Involvement of Periodontal Disease in the Pathogenesis and Exacerbation of Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis: A Review

The increasing incidence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH), along with global lifestyle changes, requires further in-depth research to elucidate the mechanisms and develop new treatment strategies. In addition, the number of patients with periodontal disease has increased recently, suggesting that periodontal disease is sometimes associated with systemic conditions. In this review, we summarize recent studies linking periodontal disease and NAFLD, the concept of the mouth-gut-liver axis, oral and intestinal microbiota, and liver disease. We suggest new research directions toward a detailed mechanistic understanding and novel targets for treatment and prevention. Forty years have passed since the concepts of NAFLD and NASH were first proposed. however, no effective prevention or treatment has been established. We also found that the pathogenesis of NAFLD/NASH is not limited to liver-related diseases but has been reported to be associated with various systemic diseases and an increasing number of causes of death. In addition, changes in the intestinal microbiota have been shown to be a risk factor for periodontal diseases, such as atherosclerosis, diabetes, rheumatoid arthritis, nonalcoholic fatty liver disease, and obesity.

Meta-analysis of the diagnostic accuracy of serum type IV collagen 7S concentration for the staging of liver fibrosis in nonalcoholic fatty liver disease

AIM

We aimed to evaluate the diagnostic accuracy of the measurement of serum type IV collagen 7S (T4C7S) concentration for the staging of liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

A systematic search or published works was carried out using the PubMed, Cochrane Library, and Web of Science Core Collection databases for studies of the accuracy of serum T4C7S concentration for the staging of fibrosis using Fibrosis stage (F)0-4 in patients with NAFLD diagnosed by liver biopsy.

RESULTS

Nine articles describing 1475 participants with NAFLD were included. For fibrosis ≥F1, with n = 849, summary estimates of sensitivity of 0.79, specificity of 0.69, and area under the curve (AUC) of 0.80 were obtained using a median T7C4S cut-off value of 4.6 ng/ml. For fibrosis ≥F2, with n = 1,090, summary estimates of sensitivity of 0.78, specificity of 0.78, and AUC of 0.84 were obtained using a median cut-off value of 4.9 ng/ml. For fibrosis ≥F3, with n = 1311 participants and a median cut-off value of 5.4 ng/ml, a pooled sensitivity of 0.82, specificity of 0.81, and AUC of 0.83 were obtained. For fibrosis ≥F4, with n = 753 and a median cut-off value of 6.6 ng/ml, a pooled sensitivity of 0.85, specificity of 0.81, and AUC of 0.85 were obtained.

CONCLUSIONS

Serum T4C7S concentration was found to be an accurate method of staging liver fibrosis in patients with NAFLD.

Long-term trends in mortality risk associated with short-term exposure to air pollution in 10 Japanese cities between 1977 and 2015

BACKGROUND AND AIM

Short-term associations between air pollution and mortality have been well reported in Japan, but the historical changes in mortality risk remain unknown. We examined temporal changes in the mortality risks associated with short-term exposure to four criteria air pollutants in selected Japanese cities.

METHODS

We collected daily mortality data for non-accidental causes (n = 5,748,206), cardiovascular (n = 1,938,743) and respiratory diseases (n = 777,266), and air pollutants (sulfur dioxide [SO₂], nitrogen dioxide [NO₂], suspended particulate matter [SPM], and oxidants [Ox]) in 10 cities from 1977 to 2015. We performed two-stage analysis with 5-year stratification to estimate the relative risk (RR) of mortality per 10-unit increase in the 2-day moving average of air pollutant concentrations. In the first stage, city-specific associations were assessed using a quasi-Poisson generalized linear regression model. In the second stage, city-specific estimates were pooled using a random-effects meta-analysis. Linear trend and ratio of relative risks (RRR) were computed to examine temporal changes.

RESULTS

When stratifying the analysis by every 5 years, average concentrations in each sub-period decreased for SO₂, NO₂, and SPM (14.2-2.3 ppb, 29.4-17.5 ppb, 52.1-20.6 μg/m³, respectively) but increased for Ox (29.1-39.1 ppb) over the study period. We found evidence of a negative linear trend in the risk of cardiovascular mortality associated with SPM across sub-periods. However, the risks of non-accidental and respiratory mortality per 10-unit increase in SPM concentration were significantly higher in the most recent period than in the earliest period. Other gaseous pollutants did not show such temporal risk change. The risks posed by these pollutants were slightly to moderately heterogeneous in the different cities.

CONCLUSIONS

The mortality risks associated with short-term exposure to SPM changed, with different trends by cause of death, in 10 cities over 39 years whereas the risks for other gaseous pollutants were relatively stable.

Daily temperature effects on under-five mortality in a tropical climate country and the role of local characteristics

BACKGROUND

Climate change and its subsequent effects on temperature have raised global public health concerns. Although numerous epidemiological studies have shown the adverse health effects of temperature, the association remains unclear for children aged below five years old and those in tropical climate regions.

METHODS

We conducted a two-stage time-stratified case-crossover study to examine the association between temperature and under-five mortality, spanning the period from 2014 to 2018 across all six regions in Malaysia. In the first stage, we estimated region-specific temperature-mortality associations using a conditional Poisson regression and distributed lag nonlinear models. We used a multivariate meta-regression model to pool the region-specific estimates and examine the potential role of local characteristics in the association, which includes geographical information, demographics, socioeconomic status, long-term temperature metrics, and healthcare access by region.

RESULTS

Temperature in Malaysia ranged from 22 °C to 31 °C, with a mean of 27.6 °C. No clear seasonality was observed in under-five mortality. We found no strong evidence of the association between temperature and under-five mortality, with an "M-" shaped exposure-response curve. The minimum mortality temperature (MMT) was identified at 27.1 °C. Among several local characteristics, only education level and hospital bed rates reduced the residual heterogeneity in the association. However, effect modification by these variables were not significant.

CONCLUSION

This study suggests a null association between temperature and under-five mortality in Malaysia, which has a tropical climate. The "M-" shaped pattern suggests that under-fives may be vulnerable to temperature changes, even with a small temperature change in reference to the MMT. However, the weak risks with a large uncertainty at extreme temperatures remained inconclusive. Potential roles of education level and hospital bed rate were statistically inconclusive.

Real-world assessment of SmartExam, a novel FibroScan computational method: A retrospective single-center cohort study

BACKGROUND AND AIM

SmartExam is a novel computational method compatible with FibroScan that uses a software called SmartDepth and continuous controlled attenuation parameter measurements to evaluate liver fibrosis and steatosis. This retrospective study compared the diagnostic accuracy of conventional and SmartExam-equipped FibroScan for liver stiffness measurement (LSM).

METHODS

The liver stiffness and the associated controlled attenuation parameters of 167 patients were measured using conventional and SmartExam-Equipped FibroScan as well as reference methods like magnetic resonance elastography (MRE) and magnetic resonance imaging-based proton density fat fraction (MRI-PDFF) measurements to assess its diagnostic performance. M or XL probes were selected based on the probe-to-liver capsule distance for all FibroScan examinations.

RESULTS

The liver stiffness and controlled attenuation parameter (CAP) correlation coefficients calculated from conventional and SmartExam-equipped FibroScan were 0.97 and 0.82, respectively. Using MRE/MRI-PDFF as a reference and the DeLong test for analysis, LSM and the area under the receiver operating characteristic curve for CAP measured by conventional and SmartExam-equipped FibroScan showed no significant difference. However, the SmartExam-equipped FibroScan measurement (33.6 s) took 1.4 times longer than conventional FibroScan (23.2 s).

CONCLUSIONS

SmartExam has a high diagnostic performance comparable with that of conventional FibroScan. Because the results of the conventional and SmartExam-equipped FibroScan were strongly correlated, it can be considered useful for assessing the fibrosis stage and steatosis grade of the liver in clinical practice, with less variability but little longer measurement time compared with the conventional FibroScan.

Non-invasive imaging biomarkers for liver steatosis in non-alcoholic fatty liver disease: present and future

Non-alcoholic fatty liver disease is currently the most common chronic liver disease, affecting up to 25% of the global population. Simple fatty liver, in which fat is deposited in the liver without fibrosis, has been regarded as a benign disease in the past, but it is now known to be prognostic. In the future, more emphasis should be placed on the quantification of liver fat. Traditionally, fatty liver has been assessed by histological evaluation, which requires an invasive examination; however, technological innovations have made it possible to evaluate fatty liver by non-invasive imaging methods, such as ultrasonography, computed tomography, and magnetic resonance imaging. In addition, quantitative as well as qualitative measurements for the detection of fatty liver have become available. In this review, we summarize the currently used qualitative evaluations of fatty liver and discuss quantitative evaluations that are expected to further develop in the future.

Associations Between Extreme Temperatures and Cardiovascular Cause-Specific Mortality: Results From 27 Countries

BACKGROUND

Cardiovascular disease is the leading cause of death worldwide. Existing studies on the association between temperatures and cardiovascular deaths have been limited in geographic zones and have generally considered associations with total cardiovascular deaths rather than cause-specific cardiovascular deaths.

METHODS

We used unified data collection protocols within the Multi-Country Multi-City Collaborative Network to assemble a database of daily counts of specific cardiovascular causes of death from 567 cities in 27 countries across 5 continents in overlapping periods ranging from 1979 to 2019. City-specific daily ambient temperatures were obtained from weather stations and climate reanalysis models. To investigate cardiovascular mortality associations with extreme hot and cold temperatures, we fit case-crossover models in each city and then used a mixed-effects meta-analytic framework to pool individual city estimates. Extreme temperature percentiles were compared with the minimum mortality temperature in each location. Excess deaths were calculated for a range of extreme temperature days.

RESULTS

The analyses included deaths from any cardiovascular cause (32 154  935), ischemic heart disease (11 745 880), stroke (9 351 312), heart failure (3 673 723), and arrhythmia (670 859). At extreme temperature percentiles, heat (99th percentile) and cold (1st percentile) were associated with higher risk of dying from any cardiovascular cause, ischemic heart disease, stroke, and heart failure as compared to the minimum mortality temperature, which is the temperature associated with least mortality. Across a range of extreme temperatures, hot days (above 97.5th percentile) and cold days (below 2.5th percentile) accounted for 2.2 (95% empirical CI [eCI], 2.1-2.3) and 9.1 (95% eCI, 8.9-9.2) excess deaths for every 1000 cardiovascular deaths, respectively. Heart failure was associated with the highest excess deaths proportion from extreme hot and cold days with 2.6 (95% eCI, 2.4-2.8) and 12.8 (95% eCI, 12.2-13.1) for every 1000 heart failure deaths, respectively.

CONCLUSIONS

Across a large, multinational sample, exposure to extreme hot and cold temperatures was associated with a greater risk of mortality from multiple common cardiovascular conditions. The intersections between extreme temperatures and cardiovascular health need to be thoroughly characterized in the present day-and especially under a changing climate.

The association of COVID-19 incidence with temperature, humidity, and UV radiation - A global multi-city analysis

BACKGROUND AND AIM

The associations between COVID-19 transmission and meteorological factors are scientifically debated. Several studies have been conducted worldwide, with inconsistent findings. However, often these studies had methodological issues, e.g., did not exclude important confounding factors, or had limited geographic or temporal resolution. Our aim was to quantify associations between temporal variations in COVID-19 incidence and meteorological variables globally.

METHODS

We analysed data from 455 cities across 20 countries from 3 February to 31 October 2020. We used a time-series analysis that assumes a quasi-Poisson distribution of the cases and incorporates distributed lag non-linear modelling for the exposure associations at the city-level while considering effects of autocorrelation, long-term trends, and day of the week. The confounding by governmental measures was accounted for by incorporating the Oxford Governmental Stringency Index. The effects of daily mean air temperature, relative and absolute humidity, and UV radiation were estimated by applying a meta-regression of local estimates with multi-level random effects for location, country, and climatic zone.

RESULTS

We found that air temperature and absolute humidity influenced the spread of COVID-19 over a lag period of 15 days. Pooling the estimates globally showed that overall low temperatures (7.5 °C compared to 17.0 °C) and low absolute humidity (6.0 g/m3 compared to 11.0 g/m3) were associated with higher COVID-19 incidence (RR temp =1.33 with 95%CI: 1.08; 1.64 and RR AH =1.33 with 95%CI: 1.12; 1.57). RH revealed no significant trend and for UV some evidence of a positive association was found. These results were robust to sensitivity analysis. However, the study results also emphasise the heterogeneity of these associations in different countries.

CONCLUSION

Globally, our results suggest that comparatively low temperatures and low absolute humidity were associated with increased risks of COVID-19 incidence. However, this study underlines regional heterogeneity of weather-related effects on COVID-19 transmission.

Potential effect of heat adaptation on association between number of heatstroke patients transported by ambulance and wet bulb globe temperature in Japan

This study analyzed the association between heatstroke incidence and daily maximum wet bulb globe temperature (WBGT) for all 47 prefectures in Japan by age group and severity using time-series analysis, controlling for confounders, such as seasonality and long-term trends. With the obtained association, the relative risk between the reference WBGT (defined as the value at which heatstroke starts to increase) and the daily maximum WBGT at 30 °C (RR_wbgt30) of each prefecture were calculated. For the heatstroke data, the daily number of heatstroke patients transported by ambulance at the prefecture level, provided by the Fire and Disaster Management Agency, was utilized. The analysis was conducted for age groups of 7-17 y, 18-64 y, and ≥65 y, and for severity of Deceased, Severe, Moderate (combined as DSM), and Mild. The analysis period was set from May 1 to September 30, 2015-2019. Finally, the correlation between RR_wbgt30 and the average daily maximum WBGT during the analysis period (aveWBGTms) of each prefecture was analyzed to examine the regionality of heatstroke incidence. The result showed that RR_wbgt30 is negatively correlated with aveWBGTms for the age group 18-64 y and ≥65 y (except for the age group 7-17 y) and for severity. The natural logarithm of the RR_wbgt30 of all 47 prefectures ranged from 2.0 to 8.2 for the age group 7-17 y, 1.1 to 4.0 for the age group 18-64 y, 1.8 to 6.0 for the age group ≥65 y, and 1.0 to 3.6 for DSM, and 0.9 to 4.0 for Mild. This regionality can be attributed to the effects of heat adaptation, where people in hotter regions are accustomed to implementing measures against hot environments and are more heat acclimatized than people in cooler regions.

Diagnostic comparison of vibration-controlled transient elastography and MRI techniques in overweight and obese patients with NAFLD

Non-invasive imaging techniques have greatly advanced the assessment of liver fibrosis and steatosis but are not fully evaluated in overweight patients. We evaluated the diagnostic performance of vibration-controlled transient elastography (VCTE) and magnetic resonance elastography (MRE) to assess fibrosis and controlled attenuation parameter (CAP) and MR imaging (MRI)-proton density fat fraction (MRI-PDFF) to assess steatosis in overweight and obese patients with non-alcoholic fatty liver disease (NAFLD). We included 163 biopsy-proven patients with NAFLD who underwent VCTE, MRE/MRI-PDFF, and liver biopsy (years 2014-2020) who were classified according to their body mass index (BMI) as normal (BMI < 25 kg/m², n = 38), overweight (25 ≤ BMI < 30 kg/m², n = 68), and obese (BMI ≥ 30 kg/m², n = 57). VCTE and MRE detected fibrosis of stages ≥ 2, ≥ 3, and 4 with an area under the receiver operating curve (AUROC) of 0.83-0.94 (VCTE) and 0.85-0.95 (MRE) in all groups, without considerable differences. MRI-PDFF detected steatosis of grades ≥ 2 and 3 with high AUROC in all groups (0.81-1.00). CAP's diagnostic ability (0.63-0.95) was lower than that of MRI-PDFF and decreased with increasing BMI compared to MRI-PDFF. VCTE and MRE similarly accurately assess fibrosis, although MRI-PDFF is more accurate than CAP in detecting steatosis in overweight and obese patients with NAFLD.

The burden of heat-related stroke mortality under climate change scenarios in 22 East Asian cities

BACKGROUND

Stroke is a leading cause of death and disability in East Asia. Owing to the aging population and high prevalence of stroke, East Asia might suffer a disproportionately heavy burden of stroke under the changing climate. However, the evidence relevant is still limited in this area.

OBJECTIVE

To evaluate the stroke mortality risk due to heat exposure in East Asia and predict its burden under various future climate change scenarios.

METHODS

We conducted a multi-center observational study and collected data from 22 representative cities in three main East Asian countries (i.e., China, Japan, and South Korea) from 1972 to 2015. The two-stage time-series analyses were applied to estimate the effects of heat on stroke mortality at the regional and country level. We further projected the burden of heat-related stroke mortality using 10 global climate models (GCMs) under four shared socioeconomic pathway and representative concentration pathway (SSP-RCP) scenarios, including SSP1-RCP1.9, SSP1-RCP2.6, SSP2-RCP4.5, and SSP5-RCP8.5 scenarios.

RESULTS

In the present study, a total of 287,579 stroke deaths were collected during the warm season. Heat was significantly associated with an increased risk of stroke mortality. Overall, compared with the 2010 s, the heat-related attributable fraction (AF) was projected to increase in the 2090 s, with increments ranging from 0.8 % to 7.5 % across various climate change scenarios. The heat-related AF was projected to reach 11.9 % (95 % empirical confidence interval [eCI]: 6.1 %, 17.5 %) in the 2090 s under the SSP5-RCP8.5 scenario in China, while the corresponding estimates were 6.6 % (95 % eCI: 2.5 %, 11.0 %) and 5.1 % (95 % eCI: 1.2 %, 9.1 %) for Japan and South Korea, respectively.

CONCLUSIONS

Climate change will exacerbate the burden of heat-related stroke mortality but with considerable geographical heterogeneity in East Asia.

Associations of segment-specific pulse wave velocity with vascular calcification: the Atherosclerosis Risk in Communities (ARIC) Study

Background

Pulse wave velocity (PWV) is a non-invasive measure of arterial stiffness and a predictor of cardiovascular disease (CVD). Vascular calcification, especially coronary artery calcium (CAC) measured by computed tomography (CT), is one of the strongest predictors of CVD but requires radiation for measurement. PWV may be helpful to identify persons with vascular calcification who may benefit from formal assessment of vascular calcification with CT. However, the associations between PWV and vascular calcification across different vascular beds have not been fully investigated.

Purpose

The aims of this study were to quantify the association between PWV and calcification at different segments and to explore whether PWV can identify individuals with vascular calcification beyond traditional risk factors.

Methods

Among 1486 ARIC Study participants (mean age 79.3 [SD 4.2] years), we measured PWV by OMRON VP1000plus at the following segments: heart-carotid (hcPWV), heart-femoral (hfPWV), carotid-femoral (cfPWV), heart-ankle (haPWV), brachial-ankle (baPWV) and femoral-ankle (faPWV). Participants were stratified into four groups based on quartiles of each PWV measure. Dependent (i.e., outcome) variables were high calcium score (≥75th percentile of Agatston score by CT) of the following vascular beds (including valves): coronary arteries, aortic valve ring, aortic valve, mitral valve, ascending aorta, and descending aorta. We ran multivariable logistic regression models and assessed c-statistics as a measure of prediction discrimination.

Results

Only cfPWV was significantly positively associated with high CAC (adjusted odds ratio [OR] for the highest vs. lowest quartile: 1.73 [95% CI: 1.17–2.55]) (green dot in figure). The associations were overall most evident for descending aorta calcification, with significantly positive results for hfPWV (gold dot in figure), cfPWV (green dot), haPWV (emerald dot), and baPWV (blue dot). For example, adjusted OR for the highest vs. lowest quartile of cfPWV was 4.08 (2.70–6.24). hfPWV and cfPWV were significantly associated with mitral valve calcification as well. In contrast, faPWV (purple dots) was inversely associated with calcification of aortic valve ring, ascending aorta, and descending aorta. For descending aorta calcification, even the second highest quartile of the following measures demonstrated significant adjusted OR: hfPWV (3.21 [2.11–4.95]), cfPWV (2.11 [1.40–3.20]), and baPWV (1.75 [1.14–2.69]). Simultaneously adding cfPWV and hfPWV improved c-statistic for CAC (Δc-statistic 0.011 [0.0007–0.022]) and descending aorta calcification (0.035 [0.017–0.053]).

Conclusions

The associations of PWV with vascular calcification varied substantially across segments, with descending aorta calcification most closely linked to PWV measures and cfPWV most robustly associated with calcification of multiple vascular beds. cfPWV and hfPWV, together, improved discrimination of high CAC beyond traditional risk factors.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The National Heart, Lung, and Blood Institute, National Institutes of Health

Comparison of long‐term prognosis between non‐obese and obese patients with non‐alcoholic fatty liver disease

Background and Aim

Non‐alcoholic fatty liver disease (NAFLD) can progress in non‐obese patients as in obese patients. Reports on long‐term prognosis in non‐obese NAFLD patients are controversial. Therefore, we aimed to examine the long‐term prognosis of non‐obese patients with NAFLD.

Methods

This single‐center, retrospective cohort study enrolled biopsy‐proven non‐obese and obese NAFLD patients between January 2002 and December 2011 and followed them up until 31 March 2021, for death and clinical events (cardiovascular and liver‐related events and extrahepatic cancers).

Results

Of the 223 NAFLD patients, 58 (26.0%) were non‐obese. Compared with obese patients, they had a lower fibrosis stage (0.8 ± 0.80 vs 1.2 ± 0.91; P = 0.004), milder lobular inflammation (0.9 ± 0.7 vs 1.1 ± 0.7; P = 0.02), and significantly lower serum creatinine, total bilirubin, ferritin, and type IV collagen 7S and higher high‐density lipoprotein levels. After a median follow‐up of 8.9 years, no significant difference was noted in mortality between the two groups (2 [3.4%] non‐obese vs 5 [3.0%] obese; log‐rank test, P = 0.63). Twelve patients (20.7%) in the non‐obese group and 32 (19.4%) in the obese group had clinical events. Although the obese group had a higher incidence of clinical events during the first 10 years of follow‐up, the non‐obese group had a higher incidence after that (log‐rank test, P = 0.67). The non‐obese group had a high incidence of malignancy (9 [15.5%] non‐obese vs 14 [8.3%] obese; P = 0.13).

Conclusion

Non‐obese NAFLD does not necessarily have a good prognosis, and some cases have a poor prognosis such as extrahepatic cancers. Further validation is required in the future.

The effects of night-time warming on mortality burden under future climate change scenarios: a modelling study

BACKGROUND

The health impacts of climate warming are usually quantified based on daily average temperatures. However, extra health risks might result from hot nights. We project the future mortality burden due to hot nights.

METHODS

We selected the hot night excess (HNE) to represent the intensity of night-time heat, which was calculated as the excess sum of high temperature during night time. We collected historical mortality data in 28 cities from three east Asian countries, from 1981 to 2010. The associations between HNE and mortality in each city were firstly examined using a generalised additive model in combination with a distributed lag non-linear model over lag 0-10 days. We then pooled the cumulative associations using a univariate meta-regression model at the national or regional levels. Historical and future hourly temperature series were projected under two scenarios of greenhouse-gas emissions from 1980-2099, with ten general circulation models. We then projected the attributable fraction of mortality due to HNE under each scenario.

FINDINGS

Our dataset comprised 28 cities across three countries (Japan, South Korea, and China), including 9 185 598 deaths. The time-series analyses showed the HNE was significantly associated with increased mortality risks, the relative mortality risk on days with hot nights could be 50% higher than on days with non-hot nights. Compared with the rise in daily mean temperature (lower than 20%), the frequency of hot nights would increase more than 30% and the intensity of hot night would increase by 50% by 2100s. The attributable fraction of mortality due to hot nights was projected to be 3·68% (95% CI 1·20 to 6·17) under a strict emission control scenario (SSP126). Under a medium emission control scenario (SSP245), the attributable fraction of mortality was projected to increase up to 5·79% (2·07 to 9·52), which is 0·95% (-0·39 to 2·29) more than the attributable fraction of mortality due to daily mean temperature.

INTERPRETATION

Our study provides evidence for significant mortality risks and burden in association with night-time warming across Japan, South Korea, and China. Our findings suggest a growing role of night-time warming in heat-related health effects in a changing climate.

FUNDING

The National Natural Science Foundation of China, Shanghai International Science and Technology Partnership Project.

Efficacy and safety of guanabenz acetate treatment for non-alcoholic fatty liver disease: a study protocol for a randomised investigator-initiated phase IIa study

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is a metabolic syndrome phenotype in the liver and thus obviously associated with metabolic abnormalities, including insulin resistance-related to hyperglycaemic and hyperlipidaemia. The prevalence of NAFLD is increasing worldwide. However, currently, there is no consensus regarding the efficacy and safety of drugs used to treat patients with NAFLD/non-alcoholic steatohepatitis (NASH). Guanabenz acetate, a selective α2-adrenoceptor stimulator used in the treatment of hypertension, binds at a high-affinity constant to a nuclear transcriptional coregulator, helicase with zinc finger 2 (Helz2) and inhibits Helz2-medaited steatosis in the liver; chronic oral administration of guanabenz acetate produces a dose-dependent inhibition of lipid accumulation by inhibiting lipogenesis and activating fatty acid Β-oxidation in the liver of obese mice, resulting in improvement of insulin resistance and hyperlipidaemia. Taken all together, guanabenz acetate has a potentially effective in improving the development of NAFLD/NASH and metabolic abnormalities. In this randomised, open label, parallel-group, phase IIa study, we made attempts to conduct a proof-of-concept assessment by evaluating the efficacy and safety of guanabenz acetate treatment in patients with NAFLD/NASH.

METHODS AND ANALYSIS

A total of 28 adult patients with NAFLD or NASH and hypertension complications meeting the inclusion/exclusion criteria will be enrolled. Patients will be randomised to receive either 4 or 8 mg guanabenz acetate (n=14 per group). Blood tests and MRI will be performed 16 weeks after commencement of treatment. The primary endpoint will be the percentage reduction in hepatic fat content (%) measured using MRI-proton density fat fraction from baseline by at least 3.46% at week 16 after treatment initiation.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of Yokohama City University Hospital before participant enrolment (YCU021001). The results of this study will be submitted for publication in international peer-reviewed journals, and the key findings will be presented at international scientific conferences. Participants wishing to know the results of this study will be contacted directly on data publication.

TRIAL REGISTRATION NUMBER

This trial is registered with ClinicalTrials.gov (number: NCT05084404).

PROTOCOL VERSION

V.1.1, 19 August 2021.

Influence of liver stiffness heterogeneity on staging fibrosis in patients with nonalcoholic fatty liver disease

BACKGROUND AND AIMS

Despite that hepatic fibrosis often affects the liver globally, spatial distribution can be heterogeneous. This study aimed to investigate the effect of liver stiffness (LS) heterogeneity on concordance between MR elastography (MRE)-based fibrosis staging and biopsy staging in patients with NAFLD.

APPROACH AND RESULTS

We retrospectively evaluated data from 155 NAFLD patients who underwent liver biopsy and 3 Tesla MRE and undertook a retrospective validation study of 169 NAFLD patients at three hepatology centers. Heterogeneity of stiffness was assessed by measuring the range between minimum and maximum MRE-based LS measurement (LSM). Variability of LSM was defined as the stiffness range divided by the maximum stiffness value. The cohort was divided into two groups (homogenous or heterogeneous), according to whether variability was below or above the average for the training cohort. Based on histopathology and receiver operating characteristic (ROC) analysis, optimum LSM thresholds were determined for MRE-based fibrosis staging of stage 4 (4.43, kPa; AUROC, 0.89) and stage ≥3 (3.93, kPa; AUROC, 0.89). In total, 53 had LSM above the threshold for stage 4. Within this group, 30 had a biopsy stage of <4. In 86.7% of these discordant cases, variability of LSM was classified as heterogeneous. In MRE-based LSM stage ≥3, 88.9% of discordant cases were classified as heterogeneous. Results of the validation cohort were similar to those of the training cohort.

CONCLUSIONS

Discordance between biopsy- and MRE-based fibrosis staging is associated with heterogeneity in LSM, as depicted with MRE.

Association of Serum and Fecal Bile Acid Patterns With Liver Fibrosis in Biopsy-Proven Nonalcoholic Fatty Liver Disease: An Observational Study

INTRODUCTION

No reports on both blood and fecal bile acids (BAs) in patients with nonalcoholic fatty liver disease (NAFLD) exist. We simultaneously assessed the serum and fecal BA patterns in healthy participants and those with NAFLD.

METHODS

We collected stool samples from 287 participants from 5 hospitals in Japan (healthy control [HC]: n = 88; mild fibrosis: n = 104; and advanced fibrosis group: n = 95). Blood samples were collected and analyzed for serum BAs and 7α-hydroxy-4-cholesten-3-one (C4)-a surrogate marker for BA synthesis ability-from 141 patients. Concentrations of BAs, including cholic acid (CA), deoxycholic acid (DCA), chenodeoxycholic acid, ursodeoxycholic acid, and lithocholic acid (LCA), were measured using liquid chromatography-mass spectrometry.

RESULTS

The total fecal BA concentration was significantly higher in the NAFLD group with worsening of fibrosis than in the HC group. Most of the fecal BAs were secondary and unconjugated. In the fecal BA fraction, CA, DCA, chenodeoxycholic acid, ursodeoxycholic acid, and LCA were significantly higher in the NAFLD than in the HC group. The total serum BA concentration was higher in the NAFLD group with worsening of fibrosis than in the HC group. In the serum BA fraction, CA, LCA, and C4 concentrations were significantly higher in the NAFLD than in the HC group.

DISCUSSION

Fecal and serum BA and C4 concentrations were high in patients with NAFLD with worsening of fibrosis, suggesting involvement of abnormal BA metabolism in NAFLD with fibrosis progression. Abnormalities in BA metabolism may be a therapeutic target in NAFLD with fibrosis.

TMEM16A blockers T16Ainh-A01 and benzbromarone do not modulate the regulation of sweating and cutaneous vasodilatation in humans in vivo

NEW FINDINGS

What is the central question of this study? Do transmembrane member 16A (TMEM16A) blockers modulate the activation of heat loss responses of sweating and cutaneous vasodilatation? What are the main finding and its importance? Relative to the vehicle control site, TMEM16A blockers T16Ainh-A01 and benzbromarone had no effect on sweat rate or cutaneous vascular conductance during whole-body heating inducing a 1.1 ± 0.1°C increase in core temperature above baseline resting levels. These results suggest that TMEM16A blockers T16Ainh-A01 and benzbromarone do not modulate the regulation of sweating and cutaneous vasodilatation during whole-body heat stress.

ABSTRACT

Animal and in vitro studies suggest that transmembrane member 16A (TMEM16A), a Ca²⁺ -activated Cl^- channel, contributes to regulating eccrine sweating. However, direct evidence supporting this possibility in humans is lacking. We assessed the hypothesis that TMEM16A blockers attenuate sweating during whole-body heating in humans. Additionally, we assessed the associated changes in the heat loss response of cutaneous vasodilatation to determine if a functional role of TMEM16A may exist. Twelve young (24 ± 2 years) adults (six females) underwent whole-body heating using a water-perfused suit to raise core temperature 1.1 ± 0.1°C above baseline. Sweat rate and cutaneous vascular conductance (normalized to maximal conductance via administration of sodium nitroprusside) were evaluated continuously at four forearm skin sites treated continuously by intradermal microdialysis with (1) lactated Ringer's solution (control), (2) 5% dimethyl sulfoxide (DMSO) serving as a vehicle control, or (3) TMEM16A blockers 1 mM T16Ainh-A01 or 2 mM benzbromarone dissolved in 5% DMSO solution. All drugs were administered continuously via intradermal microdialysis. Whole-body heating increased core temperature progressively and this was paralleled by an increase in sweat rate and cutaneous vascular conductance at all skin sites. However, sweat rate (all P > 0.318) and cutaneous vascular conductance (all P ≥ 0.073) did not differ between the vehicle control site relative to the TMEM16A blocker-treated sites. Collectively, our findings indicate that TMEM16A blockers T16Ainh-A01 and benzbromarone do not modulate the regulation of sweating and cutaneous vasodilatation during whole-body heating in young adults in vivo.

Coarse Particulate Air Pollution and Daily Mortality: A Global Study in 205 Cities

RATIONALE

The associations between ambient coarse particulate matter (PM2.5-10) and daily mortality is not fully understood at a global scale.

OBJECTIVES

To evaluate the short-term associations between PM2.5-10 and total, cardiovascular, and respiratory mortality across multiple countries/regions worldwide.

METHODS

We collected daily mortality (total, cardiovascular, respiratory) and air pollution data from 205 cities in 20 countries/regions. Concentrations of PM2.5-10 were computed as the difference between inhalable and fine particulate matter. A two-stage time-series analytic approach was applied, with over-dispersed generalized linear models and multilevel meta-analysis. We fitted two-pollutant models to test the independent effect of PM2.5-10 from co-pollutants (fine particulate matter, nitrogen dioxide, sulfur dioxide, ozone, and carbon monoxide). Exposure-response relationship curves were pooled and regional analyses were conducted.

MEASUREMENTS AND MAIN RESULTS

A 10 μg/m3 increase in PM2.5-10 concentration on lag 0-1 day was associated with increments of 0.51% (95% confidence interval [CI]: 0.18%, 0.84%), 0.43% (95%CI: 0.15%, 0.71%) and 0.41% (95%CI: 0.06%, 0.77%) in total, cardiovascular, and respiratory mortality, respectively. The associations varied by country and region. These associations were robust to adjustment by all co-pollutants in two-pollutant models, especially for PM2.5. The exposure-response curves for total, cardiovascular, and respiratory mortality were positive, with steeper slopes at lower exposure ranges and without discernible thresholds.

CONCLUSIONS

This study provides novel global evidence on the robust and independent associations between short-term exposure to ambient PM2.5-10 and total, cardiovascular and respiratory mortality, suggesting the need to establish a unique guideline or regulatory limit for daily concentrations of PM2.5-10.

Two differentially methylated region networks in nonalcoholic fatty liver disease, viral hepatitis, and hepatocellular carcinoma

Background

We previously reported that two differentially methylated region (DMR) networks identified by DMR and co-methylation analyses are strongly correlated with the fibrosis stages of nonalcoholic fatty liver disease (NAFLD). In the current study, we examined these DMR networks in viral hepatitis and hepatocellular carcinoma (HCC).

Methods

We performed co-methylation analysis of DMRs using a normal dataset (GSE48325), two NAFLD datasets (JGAS000059 and GSE31803), and two HCC datasets (GSE89852 and GSE56588). The dataset GSE60753 was used for validation.

Results

One DMR network was clearly observed in viral hepatitis and two HCC populations. Methylation levels of genes in this network were higher in viral hepatitis and cirrhosis, and lower in HCC. Fatty acid binding protein 1 (FABP1), serum/glucocorticoid regulated kinase 2 (SGK2), and hepatocyte nuclear factor 4 α (HNF4A) were potential hub genes in this network. Increased methylation levels of the FABP1 gene may be correlated with reduced protection of hepatocytes from oxidative metabolites in NAFLD and viral hepatitis. The decreased methylation levels of SGK2 may facilitate the growth and proliferation of HCC cells. Decreased methylation levels of HNF4A in HCC may be associated with tumorigenesis. The other DMR network was observed in NAFLD, but not in viral hepatitis or HCC. This second network included genes involved in transcriptional regulation, cytoskeleton organization, and cellular proliferation, which are specifically related to fibrosis and/or tumorigenesis in NAFLD.

Conclusions

Our results suggest that one DMR network was associated with fibrosis and tumorigenesis in both NAFLD and viral hepatitis, while the other network was specifically associated with NAFLD progression. Furthermore, FABP1, SGK2, and HNF4A are potential candidate targets for the prevention and treatment of HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02360-4.

Combination of tofogliflozin and pioglitazone for NAFLD: Extension to the ToPiND randomized controlled trial

The incidence of nonalcoholic fatty liver disease (NAFLD) has recently increased and is related to obesity and the associated surge in type 2 diabetes mellitus (T2DM) and metabolic syndromes. This trial follows up on our previous work and forms part of the ToPiND study. We aimed to combine tofogliflozin and pioglitazone treatment for hepatic steatosis in patients with NAFLD and T2DM. In this open‐label, prospective, single‐center, randomized clinical trial, patients with NAFLD with T2DM and a hepatic fat fraction of ≥10% were assessed based on magnetic resonance imaging proton density fat fraction. Eligible patients received either 20 mg tofogliflozin or 15–30 mg pioglitazone orally, once daily for 24 weeks, followed by combination therapy with both medicines for an additional 24 weeks. The effects on diabetes mellitus and hepatic steatosis were examined at baseline and after the completion of monotherapy and combination therapy. Thirty‐two eligible patients received the combination therapy of tofogliflozin and pioglitazone. The combination therapy showed additional improvement in glycated hemoglobin compared with each monotherapy group and showed improvement in steatosis, hepatic stiffness, and alanine aminotransferase levels compared with the tofogliflozin monotherapy group. Pioglitazone monotherapy–mediated increase in body weight decreased following concomitant use of tofogliflozin. The combination therapy resulted in lower triglyceride, higher high‐density lipoprotein cholesterol, higher adiponectin, and higher ketone body levels. Conclusion: In addition to the additive effects of tofogliflozin and pioglitazone in patients with T2DM and NAFLD, combination therapy was suggested to reduce weight gain and induce cardioprotective effect. Further studies with more patients are needed to investigate the combination therapy of various drugs.

Global, regional, and national burden of mortality associated with short-term temperature variability from 2000-19: a three-stage modelling study

BACKGROUND

Increased mortality risk is associated with short-term temperature variability. However, to our knowledge, there has been no comprehensive assessment of the temperature variability-related mortality burden worldwide. In this study, using data from the MCC Collaborative Research Network, we first explored the association between temperature variability and mortality across 43 countries or regions. Then, to provide a more comprehensive picture of the global burden of mortality associated with temperature variability, global gridded temperature data with a resolution of 0·5° × 0·5° were used to assess the temperature variability-related mortality burden at the global, regional, and national levels. Furthermore, temporal trends in temperature variability-related mortality burden were also explored from 2000-19.

METHODS

In this modelling study, we applied a three-stage meta-analytical approach to assess the global temperature variability-related mortality burden at a spatial resolution of 0·5° × 0·5° from 2000-19. Temperature variability was calculated as the SD of the average of the same and previous days' minimum and maximum temperatures. We first obtained location-specific temperature variability related-mortality associations based on a daily time series of 750 locations from the Multi-country Multi-city Collaborative Research Network. We subsequently constructed a multivariable meta-regression model with five predictors to estimate grid-specific temperature variability related-mortality associations across the globe. Finally, percentage excess in mortality and excess mortality rate were calculated to quantify the temperature variability-related mortality burden and to further explore its temporal trend over two decades.

FINDINGS

An increasing trend in temperature variability was identified at the global level from 2000 to 2019. Globally, 1 753 392 deaths (95% CI 1 159 901-2 357 718) were associated with temperature variability per year, accounting for 3·4% (2·2-4·6) of all deaths. Most of Asia, Australia, and New Zealand were observed to have a higher percentage excess in mortality than the global mean. Globally, the percentage excess in mortality increased by about 4·6% (3·7-5·3) per decade. The largest increase occurred in Australia and New Zealand (7·3%, 95% CI 4·3-10·4), followed by Europe (4·4%, 2·2-5·6) and Africa (3·3, 1·9-4·6).

INTERPRETATION

Globally, a substantial mortality burden was associated with temperature variability, showing geographical heterogeneity and a slightly increasing temporal trend. Our findings could assist in raising public awareness and improving the understanding of the health impacts of temperature variability.

FUNDING

Australian Research Council, Australian National Health & Medical Research Council.