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

Les neuropathies peripheriques associees a l’infection a VIH: aspects epidemiologiques et cliniques

Contexte et justification: L’infection à VIH a pris d'ampleur au Togo et en Afrique subsaharienne. Les neuropathies périphériques (NP) constituent l’une des manifestations neurologiques les plus couramment décrites au cours de cette infection.But de l’étude: Déterminer la fréquence et les différents types de NP liées au VIH au CHU Campus et Sylvanus Olympio de Lomé.Méthode: Il s’agit d’une étude rétrospective réalisée dans le Service de Neurologie du CHU Campus et Sylvanus Olympio de Lomé sur 46 dossiers de PVVIH porteurs d’une NP de Janvier 2006 à Décembre 2015.Résultats: La fréquence des NP parmi les patients séropositifs au VIH a été de 11,38%. Les types de NP colligés ont été : PFP (55,1%), Polyneuropathie (18,36%), Radiculite zostérienne (14,28%) Polyradiculonévrite (6,13%), Mononeuropathie (4,08%) Méningoradiculonévrite (2,04%). La tranche d’âge des 20 à 50 ans a été la plus représentée (87%) ; L’âge moyen a été de 39ans. Le VIH-1a été retrouvé chez 93,5% les patients ; la sex-ratio H/F a été de 1,3 avec une prédominance de mariés monogames.Conclusion: Les NP sont relativement fréquentes et polymorphes au cours de l’infection à VIH.Mots clés: neuropathie périphérique, VIH, LoméEnglish Title: Peripheral neuropathies associated with HIV: epidemiological and clinical aspectsEnglish AbstractContext and justification: The spread of the HIV infection is progressing in Togo and in sub Saharans African countries. Peripheral neuropathies (PN) are common neurological manifestations of this infection.Purpose: To evaluate the frequency and describe the differents types of PN associated with HIV infection in CHU Campus and Sylvanus Olympio of Lome.Method: It is a retrospective study of 46 medical records of patients diagnosed PN and HIV+ in the Neurology Department of CHU Campus from January 2006 to December 2015.Results: The frequency of PN among HIV seropositive patients were 11.38%. The types of PN were: peripheral facial paralysis (55.1%), Polyneuropathy (18.36%), Herpes zoster radiculitis (14.28%), Polyradiculopathy (6.13%), Mononeuropathy (4.08%), Meningoradiculopathy (2.04%). The age bracket of 20-50 years old patients was mostly  represented (87%). The mean age was 39. HIV-1 was found among 93.5% of the patients. The sex ratio M/F was 1.3; monogamous married persons were predominantConclusion: Peripheral neuropathies occurring in the HIV infection are relatively common and polymorphous.Keywords: Peripheral neuropathy, HIV, Lom

An Analytical Expression for the Electric Field and Particle Tracing in Modelling of Be Erosion Experiments at the JET ITER-like Wall

A new analytical approximation for the electric potential profile in the presence of an oblique magnetic field and the analytical solution for the particle motion just before the impact with a plasma-facing surface are presented. These approximations are in good agreement with fluid solutions and the corresponding PIC simulations. These expressions were applied to provide effective physical erosion yields for Be, which have in a second step been used in ERO code simulations of spectroscopy at Be limiters of the JET ITER-like wall. These new analytical expressions lead to an increase of the effective physical sputtering yields of Be by deuteron impact up to 30% in comparison with earlier pure numerical simulations. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)