Variations in risks from smoking between high-income, middle-income, and low-income countries: an analysis of data from 179 000 participants from 63 countries

Impact of global smoking prevalence on mortality: a study across income groups

BACKGROUND

Smoking significantly contributes to the mortality rates worldwide, particularly in non-communicable and preventable diseases such as cardiovascular ailments, respiratory conditions, stroke, and lung cancer. This study aims to analyse the impact of smoking on global deaths, and its association with mortality across the main income groups.

METHODS

The comprehensive analysis spans 199 countries and territories from 1990 to 2019. The study categorises countries into four income groups: high income, upper middle income, lower middle income, and low income.

RESULTS

The findings underscore the profound impact of global tobacco smoking on mortality. Notably, cardiovascular disease mortality is notably affected in both upper-middle-income and high-income groups. Chronic respiratory disease mortality rates show a significant impact across all income groups. Moreover, stroke-related mortality is observed in the lower-middle, upper-middle, and high-income groups. These results highlight the pervasive influence of smoking prevalence on global mortality, affecting individuals across various socioeconomic levels.

CONCLUSION

The study underscores the critical implications of smoking on mortality rates, particularly in high-income countries. It emphasises the urgency of targeted interventions in these regions to address the specific challenges posed by tobacco smoking on public health. Policy recommendations include implementing prohibitive measures extending to indoor public areas such as workplaces and public transportation services. Furthermore, allocating funds for research on tobacco and health, is imperative to ensure policymakers are consistently informed about emerging facts and trends in this complex domain.

Assessing Global, Regional, and National Time Trends and Associated Risk Factors of the Mortality in Ischemic Heart Disease Through Global Burden of Disease 2019 Study: Population-Based Study

BACKGROUND

Ischemic heart disease (IHD) is the leading cause of death among noncommunicable diseases worldwide, but data on current epidemiological patterns and associated risk factors are lacking.

OBJECTIVE

This study assessed the global, regional, and national trends in IHD mortality and attributable risks since 1990.

METHODS

Mortality data were obtained from the Global Burden of Disease 2019 Study. We used an age-period-cohort model to calculate longitudinal age curves (expected longitudinal age-specific rate), net drift (overall annual percentage change), and local drift (annual percentage change in each age group) from 15 to >95 years of age and estimate cohort and period effects between 1990 and 2019. Deaths from IHD attributable to each risk factor were estimated on the basis of risk exposure, relative risks, and theoretical minimum risk exposure level.

RESULTS

IHD is the leading cause of death in noncommunicable disease-related mortality (118.1/598.8, 19.7%). However, the age-standardized mortality rate for IHD decreased by 30.8% (95% CI -34.83% to -27.17%) over the past 30 years, and its net drift ranged from -2.89% (95% CI -3.07% to -2.71%) in high sociodemographic index (SDI) region to -0.24% (95% CI -0.32% to -0.16%) in low-middle-SDI region. The greatest decrease in IHD mortality occurred in the Republic of Korea (high SDI) with net drift -6.06% (95% CI -6.23% to -5.88%), followed by 5 high-SDI nations (Denmark, Norway, Estonia, the Netherlands, and Ireland) and 2 high-middle-SDI nations (Israel and Bahrain) with net drift less than -5.00%. Globally, age groups of >60 years continued to have the largest proportion of IHD-related mortality, with slightly higher mortality in male than female group. For period and birth cohort effects, the trend of rate ratios for IHD mortality declined across successive period groups from 2000 to 2004 and birth cohort groups from 1985 to 2000, with noticeable improvements in high-SDI regions. In low-SDI regions, IHD mortality significantly declined in female group but fluctuated in male group across successive periods; sex differences were greater in those born after 1945 in middle- and low-middle-SDI regions and after 1970 in low-SDI regions. Metabolic risks were the leading cause of mortality from IHD worldwide in 2019. Moreover, smoking, particulate matter pollution, and dietary risks were also important risk factors, increasingly occurring at a younger age. Diets low in whole grains and legumes were prominent dietary risks in both male and female groups, and smoking and high-sodium diet mainly affect male group.

CONCLUSIONS

IHD, a major concern, needs focused health care attention, especially for older male individuals and those in low-SDI regions. Metabolic risks should be prioritized for prevention, and behavioral and environmental risks should attract more attention to decrease IHD mortality.

A novel multi-ancestry proteome-wide Mendelian randomization study implicates extracellular proteins, tubular cells, and fibroblasts in estimated glomerular filtration rate regulation

Estimated glomerular filtration rate (eGFR) impacts the concentration of plasma biomarkers confounding biomarker association studies of eGFR with reverse causation. To identify biomarkers causally associated with eGFR, we performed a proteome-wide Mendelian randomization study. Genetic variants nearby biomarker coding genes were tested for association with plasma concentration of 1,161 biomarkers in a multi-ancestry sample of 12,066 participants from the Prospective Urban and Rural Epidemiological (PURE) study. Using two-sample Mendelian randomization, individual variants' effects on biomarker concentration were correlated with their effects on eGFR and kidney traits from published genome-wide association studies (GWAS). Genetically altered concentrations of 22 biomarkers were associated with eGFR above a Bonferroni-corrected significance threshold. Five biomarkers were previously identified by GWAS (UMOD, FGF5, LGALS7, NINJ1, COL18A1). Nine biomarkers were within 1 Mb of the lead GWAS variant but the gene for the biomarker was unidentified as the candidate for the GWAS signal (INHBC, TNFRSF11A, TCN2, PXN1, PRTN3, PSMD9, TFPI, ITGB6, CA3). Single-cell transcriptomic data indicated the 22 biomarkers are expressed in kidney tubules, collecting duct, fibroblasts, and immune cells. Pathway analysis showed significant enrichment of identified biomarkers in the extracellular kidney parenchyma. Thus, using genetic regulators of biomarker concentration via proteome-wide Mendelian randomization, we identified 22 biomarkers that appear to causally impact eGFR in either a beneficial or adverse manner. The current study provides rationale for novel therapeutic targets for eGFR and emphasized a role for extracellular proteins produced by tubular cells and fibroblasts for impacting eGFR.

Association of thyroid peroxidase antibody with the RNF213 p.R4810K variant in ischemic stroke/transient ischemic attack

BACKGROUND AND AIMS

RNF213 is a susceptibility gene for moyamoya disease and vasospastic angina, with a second hit considered necessary for their development. Elevated thyroid peroxidase antibody (TPO-Ab) levels have been observed in both diseases, suggesting a possible role of TPO-Ab as a second hit for developing RNF213-related vasculopathy. We investigated the association of TPO-Ab levels with RNF213-related ischemic stroke (IS)/transient ischemic attack (TIA), other than moyamoya disease.

METHODS

From the National Cerebral and Cardiovascular Center Genome Registry, a multicenter, prospective, observational study, we enrolled patients with IS/TIA who were admitted within 1 week of onset. Patients with IS/TIA due to definite moyamoya disease or hemorrhagic stroke were excluded. Participants underwent genotyping for RNF213 p. R4810K, and baseline characteristics and TPO-Ab levels were compared between RNF213 p. R4810K variant carriers and non-carriers.

RESULTS

In total, 2090 IS/TIA patients were analyzed [733 women (35.1%); median age 74 (interquartile range, 63-81) years, baseline NIHSS score 3 (2-6)], and 85 (4.1%) of them carried the variant. Median TPO-Ab levels were significantly higher in variant carriers (8.5 IU/mL vs. 2.1 IU/mL, p < 0.01), who also showed a higher frequency of elevated TPO-Ab levels (>16 IU/mL) (27.1% vs. 4.4%). In the multivariate analysis, presence of the RNF213 p. R4810K variant (adjusted odds ratio, 12.42; 95% confidential interval, 6.23-24.75) was significantly associated with elevated TPO-Ab levels.

CONCLUSIONS

Elevated TPO-Ab levels may be significantly associated with presence of the RNF213 p. R4810K variant in IS/TIA patients. Thus, TPO-Ab may inherently modify IS/TIA development in RNF213 p. R4810K variant carriers.

A comparative study of life-years lost attributable to air particulate matter in Asia-Pacific and European countries

Air particulate matter (PM) and its harmful effects on human health are of great concern globally due to all-cause and cause-specific mortality impacts across different population groups. While Europe has made significant progress in reducing particulate air pollution-related mortality through innovative technologies and policies, many countries in Asia-Pacific region still rely on high-polluting technologies and have yet to implement effective policies to address this issue, resulting in higher levels of mortality due to air pollution in the region. This study has three aims related to quantifying life-years lost (LYL) attributable to PM, and further separated into ambient PM and household air pollution (HAP): (1) to investigate LYL by causes of death; (2) to compare LYL between Asia-Pacific (APAC) and Europe; and (3) to assess LYL across different socio-demographic index (SDI) countries. The data used come from the Institute for Health Metrics and Evaluation (IHME) and Health Effects Institute (HEI). Our results show that average LYL due to PM in APAC was greater than in Europe, with some Pacific island countries particularly affected by the exposure to HAP. Three quarters of LYL came from premature deaths by ischemic heart disease and stroke, in both continents. There were significant differences between SDI groups for causes of death due to ambient PM and HAP. Our findings call for urgent improvement of clean air to reduce indoor and outdoor air pollution-related mortality in the APAC region.

How regional versus global thresholds for physical activity and grip strength influence physical frailty prevalence and mortality estimates in PURE: a prospective multinational cohort study of community-dwelling adults

OBJECTIVES

Handgrip strength and physical activity are commonly used to evaluate physical frailty; however, their distribution varies worldwide. The thresholds that identify frail individuals have been established in high-income countries but not in low-income and middle-income countries. We created two adaptations of physical frailty to study how global versus regional thresholds for handgrip strength and physical activity affect frailty prevalence and its association with mortality in a multinational population.

DESIGN, SETTING AND PARTICIPANTS

Our sample included 137 499 adults aged 35-70 years (median age: 61 years, 60% women) from Population Urban Rural Epidemiology Studies community-dwelling prospective cohort across 25 countries, covering the following geographical regions: China, South Asia, Southeast Asia, Africa, Russia and Central Asia, North America/Europe, Middle East and South America.

PRIMARY AND SECONDARY OUTCOME MEASURES

We measured and compared frailty prevalence and time to all-cause mortality for two adaptations of frailty.

RESULTS

Overall frailty prevalence was 5.6% using global frailty and 5.8% using regional frailty. Global frailty prevalence ranged from 2.4% (North America/Europe) to 20.1% (Africa), while regional frailty ranged from 4.1% (Russia/Central Asia) to 8.8% (Middle East). The HRs for all-cause mortality (median follow-up of 9 years) were 2.42 (95% CI: 2.25 to 2.60) and 1.91 (95% CI: 1.77 to 2.06) using global frailty and regional frailty, respectively, (adjusted for age, sex, education, smoking status, alcohol consumption and morbidity count). Receiver operating characteristic curves for all-cause mortality were generated for both frailty adaptations. Global frailty yielded an area under the curve of 0.600 (95% CI: 0.594 to 0.606), compared with 0.5933 (95% CI: 0.587 to 5.99) for regional frailty (p=0.0007).

CONCLUSIONS

Global frailty leads to higher regional variations in estimated frailty prevalence and stronger associations with mortality, as compared with regional frailty. However, both frailty adaptations in isolation are limited in their ability to discriminate between those who will die during 9 years' follow-up from those who do not.

Age at smoking initiation and smoking cessation influence the incidence of stroke in China: a 10-year follow-up study

Our study aimed to explore the correlation between age at smoking initiation and smoking cessation for the risk for stroke in China. We investigated 50,174 participants from one of the urban areas of China Kadoorie Biobank (CKB) Study. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for association between smoking and incidence of stroke were estimated using Cox regression model. During a median of 10.7 years of follow-up, 4370 total stroke cases were documented. Among men, comparing current smokers to never smokers, the HR of total stroke for current smokers was 1.279 (95% CI, 1.134-1.443) for total stroke. The HRs of total stroke were 1.344 (1.151-1.570) for those started smoking at age less than 20 years, 1.254 (1.090-1.443) for those started smoking at age 20-30 years, and 1.205 (1.012-1.435) for those started smoking at age 30 year and above, with a dose-response relation (P for trend, 0.004). Comparing former smokers to current smokers, in the low pack-year group, those stopped smoking at age less than 65 years had a 18.2% decreased risk for total stroke (0.818; 0.673-0.994). The decreased risk was not found in those stopped smoking at age 65 years and above. Similar results were observed in the high pack-year group. In conclusion, we found that current smokers had a higher stroke risk than never smokers, and the risk increased with a younger age at smoking initiation. Smoking cessation can reduce the risk for stroke, especially could benefit from cessation at a younger age.

Tobacco smoking and risks of more than 470 diseases in China: a prospective cohort study

BACKGROUND

Tobacco smoking is estimated to account for more than 1 million annual deaths in China, and the epidemic continues to increase in men. Large nationwide prospective studies linked to different health records can help to periodically assess disease burden attributed to smoking. We aimed to examine associations of smoking with incidence of and mortality from an extensive range of diseases in China.

METHODS

We analysed data from the prospective China Kadoorie Biobank, which recruited 512 726 adults aged 30-79 years, of whom 210 201 were men and 302 525 were women. Participants who had no major disabilities were identified through local residential records in 100-150 administrative units, which were randomly selected by use of multistage cluster sampling, from each of the ten diverse study areas of China. They were invited and recruited between June 25, 2004, and July 15, 2008. Upon study entry, trained health workers administered a questionnaire assessing detailed smoking behaviours and other key characteristics (eg, sociodemographics, lifestyle, and medical history). Participants were followed up via electronic record linkages to death and disease registries and health insurance databases, from baseline to Jan 1, 2018. During a median 11-year follow-up (IQR 10-12), 285 542 (55·7%) participants were ever hospitalised, 48 869 (9·5%) died, and 5252 (1·0%) were lost to follow-up during the age-at-risk of 35-84 years. Cox regression yielded hazard ratios (HRs) associating smoking with disease incidence and mortality, adjusting for multiple testing.

FINDINGS

At baseline, 74·3% of men and 3·2% of women (overall 32·4%) ever smoked regularly. During follow-up, 1 137 603 International Classification of Diseases, 10th revision (ICD-10)-coded incident events occurred, involving 476 distinct conditions and 85 causes of death, each with at least 100 cases. Compared with never-regular smokers, ever-regular smokers had significantly higher risks for nine of 18 ICD-10 chapters examined at age-at-risk of 35-84 years. For individual conditions, smokers had significantly higher risks of 56 diseases (50 for men and 24 for women) and 22 causes of death (17 for men and nine for women). Among men, ever-regular smokers had an HR of 1·09 (95% CI 1·08-1·11) for any disease incidence when compared with never-regular smokers, and significantly more episodes and longer duration of hospitalisation, particularly those due to cancer and respiratory diseases. For overall mortality, the HRs were greater in men from urban areas than in men from rural areas (1·50 [1·42-1·58] vs 1·25 [1·20-1·30]). Among men from urban areas who began smoking at younger than 18 years, the HRs were 2·06 (1·89-2·24) for overall mortality and 1·32 (1·27-1·37) for any disease incidence. In this population, 19·6% of male (24·3% of men residing in urban settings and 16·2% of men residing in rural settings) and 2·8% of female deaths were attributed to ever-regular smoking.

INTERPRETATION

Among Chinese adults, smoking was associated with higher risks of morbidity and mortality from a wide range of diseases. Among men, the future smoking-attributed disease burden will increase further, highlighting a pressing need for reducing consumption through widespread cessation and uptake prevention.

FUNDING

British Heart Foundation, Cancer Research UK, Chinese Ministry of Science and Technology, Kadoorie Charitable Foundation, UK Medical Research Council, National Natural Science Foundation of China, Wellcome Trust.

Public Health Burden of Secondhand Smoking: Case Reports of Lung Cancer and a Literature Review

Secondhand smoke (SHS), composed of mainstream and sidestream smoke, is a known human carcinogen. It contains a variety of harmful substances at even higher concentrations than mainstream smoke itself, which is inhaled during firsthand smoking. Exposure to SHS, affecting more than a third of the worldwide population, increases the likelihood of lung cancer by roughly 30%, with specific contributions depending on the histological type of cancer. This study aimed to present the harmful potential of SHS through case reports and describe the burden of SHS via a literature review. From a collection of lung cancer case reports occurring in never smokers from the Olomouc district over the last 10 years, 2 cases with no risk factors for lung cancer except for significant exposure to SHS were identified. Both cases were of young women who lived in households where their parents smoked during childhood. They suffered from rarer histological types of lung cancer in which the association with SHS has not yet been analyzed. As the literature confirms, SHS has the most adverse effects in individuals exposed during childhood. It is necessary to both take measures to reduce the prevalence of SHS, especially among children in households and pay due attention to the smoking history of patients, including current and previous exposure to SHS, when obtaining anamnestic data. Furthermore, the effect of SHS on rarer histological types of lung cancer should be studied.

Metabolic, behavioural, and psychosocial risk factors and cardiovascular disease in women compared with men in 21 high-income, middle-income, and low-income countries: an analysis of the PURE study

BACKGROUND

There is a paucity of data on the prevalence of risk factors and their associations with incident cardiovascular disease in women compared with men, especially from low-income and middle-income countries.

METHODS

In the Prospective Urban Rural Epidemiological (PURE) study, we enrolled participants from the general population from 21 high-income, middle-income, and low-income countries and followed them up for approximately 10 years. We recorded information on participants' metabolic, behavioural, and psychosocial risk factors. For this analysis, we included participants aged 35-70 years at baseline without a history of cardiovascular disease, with at least one follow-up visit. The primary outcome was a composite of major cardiovascular events (cardiovascular disease deaths, myocardial infarction, stroke, and heart failure). We report the prevalence of each risk factor in women and men, their hazard ratios (HRs), and population-attributable fractions (PAFs) associated with major cardiovascular disease. The PURE study is registered with ClinicalTrials.gov, NCT03225586.

FINDINGS

In this analysis, we included 155 724 participants enrolled and followed-up between Jan 5, 2005, and Sept 13, 2021, (90 934 [58·4%] women and 64 790 [41·6%] men), with a median follow-up of 10·1 years (IQR 8·5-12·0). At study entry, the mean age of women was 49·8 years (SD 9·7) compared with 50·8 years (9·8) in men. As of data cutoff (Sept 13, 2021), 4280 major cardiovascular disease events had occurred in women (age-standardised incidence rate of 5·0 events [95% CI 4·9-5·2] per 1000 person-years) and 4911 in men (8·2 [8·0-8·4] per 1000 person-years). Compared with men, women presented with a more favourable cardiovascular risk profile, especially at younger ages. The HRs for metabolic risk factors were similar in women and men, except for non-HDL cholesterol, for which high non-HDL cholesterol was associated with an HR for major cardiovascular disease of 1·11 (95% CI 1·01-1·21) in women and 1·28 (1·19-1·39) in men, with a consistent pattern for higher risk among men than among women with other lipid markers. Symptoms of depression had a HR of 1·09 (0·98-1·21) in women and 1·42 (1·25-1·60) in men. By contrast, consumption of a diet with a PURE score of 4 or lower (score ranges from 0 to 8), was more strongly associated with major cardiovascular disease in women (1·17 [1·08-1·26]) than in men (1·07 [0·99-1·15]). The total PAFs associated with behavioural and psychosocial risk factors were greater in men (15·7%) than in women (8·4%) predominantly due to the larger contribution of smoking to PAFs in men (ie, 1·3% [95% CI 0·5-2·1] in women vs 10·7% [8·8-12·6] in men).

INTERPRETATION

Lipid markers and depression are more strongly associated with the risk of cardiovascular disease in men than in women, whereas diet is more strongly associated with the risk of cardiovascular disease in women than in men. The similar associations of other risk factors with cardiovascular disease in women and men emphasise the importance of a similar strategy for the prevention of cardiovascular disease in men and women.

FUNDING

Funding sources are listed at the end of the Article.

Determinants of tobacco smoking abstinence 1 year after major noncardiac surgery: a secondary analysis of the VISION study

BACKGROUND

Tobacco smoking is a leading preventable cause of death and increases perioperative risk. Determinants of smoking abstinence after noncardiac surgery and the association between smoking and 1-yr vascular outcomes are not fully elucidated.

METHODS

We did a prospective cohort study of 40 004 patients, aged ≥45 yr, enrolled between August 2007 and November 2013, and followed for 1 yr after surgery. Patients were categorised as never smokers, ex-smokers (quit >4 weeks preoperatively), and current smokers (smoking ≤4 weeks preoperatively). Primary outcome was abstinence at 1 yr. Secondary outcome was a composite of all-cause death, non-fatal myocardial infarction, and non-fatal stroke at 1 yr.

RESULTS

Of 4658 current smokers, 1838 (39.5%) were abstinent 1 yr after surgery. Median (inter-quartile range) time to resumption was 7 (3-23) days post-surgery. Perioperatively, 7.2% of current smokers obtained smoking cessation pharmacotherapy. Older age (adjusted risk ratio [aRR] 1.21; 95% confidence interval [CI]: 1.12-1.32); having recent coronary artery disease (aRR 1.41; 95% CI: 1.29-1.55); cancer (aRR 1.37; 95% CI: 1.18-1.59); and undergoing major vascular (aRR 1.20; 95% CI: 1.02-1.41), urgent/emergent (aRR 1.14; 95% CI: 1.05-1.23), or thoracic (aRR 1.41; 95% CI: 1.26-1.56) surgeries increased abstinence. One-year abstinence was less likely when patients stopped smoking 0-1 day (aRR 0.53; 95% CI: 0.43-0.66) and 2-14 days (aRR 0.76; 95% CI: 0.71-0.82) before surgery compared with >14 days before surgery. Current smokers (adjusted hazard ratio [aHR] 1.14; 95% CI: 1.01-1.29) and ex-smokers (aHR 1.11; 95% CI: 1.03-1.21) had higher risk of the 1-yr vascular outcome compared with never smokers.

CONCLUSIONS

Long-term tobacco abstinence is more likely after major surgery in those with serious medical comorbidities. Interventions to prevent smoking resumption after surgery remain a priority. Clinical trial registration NCT00512109.

Modifiable risk factors for prostate cancer in low- and lower-middle-income countries: a systematic review and meta-analysis

BACKGROUND

Most of the epidemiological data on prostate cancer risk factors come from high-income countries (HIC). Reducing exposure to prostate cancer modifiable risk factors may significantly lower PCa morbidity and mortality in LIC and MIC. The objective of this study was to summarize the evidence on modifiable risk factors (RFs) for PCa in LIC and lower-middle-income countries (LMIC).

METHODS

We conducted a systematic search on MEDLINE, EMBASE, and Global Health databases. We selected case-control and cohort studies from 2010 onwards that studied modifiable RFs for PCa in LIC and LMIC with a population of 30 million or more, as defined by the World Bank in January 2021. Risk of bias was assessed by the Ottawa-Newcastle tool. Individual study estimates were pooled when estimates were available for at least two studies.

RESULTS

5740 studies were initially identified; 16 studies met inclusion criteria. All were case-control studies except one retrospective cohort study. Higher fat intake was associated with a higher risk of PCa incidence with an odds ratio (OR) of 3.13 (95% CI 1.33-7.33). Higher vegetable intake (OR 0.48, 95% CI 0.24-0.97) and tea consumption (OR 0.51, 95% CI 0.32-0.83) were associated with a lower risk for PCa. There was no association between fruits, fish, and chicken consumption and risk of PCa. Alcohol consumption, smoking, red meat intake, and a BMI ≥ 25-30 kg/m² showed a trend towards an increased risk, although these were not statistically significant.

CONCLUSIONS

In LIC and LMIC, high fat intake was associated with higher risk of PCa while a diet rich in vegetables and tea intake was associated with a lower risk. Future prospective studies will be important to elucidate whether other modifiable risk factors for PCa specific to LIC and LMIC can be identified to inform impactful and cost-effective preventive strategies in these countries.