameters are very significant through all the areas. Particulate matter matches the growth of hospitalizations in areas with low chronic particulate pollution. Fewer hospitalizations strongly correspond to higher temperature and solar radiation. Relative humidity plays the same role, but with a lesser extent. The interaction between solar radiation and high temperature is also highly significant and represents surprising evidence. The solar radiation alone and combined with high temperature exert an anti-SARS-CoV-2 effect, via both the direct inactivation of virions and the stimulation of vitamin D synthesis, improving immune system function.

Luftverschmutzung als wichtiger Kofaktor bei COVID-19-Sterbefällen

Hintergrund

Die Sterblichkeit bei COVID-19 ist in Anwesenheit kardiopulmonaler Komorbiditäten erhöht. Luftverschmutzung ist ebenfalls mit einer erhöhten Sterblichkeit assoziiert, v. a. vermittelt durch kardiopulmonale Erkrankungen. Beobachtungen zu Beginn der COVID-19-Pandemie zeigten, dass die Sterblichkeit bei COVID-19 v. a. in Regionen mit stärkerer Luftverschmutzung erhöht ist. Ungeklärt ist der Einfluss von Luftverschmutzung für den Krankheitsverlauf bei COVID-19.

Methode

Es wurde eine selektive Literaturrecherche von Studien bis Anfang April 2021 in PubMed zum Zusammenhang von Luftverschmutzung und der COVID-19-Mortalität mit den Suchbegriffen „air pollution AND/OR COVID-19/coronavirus/SARS-CoV‑2 AND/OR mortality“ durchgeführt.

Ergebnisse

Aktuelle Untersuchungen belegen, dass etwa 15 % der weltweiten COVID-19-Todesfälle auf Luftverschmutzung zurückzuführen sind. Der Anteil der luftverschmutzungsbedingten COVID-19-Todesfälle in Europa liegt bei 19 %, in Nordamerika bei 17 % und in Ostasien bei 27 %. Diese Beteiligung der Luftverschmutzung an COVID-19-Todesfällen wurde mittlerweile ebenfalls durch verschiedene Studien aus den USA, Italien und England bestätigt. Luftverschmutzung und COVID-19 führen zu ähnlichen Schäden für das kardiopulmonale System, die möglicherweise den Zusammenhang zwischen Luftverschmutzung und erhöhter COVID-19-Mortalität erklären.

Schlussfolgerung

Der hier gezeigte Umweltaspekt der COVID-19-Pandemie verlangt danach, dass man verstärkt nach wirksamen Maßnahmen zur Reduzierung anthropogener Emissionen, die sowohl Luftverschmutzung als auch den Klimawandel verursachen, streben sollte.

Temperature-mortality association during and before the COVID-19 pandemic in Italy: A nationwide time-stratified case-crossover study

OBJECTIVES

To identify the associations of temperature with non-COVID-19 mortality and all-cause mortality in the pandemic 2020 in comparison with the non-COVID-19 period in Italy.

METHODS

The data on 3,189,790 all-cause deaths (including 3,134,137 non-COVID-19 deaths) and meteorological conditions in 107 Italian provinces between February 1st and November 30th in each year of 2015-2020 were collected. We employed a time-stratified case-crossover study design combined with the distributed lag non-linear model to investigate the relationships of temperature with all-cause and non-COVID-19 mortality in the pandemic and non-pandemic periods.

RESULTS

Cold temperature exposure contributed higher risks for both all-cause and non-COVID-19 mortality in the pandemic period in 2020 than in 2015-2019. However, no different change was found for the impacts of heat. The relative risk (RR) of non-COVID-19 deaths and all-cause mortality at extremely cold (2 °C) in comparison with the estimated minimum mortality temperature (19 °C) in 2020 were 1.63 (95% CI: 1.55-1.72) and 1.45 (95%CI: 1.31-1.61) respectively, which were higher than all-cause mortality risk in 2015-2019 with RR of 1.19 (95%CI: 1.17-1.21).

CONCLUSION

Cold exposure indicated stronger impacts than high temperatures on all-cause and non-COVID-19 mortality in the pandemic year 2020 compared to its counterpart period in 2015-2019 in Italy.