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result(s) for
"Reed, Carter H."
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The persistence of stress-induced physical inactivity in rats: an investigation of central monoamine neurotransmitters and skeletal muscle oxidative stress
by
Reed, Carter H.
,
Clark, Peter J.
,
Valentine, Rudy J.
in
adverse experience
,
Anxiety disorders
,
Behavior
2023
Sedentary lifestyles have reached epidemic proportions world-wide. A growing body of literature suggests that exposures to adverse experiences (e.g., psychological traumas) are a significant risk factor for the development of physically inactive lifestyles. However, the biological mechanisms linking prior stress exposure and persistent deficits in physical activity engagement remains poorly understood.
The purpose of this study was twofold. First, to identify acute stress intensity thresholds that elicit long-term wheel running deficits in rats. To that end, young adult male rats were exposed to a single episode of 0, 50, or 100 uncontrollable tail shocks and then given free access to running wheels for 9 weeks. Second, to identify stress-induced changes to central monoamine neurotransmitters and peripheral muscle physiology that may be maladaptive to exercise output. For this study, rats were either exposed to a single episode of uncontrollable tail shocks (stress) or left undisturbed in home cages (unstressed). Eight days later, monoamine-related neurochemicals were quantified by ultra-high performance liquid chromatography (UHPLC) across brain reward, motor, and emotion structures immediately following a bout of graded treadmill exercise controlled for duration and intensity. Additionally, protein markers of oxidative stress, inflammation, and metabolic activity were assessed in the gastrocnemius muscle by Western blot.
For experiment 1, stress exposure caused a shock number-dependent two to fourfold decrease in wheel running distance across the entire duration of the study. For experiment 2, stress exposure curbed an exercise-induced increase of dopamine (DA) turnover measures in the prefrontal cortex and hippocampus, and augmented serotonin (5HT) turnover in the hypothalamus and remaining cortical area. However, stress exposure also caused several monoaminergic changes independent of exercise that could underlie impaired motivation for physical activity, including a mild dopamine deficiency in the striatal area. Finally, stress potently increased HSP70 and lowered SOD2 protein concentrations in the gastrocnemius muscle, which may indicate prolonged oxidative stress.
These data support some of the possible central and peripheral mechanisms by which exposure to adverse experiences may chronically impair physical activity engagement.
Journal Article
Exercise-Induced Adaptations to the Mouse Striatal Adenosine System
2020
Adenosine acts as a key regulator of striatum activity, in part, through the antagonistic modulation of dopamine activity. Exercise can increase adenosine activity in the brain, which may impair dopaminergic functions in the striatum. Therefore, long-term repeated bouts of exercise may subsequently generate plasticity in striatal adenosine systems in a manner that promotes dopaminergic activity. This study investigated the effects of long-term voluntary wheel running on adenosine 1 (A1R), adenosine 2A (A2AR), dopamine 1 (D1R), and dopamine 2 (D2R) receptor protein expression in adult mouse dorsal and ventral striatum structures using immunohistochemistry. In addition, equilibrative nucleoside transporter 1 (ENT1) protein expression was examined after wheel running, as ENT1 regulates the bidirectional flux of adenosine between intra- and extracellular space. The results suggest that eight weeks of running wheel access spared age-related increases of A1R and A2AR protein concentrations across the dorsal and ventral striatal structures. Wheel running mildly reduced ENT1 protein levels in ventral striatum subregions. Moreover, wheel running mildly increased D2R protein density within striatal subregions in the dorsal medial striatum, nucleus accumbens core, and the nucleus accumbens shell. However, D1R protein expression in the striatum was unchanged by wheel running. These data suggest that exercise promotes adaptations to striatal adenosine systems. Exercise-reduced A1R and A2AR and exercise-increased D2R protein levels may contribute to improved dopaminergic signaling in the striatum. These findings may have implications for cognitive and behavioral processes, as well as motor and psychiatric diseases that involve the striatum.
Journal Article
The Influence of Stress and Binge-Patterned Alcohol Drinking on Mouse Skeletal Muscle Protein Synthesis and Degradation Pathways
by
Reed, Carter H
,
Clark, Peter J.
,
Bauer, Ella E.
in
AKT protein
,
Alcohol Drinking - metabolism
,
Alcohol use
2024
Adverse experiences (e.g., acute stress) and alcohol misuse can both impair skeletal muscle homeostasis, resulting in reduced protein synthesis and greater protein breakdown. Exposure to acute stress is a significant risk factor for engaging in alcohol misuse. However, little is known about how these factors together might further affect skeletal muscle health. To that end, this study investigated the effects of acute stress exposure followed by a period of binge-patterned alcohol drinking on signaling factors along mouse skeletal muscle protein synthesis (MPS) and degradation (MPD) pathways. Young adult male C57BL/6J mice participated in the Drinking in the Dark paradigm, where they received 2–4 h of access to 20% ethanol (alcohol group) or water (control group) for four days to establish baseline drinking levels. Three days later, half of the mice in each group were either exposed to a single episode of uncontrollable tail shocks (acute stress) or remained undisturbed in their home cages (no stress). Three days after stress exposure, mice received 4 h of access to 20% ethanol (alcohol) to model binge-patterned alcohol drinking or water for ten consecutive days. Immediately following the final episode of alcohol access, mouse gastrocnemius muscle was extracted to measure changes in relative protein levels along the Akt-mTOR MPS, as well as the ubiquitin-proteasome pathway (UPP) and autophagy MPD pathways via Western blotting. A single exposure to acute stress impaired Akt singling and reduced rates of MPS, independent of alcohol access. This observation was concurrent with a potent increase in heat shock protein seventy expression in the muscle of stressed mice. Alcohol drinking did not exacerbate stress-induced alterations in the MPS and MPD signaling pathways. Instead, changes in the MPS and MPD signaling factors due to alcohol access were primarily observed in non-stressed mice. Taken together, these data suggest that exposure to a stressor of sufficient intensity may cause prolonged disruptions to signaling factors that impact skeletal muscle health and function beyond what could be further induced by periods of alcohol misuse.
Journal Article
The Influence of Moderate Physical Activity on Brain Monoaminergic Responses to Binge-Patterned Alcohol Ingestion in Female Mice
2021
Monoamine neurotransmitter activity in brain reward, limbic, and motor areas play key roles in the motivation to misuse alcohol and can become modified by exercise in a manner that may affect alcohol craving. This study investigated the influence of daily moderate physical activity on monoamine-related neurochemical concentrations across the mouse brain in response to high volume ethanol ingestion. Adult female C57BL/6J mice were housed with or without 2.5 h of daily access to running wheels for 30 days. On the last 5 days, mice participated in the voluntary binge-like ethanol drinking procedure, “Drinking in the dark” (DID). Mice were sampled immediately following the final episode of DID. Monoamine-related neurochemical concentrations were measured across brain regions comprising reward, limbic, and motor circuits using ultra High-Performance Liquid Chromatography (UHPLC). The results suggest that physical activity status did not influence ethanol ingestion during DID. Moreover, daily running wheel access only mildly influenced alcohol-related norepinephrine concentrations in the hypothalamus and prefrontal cortex, as well as serotonin turnover in the hippocampus. However, access to alcohol during DID eliminated wheel running-related decreases of norepinephrine, serotonin, and 5-HIAA content in the hypothalamus, but also to a lesser extent for norepinephrine in the hippocampus and caudal cortical areas. Finally, alcohol access increased serotonin and dopamine-related neurochemical turnover in the striatum and brainstem areas, regardless of physical activity status. Together, these data provide a relatively thorough assessment of monoamine-related neurochemical levels across the brain in response to voluntary binge-patterned ethanol drinking, but also adds to a growing body of research questioning the utility of moderate physical activity as an intervention to curb alcohol abuse.
Journal Article
Corrigendum: The Influence of Moderate Physical Activity on Brain Monoaminergic Responses to Binge-Patterned Alcohol Ingestion in Female Mice
by
Reed, Carter H.
,
Clark, Peter J.
,
Buhr, Trevor J.
in
alcohol abuse
,
Behavioral Neuroscience
,
drinking in the dark
2021
[...]in the original article, there was an error in the “Drinking Data” paragraph of the Results section. [...]wheel access did not influence the amounts of fluids ingested independent of fluid type (F(1,32) = 2.87, p = 0.11), or while considering day and fluid type (F(4,123) = 0.52, p = 0.72).” Comparison between the average amount of fluid ingested (±SEM) over the 5-day DID procedure (relative to body mass) for mice that had access to alcohol and water (A) and total ethanol intake (relative to body mass) during the final DID session (B). *P < 0.05 Main effect of day, nsP > 0.05 between Run/Alcohol and Sed/Alcohol.
Journal Article
The effects of voluntary binge-patterned ethanol ingestion and daily wheel running on signaling of muscle protein synthesis and degradation in female mice
2022
Excessive ethanol ingestion can reduce skeletal muscle protein synthesis (MPS) through the disruption of signaling along the Akt-mTOR pathway and increase muscle protein degradation (MPD) through the Ubiquitin Proteasome Pathway (UPP) and autophagy. Identification of interventions that curb the disrupting effects of alcohol misuse on MPS and MPD are of central importance for the prevention of chronic health complications that arise from muscle loss. Physical activity is one potential strategy to combat the deleterious effects of alcohol on skeletal muscle. Therefore, the purpose of this study was to investigate the interaction between daily wheel running and binge-patterned ethanol consumption, through episodes of voluntary binge-patterned ethanol drinking, on signaling factors along the Akt-mTOR, Ubiquitin-Proteasome, and autophagy pathways. Adult female C57BL/6J mice received daily access to cages with or without running wheels for 2.5 h/day for five weeks. During the final five days of the study, mice received 2–4 h of daily access to sipper tubes containing water (n = 14 sedentary; n = 15 running) or 20% ethanol (n = 14 sedentary; n = 16 running) 30 min after running wheel access, using the “Drinking in the Dark” (DID) model of binge-patterned ethanol consumption. Immediately after the final episode of DID, gastrocnemius muscle was extracted. Western blotting was performed to measure proteins along Akt-mTOR, Ubiquitin-Proteasome, and autophagy pathways, and PCR was used to assess mRNA expression of atrogenes. Ethanol access increased expression of MAFbx by 82% (p = 0.048), but did not robustly influence Akt-mTOR or UPP signaling. Daily wheel access did not prevent alcohol-induced MAFbx expression; however, ethanol access decreased the phosphorylation of p70S6K by 45% in running mice (p = 0.020). These results suggest that physical activity may be insufficient to prevent alcohol-induced changes to signaling factors along pathways involved in muscle loss. Instead, binge-patterned ethanol ingestion may impair the benefits of physical activity on factors involved in MPS.
•Voluntary binge-patterned drinking increases mRNA expression of the E3 ligase MAFbx.•Binge-patterned drinking does not alter Akt/mTOR in skeletal muscle of female mice.•In wheel-running mice, binge-patterned drinking suppresses p70S6K phosphorylation.•Wheel running does not protect skeletal muscle from ethanol-induced perturbations.
Journal Article
The Influence of Binge Drinking on Skeletal Muscle Signaling Pathways and Exercise Performance
2023
Skeletal muscle mass is a very active tissue involved in processes such as glucose homeostasis, locomotion, and maintaining a high quality of life. Additionally, skeletal muscle interacts with many other biological systems and a loss in health and function of skeletal muscle, called myopathy, can lead to a reduction in quality of life. For these reasons, much work has characterized the effects of negative regulators of muscle mass such as disease, malnutrition, and aging to develop strategies to protect skeletal muscle. Chronic alcohol misuse is one negative regulator of skeletal muscle mass. However, the effects of binge drinking, a common form of alcohol misuse consumption characterized by an increase in blood alcohol concentrations to above 0.08 g/dL in a short period of time, on skeletal muscle have yet to be thoroughly explored.The objective of the work described in this dissertation is therefore three-fold. First, I sought to characterize the patterns of signaling dysregulation resulting from binge drinking in the context of stress. Adverse experiences can often precipitate binge drinking, yet the influence of the toxic combination on muscle protein synthesis and degradation signaling in skeletal muscle are not understood. Mounting evidence suggests alcohol misuse can disrupt proteostasis in skeletal muscle, however, identifying a possible therapeutic to protect skeletal muscle against these perturbations remains unexplored. Daily physical activity can positively influence pathways typically perturbed by alcohol misuse; therefore the second objective was to examine if daily physical activity could protect skeletal muscle against ethanol-induced signaling dysregulation. Varying reports suggest alcohol consumption following exercise may augment decrements in measures of performance when alcohol is consumed after a damaging bout of exercise. Thus, the final objective of this work was to explore the interaction between postexercise alcohol consumption and reductions in exercise performance.The first research study in this dissertation evaluated the influence of stress exposure and binge drinking on muscle protein synthesis and degradation signaling in skeletal muscle. Using the “Drinking in the Dark” (DID) paradigm, a behavioral assay modeling voluntary binge-patterned ethanol ingestion using rodents. During DID, mice consume 20% ethanol increasing blood alcohol concentration (BAC) to 0.08 g/dL within a 2-hour period. After 4 days of DID, mice were exposed to an acute episode of inescapable tail shocks, then completed 10 additional days of binge-patterned drinking. Gastrocnemius muscle was collected and several signaling pathways influencing muscle protein balance were assessed. Notably, acute stress exposure resulted in persistent depressions in rates of muscle protein synthesis and signaling along the Akt-mTOR pathway of protein synthesis. Stress exposure also increased markers of cellular stress in gastrocnemius muscle. Moreover, binge-patterned drinking also resulted in dysregulation of the Akt-mTOR pathway. Finally, there were no notable interactions between stress exposure and binge-patterned drinking. Taken together, these data suggest that exposure to a stressor of sufficient intensity may cause lasting disruptions to muscle homeostasis, beyond what can further by detected by high volume alcohol ingestion. The second study also examined the effects of binge drinking on signaling pathways in skeletal muscle while also evaluating the influence of daily physical activity on protecting skeletal muscle from ethanol-induced perturbations. Mice had 2.5 h of daily wheel running access for one month and then underwent five days of the “Drinking in the Dark” paradigm during the fifth and final week of the study. Binge-patterned drinking resulted in an increase in mRNA involved in protein degradation, and instead of observing physical activity protecting skeletal muscle against signaling dysregulation, binge-patterned drinking blunted possible exercise-induced adaptations. These observations provide insights into the use of physical activity as a preventative strategy to combat ethanol-induced disruptions to skeletal muscle and suggest binge-patterned drinking induces some notable disruptions in muscle protein synthesis and degradation signaling. The third study examined the influence of postexercise alcohol consumption on decrements in exercise performance. Ten male and 10 female participants completed baseline testing and 30 min of downhill running to induce muscle damage. Participants then consumed either a non-alcohol containing placebo beverage, or an alcohol containing beverage and returned to the lab 24 h later to repeat testing measures. This protocol was then repeated after a washout period and participants consumed whichever beverage they did not consume during the prior visit. Notably, post exercise alcohol consumption exacerbated the decrease in agility exercise performance, muscular work, and several measures of peak torque measured 24 h after a damaging bout of exercise. Moreover, postexercise alcohol consumption tended to increase markers of muscle damage compared to consumption of a placebo beverage. Both exercise performance and biochemical perturbations were similar in male and female participants. These data suggest alcohol consumption may augment declines in agility and maximal voluntary force production induced by eccentric exercise and that both males and females may be susceptible to these deleterious effects. Taken together, the studies in this dissertation demonstrate that binge drinking can disrupt signaling related to skeletal muscle proteostasis. Further, exposure to adverse experiences may result in persistent reductions in muscle protein synthesis and modulation of autophagy, but binge-patterned drinking in the context of acute stress exposure may not result in further disruption. Development of strategies to protect skeletal muscle against ethanol-induced perturbations have yet to be developed. Although the findings from this dissertation suggest physical activity may not protect skeletal muscle signaling pathways against binge-like alcohol ingestion, however, binge-patterned drinking may impair the benefits of physical activity. Finally, alcohol consumption following eccentric exercise may increase several indirect markers of muscle damage, resulting in reduced agility performance and muscular performance.
Dissertation
A real-time electronic symptom monitoring system for patients after discharge following surgery: a pilot study in cancer-related surgery
2020
Background
Advances in peri-operative care of surgical oncology patients result in shorter hospital stays. Earlier discharge may bring benefits, but complications can occur while patients are recovering at home. Electronic patient-reported outcome (ePRO) systems may enhance remote, real-time symptom monitoring and detection of complications after hospital discharge, thereby improving patient safety and outcomes. Evidence of the effectiveness of ePRO systems in surgical oncology is lacking. This pilot study evaluated the feasibility of a real-time electronic symptom monitoring system for patients after discharge following cancer-related upper gastrointestinal surgery.
Methods
A pilot study in two UK hospitals included patients who had undergone cancer-related upper gastrointestinal surgery. Participants completed the ePRO symptom-report at discharge, twice in the first week and weekly post-discharge. Symptom-report completeness, system actions, barriers to using the ePRO system and technical performance were examined. The ePRO surgery system is an online symptom-report that allows clinicians to view patient symptom-reports within hospital electronic health records and was developed as part of the eRAPID project. Clinically derived algorithms provide patients with tailored self-management advice, prompts to contact a clinician or automated clinician alerts depending on symptom severity. Interviews with participants and clinicians determined the acceptability of the ePRO system to support patients and their clinical management during recovery.
Results
Ninety-one patients were approached, of which 40 consented to participate (27 male, mean age 64 years). Symptom-report response rates were high (range 63–100%). Of 197 ePRO completions analysed, 76 (39%) triggered self-management advice, 72 (36%) trigged advice to contact a clinician, 9 (5%) triggered a clinician alert and 40 (20%) did not require advice. Participants found the ePRO system reassuring, providing timely information and advice relevant to supporting their recovery. Clinicians regarded the system as a useful adjunct to usual care, by signposting patients to seek appropriate help and enhancing their understanding of patients’ experiences during recovery.
Conclusion
Use of the ePRO system for the real-time, remote monitoring of symptoms in patients recovering from cancer-related upper gastrointestinal surgery is feasible and acceptable. A definitive randomised controlled trial is needed to evaluate the impact of the system on patients’ wellbeing after hospital discharge.
Journal Article
Forecasting life expectancy, years of life lost, and all-cause and cause-specific mortality for 250 causes of death: reference and alternative scenarios for 2016–40 for 195 countries and territories
by
Marquez, Neal
,
Brown, Jonathan C
,
Dolgert, Andrew
in
Acquired immune deficiency syndrome
,
Aging
,
AIDS
2018
Understanding potential trajectories in health and drivers of health is crucial to guiding long-term investments and policy implementation. Past work on forecasting has provided an incomplete landscape of future health scenarios, highlighting a need for a more robust modelling platform from which policy options and potential health trajectories can be assessed. This study provides a novel approach to modelling life expectancy, all-cause mortality and cause of death forecasts —and alternative future scenarios—for 250 causes of death from 2016 to 2040 in 195 countries and territories.
We modelled 250 causes and cause groups organised by the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) hierarchical cause structure, using GBD 2016 estimates from 1990–2016, to generate predictions for 2017–40. Our modelling framework used data from the GBD 2016 study to systematically account for the relationships between risk factors and health outcomes for 79 independent drivers of health. We developed a three-component model of cause-specific mortality: a component due to changes in risk factors and select interventions; the underlying mortality rate for each cause that is a function of income per capita, educational attainment, and total fertility rate under 25 years and time; and an autoregressive integrated moving average model for unexplained changes correlated with time. We assessed the performance by fitting models with data from 1990–2006 and using these to forecast for 2007–16. Our final model used for generating forecasts and alternative scenarios was fitted to data from 1990–2016. We used this model for 195 countries and territories to generate a reference scenario or forecast through 2040 for each measure by location. Additionally, we generated better health and worse health scenarios based on the 85th and 15th percentiles, respectively, of annualised rates of change across location-years for all the GBD risk factors, income per person, educational attainment, select intervention coverage, and total fertility rate under 25 years in the past. We used the model to generate all-cause age-sex specific mortality, life expectancy, and years of life lost (YLLs) for 250 causes. Scenarios for fertility were also generated and used in a cohort component model to generate population scenarios. For each reference forecast, better health, and worse health scenarios, we generated estimates of mortality and YLLs attributable to each risk factor in the future.
Globally, most independent drivers of health were forecast to improve by 2040, but 36 were forecast to worsen. As shown by the better health scenarios, greater progress might be possible, yet for some drivers such as high body-mass index (BMI), their toll will rise in the absence of intervention. We forecasted global life expectancy to increase by 4·4 years (95% UI 2·2 to 6·4) for men and 4·4 years (2·1 to 6·4) for women by 2040, but based on better and worse health scenarios, trajectories could range from a gain of 7·8 years (5·9 to 9·8) to a non-significant loss of 0·4 years (–2·8 to 2·2) for men, and an increase of 7·2 years (5·3 to 9·1) to essentially no change (0·1 years [–2·7 to 2·5]) for women. In 2040, Japan, Singapore, Spain, and Switzerland had a forecasted life expectancy exceeding 85 years for both sexes, and 59 countries including China were projected to surpass a life expectancy of 80 years by 2040. At the same time, Central African Republic, Lesotho, Somalia, and Zimbabwe had projected life expectancies below 65 years in 2040, indicating global disparities in survival are likely to persist if current trends hold. Forecasted YLLs showed a rising toll from several non-communicable diseases (NCDs), partly driven by population growth and ageing. Differences between the reference forecast and alternative scenarios were most striking for HIV/AIDS, for which a potential increase of 120·2% (95% UI 67·2–190·3) in YLLs (nearly 118 million) was projected globally from 2016–40 under the worse health scenario. Compared with 2016, NCDs were forecast to account for a greater proportion of YLLs in all GBD regions by 2040 (67·3% of YLLs [95% UI 61·9–72·3] globally); nonetheless, in many lower-income countries, communicable, maternal, neonatal, and nutritional (CMNN) diseases still accounted for a large share of YLLs in 2040 (eg, 53·5% of YLLs [95% UI 48·3–58·5] in Sub-Saharan Africa). There were large gaps for many health risks between the reference forecast and better health scenario for attributable YLLs. In most countries, metabolic risks amenable to health care (eg, high blood pressure and high plasma fasting glucose) and risks best targeted by population-level or intersectoral interventions (eg, tobacco, high BMI, and ambient particulate matter pollution) had some of the largest differences between reference and better health scenarios. The main exception was sub-Saharan Africa, where many risks associated with poverty and lower levels of development (eg, unsafe water and sanitation, household air pollution, and child malnutrition) were projected to still account for substantive disparities between reference and better health scenarios in 2040.
With the present study, we provide a robust, flexible forecasting platform from which reference forecasts and alternative health scenarios can be explored in relation to a wide range of independent drivers of health. Our reference forecast points to overall improvements through 2040 in most countries, yet the range found across better and worse health scenarios renders a precarious vision of the future—a world with accelerating progress from technical innovation but with the potential for worsening health outcomes in the absence of deliberate policy action. For some causes of YLLs, large differences between the reference forecast and alternative scenarios reflect the opportunity to accelerate gains if countries move their trajectories toward better health scenarios—or alarming challenges if countries fall behind their reference forecasts. Generally, decision makers should plan for the likely continued shift toward NCDs and target resources toward the modifiable risks that drive substantial premature mortality. If such modifiable risks are prioritised today, there is opportunity to reduce avoidable mortality in the future. However, CMNN causes and related risks will remain the predominant health priority among lower-income countries. Based on our 2040 worse health scenario, there is a real risk of HIV mortality rebounding if countries lose momentum against the HIV epidemic, jeopardising decades of progress against the disease. Continued technical innovation and increased health spending, including development assistance for health targeted to the world's poorest people, are likely to remain vital components to charting a future where all populations can live full, healthy lives.
Bill & Melinda Gates Foundation.
Journal Article
Pandemic preparedness and COVID-19: an exploratory analysis of infection and fatality rates, and contextual factors associated with preparedness in 177 countries, from Jan 1, 2020, to Sept 30, 2021
by
Kiernan, Samantha
,
Wiysonge, Charles Shey
,
Erickson, Megan
in
Age composition
,
Age Distribution
,
Air pollution
2022
National rates of COVID-19 infection and fatality have varied dramatically since the onset of the pandemic. Understanding the conditions associated with this cross-country variation is essential to guiding investment in more effective preparedness and response for future pandemics.
Daily SARS-CoV-2 infections and COVID-19 deaths for 177 countries and territories and 181 subnational locations were extracted from the Institute for Health Metrics and Evaluation's modelling database. Cumulative infection rate and infection-fatality ratio (IFR) were estimated and standardised for environmental, demographic, biological, and economic factors. For infections, we included factors associated with environmental seasonality (measured as the relative risk of pneumonia), population density, gross domestic product (GDP) per capita, proportion of the population living below 100 m, and a proxy for previous exposure to other betacoronaviruses. For IFR, factors were age distribution of the population, mean body-mass index (BMI), exposure to air pollution, smoking rates, the proxy for previous exposure to other betacoronaviruses, population density, age-standardised prevalence of chronic obstructive pulmonary disease and cancer, and GDP per capita. These were standardised using indirect age standardisation and multivariate linear models. Standardised national cumulative infection rates and IFRs were tested for associations with 12 pandemic preparedness indices, seven health-care capacity indicators, and ten other demographic, social, and political conditions using linear regression. To investigate pathways by which important factors might affect infections with SARS-CoV-2, we also assessed the relationship between interpersonal and governmental trust and corruption and changes in mobility patterns and COVID-19 vaccination rates.
The factors that explained the most variation in cumulative rates of SARS-CoV-2 infection between Jan 1, 2020, and Sept 30, 2021, included the proportion of the population living below 100 m (5·4% [4·0–7·9] of variation), GDP per capita (4·2% [1·8–6·6] of variation), and the proportion of infections attributable to seasonality (2·1% [95% uncertainty interval 1·7–2·7] of variation). Most cross-country variation in cumulative infection rates could not be explained. The factors that explained the most variation in COVID-19 IFR over the same period were the age profile of the country (46·7% [18·4–67·6] of variation), GDP per capita (3·1% [0·3–8·6] of variation), and national mean BMI (1·1% [0·2–2·6] of variation). 44·4% (29·2–61·7) of cross-national variation in IFR could not be explained. Pandemic-preparedness indices, which aim to measure health security capacity, were not meaningfully associated with standardised infection rates or IFRs. Measures of trust in the government and interpersonal trust, as well as less government corruption, had larger, statistically significant associations with lower standardised infection rates. High levels of government and interpersonal trust, as well as less government corruption, were also associated with higher COVID-19 vaccine coverage among middle-income and high-income countries where vaccine availability was more widespread, and lower corruption was associated with greater reductions in mobility. If these modelled associations were to be causal, an increase in trust of governments such that all countries had societies that attained at least the amount of trust in government or interpersonal trust measured in Denmark, which is in the 75th percentile across these spectrums, might have reduced global infections by 12·9% (5·7–17·8) for government trust and 40·3% (24·3–51·4) for interpersonal trust. Similarly, if all countries had a national BMI equal to or less than that of the 25th percentile, our analysis suggests global standardised IFR would be reduced by 11·1%.
Efforts to improve pandemic preparedness and response for the next pandemic might benefit from greater investment in risk communication and community engagement strategies to boost the confidence that individuals have in public health guidance. Our results suggest that increasing health promotion for key modifiable risks is associated with a reduction of fatalities in such a scenario.
Bill & Melinda Gates Foundation, J Stanton, T Gillespie, J and E Nordstrom, and Bloomberg Philanthropies.
Journal Article