Asian Chronic Obstructive Pulmonary Disease Research Articles

Clinical significance of chronic bronchitis in different racial groups

BackgroundsLimited data are available on racial differences in the clinical features of chronic bronchitis (CB) patients with chronic obstructive pulmonary disease (COPD). In this study, we aimed to compare clinical features among CB patients of different races. We also analyzed the clinical significance of CB, defined classically and based on the COPD Assessment Test (CAT), to validate the CAT-based definition.MethodsWe analyzed patient data extracted from the Korean COPD Subgroup Study (KOCOSS) cohort (2012–2021) and US Genetic Epidemiology of COPD (COPDGene) study (2008–2011). We compared clinical characteristics among CB and non-CB patients of three different races using two CB definitions.ResultsIn this study, 3,462 patients were non-Hispanic white (NHW), 1,018 were African American (AA), and 1,793 were Asian. The proportions of NHW, AA, and Asian patients with CB according to the classic definition were 27.4%, 20.9%, and 10.7%, compared with 25.2%, 30.9%, and 23.0% according to the CAT-based definition, respectively. The risk of CB prevalence was highest in NHW and lowest in Asian COPD patients. Among all races, CB patients were more likely to be current smokers, have worse respiratory symptoms and poorer health-related quality of life (HrQoL), and to have decreased lung function and exercise capacity. Most of these characteristics showed similar associations with the outcomes between the two definitions of CB. A binominal regression model revealed that CB patients of all races had an increased risk of future exacerbations according to both CB definitions, except for Asian patients with classically defined CB.ConclusionsThe presence of CB was associated with worse respiratory symptoms, HrQoL, exercise capacity and lung function, and more exacerbations, regardless of race or CB definition. The CAT-based definition may be more useful for assessing the risk of future exacerbations in Asian COPD patients.

Identification of novel candidate genes in East Asian COPD patients by the functional summary-based imputation and the unified test for molecular signatures: a transcriptome-wide association study

Identification of novel candidate genes in East Asian COPD patients by the functional summary-based imputation and the unified test for molecular signatures: a transcriptome-wide association study

Low body mass is associated with reduced left ventricular mass in Chinese elderly with severe COPD

There is limited information on the association of body mass index (BMI) with left ventricular (LV) remodeling corresponding to severity of reduced lung function in patients with chronic obstructive pulmonary disease (COPD). Therefore, we investigated whether BMI is associated with cardiac atrial and ventricular dimensions according to severity of lung functional impairment in Chinese COPD elderly. A total of 563 hospitalized COPD patients with lung function impairment and 184 patients with non-COPD (aged 65–92 years) were collected retrospectively in a cross-sectional study in a university affiliated tertiary hospital in China. BMI and cardiac echocardiographic parameters were compared according to severity of lung functional impairment in COPD patients. BMI was 22.9 ± 3.9 kg/m2 in COPD patients, 24.0 ± 4.1 kg/m2 in non-COPD patients respectively. Reduced BMI, LV mass index, LV wall thickness and left atrial diameter, and dilated right ventricle (RV) existed in COPD patients with severe lung dysfunction as compared the COPD patients with mild to moderate lung functional reduction and non-COPD patients (P < 0.05), while there were no differences in BMI and echocardiographic parameters between the COPD patients with mild to moderate lung functional decline and non-COPD patients (P > 0.05). Logistic regression analysis showed that low BMI (BMI < 18.5 kg/m2) was correlated with reduced LV mass and wall thickness, dilated RV and reduced lung function in the COPD patients with severe lung dysfunction. In conclusion, this study demonstrates that lower BMI is associated not only with dilated RV and impaired pulmonary function, but also it is related to reduced LV mass in Asian COPD elderly with severe lung dysfunction.

A Simplified Screening Questionnaire for Detecting Severe OSA in Chronic Obstructive Airway Disease in Asian Population

The aim of this study was to develop a simplified screening questionnaire to detect the existence of severe obstructive sleep apnea (OSA) in chronic obstructive pulmonary disease (COPD) patients to reduce mortality and hospitalization rates. Seventy-seven stable Asian COPD patients aged 69.2 ± 11.5 years were retrospectively analyzed into the development group. The simplified screening questionnaire was developed from factors identified from sleep surveys and demographic data to predict severe OSA. Receiver operating characteristic (ROC) curve analysis was used to validate the simplified screening questionnaire. Data from another 78 stable COPD patients were used for validation. The apnea-hypopnea index was similar between the development and validation groups (26.3 ± 21.9 and 27.6 ± 21.1, respectively). After logistic regression analysis in the development group, snoring, body mass index ≥27.5 kg/m2, witnessed apnea and coronary artery disease were incorporated into the screening questionnaire to predict OSA. When this questionnaire was applied to the validation group, the results were similar. The simplified screening questionnaire developed is useful in identifying severe OSA in COPD patients.

Management of COPD in Asia: A position statement of the Asian Pacific Society of Respirology

Chronic obstructive pulmonary disease (COPD) is a major disease in Asia. However, how to manage specifically Asian COPD patients has not been proposed. Awareness of COPD is very low and underdiagnosis/undertreatment is common in Asian countries. Low utilization of pulmonary function test and inhalers is also a problem. Moreover, high smoking prevalence and air pollution are barriers to managing Asian patients with COPD. The relatively low body mass index of Asian patients with COPD can increase their risk for experiencing adverse effects from COPD drugs. Physicians should consider the unique features of Asian populations with COPD such as the high prevalence rates of bronchiectasis and tuberculosis-destroyed lungs, biomass smoke exposure and parasitic infection.

Fixed-Dose Combinations of Long-Acting Bronchodilators for the Management of COPD: Global and Asian Perspectives.

Maintenance bronchodilator therapy with long-acting β-agonists (LABAs) and long-acting muscarinic antagonists (LAMAs) is the cornerstone treatment for patients with stable chronic obstructive pulmonary disease (COPD). Fixed-dose combinations (FDCs) of LABA/LAMA are recommended for the majority of symptomatic COPD patients by global guidelines; regional guidelines such as the Japanese and Korean guidelines also provide similar recommendations for the use of LABA/LAMA FDCs. This review comprehensively describes the latest clinical evidence from key studies on the efficacy and safety of four approved LABA/LAMA fixed-dose combinations: indacaterol/glycopyrronium, vilanterol/umeclidinium, formoterol/aclidinium, and olodaterol/tiotropium. Additionally, in this review we describe the rationale behind the use of LABA/LAMA FDC therapy, key findings from the preclinical and clinical trial evaluation of respective LABA and LAMA monocomponents, and the efficacy and safety of LABA/LAMA FDCs. Special emphasis is placed on the clinical evidence for the monocomponents and LABA/LAMA FDCs from the Asian population. This detailed overview of the efficacy and safety of LABA/LAMA FDCs in global and Asian COPD patients is envisaged to provide a better understanding of the benefits of these therapies and to inform healthcare providers and patients on their appropriate use.Funding: Novartis Pharma K.K.Electronic supplementary materialThe online version of this article (10.1007/s12325-019-0893-3) contains supplementary material, which is available to authorized users.

Identification of chronic obstructive pulmonary disease subgroups in 13 Asian cities.

Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition that can differ in its clinical manifestation, structural changes and response to treatment. To identify subgroups of COPD with distinct phenotypes, evaluate the distribution of phenotypes in four related regions and calculate the 1-year change in lung function and quality of life according to subgroup. Using clinical characteristics, we performed factor analysis and hierarchical cluster analysis in a cohort of 1676 COPD patients from 13 Asian cities. We compared the 1-year change in forced expiratory volume in one second (FEV1), modified Medical Research Council dyspnoea scale score, St George's Respiratory Questionnaire (SGRQ) score and exacerbations according to subgroup derived from cluster analysis. Factor analysis revealed that body mass index, Charlson comorbidity index, SGRQ total score and FEV1 were principal factors. Using these four factors, cluster analysis identified three distinct subgroups with differing disease severity and symptoms. Among the three subgroups, patients in subgroup 2 (severe disease and more symptoms) had the most frequent exacerbations, most rapid FEV1 decline and greatest decline in SGRQ total score. Three subgroups with differing severities and symptoms were identified in Asian COPD subjects.

Association between glutathione S-transferase gene M1 and T1 polymorphisms and chronic obstructive pulmonary disease risk: A meta-analysis.

Chronic obstructive pulmonary disease (COPD) is a severe lung disease characterized by long-term breathing problems. A series of studies have indicated that the glutathione S-transferase genes M1 and T1 are associated with COPD susceptibility; however, the result still remains inconclusive. This meta-analysis was performed to estimate the effect of GSTM1 and GSTT1 polymorphisms in COPD risk. Eligible case-control studies published between January 2000 and December 2017 was searched and retrieved. A total of 37 articles were screened out, including 4674 COPD patients and 5006 controls. Overall, our results found that GSTM1 and GSTT1 null genotypes significantly increased the risk of COPD (GSTM1: odds ratio [OR] = 1.52, 95% confidence interval [CI] = 1.31-1.77, P <.00001; GSTT1: OR = 1.28, 95% CI = 1.09-1.50, P = .003). Subgroup analysis by ethnicity suggested that there was a close association between GSTM1 null polymorphism and COPD susceptibility in each studied ethnicity, while GSTT1 null polymorphism only showed association with Asian COPD patients. Moreover, we also found that joint GSTM1/GSTT1 null genotypes showed a high association with increased COPD susceptibility (OR = 1.42, 95% CI = 1.21-1.66, P < .0001). In conclusion, our results indicated that GSTM1 null, GSTT1 null, and the combined GSTM1/GSTT1 null genotypes might be risk factors in the development of COPD. However, future case-control studies with large-scale participants are still required to further estimate these associations.

Year in review 2017: Chronic obstructive pulmonary disease and asthma.

Year in review 2017: Chronic obstructive pulmonary disease and asthma.

Association of the IL-13 polymorphisms rs1800925 and rs20541 with chronic obstructive pulmonary disease risk: An updated meta-analysis.

The aim of this study was to investigate if 2 common single nucleotide polymorphisms (SNPs) in the interleukin-13 (IL-13) gene, rs1800925 and rs20541 are associated with chronic obstructive pulmonary disease (COPD) risk.Case–control association studies were retrieved systematically from PubMed, Scopus, ISI Web of Science, China National Knowledge Infrastructure, and Wanfang databases using standardized subject terms.Eleven studies including 3077 participants (1896 cases and 1181 controls) were analyzed. Evidence for a positive association between the T allele of the IL-13 SNP rs1800925 and COPD risk was found in the overall population (odds ratio [OR] = 1.57, 95% confidence interval [95% CI]: 1.21–2.04, Pz = .001). In subgroup analysis according to ethnicity, the T allele of rs1800925 was associated with an increased risk of COPD in Asians (OR = 1.88, 95% CI: 1.23–2.87, Pz = .004) and Caucasians (OR = 1.30, 95% CI: 1.01–1.67, Pz = .041), respectively. For rs20541, the results suggested an association between rs20541 and COPD risk in Caucasians under the recessive model (OR = 2.79, 95% CI: 1.13–6.92, Pz = .026), whereas this SNP was not associated with COPD in Asians.This meta-analysis suggests that the T allele of rs1800925 is associated with the increased risk of COPD in both Asians and Caucasians, whereas rs20541 is associated with the risk of COPD in Caucasians but not in Asians.

Incidence and risk factors of atrial fibrillation in Asian COPD patients.

ObjectiveTo investigate the incidence and risk factors of atrial fibrillation (AF) in Asian chronic obstructive pulmonary disease (COPD) patients.Patients and methodsWe selected a study population older than 40 years with a COPD diagnosis and who had used at least one inhaled bronchodilator medication between 1998 and 2012. The date of the index COPD diagnosis was defined as the index date. We excluded patients with a history of AF, significant mitral valve disease, disorders of the thyroid gland, or ischemic heart disease before the index date. We followed all patients from the index date to the day of AF occurrence, the day of death, or the date of December 31, 2013. The baseline of comorbidities was identified before the index date. Comorbidities included hypertension, diabetes mellitus, end-stage renal disease, congenital heart failure, stroke, peripheral arterial occlusive disease, and malignancy.ResultsWe included 6,208 COPD patients and 12,409 patients without COPD. The incidence of AF was higher in COPD patients than in those without COPD. The adjusted hazard ratio (HR) for AF among those with COPD was 2.23 with a 95% confidence interval (CI) of 1.98–2.51 compared to those without COPD. After multiple analyses, patients with hypertension (HR 1.43 [95% CI =1.26–1.62]) or heart failure (HR 2.36 [95% CI =1.81–3.08]) were found to have a significantly higher incidence of AF than those without these conditions.ConclusionIt is important for physicians to monitor, prevent, and provide early intervention for AF in COPD patients with hypertension or heart failure.

Risk and clinical predictors of osteoporotic fracture in East Asian patients with chronic obstructive pulmonary disease: a population-based cohort study.

IntroductionOsteoporosis is becoming an impending epidemic in the Asia-Pacific region. The association between risk of osteoporotic fracture (OTPF) and chronic obstructive pulmonary disease (COPD) in East Asian patients is yet to be fully examined. We conducted a nationwide population-based retrospective cohort study of 98,700 patients aged ≥50 years with or without COPD using a national administrative claims dataset.Materials and MethodsThe patients were divided into COPD and comparison groups comprising 19,740 and 78,960 patients, respectively. The groups were 1 to 4 matched for age, gender, index date, diabetes mellitus, pre-existing osteoporosis and chronic kidney disease. Information such as the geographic area where southern part represented more sunshine exposure, smoking-related diagnoses, alcohol use disorder, whether there was regular use of inhaled corticosteroids and oral corticosteroids, vitamin D prescriptions, Charlson-Deyo comorbidity index score, and other relevant medical comorbidities were extracted for analysis. They were followed up until OTPF or the end of the year 2013. The outcome measure was an osteoporotic vertebral fracture and other long-bone fractures. A multivariate Cox model was constructed to derive adjusted hazard ratios (aHR) for OTPF with corresponding 95% confidence intervals (CI) after controlling for age, sex, insurance premium category, vitamin D prescription, osteoporosis, and coronary heart disease (CHD). Kaplan–Meier curves of the probability of OTPF-free survival for each cohort were compared using the log-rank test. Patients with OTPF during the first follow-up year were excluded from the overall risk calculation. Contributing factors to the increased risk of OTPF in COPD patients were examined in a sensitivity analysis.ResultsAfter a total follow-up of 68,743 patient-years for the COPD group and 278,051 patient-years for the matched comparison group, the HR for OTPF was 1.24 (95% CI [1.02–1.51]; P = 0.0322) in COPD patients. The aHR was increased by 30% for vertebral OTPF (aHR = 1.297, 95% CI [1.020–1.649]; P = 0.0339). Differential lag time sensitivity analysis revealed a progressively elevated risk up to 8-fold increase in women (aHR = 8.0 (95% CI [1.81–35.4]; P < 0.01)) during the fifth follow-up year. COPD patients with pre-existing osteoporosis or given vitamin D prescription harbor a sustained increased risk up to the 5th (aHR, 4.1; 95% CI [1.61–10.35]) and third (aHR, 2.97; 95% CI [1.48–5.97]) follow-up year, respectively.ConclusionsOur nationwide population-based cohort study demonstrates that East Asian COPD patients aged 50 and beyond do harbor a modestly increased risk for osteoporotic vertebral fractures particularly for those who are female, have pre-existing osteoporosis or require vitamin D prescription.

Postoperative Complications After Coronary Artery Bypass Grafting in Patients With Chronic Obstructive Pulmonary Disease.

Coronary artery disease is common in patients with chronic obstructive pulmonary disease (COPD). Previous studies have shown that patients with COPD have a higher risk of mortality than those without COPD after coronary artery bypass grafting (CABG). However, most of the previous studies were small, single-center studies with limited case numbers (or their only focus was mortality). The aim of our study was to focus on readmission, acute myocardial infarction (AMI), acute respiratory failure (ARF), cerebrovascular accident, and venous thromboembolism rates after CABG in an Asian COPD population.We conducted a nationwide case–control study in Taiwan using the claims database of hospitalization between January 1, 2009 and December 31, 2013. Patients with COPD before CABG were defined as the case groups. Each case was propensity score-matched by age, sex, hypertension, diabetes, dyslipidemia, cardiovascular disease, cerebrovascular disease, and chronic kidney disease, with 2 controls selected from CABG patients without COPD. The outcomes of interest were mortality, wound infection, and the readmission rate over 30 days for the following diseases: AMI, pneumonia, ARF, cerebrovascular accident, and venous thromboembolism.There were 14,858 patients without COPD and 758 patients with COPD who underwent CABG. After propensity score matching, the 30-day mortality and 30-day readmission rates and AMI were higher in the non-COPD group. The incidences of pneumonia and ARF after CABG were higher in the COPD group.Chronic obstructive pulmonary disease does not necessarily lead to mortality, readmission, or AMI after CABG, and the major respiratory complications associated with CABG in patients with COPD were pneumonia and ARF.

Association of interleukin-1β -511C/T promoter polymorphism with COPD risk: a meta-analysis.

Studies examining the role of interleukin (IL)-1β -511C/T promoter polymorphism in the pathogenesis of chronic obstructive pulmonary disease (COPD) have shown inconsistent results. This meta-analysis was performed to assess the association between the IL-1β-511C/T promoter polymorphism and COPD susceptibility. Published case-control, cross-sectional, and cohort studies from Pubmed, Embase, and China National Knowledge Infrastructure databases were retrieved. Data were extracted and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Twelve studies with 1692 cases and 2009 controls were included in this meta-analysis. Pooled effect size showed an overall but not significantly decreased risk of IL-1β-511 C/T with COPD susceptibility (OR = 0.89, 95%CI = 0.78-1.01) in a complete overdominant genetic model (TT+CC vs CT), indicating that homozygous individuals (CC and TT) have a decreased risk for COPD compared with heterozygotes (CT). In subgroup analysis by ethnicity, IL-1β-511C/T was significantly correlated with a decreased risk of COPD in Asians (OR = 0.73, 95%CI = 0.60-0.88, P = 0.001), but not in Caucasians (OR = 1.02, 95%CI = 0.83- 1.24, P = 0.46), confirming a protective role of IL-1β-511C/T in COPD in Asians. Moreover, after excluding studies that included populations not in Hardy-Weinberg equilibrium, the pooled results were robust and no publication bias was observed. This meta-analysis suggests that the IL-1β-511C/T promoter polymorphism deceases the risk of COPD in Asians.

Association of vitamin D-binding protein variants with chronic obstructive pulmonary disease: a meta-analysis.

Gene polymorphism of vitamin D-binding protein (VDBP) correlates with chronic obstructive pulmonary disease (COPD), but the results remain inconclusive. We aimed to explore the association between VDBP gene polymorphism and COPD. We searched MEDLINE, Embase, Web of Science, and China National Knowledge Infrastructure for publications addressing the association between VDBP gene polymorphism and COPD. After qualitative evaluation, randomized controlled trials were pooled using either a fixed- or a random-effect model depending upon the degree of heterogeneity. Eleven studies with 3144 subjects were included. The genotype group-specific component (GC)*1F-1F was significantly associated with COPD in Asians [odds ratio (OR) = 1.73, 95% confidence interval (CI) = 1.07-2.81, P = 0.03], but not in Caucasians (OR = 1.44, 95%CI = 0.57-3.66, P = 0.45). A protective effect of GC*1F-1S was observed in Asians (OR = 0.70, 95%CI = 0.55-0.89, P = 0.003) but not in Caucasians (OR = 0.93, 95%CI = 0.69-1.24, P = 0.61). There was no association of GC*1S-1S, GC*2-1S and GC*1F-2 with COPD. As for alleles, GC*1F was a risk factor, whereas GC*1S was protective against COPD in Asians; GC*2 was not protective. The genotype GC*1F-1F or allele GC*1F was associated with increased susceptibility to COPD in Asians. No protective effect of genotype GC*2-2 against COPD was found. The protective effects of GC*1F-1S and GC*1S were observed in Asians but not in Caucasians. The VDBP gene polymorphism could be a potential marker for screening of COPD.

Dual role of vitamin D-binding protein 1F allele in chronic obstructive pulmonary disease susceptibility: a meta-analysis.

Vitamin D-binding protein (DBP), a highly polymorphic serum protein, encoded by GC gene, is important in the development of chronic obstructive pulmonary disease (COPD). This meta-analysis was performed to assess the association between GC polymorphisms (1F, 1S, and 2 alleles) and COPD susceptibility. Published case-control studies were retrieved from the Pubmed, Embase, and China National Knowledge Infrastructure databases. After data extraction, pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Seven case-control studies were included. Pooled effect size showed that GC polymorphisms were not significantly associated with COPD susceptibility. According to ethnicity, the 1F allele was significantly correlated with COPD susceptibility in Asians (1F vs 1S, OR: 1.52, 95%CI: 1.16-2.00 and 1F vs 2, OR: 1.87, 95%CI: 1.42-2.44), indicating that individuals with the 1F allele have an increased risk of COPD compared to those with the 1S or 2 allele. However, the 1F allele was associated with a lower, insignificant risk of COPD than the 1S and 2 alleles in Caucasians (1F vs 1S, OR: 0.83, 95%CI: 0.64-1.08 and 1F vs 2, OR: 0.73, 95%CI: 0.54-0.98). Moreover, no significant association was found for the 1S and 2 alleles in Asians (OR: 1.23, 95%CI: 0.90- 1.69) and Caucasians (OR: 0.89, 95%CI: 0.70-1.13). After excluding each study, the pooled results were robust and no publication bias was observed. We found that the GC 1F allele confers a risk of COPD in Asians, whereas the 1F allele may protect against COPD in Caucasians.

Interleukin-1B-31T/C promoter polymorphism and chronic obstructive pulmonary disease risk: a meta-analysis.

IntroductionThe role of interleukin (IL)-1β –31T/C promoter polymorphism in the pathogenesis of chronic obstructive pulmonary disease (COPD) has been studied with inconsistent results. This meta-analysis was performed to assess the association of IL-1β –31T/C promoter polymorphism with COPD susceptibility.Material and methodsPublished case-control studies from PubMed and China National Knowledge Infrastructure (CNKI) databases were retrieved. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated.ResultsSix case-control studies were included in this meta-analysis. The pooled effect size showed that IL-1β -31T/C was significantly associated with COPD susceptibility in an overdominant genetic model (CC+TT vs. TC, OR: 0.77, 95% CI: 0.63–0.94), indicating that homozygotes (CC and TT) had a decreased risk for COPD compared with heterozygotes (TC). In the subgroup analysis by ethnicity, the results indicated that IL-1β –31T/C was significantly correlated with COPD susceptibility in Asians (overdominant model, OR: 0.75, 95% CI: 0.61–0.93), further suggesting a protective role of IL-1β –31T/C in COPD pathogenesis in Asians. Moreover, after excluding the study without Hardy-Weinberg equilibrium, the pooled results were robust and no publication bias was found in this study.ConclusionsThis meta-analysis suggests that IL-1β –31T/C promoter polymorphism confers protection against COPD in Asians.

Year in review 2012: Asthma and chronic obstructive pulmonary disease

Year in review 2012: Asthma and chronic obstructive pulmonary disease

Association of -238G/A and -863C/A polymorphisms in the TNF-α gene with chronic obstructive pulmonary disease based on a meta-analysis

Chronic obstructive pulmonary disease (COPD) is a chronic systemic inflammatory disease; increasing evidence indicates that the TNF-α polymorphism is associated with progression of this disease. Few studies have focused upon association between TNF-α -238G/A or -863C/A polymorphism and COPD risk. Reported associations have been controversial because of small sample size and varied study design among the different studies. We performed a meta-analysis to assess the correlation of these two polymorphisms in the TNF-α gene with COPD risk. A comprehensive search was conducted to identify all published articles on the association between TNF-α -238G/A or -863C/A polymorphism and COPD risk from different databases. Pooled odds ratios (ORs) with 95% confidence intervals (CI) were calculated, and the heterogeneity and publication bias were assessed. Eight articles with 10 eligible studies met our inclusion criteria; six studies were of the -238G/A polymorphism and the others involved the -863C/A polymorphism. In the case of the -863C/A polymorphism, significant association was detected only in Asians in the A allele carriers (GA+AA versus GG genotype) and allele (A versus G allele) model (OR = 0.505, 95%CI = 0.321-0.795 and OR = 0.560, 95%CI = 0.368-0.851, respectively). However, no significant association was detected for the -238G/A polymorphism. No evidence of between-study heterogeneity and publication bias was detected. We suggest a potentially protective role of the A allele in the TNF-α -863C/ A polymorphism against developing COPD in Asians. This hypothesis needs further studies for confirmation.

Lack of Association Between the TGF-β1 Gene and Development of COPD in Asians: A Case–Control Study and Meta-analysis

Abnormalities in the transforming growth factor-β(1) (TGF-β(1)) gene are thought to be linked to chronic obstructive pulmonary disease (COPD). We investigated the association between the single nuclear polymorphisms (SNPs) of TGF-β(1) and the risk of COPD in a case-control study and meta-analysis. We genotyped 160 cases and 177 control subjects in a local hospital using the Mass-Array(TM) Technology Platform and then tested the association of four SNPs in TGF-β(1) (rs6957, rs1800469, rs2241712, and rs2241718) with COPD. Plasma TGF-β(1) level measurement was performed later. A database covering all papers published up to October 30, 2010, was then reviewed. Statistical analysis was performed using Revman 5.0 and STATA 11.0 software. No association was found between TGF-β(1) gene SNPs and an increased risk of COPD in Asians. By meta-analysis, the link of two polymorphisms, rs1800469 and rs1982073, was investigated in seven and eight studies, respectively, involving 1,508 COPD patients and 2,608 control subjects. The results showed that there was no significant association between an increased risk of COPD in carriers of the T allele (TT+TC) versus the CC genotype in rs1800469 and rs1982073. In ethnic subgroup analysis, the risk of COPD associated with the rs1800469 T allele was not significantly elevated among Asians. TGF-β(1) gene polymorphisms are not associated with an increased risk of COPD in the Asian population.