Effects of elevated systolic blood pressure on ischemic heart disease: a Burden of Proof study

Comparison of hypotension incidence between remimazolam and propofol in patients with hypertension undergoing neurosurgery: prospective, randomized, single-blind trial

BACKGROUND

Remimazolam, a newer benzodiazepine that targets the GABAA receptor, is thought to allow more stable blood pressure management during anesthesia induction. In contrast, propofol is associated with vasodilatory effects and an increased risk of hypotension, particularly in patients with comorbidities. This study aimed to identify medications that can maintain stable vital signs throughout the induction phase.

METHODS

We conducted a single-center, two-group, randomized controlled trial to investigate and compare the incidence of hypotension between remimazolam- and propofol-based total intravenous anesthesia (TIVA). We selected patients aged between 19 and 75 years scheduled for neurosurgery under general anesthesia, who were classified as American Society of Anesthesiologists Physical Status I-III and had a history of hypertension.

RESULTS

We included 94 patients in the final analysis. The incidence of hypotension was higher in the propofol group (91.3%) than in the remimazolam group (85.4%; P = 0.057). There was no significant difference in the incidence of hypotension among the various antihypertensive medications despite the majority of patients being on multiple medications. In comparison with the propofol group, the remimazolam group demonstrated a higher heart rate immediately after intubation.

CONCLUSIONS

Our study indicated that the hypotension incidence of remimazolam-based TIVA was comparable to that of propofol-based TIVA throughout the induction phase of EEG-guided anesthesia. Both remimazolam and propofol may be equally suitable for general anesthesia in patients undergoing neurosurgery.

TRIAL REGISTRATION

Clinicaltrials.gov (NCT05164146).

Global burden and strength of evidence for 88 risk factors in 204 countries and 811 subnational locations, 1990-2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND

Understanding the health consequences associated with exposure to risk factors is necessary to inform public health policy and practice. To systematically quantify the contributions of risk factor exposures to specific health outcomes, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 aims to provide comprehensive estimates of exposure levels, relative health risks, and attributable burden of disease for 88 risk factors in 204 countries and territories and 811 subnational locations, from 1990 to 2021.

METHODS

The GBD 2021 risk factor analysis used data from 54 561 total distinct sources to produce epidemiological estimates for 88 risk factors and their associated health outcomes for a total of 631 risk-outcome pairs. Pairs were included on the basis of data-driven determination of a risk-outcome association. Age-sex-location-year-specific estimates were generated at global, regional, and national levels. Our approach followed the comparative risk assessment framework predicated on a causal web of hierarchically organised, potentially combinative, modifiable risks. Relative risks (RRs) of a given outcome occurring as a function of risk factor exposure were estimated separately for each risk-outcome pair, and summary exposure values (SEVs), representing risk-weighted exposure prevalence, and theoretical minimum risk exposure levels (TMRELs) were estimated for each risk factor. These estimates were used to calculate the population attributable fraction (PAF; ie, the proportional change in health risk that would occur if exposure to a risk factor were reduced to the TMREL). The product of PAFs and disease burden associated with a given outcome, measured in disability-adjusted life-years (DALYs), yielded measures of attributable burden (ie, the proportion of total disease burden attributable to a particular risk factor or combination of risk factors). Adjustments for mediation were applied to account for relationships involving risk factors that act indirectly on outcomes via intermediate risks. Attributable burden estimates were stratified by Socio-demographic Index (SDI) quintile and presented as counts, age-standardised rates, and rankings. To complement estimates of RR and attributable burden, newly developed burden of proof risk function (BPRF) methods were applied to yield supplementary, conservative interpretations of risk-outcome associations based on the consistency of underlying evidence, accounting for unexplained heterogeneity between input data from different studies. Estimates reported represent the mean value across 500 draws from the estimate's distribution, with 95% uncertainty intervals (UIs) calculated as the 2·5th and 97·5th percentile values across the draws.

FINDINGS

Among the specific risk factors analysed for this study, particulate matter air pollution was the leading contributor to the global disease burden in 2021, contributing 8·0% (95% UI 6·7-9·4) of total DALYs, followed by high systolic blood pressure (SBP; 7·8% [6·4-9·2]), smoking (5·7% [4·7-6·8]), low birthweight and short gestation (5·6% [4·8-6·3]), and high fasting plasma glucose (FPG; 5·4% [4·8-6·0]). For younger demographics (ie, those aged 0-4 years and 5-14 years), risks such as low birthweight and short gestation and unsafe water, sanitation, and handwashing (WaSH) were among the leading risk factors, while for older age groups, metabolic risks such as high SBP, high body-mass index (BMI), high FPG, and high LDL cholesterol had a greater impact. From 2000 to 2021, there was an observable shift in global health challenges, marked by a decline in the number of all-age DALYs broadly attributable to behavioural risks (decrease of 20·7% [13·9-27·7]) and environmental and occupational risks (decrease of 22·0% [15·5-28·8]), coupled with a 49·4% (42·3-56·9) increase in DALYs attributable to metabolic risks, all reflecting ageing populations and changing lifestyles on a global scale. Age-standardised global DALY rates attributable to high BMI and high FPG rose considerably (15·7% [9·9-21·7] for high BMI and 7·9% [3·3-12·9] for high FPG) over this period, with exposure to these risks increasing annually at rates of 1·8% (1·6-1·9) for high BMI and 1·3% (1·1-1·5) for high FPG. By contrast, the global risk-attributable burden and exposure to many other risk factors declined, notably for risks such as child growth failure and unsafe water source, with age-standardised attributable DALYs decreasing by 71·5% (64·4-78·8) for child growth failure and 66·3% (60·2-72·0) for unsafe water source. We separated risk factors into three groups according to trajectory over time: those with a decreasing attributable burden, due largely to declining risk exposure (eg, diet high in trans-fat and household air pollution) but also to proportionally smaller child and youth populations (eg, child and maternal malnutrition); those for which the burden increased moderately in spite of declining risk exposure, due largely to population ageing (eg, smoking); and those for which the burden increased considerably due to both increasing risk exposure and population ageing (eg, ambient particulate matter air pollution, high BMI, high FPG, and high SBP).

INTERPRETATION

Substantial progress has been made in reducing the global disease burden attributable to a range of risk factors, particularly those related to maternal and child health, WaSH, and household air pollution. Maintaining efforts to minimise the impact of these risk factors, especially in low SDI locations, is necessary to sustain progress. Successes in moderating the smoking-related burden by reducing risk exposure highlight the need to advance policies that reduce exposure to other leading risk factors such as ambient particulate matter air pollution and high SBP. Troubling increases in high FPG, high BMI, and other risk factors related to obesity and metabolic syndrome indicate an urgent need to identify and implement interventions.

FUNDING

Bill & Melinda Gates Foundation.

Optimal Medical Therapy for Stable Ischemic Heart Disease in 2024: Focus on Blood Pressure and Lipids

Hypertension and dyslipidemia are 2 highly prevalent and modifiable risk factors in patients with stable ischemic heart disease. Multiple lines of evidence demonstrate that lowering blood pressure and low-density lipoprotein cholesterol improves clinical outcomes in patients with ischemic heart disease. Accordingly, clinical guidelines recommend intensive treatment targets for these high-risk patients. This article summarizes the pathophysiology, supporting evidence, and treatment recommendations for management of hypertension and dyslipidemia among patients with manifest ischemic heart disease and points to future research and unmet clinical needs.

Design, synthesis, and biological evaluation of some new 2-phenyl-3,6-pyridazinedione derivatives as PDE-5 inhibitors

Various 2-phenyl-3,6-pyridazinedione derivatives 4a-j, 5a-c, 6a,b, 7a-c, 8, 9, 10a-d, and 11a-d, were effectivelysynthesized, and tested for their potential inhibition of phosphodiesterase enzyme at 10 µM. Then fourteen compounds exhibiting the highest inhibition 4b, 4d, 4e, 4g, 4h, 4i, 5a, 6a,b, 7c, 10a,b, 11a, and 11d were selected for screening their PDE-5 inhibition, where compounds 4b,g,h, and 11a revealed promising PDE-5 inhibition having IC50 values = 25, 53, 22, and 42 nM, respectively in comparison with Sildenafil (IC50 = 16 nM). Additionally, these four most active compounds were safe to normal fibroblast cell line WI-38. Moreover, 4f, 4h, 4j, 10d, and 11d had almost the same anti-proliferative effect against the aortic cell line as Sildenafil. Furthermore, molecular docking illustrated that the binding of the target compounds with the key amino acids in the binding site of PDE-5 (PDB 2H42) was like to that of the cocrystallized ligand Sildenafil. Additionally, molecular dynamics simulation for the most active compound 4h revealed high stability of the 4h -PDE5 complex explaining its promising activity as a PDE-5 inhibitor. Therefore, the 2-phenyl-3,6-pyridazinedione scaffold can be considered an important core for designing more promising PDE-5 inhibitors.

Hypertension: Causes and Consequences of Circadian Rhythms in Blood Pressure

Hypertension is extremely common, affecting approximately 1 in every 2 adults globally. Chronic hypertension is the leading modifiable risk factor for cardiovascular disease and premature mortality worldwide. Despite considerable efforts to define mechanisms that underlie hypertension, a potentially major component of the disease, the role of circadian biology has been relatively overlooked in both preclinical models and humans. Although the presence of daily and circadian patterns has been observed from the level of the genome to the whole organism, the functional and structural impact of biological rhythms, including mechanisms such as circadian misalignment, remains relatively poorly defined. Here, we review the impact of daily rhythms and circadian systems in regulating blood pressure and the onset, progression, and consequences of hypertension. There is an emphasis on the impact of circadian biology in relation to vascular disease and end-organ effects that, individually or in combination, contribute to complex phenotypes such as cognitive decline and the loss of cardiac and brain health. Despite effective treatment options for some individuals, control of blood pressure remains inadequate in a substantial portion of the hypertensive population. Greater insight into circadian biology may form a foundation for novel and more widely effective molecular therapies or interventions to help in the prevention, treatment, and management of hypertension and its related pathophysiology.

Health effects associated with chewing tobacco: a Burden of Proof study

Chewing tobacco use poses serious health risks; yet it has not received as much attention as other tobacco-related products. This study synthesizes existing evidence regarding the health impacts of chewing tobacco while accounting for various sources of uncertainty. We conducted a systematic review and meta-analysis of chewing tobacco and seven health outcomes, drawing on 103 studies published from 1970 to 2023. We use a Burden of Proof meta-analysis to generate conservative risk estimates and find weak-to-moderate evidence that tobacco chewers have an increased risk of stroke, lip and oral cavity cancer, esophageal cancer, nasopharynx cancer, other pharynx cancer, and laryngeal cancer. We additionally find insufficient evidence of an association between chewing tobacco and ischemic heart disease. Our findings highlight a need for policy makers, researchers, and communities at risk to devote greater attention to chewing tobacco by both advancing tobacco control efforts and investing in strengthening the existing evidence base.

Health effects associated with exposure to secondhand smoke: a Burden of Proof study

Despite a gradual decline in smoking rates over time, exposure to secondhand smoke (SHS) continues to cause harm to nonsmokers, who are disproportionately children and women living in low- and middle-income countries. We comprehensively reviewed the literature published by July 2022 concerning the adverse impacts of SHS exposure on nine health outcomes. Following, we quantified each exposure-response association accounting for various sources of uncertainty and evaluated the strength of the evidence supporting our analyses using the Burden of Proof Risk Function methodology. We found all nine health outcomes to be associated with SHS exposure. We conservatively estimated that SHS increases the risk of ischemic heart disease, stroke, type 2 diabetes and lung cancer by at least around 8%, 5%, 1% and 1%, respectively, with the evidence supporting these harmful associations rated as weak (two stars). The evidence supporting the harmful associations between SHS and otitis media, asthma, lower respiratory infections, breast cancer and chronic obstructive pulmonary disease was weaker (one star). Despite the weak underlying evidence for these associations, our results reinforce the harmful effects of SHS on health and the need to prioritize advancing efforts to reduce active and passive smoking through a combination of public health policies and education initiatives.

Mechanisms and treatment of obesity-related hypertension-Part 1: Mechanisms

The prevalence of obesity has tripled over the past five decades. Obesity, especially visceral obesity, is closely related to hypertension, increasing the risk of primary (essential) hypertension by 65%-75%. Hypertension is a major risk factor for cardiovascular disease, the leading cause of death worldwide, and its prevalence is rapidly increasing following the pandemic rise in obesity. Although the causal relationship between obesity and high blood pressure (BP) is well established, the detailed mechanisms for such association are still under research. For more than 30 years sympathetic nervous system (SNS) and kidney sodium reabsorption activation, secondary to insulin resistance and compensatory hyperinsulinemia, have been considered as primary mediators of elevated BP in obesity. However, experimental and clinical data show that severe insulin resistance and hyperinsulinemia can occur in the absence of elevated BP, challenging the causal relationship between insulin resistance and hyperinsulinemia as the key factor linking obesity to hypertension. The purpose of Part 1 of this review is to summarize the available data on recently emerging mechanisms believed to contribute to obesity-related hypertension through increased sodium reabsorption and volume expansion, such as: physical compression of the kidney by perirenal/intrarenal fat and overactivation of the systemic/renal SNS and the renin-angiotensin-aldosterone system. The role of hyperleptinemia, impaired chemoreceptor and baroreceptor reflexes, and increased perivascular fat is also discussed. Specifically targeting these mechanisms may pave the way for a new therapeutic intervention in the treatment of obesity-related hypertension in the context of 'precision medicine' principles, which will be discussed in Part 2.

Cumulative Blood Pressure in Early Adulthood and Coronary Artery Calcium and Carotid Intima-Media Thickness in Middle Age Among Adults With Maintained Blood Pressure of <130/80 mm Hg: A Post Hoc Analysis

BACKGROUND

To examine the association of blood pressure (BP) levels with coronary artery calcium and carotid intima-media thickness (CIMT) in people with maintained BP below the hypertension range based on current definitions.

METHODS AND RESULTS

In this post hoc analysis of the CARDIA (Coronary Artery Risk Development in Young Adults) prospective observational cohort study conducted in 4 US cities, we examined 1233 study participants (mean [SD] age at year 20 examination was 45.3 [3.5] years; 65.4% women). Participants with BP assessments across 20 years and untreated BP of <130/80 mm Hg were included. Multivariable logistic or linear regression models, adjusted for age, sex, race, education, diabetes, body mass index, serum creatinine, smoking, alcohol intake, physical activity, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides, were used to examine the associations between cumulative BP measures with coronary artery calcium and CIMT. Higher long-term cumulative systolic BP and pulse pressure across early adulthood were associated with higher CIMT (both P<0.001) but not coronary artery calcium in the multivariable-adjusted model. The associations remained significant even after adjustment for a single BP measurement at year 0 or year 20. The odds ratio (OR) of a maximal CIMT >1.01 mm was ≈50% higher per 1-SD increase in systolic BP (OR, 1.50 [95% CI, 1.19-1.88]) and pulse pressure (OR, 1.46 [95% CI, 1.19-1.79]). Similar findings for CIMT were observed among individuals with a coronary artery calcium score of 0 as well as those with maintained BP of <120/80 mm Hg throughout young adulthood.

CONCLUSIONS

Long-term cumulative systolic BP and pulse pressure across early adulthood within the nonhypertensive range were associated with adverse midlife alterations in CIMT.

Health effects associated with exposure to intimate partner violence against women and childhood sexual abuse: a burden of proof study

The health impacts of intimate partner violence against women and childhood sexual abuse are not fully understood. Here we conducted a systematic review by comprehensively searching seven electronic databases for literature on intimate partner violence-associated and childhood sexual abuse-associated health effects. Following the burden of proof methodology, we evaluated the evidence strength linking intimate partner violence and/or childhood sexual abuse to health outcomes supported by at least three studies. Results indicated a moderate association of intimate partner violence with major depressive disorder and with maternal abortion and miscarriage (63% and 35% increased risk, respectively). HIV/AIDS, anxiety disorders and self-harm exhibited weak associations with intimate partner violence. Fifteen outcomes were evaluated for their relationship to childhood sexual abuse, which was shown to be moderately associated with alcohol use disorders and with self-harm (45% and 35% increased risk, respectively). Associations between childhood sexual abuse and 11 additional health outcomes, such as asthma and type 2 diabetes mellitus, were found to be weak. Although our understanding remains limited by data scarcity, these health impacts are larger in magnitude and more extensive than previously reported. Renewed efforts on violence prevention and evidence-based approaches that promote healing and ensure access to care are necessary.

Red Meat Consumption and Cancer Risk: A Systematic Analysis of Global Data

The association between red meat consumption and cancer risk remains a controversy. In this study, we systematically collected and analyzed global data (from Our World in Data and Global Cancer Observatory) to investigate this association for the first time. Our results confirmed significant positive associations between red meat consumption (RMC) and overall cancer incidence (0.798, p < 0.001), or colorectal cancer incidence (0.625, p < 0.001). Several previously unreported cancer types linked to RMC were also unveiled. Gross domestic product (GDP) per capita were found to have an impact on this association. However, even after controlling it, RMC remained significantly associated with cancer incidence (0.463, p < 0.001; 0.592, p < 0.001). Meanwhile, after controlling GDP per capita, the correlation coefficients between white meat consumption and overall cancer incidence were found to be much lower and insignificant, at 0.089 (p = 0.288) for poultry consumption and at -0.055 (p = 0.514) for seafood and fish consumption. Notably, an interesting comparison was performed between changes of colorectal cancer incidence and RMC in many countries and regions. A lag of 15-20 years was found, implying causality between RMC and cancer risk. Our findings will contribute to the development of more rational meat consumption concept.

Effects of curcumin on blood pressure: A systematic review and dose-response meta-analysis

AIMS

This systematic review and dose-response meta-analysis were conducted to summarize data from available clinical trials on the effects of curcumin supplementation on systolic BP (SBP) and diastolic BP (DBP).

DATA SYNTHESIS

Using related keywords, multiple databases, including the Web of Sciences, Scopus, Embase, PubMed, Cochrane Library, and Google Scholar, were searched until November 2022. We chose the studies that examined the effects of curcumin on systolic blood pressure (SBP) and diastolic blood pressure (DBP). Seventeen eligible studies with a total sample size of 1377 participants were included in the meta-analysis. The findings of the meta-analysis did not indicate any significant effect of curcumin on SBP (WMD = -0.06 mmHg, 95% CI: -0.62, 0.50, p = 0.85; I2 = 44.2%) and DBP (WMD = -0.18 mmHg, 95% CI: -1.17, 0.82, p = 0.62; I2 = 77.2%). Moreover, in our dose-response analysis, we found that the dose and duration of curcumin supplementation were non-significantly associated with the reduction of SBP and DBP. However, subgroup analysis revealed a significant reduction only in DBP levels (WMD: -0.76 mmHg, 95% CI: -1.46,-0.05; P = 0.03) but not in SBP in studies with ≥12-week supplementation. Also, a significant reduction in SBP (WMD: -1.55 mmHg, 95% CI: -2.85, -0.25; P = 0.01) and DBP (WMD: -1.73 mmHg, 95% CI: 2.67, -0.79; P < 0.01) was noticed by curcumin supplementation in studies performed on women.

CONCLUSIONS

The current study suggests that consuming curcumin may improve DBP when administered for long durations ≥12 weeks. However, more trials are required to confirm these findings.

Hypertensive Heart Failure

Despite overwhelming epidemiological evidence, the contribution of hypertension (HTN) to heart failure (HF) development has been undermined in current clinical practice. This is because approximately half of HF patients have been labeled as suffering from HF with preserved left ventricular (LV) ejection fraction (EF) (HFpEF), with HTN, obesity, and diabetes mellitus (DM) being considered virtually equally responsible for its development. However, this suggestion is obviously inaccurate, since HTN is by far the most frequent and devastating morbidity present in HFpEF. Further, HF development in obesity or DM is rare in the absence of HTN or coronary artery disease (CAD), whereas HTN often causes HF per se. Finally, unlike HTN, for most major comorbidities present in HFpEF, including anemia, chronic kidney disease, pulmonary disease, DM, atrial fibrillation, sleep apnea, and depression, it is unknown whether they precede HF or result from it. The purpose of this paper is to provide a contemporary overview on hypertensive HF, with a special emphasis on its inflammatory nature and association with autonomic nervous system (ANS) imbalance, since both are of pathophysiologic and therapeutic interest.

Effective Prediction of Mortality by Heart Disease Among Women in Jordan Using the Chi-Squared Automatic Interaction Detection Model: Retrospective Validation Study

BACKGROUND

Many current studies have claimed that the actual risk of heart disease among women is equal to that in men. Using a large machine learning algorithm (MLA) data set to predict mortality in women, data mining techniques have been used to identify significant aspects of variables that help in identifying the primary causes of mortality within this target category of the population.

OBJECTIVE

This study aims to predict mortality caused by heart disease among women, using an artificial intelligence technique-based MLA.

METHODS

A retrospective design was used to retrieve big data from the electronic health records of 2028 women with heart disease. Data were collected for Jordanian women who were admitted to public health hospitals from 2015 to the end of 2021. We checked the extracted data for noise, consistency issues, and missing values. After categorizing, organizing, and cleaning the extracted data, the redundant data were eliminated.

RESULTS

Out of 9 artificial intelligence models, the Chi-squared Automatic Interaction Detection model had the highest accuracy (93.25%) and area under the curve (0.825) among the build models. The participants were 62.6 (SD 15.4) years old on average. Angina pectoris was the most frequent diagnosis in the women's extracted files (n=1,264,000, 62.3%), followed by congestive heart failure (n=764,000, 37.7%). Age, systolic blood pressure readings with a cutoff value of >187 mm Hg, medical diagnosis (women diagnosed with congestive heart failure were at a higher risk of death [n=31, 16.58%]), pulse pressure with a cutoff value of 98 mm Hg, and oxygen saturation (measured using pulse oximetry) with a cutoff value of 93% were the main predictors for death among women.

CONCLUSIONS

To predict the outcomes in this study, we used big data that were extracted from the clinical variables from the electronic health records. The Chi-squared Automatic Interaction Detection model-an MLA-confirmed the precise identification of the key predictors of cardiovascular mortality among women and can be used as a practical tool for clinical prediction.

The Effect of Non-Surgical Periodontal Treatment on Patients with Combined Refractory Arterial Hypertension and Stage III, Grade B Periodontitis: A Preliminary Prospective Clinical Study

We sought to evaluate the effects of non-surgical periodontal treatment (NSPT) on periodontal clinical parameters, systemic blood pressure (BP), and plasma levels of systemic inflammation markers in patients with combined refractory arterial hypertension (RAH) and stage III grade B periodontitis. Twenty-seven participants with RAH and periodontitis received NSPT. The analyzed clinical parameters were probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PI). An assessment was performed for systemic BP, complete blood count, coagulogram, creatinine measurement, C-reactive protein (CRP), glycated hemoglobin, cholesterol, glutamic oxaloacetic transaminase, glutamate pyruvic transaminase, waist-hip ratio, and body mass index. In the follow-up period, twenty-two patients were evaluated at baseline and after 90 and 180 days. The data were submitted for statistical analysis (α = 0.05%). As expected, the clinical results showed a significant improvement in the percentages of PI, BOP, PD, and CAL, which were statistically significant at 90 and 180 days (p < 0.0001). Importantly, NSPT significantly reduced the blood level of CRP (p < 0.02). However, no significant reduction in BP parameters was noted in the evaluated follow-up periods. NSPT, despite the benefits in periodontal clinical parameters, reduced the plasma level of CRP but not the BP in patients with combined RAH and periodontitis.

Sortilin and hypertension

PURPOSE OF REVIEW

The current review aims to present the latest scientific updates on the role of Sortilin in the pathophysiology of hypertension.

RECENT FINDINGS

The main focus of this systematic overview is on the functional contribution of Sortilin to the pathogenesis of hypertension. Sortilin is a glycoprotein mostly known for its actions as a trafficking molecule directing proteins to specific secretory or endocytic compartments of the cell. Emerging evidence indicates that Sortilin is associated with pathological conditions, including inflammation, arteriosclerosis, dyslipidemia, insulin resistance, and vascular calcification. Most recently, Sortilin has been shown to finely control endothelial function and to drive hypertension by modulating sphingolipid/ceramide homeostasis and by triggering oxidative stress.

SUMMARY

The latest findings linking Sortilin and hypertension that are herein discussed can inspire novel areas of research which could eventually lead to the discovery of new therapeutic strategies in cardiovascular medicine.

The Burden of Proof studies: assessing the evidence of risk

Exposure to risks throughout life results in a wide variety of outcomes. Objectively judging the relative impact of these risks on personal and population health is fundamental to individual survival and societal prosperity. Existing mechanisms to quantify and rank the magnitude of these myriad effects and the uncertainty in their estimation are largely subjective, leaving room for interpretation that can fuel academic controversy and add to confusion when communicating risk. We present a new suite of meta-analyses-termed the Burden of Proof studies-designed specifically to help evaluate these methodological issues objectively and quantitatively. Through this data-driven approach that complements existing systems, including GRADE and Cochrane Reviews, we aim to aggregate evidence across multiple studies and enable a quantitative comparison of risk-outcome pairs. We introduce the burden of proof risk function (BPRF), which estimates the level of risk closest to the null hypothesis that is consistent with available data. Here we illustrate the BPRF methodology for the evaluation of four exemplar risk-outcome pairs: smoking and lung cancer, systolic blood pressure and ischemic heart disease, vegetable consumption and ischemic heart disease, and unprocessed red meat consumption and ischemic heart disease. The strength of evidence for each relationship is assessed by computing and summarizing the BPRF, and then translating the summary to a simple star rating. The Burden of Proof methodology provides a consistent way to understand, evaluate and summarize evidence of risk across different risk-outcome pairs, and informs risk analysis conducted as part of the Global Burden of Diseases, Injuries, and Risk Factors Study.