Purpose: Ischemic stroke (IS), one of the two main subtypes of stroke, occurs due to brain ischemia as a result of thrombosis of a cerebral blood vessel. IS is one of the most important neurovascular causes of death and disability. It is affected by many risk factors, such as smoking and high body mass index (BMI), which are also critical in the preventive control of other cardiovascular and cerebrovascular diseases. However, there are still few systematic analyses of the current and predicted disease burden, as well as the attributable risk factors for ischemic stroke. Methods: Based on the GBD2019 database, we used age-standardized mortality rate (ASMR) and disability-adjusted life year (ASDR) to systematically present the geographical distribution and trends of ischemic stroke disease burden worldwide from 1990 to 2019 by calculating the estimated annual percentage change (EAPC), and to analyze and predict the death number of IS accounted by seven major risk factors for 2020-2030. Results: Between 1990 and 2019, the global number of IS deaths increased from 2.04 million to 3.29 million and is expected to increase further to 4.90 million by 2030. The downward trend was more pronounced in women, young people, and high social-demographic index (SDI) regions. At the same time, a study of attributable risk factors for IS found that two behavioral factors, smoking and diet in high sodium, and five metabolic factors, including high systolic blood pressure, high low-density lipoprotein cholesterol, kidney dysfunction, high fast plasma glucose, and high BMI, are major contributors to the increased disease burden of IS now and in the future. Conclusions: Our study provides the first comprehensive summary for the last thirty years and the prediction of the global burden of IS and its attributable risk factors until 2030, providing detailed statistics for decision-making on the prevention and control of IS globally. Inadequate control of the seven risk factors would lead to an increased disease burden of IS in young people, especially in low SDI regions. Our study identifies high-risk populations and helps public health professionals develop targeted preventive strategies to reduce the global disease burden of ischemic stroke.

Background: The incidence and mortality of esophageal cancer are high, with 5.90 new cases and 5.48 deaths per 100 000 people worldwide in 2017. The prognosis of esophageal cancer is poor, with an overall 5‐year survival rate of less than 20%. Esophageal cancer in different geographical locations has different etiologies, and the incidence and mortality of esophageal cancer continue to rise in some regions.Methods: We collected incidence and mortality data by age and gender for 195 countries and territories from 1990 to 2017 in the Global Burden of Disease (GBD) database. And we used these data to calculate the estimated annual percentage change (EAPC) to quantify trends in morbidity and mortality. Then we analyzed the gender‐ and age‐specific incidence and mortality in esophageal cancer to targeted high‐risk populations. Finally, we analyzed the correlation between the age‐standardized mortality rate (ASMR) and both the EAPC and social‐demographic index (SDI), and we calculated the Pearson correlation coefficient.Results: We found that Malawi, East Asia, and high‐middle SDI regions had the highest age‐standardized incidence rate (ASIR) and ASMR, and the ASIR and ASMR in western Sub‐Saharan Africa showed an upward trend. Our study also showed that the incidence and mortality in esophageal cancer were highest in men and in the 70+ years age group, and they presented a decreasing trend in most regions, but the 15‐49 years age groups in Australasia, Caribbean, and Oceania and the 70+ years age group in High‐Income North America, Oceania and high‐SDI regions presented an increasing trend. There were significant negative associations between ASMR at baseline and EAPC and between ASMR and SDI in 2017.Conclusion: By analyzing the global distribution of incidence and mortality in esophageal cancer, trends over time, and gender and age specificity, we can understand the heterogeneity of its global trends. This heterogeneity can help us to identify high‐risk groupsand to provide clues for the exploration of the etiology and early prevention of the disease.

INTRODUCTION: Stomach cancer is a serious global public health problem. The current burden of stomach cancer and its trends across time and location need to be understood to develop effective preventive strategies. METHODS: Data were obtained from the Global Burden of Disease study. The burden of stomach cancer and variations in time and geographical regions were assessed according to the age-standardized rate and estimated annual percentage change (EAPC) of the incidence and mortality rate between 1991 and 2017. We also investigated the associations between the relevant rates and sociodemographic index (SDI). RESULTS: Overall, the age-standardized incidence rate (EAPC = −1.36, 95% confidence interval [CI]: −1.47 to −1.25), age-standardized mortality rate (EAPC = −2.2, 95% CI: −2.29 to −2.12), and age-standardized disability-adjusted life years rate (EAPC = −2.52, 95% CI: −2.63 to −2.43) decreased worldwide from 1990 to 2017. This trend varied across different countries and regions and according to sex and age. SDI had a significant negative correlation with the age-standardized mortality rate (P < 0.01, r = −0.28) and age-standardized disability-adjusted life years rate (P < 0.01, r = −0.31). Similar negative correlations were observed between SDI and the EAPC. DISCUSSION: The observed correlation between SDI and disease burden suggests that strategically implementing the screening and eradication of Helicobacter pylori, improving the medical level in countries with low SDI, and promoting the implementation of tobacco cessation policies would help reduce the disease burden of stomach cancer.

Background: Carotid intima‐media thickness (cIMT) has been widely used as a predictor of future cardiovascular disease (CVD); however, various definitions of cIMT exist. This study provides a systematic review and meta‐analysis of the associations between different cIMT definitions and CVD. Methods and results: A systematic review of the different cIMT definitions used in prospective cohort studies was performed. The relationships between cIMT of different definitions (common carotid artery IMT [CCA‐IMT], internal carotid artery IMT [ICA‐IMT], combined segments [combined‐IMT], mean CCA‐IMT, and maximum CCA‐IMT) with future stroke, myocardial infarction (MI), and CVD events were analyzed using random effects models. Among 2287 articles, 18 articles (14 studies) with >10 different cIMT definitions were identified and included in our meta‐analysis. After adjusting for age and sex, a 1‐SD increase in CCA‐IMT was associated with future stroke (hazard ratio [HR], 1.32 [95% CI, 1.27–1.38]), MI (HR, 1.27 [95% CI, 1.22–1.33]), and CVD events (HR, 1.28 [95% CI, 1.19–1.37]). A 1‐SD increase in ICA‐IMT was related to future stroke (HR, 1.25 [95% CI, 1.11–1.42]) and CVD events (HR, 1.25 [95% CI, 1.04–1.50]) but not MI (HR, 1.26 [95% CI, 0.98–1.61]). A 1‐SD increase in combined‐IMT was associated with future stroke (HR, 1.30 [95% CI, 1.08–1.57]) and CVD events (HR, 1.36 [95% CI, 1.23–1.49]). Maximum CCA‐IMT was more strongly related than mean CCA‐IMT with risk of MI, and both measures were similarly associated with stroke and CVD events. Conclusions: Combined‐IMT is more strongly associated with CVD events compared with single‐segment cIMT definitions. Maximum CCA‐IMT shows a stronger association with MI than mean CCA‐IMT. Further research is warranted to validate our findings and to standardize the cIMT measurement protocol, as well as to explore underlying mechanisms.

It is extremely expensive to conduct large sample size array- or sequencing based genome scale association studies. For a quantitative trait, an extreme case-control study design may improve the power and reduce the cost of variant calling. We investigated the performance of extreme study design when various proportions of samples are selected from the tails of phenotype distribution. Using simulations, we show that when risk genotypes become rare in the population and effect size is relatively small, it is beneficial to carry out an extreme sampling study. In particular, the number of selected cases and controls can even be unbalanced such that power is further increased, compared with a balanced selection. Our application to two data sets: methadone dose data and yearling weight data, demonstrated that similar results for full data analysis can be obtained using extreme sampling with only a fraction of the data. Using power analysis with simulated data and an experimental data application, we conclude that when full data is unavailable due to restricted budget, it is rewarding to employ an extreme sampling design in the sense that there can be immense cost reductions and qualitatively similar power as in the full data analysis.