The Prevalence of Chronic Obstructive Pulmonary Disease by the Global Lung Initiative Equations in North-Western Russia.

BACKGROUND: The prevalence of chronic obstructive pulmonary disease (COPD) varies in different countries, while the cut-off for airflow obstruction (AO) is still contested. No COPD prevalence data based on the Global Lung Initiative (GLI) 2012 equations are available in Russia. OBJECTIVES: This study aims to assess AO prevalence by the GLI lower limit of normal (GLI-LLN) and the fixed cut-off, to identify AO risk factors and to assess the diagnostic value of respiratory symptoms in north-western Russia. METHODS: In a north-western Russian population-based sample of 2,974 adults aged 35-70 years, data on socio-demographics, smoking, occupational exposures and respiratory symptoms were collected, and spirometry was performed before and after bronchodilator (BD) administration. RESULTS: The AO prevalence was 6.8% (95% CI 5.8-7.9) based on the fixed and 4.8% (95% CI 3.9-5.7) based on the GLI-LLN cut-off. 22.5% of the participants with post-BD AO had a positive bronchodilator test, and 1% showed a paradoxical BD response. Of the environmental factors studied, only smoking was independently associated with AO (odds ratio 2.47, 95% CI 1.60-3.82). The positive predictive value of respiratory symptoms for AO was 11% based on the fixed and 8% based on the GLI-LLN cut-off. CONCLUSIONS: In a sample of adults in north-western Russia, the AO prevalence by the GLI-LLN cut-off was lower than that by the fixed cut-off. The predictive value of respiratory symptoms was low.

The RESPECT study: RESearch on the PrEvalence and the diagnosis of COPD and its Tobacco-related etiology: a study protocol.

BACKGROUND: Smoking remains a leading health risk factor among Europeans. Tobacco, together with other factors, will lead to an expansive epidemic of chronic diseases, including COPD, among the working population in Russia. The general aim of the RESearch on the PrEvalence and the diagnosis of COPD and its Tobacco-related etiology (RESPECT) study is to gain a better understanding of the prevalence, pathogenesis and symptoms of COPD. METHODS/DESIGN: The RESPECT study is a prospective, population-based cohort study of subjects aged 35-70 years in two north-west regions of the Russian Federation (Saint Petersburg and Arkhangelsk). The study includes three components: a cross-sectional study (prevalence), a case-control study and a cohort study (diagnostic). An investigator who interviewed the patient completed three questionnaires. Spirometry, including a reversibility test, was offered to all participants. Individuals displaying forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < 0.7 and/or FEV1/FVC < the lower limit of normal before and/or after bronchodilation were included in a follow-up study and were examined by a pulmonologist using a standardized comprehensive examination protocol. A future case-control study of two matched groups of patients (heavy smokers with COPD versus heavy smokers without COPD) will provide information on which factors (biomarkers, including pneumoproteins, in serum and induced sputum) are related to tobacco-induced COPD. DISCUSSION: In total, 3133 individuals (2122 from St. Petersburg and 1012 from Arkhangelsk) aged 35-70 years agreed to participate in this study and met the inclusion criteria. In total, 2974 participants met the quality criteria for spirometry, and 2388 reversibility tests were performed. A cohort of newly defined obstructive pulmonary disease patients (247 persons) was established for follow-up investigation. The RESPECT study will provide information regarding the prevalence of COPD in the north-west region of the Russian Federation. Moreover, the comprehensive RESPECT database will enable us to explore new research questions, provide novel insight into the risk factors and different phenotypes of COPD, and contribute to an improved understanding of the reasons why some heavy smokers develop the disease whereas others do not. CLINICAL TRIAL REGISTRATION: NCT02307799 (the release date: 12/01/2014).

Inflammatory parameters and pulmonary biomarkers in smokers with and without chronic obstructive pulmonary disease (COPD).

BACKGROUND: We organized this study in order to investigate differences in serum inflammatory profiles and circulating serum pneumoproteins between smokers with and without chronic obstructive pulmonary disease (COPD). METHODS: Patients aged 35-70 years with COPD and a smoking history ≥10 pack-years (cases, n=38) and 38 participants with the same smoking history without COPD (controls) were included in a comparative study conducted as part of a population-based cross-sectional study with 2,388 individuals in northwestern Russia. Cases and controls were matched for age and smoking history. Airflow obstruction (AO) was defined using forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) <0.70 and/or FEV1/FVC < lower limit of the normal cut-off values. Patients at risk for COPD were reassessed using a standardized diagnostic work-up protocol. Several parameters, among which four inflammatory biomarkers [the high-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6, IL-8, and tumor necrosis factor-α (TNF-α) levels] and two pneumoproteins [surfactant protein D (SP-D) and Clara cell secretory protein 16 (CC16)], were measured in the peripheral blood. Systemic inflammation was defined as at least 2 or more elevated biomarker levels. RESULTS: Out of all smokers, 57.9% with normal spirometry and 36.8% with COPD did not have systemic inflammation, whereas 44.7% of the patients with COPD and 5.3% of the patients without AO demonstrated at least two elevated biomarker levels. No difference in age, gender, and smoking history, environmental and occupational exposure was found between the non-inflamed and the inflamed smokers. Of all risk factors studied, only COPD was associated with systemic inflammation [odds ratio (OR) 11.42, 95% confidence interval (CI): 2.13-58.84]. CONCLUSIONS: Our study describes the systemic inflammatory network pattern associated with COPD and how it differs from the pattern in smokers with normal lung function. Systemic inflammation is not present in all smokers with COPD; in contrast, some non-obstructed smokers are characterized by systemic inflammation. From this perspective, smoking itself could be seen as a disease and studied accordingly. TRIAL REGISTRATION: NCT02307799.

Spirometry is not enough to diagnose COPD in epidemiological studies: a follow-up study.

A hallmark of the diagnosis of chronic obstructive pulmonary disease (COPD) is the measurement of post-bronchodilator (post-BD) airflow obstruction (AO) by spirometry, but spirometry is not enough for the provision of a clinical diagnosis. In the majority of previous epidemiological studies, COPD diagnosis has been based on spirometry and a few clinical characteristics. The aim of our study was to identify outcomes in patients newly diagnosed with airflow obstruction (AO) based on a diagnostic work-up conducted as part of a population-based cross-sectional study in North-Western Russia. Spirometry was performed before (pre-BD) and after BD administration, and AO was defined using the FEV1/FVC <0.70 and FEV1/FVC