Plasma Ammonia Levels in Newborns with Asphyxia

How to Cite This Article: Khalessi N, Khosravi N, Mirjafari M, Afsharkhas L. Plasma Ammonia Levels in Newborns with Asphyxia. Iran J Child Neurol. Winter 2016; 10(1):42-46.AbstractObjectivePerinatal asphyxia may result in hypoxic damage in various body organs, especially in the central nervous system. It could induce cascade of biochemical events leading to the cell death and metabolic changes, eventually may increase plasma ammonia levels. The purpose of this study was to determine the prevalence of hyperammonemia in neonates with asphyxia and to find the relationship between ammonia levels and severity of asphyxia.Material & MethodsIn this cross-sectional study, we included 100 neonates with perinatal asphyxia in the Neonatal Intensive Care Unit of Ali-Asghar Hospital, Iran University of Medical Science, Tehran, Iran in 2010-2011. All full term patients diagnosed of asphyxia were enrolled. The relationship between plasma ammonia levels and sex, gestational age, birth weight and severity of asphyxia were determined.Data were analyzed using SPSS software.ResultsFifty six percent of neonates were male. The mean gestational age was 38.0± 1.2 wk. Mean plasma ammonia level was 222 ± 100 μg/dl and 20% of the neonates had hyperammonemia. It was not associated with gender, gestational age, birth weight, and asphyxia severity. Six patients died and mean plasma ammonia levels was 206±122 μg/dl. In this group, there was no significant relation between plasma ammonia levels and severity of asphyxia. No significant different was seen between plasma ammonia in dead and lived neonates.ConclusionAccording to high prevalence of hyperammonemia in neonatal asphyxia, measurement of plasma ammonia levels, is suggested to improve management of asphyxia

Molecular Methods for Identification of Acinetobacter Species by Partial Sequencing of the rpoB and 16S rRNA Genes.

BACKGROUND Acinetobacter spp. is a diverse group of Gram-negative bacteria which are ubiquitous in soil and water, and an important cause of nosocomial infections. The purpose of this study was to identify a collection of Acinetobacter spp. clinical isolates accurately and to investigate their antibiotic susceptibility patterns. MATERIALS AND METHODS A total of 197 non-duplicate clinical isolates of Acinetobacter spp. isolates identified using conventional biochemical tests. The molecular technique of PCR-RFLP and sequence analysis of rpoB and 16S rRNA genes was applied for species identification. Antimicrobial susceptibility test was performed with a disk diffusion assay. RESULTS Based on 16S rRNA and rpoB genes analysis separately, most of clinical isolates can be identified with high bootstrap values. However, the identity of the isolate 555T was uncertain due to high similarity of A. grimontii and A. junii. Identification by concatenation of 16S rRNA and rpoB confirmed the identity of clinical isolates of Acenitobacer to species level confidently. Accordingly, the isolate 555T assigned as A. grimontii due to 100% similarity to A. grimontii. Moreover, this isolate showed 98.64% to A. junii. Besides, the identity of the isolates 218T and 364T was confirmed as Genomic species 3 and A. calcoaceticus respectively. So, the majority of Acinetobacter spp. isolates, were identified as: A. baumannii (131 isolates, 66%), A. calcoaceticus (9 isolates, 4.5%), and A. genomosp 16 (8 isolates, 4%). The rest of identified species showed the lower frequencies. In susceptibility test, 105 isolates (53%), presented high antibiotic resistance of 90% to ceftriaxone, piperacillin, piperacillin tazobactam, amikacin, and 81% to ciprofloxacin. CONCLUSION Sequence analysis of the 16S rRNA and rpoB spacer simultaneously was able to do identification of Acinetobacter spp. to species level. A.baumannii was identified as the most prevalent species with high antibiotic resistance. Other species showed lower frequencies ranged from 4 to 9 strains

The Prevalence of Acute Kidney Injury in Neonates with Asphyxia

Introduction: Asphyxia is a common cause of mortality and morbidity among neonates. Following severe asphyxia and ischemia, reperfusion occurs which damages vital organs like the kidneys. This study was conducted to determine the prevalence of AKI based on the definition of a serum creatinine level higher than 1.5 mg/dL, in neonates with asphyxia.Materials and Methods: This retrospective study was performed in Ali-Asghar and Shahid-Akbar-Abadi Hospitals, Tehran, Iran in a period of one year. The medical documents of all newborns diagnosed with asphyxia were studied. The asphyxia grade was determined according to the asphyxia Sarnat criteria. The kidney function was evaluated based on the serum creatinine level.Results: Thirty-eight cases met the inclusion criteria. There were 13 Sarnat grade-1 cases (34.2%), 19 grade 2 cases (50%), and 6 grade 3 patients (17.6%).  Three (7.8%) patients (2 patients in grade 3 and one patient in grade 2 of the Sarnat grading scale) developed AKI. AKI was detected in 33% of the patients in grade 3 and 5.2% of the patients in grade 2 of the Sarnat grading scale. Nine patients (23%) died, of whom 83% were in grade 3 and 16.9% in grade 2 of asphyxia.Conclusions: AKI developed in 7.8% of the cases, of whom 33% were in grade 3 and 5.2% were in grade 2 of the Sarnat grading scale. The low rate of AKI development in our study might be duo to the small sample size and patient mortality in the first 3 days of life.Keywords: Acute kidney injury; Neonates; Asphyxia

Association of adherence to the dietary approach to stop hypertension and Mediterranean diets with blood pressure in a non-hypertensive population: Results from Isfahan Salt Study (ISS)

Abstract Background and aims Hypertension is among the major risk factors for cardiovascular events in the Iranian population. This cross-sectional study was designed to examine the association of adherence to the dietary approaches to stop hypertension (DASH) and Mediterranean (MED) dietary patterns with the distribution of blood pressure and pre-hypertension prevalence. Methods and results This cross-sectional study was carried out in 1363 non-hypertensive adults. Adherence to the DASH and MED diets was calculated using a semi-quantitative food frequency questionnaire (FFQ). Hypertension was measured by the standard method. Multiple logistic regression was applied to obtain the odds ratio of pre-hypertension in the tertiles of MED and DASH dietary patterns. Compared to the lowest, participants with the highest adherence to the DASH dietary pattern had significantly lower systolic blood pressure (SBP) (111.3 ± 11.8 vs. 112.8 ± 12.5; P = 0.010) and diastolic blood pressure (DBP) (70.7 ± 9.2 vs. 71.8 ± 9.8; 0.042). There was no significant difference in the mean SBP and DBP among the participants across tertiles of MED or diet adherence. Higher scores of the DASH and MED diets were inversely associated with lower SBP after adjustment for all potential confounders (OR = −0.04, 95% CI = −0.29, −0.01, P = 0.039) and (OR = −0.04, 95% CI = −0.72, −0.02, P = 0.044), respectively. Also, DASH and MED dietary patterns was associated with reduced OR of pre-hypertension occurrence by 13% (OR: 0.87; 95% CI: 0.70–0.98; P for trend = 0.042) and 16% ([OR: 0.84; 95% CI: 0.69–0.97; P trend = 0.035), respectively. Conclusion Adherence to the DASH and MED diets was inversely associated with the odds for pre-hypertension and SBP

Popularity and Harms of Aural Foreign Bodies: A Descriptive Study of Patients in Baqiyatallah University Hospital, Tehran, Iran.

peer reviewed[en] OBJECTIVE: To evaluate the prevalence of external ear complications among Iranian aural foreign body users attending to otolaryngology clinic of our hospital. METHODS: In this cross-sectional study patients attending to Otolaryngology clinics of Baqiyatallah hospital were enrolled regardless of their age, gender and reason of attending. Patients between 15 and 60 years of age were included in the present study. Those with positive history of chronic ear diseases, ear surgery, congenital ear disorders, trauma to ear or head and neck region or shock wave trauma were excluded from the study. Demographic information as well as data on chief complaint, educational level, frequency and type of used foreign body and findings of physical examination and Otoscopy by a single otolaryngologist were recorded in a predesigned checklist. RESULTS: Eventually 362 patients (232 male and 130 female) with a mean age of 40.32 ± 16.90 years underwent analysis. Of all patients 244 (67.2%) were using a kind of aural foreign body frequently and Cotton bud was the most popular (63.5%) used foreign body among patients. Drying ear canal was the most common (54.9%) reason of using AFBs among study individuals followed by itching (29.5%) and pyorrhea (11.06%). Also 11 (4.5%) patients were using AFBs as a habit with no specific reason. Itching was the most prevalent symptom reported by both aural foreign body users (78%) and non-users (45.5%); however it was significantly higher among AFB users (p = 0.026). Also hearing loss was significantly more reported by AFB users (p = 0.033). A majority of patients had normal physical examination in both AFB users and non-users group. Inflammation of ear canal was significantly more detected in AFB users (p = 0.004). In addition, rate of right ear wax impaction was higher among AFB users (p = 0.016). CONCLUSION: In conclusion we realized that 67.2% of patients attending to Otolaryngology clinic of our hospital were using a kind of aural foreign bodies and itching was the most common chief complaint of these patients

Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49\ub74% (95% uncertainty interval [UI] 46\ub74–52\ub70). The TFR decreased from 4\ub77 livebirths (4\ub75–4\ub79) to 2\ub74 livebirths (2\ub72–2\ub75), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83\ub78 million people per year since 1985. The global population increased by 197\ub72% (193\ub73–200\ub78) since 1950, from 2\ub76 billion (2\ub75–2\ub76) to 7\ub76 billion (7\ub74–7\ub79) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2\ub70%; this rate then remained nearly constant until 1970 and then decreased to 1\ub71% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2\ub75% in 1963 to 0\ub77% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2\ub77%. The global average age increased from 26\ub76 years in 1950 to 32\ub71 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59\ub79% to 65\ub73%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1\ub70 livebirths (95% UI 0\ub79–1\ub72) in Cyprus to a high of 7\ub71 livebirths (6\ub78–7\ub74) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0\ub708 livebirths (0\ub707–0\ub709) in South Korea to 2\ub74 livebirths (2\ub72–2\ub76) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0\ub73 livebirths (0\ub73–0\ub74) in Puerto Rico to a high of 3\ub71 livebirths (3\ub70–3\ub72) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2\ub70% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress. Funding: Bill & Melinda Gates Foundation

Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49·4% (95% uncertainty interval [UI] 46·4–52·0). The TFR decreased from 4·7 livebirths (4·5–4·9) to 2·4 livebirths (2·2–2·5), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83·8 million people per year since 1985. The global population increased by 197·2% (193·3–200·8) since 1950, from 2·6 billion (2·5–2·6) to 7·6 billion (7·4–7·9) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2·0%; this rate then remained nearly constant until 1970 and then decreased to 1·1% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2·5% in 1963 to 0·7% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2·7%. The global average age increased from 26·6 years in 1950 to 32·1 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59·9% to 65·3%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1·0 livebirths (95% UI 0·9–1·2) in Cyprus to a high of 7·1 livebirths (6·8–7·4) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0·08 livebirths (0·07–0·09) in South Korea to 2·4 livebirths (2·2–2·6) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0·3 livebirths (0·3–0·4) in Puerto Rico to a high of 3·1 livebirths (3·0–3·2) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2·0% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress

Population and fertility by age and sex for 195 countries and territories, 1950-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. METHODS: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10-54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10-14 years and 50-54 years was estimated from data on fertility in women aged 15-19 years and 45-49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation