Ethnic differences in smoking intensity and COPD risk: an observational study in primary care

Obtaining the Most Accurate, Explainable Model for Predicting Chronic Obstructive Pulmonary Disease: Triangulation of Multiple Linear Regression and Machine Learning Methods

BACKGROUND

Lung disease is a severe problem in the United States. Despite the decreasing rates of cigarette smoking, chronic obstructive pulmonary disease (COPD) continues to be a health burden in the United States. In this paper, we focus on COPD in the United States from 2016 to 2019.

OBJECTIVE

We gathered a diverse set of non-personally identifiable information from public data sources to better understand and predict COPD rates at the core-based statistical area (CBSA) level in the United States. Our objective was to compare linear models with machine learning models to obtain the most accurate and interpretable model of COPD.

METHODS

We integrated non-personally identifiable information from multiple Centers for Disease Control and Prevention sources and used them to analyze COPD with different types of methods. We included cigarette smoking, a well-known contributing factor, and race/ethnicity because health disparities among different races and ethnicities in the United States are also well known. The models also included the air quality index, education, employment, and economic variables. We fitted models with both multiple linear regression and machine learning methods.

RESULTS

The most accurate multiple linear regression model has variance explained of 81.1%, mean absolute error of 0.591, and symmetric mean absolute percentage error of 9.666. The most accurate machine learning model has variance explained of 85.7%, mean absolute error of 0.456, and symmetric mean absolute percentage error of 6.956. Overall, cigarette smoking and household income are the strongest predictor variables. Moderately strong predictors include education level and unemployment level, as well as American Indian or Alaska Native, Black, and Hispanic population percentages, all measured at the CBSA level.

CONCLUSIONS

This research highlights the importance of using diverse data sources as well as multiple methods to understand and predict COPD. The most accurate model was a gradient boosted tree, which captured nonlinearities in a model whose accuracy is superior to the best multiple linear regression. Our interpretable models suggest ways that individual predictor variables can be used in tailored interventions aimed at decreasing COPD rates in specific demographic and ethnographic communities. Gaps in understanding the health impacts of poor air quality, particularly in relation to climate change, suggest a need for further research to design interventions and improve public health.

Chronic Obstructive Pulmonary Disease and Its Acute Exacerbation before Colon Adenocarcinoma Treatment Are Associated with Higher Mortality: A Propensity Score-Matched, Nationwide, Population-Based Cohort Study

Simple Summary

This is the first study to reveal that hospitalization frequency for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) before colon adenocarcinoma treatment is a severity-dependent and independent prognostic factor for overall survival in patients with stage I–III colon cancer receiving surgical resection and standard treatments. In patients with colon adenocarcinoma undergoing curative resection, those with chronic obstructive pulmonary disease (COPD) had poorer survival outcomes than had those without COPD. Hospitalization for AECOPD at least once within 1 year before colon adenocarcinoma diagnosis is an independent risk factor for poor overall survival in these patients, and a higher number of hospitalizations for AECOPD within 1 year before diagnosis was associated with poorer survival. Our study may be applied to accentuate the importance of COPD management, particularly the identification of frequent exacerbators and the prevention of AECOPD, before standard colon adenocarcinoma treatments are initiated.

Abstract

Purpose: To investigate whether chronic obstructive pulmonary disease (COPD) and COPD severity (acute exacerbation of COPD (AECOPD)) affect the survival outcomes of patients with colon adenocarcinoma receiving standard treatments. Methods: From the Taiwan Cancer Registry Database, we recruited patients with clinical stage I–III colon adenocarcinoma who had received surgery. The Cox proportional hazards model was used to analyze all-cause mortality. We categorized the patients into COPD and non-COPD (Group 1 and 2) groups through propensity score matching. Results: In total, 1512 patients were eligible for further comparative analysis between non-COPD (1008 patients) and COPD (504 patients) cohorts. In the multivariate Cox regression analysis, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) for all-cause mortality for Group 1 compared with Group 2 was 1.17 (1.03, 1.29). In patients with colon adenocarcinoma undergoing curative resection, the aHRs (95% CIs) for all-cause mortality in patients with hospitalization frequencies of ≥1 and ≥2 times for AECOPD within 1 year before adenocarcinoma diagnosis were 1.08 (1.03, 1.51) and 1.55 (1.15, 2.09), respectively, compared with those without AECOPD. Conclusion: In patients with colon adenocarcinoma undergoing curative resection, COPD was associated with worse survival outcomes. Being hospitalized at least once for AECOPD within 1 year before colon adenocarcinoma diagnosis was an independent risk factor for poor overall survival in these patients, and a higher number of hospitalizations for AECOPD within 1 year before diagnosis was associated with poorer survival. Our study highlights the importance of COPD management, particularly the identification of frequent exacerbators and the prevention of AECOPD before standard colon adenocarcinoma treatments are applied.

Genetic Factors Associated with COPD Depend on the Ancestral Caucasian/Amerindian Component in the Mexican Population

Genetic variability influences the susceptibility to and severity of complex diseases; there is a lower risk of COPD in Hispanics than in non-Hispanic Caucasians. In this study, we included 830 Mexican-Mestizo subjects; 299 were patients with COPD secondary to tobacco smoking, and 531 were smokers without COPD. We employed a customized genotyping array of single nucleotide polymorphisms (SNPs). The population structure was evaluated by principal component analysis and allele association through a logistic regression model and haplotype identification. In this study, 118 individuals were identified with a high Caucasian component and 712 with a high Amerindian component. Independent of the ancestral contribution, two SNPs were associated with a reduced risk (p ≤ 0.01) of developing COPD in the CYP2A6 (rs4105144) and CYP2B6 (rs10426235) genes; however, a haplotype was associated with an increased risk of COPD (p = 0.007, OR = 2.47) in the CHRNA5-CHRNA3 loci among smokers with a high Caucasian component. In Mexican-Mestizo smokers, there are SNPs in genes that encode proteins responsible for the metabolism of nicotine associated with a lower risk of COPD; individuals with a high Caucasian component harboring a haplotype in the CHRNA5-CHRNA3 loci have a higher risk of suffering from COPD.

Ethnic Variance in Prevalence of COPD among Smokers in a Real World Setting

INTRODUCTION

Chronic Obstructive Pulmonary Disease (COPD) is characterized by persistent and progressive airflow limitation generally caused by prolonged cigarette smoking. Ethnic differences have been reported regarding COPD risk from smoking. The purpose of this study was to compare COPD prevalence in Hispanic and Caucasian smokers in a real-world setting. We studied consecutive patients referred to the community-based pulmonary practice. Hispanic and Caucasian smokers were included in the study.

METHODS

The clinical diagnosis of COPD was recorded from the chart. COPD was defined by PFT using GOLD criteria. Exclusion criteria were other ethnicities, non-smokers, and patients with a history of asthma /other pulmonary conditions. We reviewed a total of 1,313 consecutive PFTs of which 797 patients met our inclusion criteria.

RESULTS AND DISCUSSION

The prevalence of COPD among Hispanics was found to be lower by both clinical diagnosis as well as by spirometry compared to Caucasians (41.6% vs 54.2%). In Hispanics, clinical diagnosis was 91% higher by PFT, whereas for Caucasians, it was 6% lower. The odds of developing COPD (diagnosed based on FEV1/FVC ratio <70%) in the Caucasians are 4.1 times higher than Hispanics (Odds Ratio: 4.1; 95%CI: 2.8-5.9). Hispanic smokers have a lower prevalence of COPD both by the clinical diagnosis as well as by PFT. There is a significant disconnection between clinical and PFT diagnosis of COPD in Hispanic patients.

CONCLUSION

The genetic basis of lower COPD risk and prevalence in Hispanics needs to be better understood. Spirometry threshold criteria for confirming a diagnosis of COPD may need to be modified based on ethnicity in clinical practice.

Exclusive E-Cigarette Users Report Lower Levels of Respiratory Symptoms Relative to Dual E-Cigarette and Cigarette Users

INTRODUCTION

Exclusive e-cigarette use has been shown to be associated with reduced levels of respiratory symptoms relative to smoking combustible cigarettes; this association has been less frequently studied in smokers using advanced-generation e-cigarette devices. Advanced-generation devices generate denser vapor than either early generation or pod-style devices, and engender longer inhalations; these vaping topography patterns may contribute to respiratory symptoms.

METHODS

In a single-session, cross-sectional study of exclusive e-cigarette users (N = 59) and dual users of e-cigarettes and cigarettes (N = 54), participants completed questionnaires, including the American Thoracic Society Questionnaire (ATSQ) and were videotaped vaping their own device in the lab for 1 hour. Using a hierarchical regression method, we examined whether topography variables, level of nicotine concentration used in their e-cigarette device in the past month, e-cigarette dependence, amount of e-cigarette use in the past month, and smoking status (any smoking in the last month vs. none) predicted ATSQ score severity.

RESULTS

There was a significant mean difference in ATSQ score across smoking status, with greater ATSQ scores for vapers who also smoked cigarettes (19.0, SD = 6.7) than for exclusive vapers (13.4, SD = 5.3). In the final model, of the predictors of interest, only cigarette smoking status predicted significantly greater ATSQ scores (overall F = 2.51, p = .006; R2 = .26; smoking status β = 0.39, p < .0001).

CONCLUSIONS

Findings suggest that differences in respiratory symptoms between dual and exclusive e-cigarette users appear to be attributable to combustible cigarette smoking, rather than more intense or frequent e-cigarette use across groups.

IMPLICATIONS

In this comparison of exclusive advanced-generation vape device users (N = 59) versus dual users of these devices and combustible cigarettes (N = 54), we set out to determine the extent to which smoking status and e-cigarette use variables predicted self-reported respiratory symptom severity. We found that dual users showed greater respiratory symptom severity (ATSQ scores) than exclusive vapers. Despite examining vaping topography and other variables, smoking status and race were the only significant predictor of respiratory symptoms. We conclude that combustible cigarette use, not individual vaping topography, likely accounts for differences in respiratory symptoms between dual users and exclusive vapers.

Burden of Obstructive Lung Disease in Iran: Prevalence and Risk Factors for COPD in North of Iran

BACKGROUND

Globally chronic obstructive pulmonary disease (COPD) was reported as the fourth leading cause of death (5.1%) in 2004 and is projected to occupy the third position (8.6%) in 2030. The goal of the present project is to describe the prevalence and risk factors of COPD in a province in the north of Iran.

METHODS

This study followed a stratified cluster sampling strategy with proportional allocation within strata. The stratification of the sample according to the 31 provinces of Iran is incorporated in the sampling process. The single most important outcome measure obtained as part of this protocol was spirometry before and after the administration of 200 mg (2 puffs) of salbutamol. The descriptive statistics for categorical variables included the number and percent and for continues variables included the mean ± SD.

RESULTS

A total of 1007 subjects were included in the study. Among all participants, 46 (5%) subjects had COPD on the basis of symptoms and 43 (8.3%) subjects had COPD on the basis of spirometry criteria. In univariate analysis, urban inhabitants in comparison with rural inhabitants had lower COPD risk (OR: 0.48; 95% CI: 0.24-0.95), smoker had higher risk compared with nonsmokers (OR: 1.97; 95% CI: 1.01-3.82), and subjects with exposure to dust (OR: 2.07; 95% CI: 1.09-3.94) had higher risk compared with contrary status.

CONCLUSIONS

This study showed that occupational and environmental smoke exposure was associated with COPD. A new design of preventive measures must be taken to control cooking energy and cooking stoves, particularly in rural areas.

The effects of hidden female smokers on the association between smoking and chronic obstructive pulmonary disease in Korean adults

OBJECTIVE

Smoking is an important causative factor of chronic obstructive pulmonary disease (COPD), and females are considered more susceptible to the effects of smoking than males. However, in previous Korean studies, the effects of sex differences on the association between smoking and COPD have been controversial. In this study, the effects of sex differences on the association between smoking and COPD and the effects of female hidden smokers on that association in Korean adults were investigated.

METHODS

Data were acquired from the Korea National Health and Nutrition Examination Surveys (KNHANES).

RESULTS

The multivariate logistic regression analysis showed that self-reported smoking status for ex-smoker and current smoker correlated with COPD (odds ratio, OR: 1.67 and OR: 2.41, respectively). Self-reported smoking status for ex-smoker and current smoker correlated with COPD in men (OR: 1.61, OR: 2.43, respectively). Female self-reported current smoking status correlated with COPD (OR: 2.52), but female ex-smoker status was not significantly correlated with COPD. The ratios of cotinine-verified to self-reported smoking rates were 1.95 for women and 1.07 for men.

CONCLUSION

The results of this study were that sex differences might affect the association between COPD and smoking and that female hidden smoking might affect the association between smoking and COPD in Korean adults.

A Between Ethnicities Comparison of Chronic Obstructive Pulmonary Disease Genetic Risk

Heterogeneity of lung function levels and risk for developing chronic obstructive pulmonary disease (COPD) among people exposed to the same environmental risk factors, such as cigarette smoking, suggest an important role of genetic factors in COPD susceptibility. To investigate the possible role of different genetic factors in COPD susceptibility across ethnicities. We used a population-stratified analysis for: (i) identifying ethnic-specific genetic susceptibility loci, (ii) developing ethnic-specific polygenic risk prediction models using those SNPs, and (iii) validating the models with an independent dataset. We elucidated substantial differences in SNP heritability and susceptibility loci for the disease across ethnicities. Furthermore, the application of three ethnic-specific prediction models to an independent dataset showed that the best performance is achieved when the prediction model is applied to a dataset with the matched ethnic sample. Our study validates the necessity of considering ethnic differences in COPD risk; understanding these differences might help in preventing COPD and developing therapeutic strategies.

COPD and asthma in patients with opioid dependency: a cross-sectional study in primary care

Patients treated for drug addiction have high asthma and COPD prevalence rates. The relative contributions of cigarette smoking, smoking intensity and possible smoking of other substances has not been described. We aimed to describe the prevalence and determinants of asthma and COPD in patients prescribed methadone as opioid substitution therapy (OST). In a cross-sectional study of an anonymised patient-level primary care dataset of UK inner-city general practices (n = 46), 321,395 patients aged ≥18 years were identified. A total of 676 (0.21%) had a record of a methadone ever issued in primary care. The association between respiratory disease and methadone prescribing was examined using logistic regression. Models were adjusted for potential effects of clustering by practice. A total of 97.3% of patients prescribed methadone were cigarette smokers, either current (81.2%) or ex-smokers (16.1%). The prevalences of asthma and COPD were higher in methadone patients (14.2% and 12.4%, respectively) compared to non-methadone patients (4.4% and 1.1%, respectively). Methadone was an independent determinant of asthma, adjusting for smoking status (OR 3.21; 95% CI: 2.52, 4.10) or for smoking intensity (3.08; 2.27, 4.19), and of COPD, adjusting for smoking status (6.00; 4.61, 7.80) or for smoking intensity (5.80; 4.12, 8.17). COPD and asthma prevalence were substantially higher in those prescribed methadone compared to those never prescribed methadone. Prescription of methadone was an independent predictor for both COPD and asthma, even after adjustment for smoking status and smoking intensity. Possible explanations include confounding by association with smoking of heroin or crack cocaine, both of which may have a causal association with COPD and asthma.

Obesity Predicts Liver Function Testing and Abnormal Liver Results

OBJECTIVE

Abnormal liver function tests in children and young people (CYP) predict a greater burden of liver disease in adulthood, especially in the context of obesity. This study aimed to determine whether obesity and metabolic risk factors predict liver function testing and abnormal liver test results in CYP.

METHODS

This was a retrospective cross-sectional population study using electronic health care records from 257,746 CYP aged 10 to 25 years who were registered with 170 contiguous general practices in London, UK. Demographic and clinical data were extracted, including serum alanine aminotransferase (ALT) tests between 2015 and 2017. BMI category thresholds were adjusted according to age group and ethnicity.

RESULTS

Fourteen percent of CYP had ALT measured, of whom 5.4% had abnormal results; 36.3% had BMI indicating overweight or obesity. Nonalcoholic fatty liver disease was the most common liver diagnosis. Multivariate analyses demonstrated that overweight or obesity was an independent predictor of ALT testing in young people (ages 18-25) but not in children (ages 10-17) and of abnormal test results in all CYP, irrespective of ALT threshold.

CONCLUSIONS

Overweight and obesity are predictors of liver testing (not in children) and abnormal test results, irrespective of ALT threshold. Given the rising prevalence of metabolic dysfunction, a coordinated strategy is needed for liver testing and interpreting results in this young population.

Depression and cause-specific mortality in an ethnically diverse cohort from the UK: 8-year prospective study

BACKGROUND

Depression is associated with increased mortality, however, little is known about its variation by ethnicity.

METHODS

We conducted a cohort study of individuals with ICD-10 unipolar depression from secondary mental healthcare, from an ethnically diverse location in southeast London, followed for 8 years (2007-2014) linked to death certificates. Age- and sex- standardised mortality ratios (SMRs), with the population of England and Wales as a standard population were derived. Hazard ratios (HRs) for mortality were derived through multivariable regression procedures.

RESULTS

Data from 20 320 individuals contributing 91 635 person-years at risk with 2366 deaths were used for analyses. SMR for all-cause mortality in depression was 2.55(95% CI 2.45-2.65), with similar trends by ethnicity. Within the cohort with unipolar depression, adjusted HR (aHRs) for all-cause mortality in ethnic minority groups relative to the White British group were 0.62(95% CI 0.53-0.74) (Black Caribbean), 0.53(95% CI 0.39-0.72) (Black African) and 0.69(95% CI 0.52-0.90) (South Asian). Male sex and alcohol/substance misuse were associated with an increased all-cause mortality risk [aHR:1.94 (95% CI 1.68-2.24) and aHR:1.18 (95% CI 1.01-1.37) respectively], whereas comorbid anxiety was associated with a decreased risk [aHR: 0.72(95% CI 0.58-0.89)]. Similar associations were noted for natural-cause mortality. Alcohol/substance misuse and male sex were associated with a near-doubling in unnatural-cause mortality risk, whereas Black Caribbean individuals with depression had a reduced unnatural-cause mortality risk, relative to White British people with depression.

CONCLUSIONS

Although individuals with depression experience an increased mortality risk, marked heterogeneity exists by ethnicity. Research and practice should focus on addressing tractable causes underlying increased mortality in depression.

Prevalence and outcomes of non-alcoholic fatty liver disease (NAFLD) among Asian American adults in the United States

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) affects about 25% of the general population worldwide. Although epidemiology of NAFLD is well studied in the United States, there is paucity of data for the Asian Americans. Our aim was to assess the prevalence and risk factors for NAFLD among Asian Americans.

METHODS

We utilized NHANES data for 2011-2016. We defined NAFLD using recently derived US-FLI. Relative risks (RRs) and population attributable fractions (PAFs) of metabolic components on atherosclerotic cardiovascular disease (ASCVD) and advanced fibrosis were calculated for Asian Americans, and these rates were compared to non-Hispanic whites.

RESULTS

NAFLD prevalence was 18.3% among Asian Americans and 28.4% among non-Hispanic whites. Asian Americans with NAFLD had lower BMI and waist circumference than non-Hispanic whites with NAFLD and were less likely to have metabolic syndrome, cardiovascular disease (CVD), chronic obstructive pulmonary disease, cancer and incident ASCVD (P < 0.05). Hyperlipidaemia had the highest attributable fraction (76.6%) for risk of ASCVD among Asian Americans with NAFLD, followed by diabetes (24.0%), current smoking (9.2%), and obesity (3.7%). Advanced fibrosis in Asian American with NAFLD was independently associated with presence of type 2 diabetes (RR = 2.70, 95% CI: 1.00-7.27).

CONCLUSIONS

Asian Americans have lower prevalence of NAFLD than non-Hispanic whites. However, Asian Americans with NAFLD have similar risk factors for advanced fibrosis and ASCVD than non-Hispanic Whites.