The Obstructive Lung Disease in Northern Sweden Chronic Obstructive Pulmonary Disease Study: design, the first year participation and mortality

ERS International Congress 2023: highlights from the Basic and Translational Sciences Assembly

Early career members of Assembly 3 (Basic and Translational Sciences) of the European Respiratory Society (ERS) summarise the key messages discussed during six selected sessions that took place at the ERS International Congress 2023 in Milan, Italy. Aligned with the theme of the congress, the first session covered is "Micro- and macro-environments and respiratory health", which is followed by a summary of the "Scientific year in review" session. Next, recent advances in experimental methodologies and new technologies are discussed from the "Tissue modelling and remodelling" session and a summary provided of the translational science session, "What did you always want to know about omics analyses for clinical practice?", which was organised as part of the ERS Translational Science initiative's aims. The "Lost in translation: new insights into cell-to-cell crosstalk in lung disease" session highlighted how next-generation sequencing can be integrated with laboratory methods, and a final summary of studies is presented from the "From the transcriptome landscape to innovative preclinical models in lung diseases" session, which links the transcriptome landscape with innovative preclinical models. The wide range of topics covered in the selected sessions and the high quality of the research discussed demonstrate the strength of the basic and translational science being presented at the international respiratory conference organised by the ERS.

All-cause and cause-specific mortality by spirometric pattern and sex - a population-based cohort study

BACKGROUND

Chronic airway obstruction (CAO) and restrictive spirometry pattern (RSP) are associated with mortality, but sex-specific patterns of all-cause and specific causes of death have hardly been evaluated.

OBJECTIVES

To study the possible sex-dependent differences of all-cause mortality and patterns of cause-specific mortality among men and women with CAO and RSP, respectively, to that of normal lung function (NLF).

DESIGN

Population-based prospective cohort study.

METHODS

Individuals with CAO [FEV1/vital capacity (VC) < 0.70], RSP [FEV1/VC ⩾ 0.70 and forced vital capacity (FVC) < 80% predicted] and NLF (FEV1/VC ⩾ 0.70 and FVC ⩾ 80% predicted) were identified within the Obstructive Lung Disease in Northern Sweden (OLIN) studies in 2002-2004. Mortality data were collected through April 2016, totally covering 19,000 patient-years. Cox regression and Fine-Gray regression accounting for competing risks were utilized to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) adjusted for age, body mass index, sex, smoking habits and pack-years.

RESULTS

The adjusted hazard for all-cause mortality was higher in CAO and RSP than in NLF (HR, 95% CI; 1.69, 1.31-2.02 and 1.24, 1.06-1.71), and the higher hazards were driven by males. CAO had a higher hazard of respiratory and cardiovascular death than NLF (2.68, 1.05-6.82 and 1.40, 1.04-1.90). The hazard of respiratory death was significant in women (3.41, 1.05-11.07) while the hazard of cardiovascular death was significant in men (1.49, 1.01-2.22). In RSP, the higher hazard for respiratory death remained after adjustment (2.68, 1.05-6.82) but not for cardiovascular death (1.11, 0.74-1.66), with a similar pattern in both sexes.

CONCLUSION

The higher hazard for all-cause mortality in CAO and RSP than in NLF was male driven. CAO was associated with respiratory death in women and cardiovascular death in men, while RSP is associated with respiratory death, similarly in both sexes.

Lung Function Trajectories and Associated Mortality among Adults with and without Airway Obstruction

Rationale: Spirometry is essential for diagnosis and assessment of prognosis in patients with chronic obstructive pulmonary disease (COPD). Objectives: To identify FEV1 trajectories and their determinants on the basis of annual spirometry measurements among individuals with and without airway obstruction (AO) and to assess mortality in relation to trajectories. Methods: From 2002 through 2004, individuals with AO (FEV1/VC < 0.70, n = 993) and age- and sex-matched nonobstructive (NO) referents were recruited from population-based cohorts. Annual spirometry until 2014 was used in joint-survival latent-class mixed models to identify lung function trajectories. Mortality data were collected during 15 years of follow-up. Measurements and Main Results: Three trajectories were identified among the subjects with AO and two among the NO referents. Trajectory membership was driven by baseline FEV1% predicted (FEV1%pred) in both groups and also by pack-years in subjects with AO and current smoking in NO referents. Longitudinal FEV1%pred depended on baseline FEV1%pred, pack-years, and obesity. The trajectories were distributed as follows: among individuals with AO, 79.6% in AO trajectory 1 (FEV1 high with normal decline), 12.8% in AO trajectory 2 (FEV1 high with rapid decline), and 7.7% in AO trajectory 3 (FEV1 low with normal decline) (mean, 27, 72, and 26 ml/yr, respectively) and, among NO referents, 96.7% in NO trajectory 1 (FEV1 high with normal decline) and 3.3% in NO trajectory 2 (FEV1 high with rapid decline) (mean, 34 and 173 ml/yr, respectively). Hazard for death was increased for AO trajectories 2 (hazard ratio [HR], 1.56) and 3 (HR, 3.45) versus AO trajectory 1 and for NO trajectory 2 (HR, 2.99) versus NO trajectory 1. Conclusions: Three different FEV1 trajectories were identified among subjects with AO and two among NO referents, with different outcomes in terms of FEV1 decline and mortality. The FEV1 trajectories among subjects with AO and the relationship between low FVC and trajectory outcome are of particular clinical interest.

Postural control among individuals with and without chronic obstructive pulmonary disease: A cross-sectional study of motor and sensory systems

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is considered a heterogenic syndrome with systemic effects, including muscle dysfunction. There is evidence of postural control impairments among individuals with COPD, partly related to muscle weakness. However, research is scarce regarding the other underlying systems of postural control, such as the visual, somatosensory and vestibular system. The aim was to compare postural control, as well as the motor and sensory systems, between individuals with and without COPD.

METHODS

Twenty-two participants with COPD (mean age 74.0 ±6.2 years) and 34 non-obstructive references (mean age 74.9 ±4.9 years) participated in this cross-sectional study. Postural control was assessed with center of pressure trajectory of postural sway in quiet as well as a limits of stability test, calculating mediolateral and anteroposterior amplitudes for each test. Assessment of function in the motor system included maximum hand grip strength, as well as maximum strength in muscles around the hip, knee and ankle joints. Visual acuity, pressure sensibility, proprioception, vestibular screening, and reaction time were also included. Data was compared between groups, and significant differences in postural control were further analyzed with an orthogonal projection of latent structures regression model.

RESULTS

There was a significantly increased sway amplitude in the mediolateral direction in quiet stance on soft surface with eyes open (p = 0.014) as well as a smaller anteroposterior amplitude in the limits of stability test (p = 0.019) in the COPD group. Regression models revealed that the mediolateral amplitude was related to visual acuity and the burden of tobacco smoking assessed as pack-years. Further, muscle strength associated with anteroposterior amplitude in limits of stability test in the COPD group, and with age and ankle dorsal flexion strength among the referents. Besides for lower ankle plantar flexion strength in the COPD group, there were however no significant differences in muscle strength.

CONCLUSIONS

Individuals with COPD had a decreased postural control and several factors were associated with the impairments. The findings imply that the burden of tobacco smoking and reduced visual acuity relate to increased postural sway in quiet stance, and that muscle weakness is related to decreased limits of stability, among individuals with COPD.

Large underreporting of COPD as cause of death-results from a population-based cohort study

BACKGROUND

In 2019, WHO estimated COPD to be the third leading cause of death in the world. However, COPD is probably underestimated as cause of death due to the well-known under-diagnosis.

AIM

To evaluate the proportion of and factors associated with COPD recorded as cause of death in a long-term follow-up of a population-based COPD cohort.

METHODS

The study population includes all individuals (n = 551) with COPD defined as chronic airway obstruction (post-bronchodilator FEV₁/FVC<0.70) + respiratory symptoms identified after re-examinations of four population-based cohorts. Mortality and underlying or contributing cause of death following ICD-10 classification were collected from the Swedish National Board of Health and Welfares register from date of examination in 2002-04 until 2016.

RESULTS

The study sample consisted of 32.3% GOLD 1, 55.9% GOLD 2, and 11.8% GOLD 3-4. The mean follow-up time was 10.3 (SD3.77) years and the cumulative mortality 45.0%. COPD (ICD-10 J43-J44) was recorded on 28.2% (n = 70) of the death certificates (11.1%, 25.7% and 57.1% by GOLD stage), whereof n = 35 had COPD recorded as underlying and n = 35 as contributing cause of death. To have COPD recorded as cause of death was independently associated with ex- and current smoking and a self-reported physician diagnosis of COPD, while male sex, overweight/obesity and higher FEV₁% of predicted associated with the absence.

CONCLUSIONS

COPD was largely underreported cause of death. Even among those with severe/very severe disease, COPD was only mentioned on 57.1% of the death certificates.

Airway regulatory T cells are decreased in COPD with a rapid decline in lung function

Background

Differences in the expression of regulatory T cells (Tregs) have been suggested to explain why some smokers develop COPD and some do not. Upregulation of Tregs in response to smoking would restrain airway inflammation and thus the development of COPD; while the absense of such upregulation would over time lead to chronic inflammation and COPD. We hypothesized that—among COPD patients—the same mechanism would affect rate of decline in lung function; specifically, that a decreased expression of Tregs would be associated with a more rapid decline in FEV₁.

Methods

Bronchoscopy with BAL was performed in 52 subjects recruited from the longitudinal OLIN COPD study; 12 with COPD and a rapid decline in lung function (loss of FEV₁ ≥ 60 ml/year), 10 with COPD and a non-rapid decline in lung function (loss of FEV₁ ≤ 30 ml/year), 15 current and ex-smokers and 15 non-smokers with normal lung function. BAL lymphocyte subsets were determined using flow cytometry.

Results

The proportions of Tregs with regulatory function (FoxP3⁺/CD4⁺CD25^bright) were significantly lower in COPD subjects with a rapid decline in lung function compared to those with a non-rapid decline (p = 0.019). This result was confirmed in a mixed model regression analysis in which adjustments for inhaled corticosteroid usage, smoking, sex and age were evaluated. No significant difference was found between COPD subjects and smokers or non-smokers with normal lung function.

Conclusions

COPD subjects with a rapid decline in lung function had lower proportions of T cells with regulatory function in BAL fluid, suggesting that an inability to suppress the inflammatory response following smoking might lead to a more rapid decline in FEV₁.

Trial registration Clinicaltrials.gov identifier NCT02729220

Cardiac biomarkers of prognostic importance in chronic obstructive pulmonary disease

Background

Ischemic heart disease is common in COPD and associated with worse prognosis. This study aimed to investigate the presence and prognostic impact of biomarkers of myocardial injury and ischemia among individuals with COPD and normal lung function, respectively.

Methods

In 2002–04, all individuals with airway obstruction (FEV₁/VC < 0.70, n = 993) were identified from population-based cohorts, together with age and sex-matched non-obstructive referents. At re-examination in 2005, spirometry, Minnesota-coded ECG and analyses of high-sensitivity cardiac troponin I (hs-cTnI) were performed in individuals with COPD (n = 601) and those with normal lung function (n = 755). Deaths were recorded until December 31st, 2010.

Results

Hs-cTnI concentrations were above the risk stratification threshold of ≥5 ng/L in 31.1 and 24.9% of those with COPD and normal lung function, respectively. Ischemic ECG abnormalities were present in 14.8 and 13.4%, while 7.7 and 6.6% had both elevated hs-cTnI concentrations and ischemic ECG abnormalities. The 5-year cumulative mortality was higher in those with COPD than those with normal lung function (13.6% vs. 7.7%, p < 0.001). Among individuals with COPD, elevated hs-cTnI both independently and in combination with ischemic ECG abnormalities were associated with an increased risk for death (adjusted hazard ratio [HR]; 95% confidence interval [CI] 2.72; 1.46–5.07 and 4.54; 2.25–9.13, respectively). Similar associations were observed also among individuals with COPD without reported ischemic heart disease.

Conclusions

In this study, elevated hs-cTnI concentrations in combination with myocardial ischemia on the electrocardiogram were associated with a more than four-fold increased risk for death in a population-based COPD-cohort, independent of disease severity.

An epidemiologic study of physician-diagnosed chronic obstructive pulmonary disease in the Turkish population: COPDTURKEY-1

Background/aim

Chronic obstructive pulmonary disease (COPD) is a common disease characterized by persistent airflow limitation and respiratory symptoms. It is a leading cause of morbidity and mortality all over the world. Our data on COPD in Turkey are limited. This study was intended to examine the epidemiologic characteristics of COPD in the Turkish population, between 2012 and 2016.

Materials and methods

This population-based, descriptive, surveillance study examined physician-diagnosed COPD prevalence, incidence, and mortality in Turkey. The database of the Social Security System of Turkey was scanned and ICD-10 J44.0-J44.9 codes for diagnostic and/ or therapeutic purposes were evaluated retrospectively.

Results

In 2016, there were 3,434,262 cases of COPD (56.2% men) in Turkey, and the mean age of patients was 61.62 ± 14.76 years. From 2012 to 2016, the annual overall prevalence rates of physician-diagnosed COPD rose from 4.3% to 5.8%, which was a 35.0% relative increase (P < 0.05). In women, this rate rose from 3.7% to 5.1% (38% increase), and in men, it rose from 4.9% to 6.7% (37% increase). During the study period, the overall incidence decreased from 8.5 per 1000 adults in 2012 to 6.3 per 1000 adults in 2016, representing a decrease of 26.6% (P < 0.001). The annual incidence rates of physician-diagnosed COPD decreased 25.4% in women and 27.9% in men. The overall mortality was 4.3% in 2012, and 4.2% in 2016. The mortality rate in women was 3.5% in 2012 and 3.7% in 2016, and 5% in 2012 and 4.7% in 2016 in men. The mean prevalence by region was 5.26% (range 3.79%–7.65%). The Black Sea region had the highest COPD prevalence.

Conclusion

COPD is a very common and serious cause of morbidity and mortality in Turkey, as it is worldwide. Current data will contribute to a better understanding of the epidemiologic dimension of COPD in our country.

The impact of comorbidities on mortality among men and women with COPD: report from the OLIN COPD study

BACKGROUND

Comorbidities probably contribute to the increased mortality observed among subjects with chronic obstructive pulmonary disease (COPD), but sex differences in the prognostic impact of comorbidities have rarely been evaluated in population-based studies. The aim of this study was to evaluate the impact of common comorbidities, cardiovascular disease (CVD), diabetes mellitus (DM), and anxiety/depression (A/D), on mortality among men and women with and without airway obstruction in a population-based study.

METHODS

All subjects with airway obstruction [forced expiratory volume in 1 second (FEV₁)/(forced) vital capacity ((F)VC) <0.70, n = 993] were, together with age- and sex-matched referents, identified after examinations of population-based cohorts in 2002-2004. Spirometric groups: normal lung function (NLF) and COPD (post-bronchodilator FEV₁/(F)VC <0.70) and additionally, LLN-COPD (FEV₁/(F)VC <lower limit of normal). Mortality data was collected until December 2015.

RESULTS

In COPD, the prevalence of CVD and DM was higher in men, whereas the prevalence of A/D was higher in women. The cumulative mortality was significantly higher in COPD than NLF, and higher in men than women in both groups. Among women with COPD, CVD and A/D but not DM increased the risk of death independent of age, body mass index, smoking habits, and disease severity, whereas among men DM and A/D but not CVD increased the risk for death. When the LLN criterion was applied, the pattern was similar.

CONCLUSION

There were sex-dependent differences regarding the impact of comorbidities on prognosis in COPD. Even though the prevalence of CVD was higher in men, the impact of CVD on mortality was higher in women, and despite higher prevalence of A/D in women, the impact on mortality was similar in both sexes. The reviews of this paper are available via the supplemental material section.

Cytotoxic lymphocytes in COPD airways: increased NK cells associated with disease, iNKT and NKT-like cells with current smoking

BACKGROUND

Cytotoxic lymphocytes are increased in the airways of COPD patients. Whether this increase is driven primarily by the disease or by smoking is not clear, nor whether it correlates with the rate of decline in lung function.

METHODS

Bronchoscopy with BAL was performed in 52 subjects recruited from the longitudinal OLIN COPD study according to pre-determined criteria; 12 with COPD and a rapid decline in lung function (loss of FEV₁ ≥ 60 ml/year), 10 with COPD and a non-rapid decline in lung function (loss of FEV₁ ≤ 30 ml/year), 15 current and ex-smokers and 15 non-smokers with normal lung function. BAL lymphocyte subsets were determined using flow cytometry.

RESULTS

In BAL fluid, the proportions of NK, iNKT and NKT-like cells all increased with pack-years. Within the COPD group, NK cells - but not iNKT or NKT-like cells - were significantly elevated also in subjects that had quit smoking. In contrast, current smoking was associated with a marked increase in iNKT and NKT-like cells but not in NK cells. Rate of lung function decline did not significantly affect any of the results.

CONCLUSIONS

In summary, increased proportions of NK cells in BAL fluid were associated with COPD; iNKT and NKT-like cells with current smoking but not with COPD. Interestingly, NK cell percentages did not normalize in COPD subjects that had quit smoking, indicating that these cells might play a role in the continued disease progression seen in COPD even after smoking cessation.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT02729220 .

Proteolytic biomarkers are related to prognosis in COPD- report from a population-based cohort

BACKGROUND

The imbalance between proteases and anti-proteases is considered to contribute to the development of COPD. Our aim was to evaluate the protease MMP-9, the antiprotease TIMP-1 and the MMP-9/TIMP-1-ratio as biomarkers in relation to prognosis. Prognosis was assessed as lung function decline and mortality. This was done among subjects with COPD in a population-based cohort.

METHODS

In 2005, clinical examinations including spirometry and peripheral blood sampling, were made in a longitudinal population-based cohort. In total, 1542 individuals participated, whereof 594 with COPD. In 2010, 1031 subjects participated in clinical examinations, and 952 subjects underwent spirometry in both 2005 and 2010. Serum MMP-9 and TIMP-1 concentrations were measured with enzyme linked immunosorbent assay (ELISA). Mortality data were collected from the Swedish national mortality register from the date of examination in 2005 until 31st December 2010.

RESULTS

The correlation between biomarkers and lung function decline was similar in non-COPD and COPD, but only significant for MMP-9 and MMP-9/TIMP-1-ratio in non-COPD. Mortality was higher in COPD than non-COPD (16% vs. 10%, p = 0.008). MMP-9 concentrations and MMP-9/TIMP-1 ratios in 2005 were higher among those who died during follow up, as well as among those alive but not participating in 2010, when compared to those participating in the 2010-examination. In non-COPD, male sex, age, burden of smoking, heart disease and MMP-9/TIMP-1 ratio were associated with increased risk for death, while increased TIMP-1 was protective. Among those with COPD, age, current smoking, increased MMP-9 and MMP-9/TIMP-1 ratio were associated with an increased risk for death.

CONCLUSIONS

The expected association between these biomarkers and lung function decline in COPD was not confirmed in this population-based study, probably due to a healthy survivor effect. Still, it is suggested that increased proteolytic imbalance may be of greater prognostic importance in COPD than in non-COPD.

The COPD Assessment Test (CAT) can screen for fatigue among patients with COPD

BACKGROUND

Fatigue is one of the most common symptoms among subjects with chronic obstructive pulmonary disease (COPD), but is rarely identified in clinical practice. The aim of this study was to evaluate the association between fatigue and health-related quality of life (HRQoL) assessed with clinically useful instruments, both among subjects with and without COPD. Further, to investigate the association between fatigue and the COPD Assessment Test (CAT)-energy question.

METHODS

Data were collected in 2014 within the population-based OLIN COPD study. Subjects with ( n = 367) and without ( n = 428) COPD participated in clinical examinations including spirometry and completed questionnaires about fatigue (FACIT-Fatigue, clinically relevant fatigue ⩽43), and HRQoL (EQ-5D-VAS, lower score = worse health; CAT, lower score = fewer symptoms/better health).

RESULTS

Subjects with clinically relevant fatigue had worse HRQoL measured with EQ-5D-VAS, regardless of having COPD or not. Decreasing EQ-5D-VAS scores, any respiratory symptoms and anxiety/depression were associated with clinically relevant fatigue also when adjusted for confounders. Among subjects with COPD, clinically relevant fatigue was associated with increasing total CAT score, and CAT score ⩾10. The proportion of subjects with clinically relevant fatigue increased significantly, with a higher score on the CAT-energy question, and nearly 50% of those with a score of 2, and 70% of those with a score of ⩾3, had clinically relevant fatigue.

CONCLUSIONS

Fatigue was associated with respiratory symptoms, anxiety/depression and worse HRQoL when using the clinically useful instruments EQ-5D-VAS and CAT. The CAT-energy question can be used to screen for fatigue in clinical practice, using a cut-off of ⩾2.

Effectiveness of a respiratory rehabilitation programme in patients with chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the effectiveness of the multidisciplinary respiratory rehabilitation (RR) programme in patients with severe or very severe chronic obstructive pulmonary disease pre the RR programme, at the end of the programme and one year after the RR, measuring changes in ability to exercise (walking test), effort tolerance(forced expiratory volume (FEV1)) and health-related quality of life.

METHOD

Quasi-experimental single group design. We included patients diagnosed with severe or very severe chronic obstructive pulmonary disease (stages III and IV of the GOLD classification) who entered the rehabilitation programme for the years 2011 and 2012. Demographic data, questionnaires on general health-related quality of life (SF-36) and specific to respiratory patients (St George's Respiratory Questionnaire), FEV1% and exercise capacity test (running test 6minutes) were collected. Data were collected before the RR programme, at the end of the RR programme and a year after completing the program.

RESULTS

No significant differences in FEV1% values were observed. Regarding exercise capacity, an increase in distance walked in the walking test was noted, which changed significantly after training, 377±59.7 to 415±79 m after one year (P<.01). A statistically significant improvement in mean scores of HRQoL was observed, except for the emotional role dimension of the SF-36 questionnaire.

CONCLUSION

A pulmonary rehabilitation programme for 8 weeks improved the exercise capacity, dyspnoea and quality of life of patients with severe and very severe chronic obstructive pulmonary disease.

From COPD epidemiology to studies of pathophysiological disease mechanisms: challenges with regard to study design and recruitment process: Respiratory and Cardiovascular Effects in COPD (KOLIN)

Background: Chronic obstructive pulmonary disease (COPD) is a largely underdiagnosed disease including several phenotypes. In this report, the design of a study intending to evaluate the pathophysiological mechanism in COPD in relation to the specific phenotypes non-rapid and rapid decline in lung function is described together with the recruitment process of the study population derived from a population based study. Method: The OLIN COPD study includes a population-based COPD cohort and referents without COPD identified in 2002-04 (n = 1986), and thereafter followed annually since 2005. Lung function decline was estimated from baseline in 2002-2004 to 2010 (first recruitment phase) or to 2012/2013 (second recruitment phase). Individuals who met the predefined criteria for the following four groups were identified; group A) COPD grade 2-3 with rapid decline in FEV₁ and group B) COPD grade 2-3 without rapid decline in FEV₁ (≥60 and ≤30 ml/year, respectively), group C) ever-smokers, and group D) non-smokers with normal lung function. Groups A-C included ever-smokers with >10 pack years. The intention was to recruit 15 subjects in each of the groups A-D. Results: From the database groups A-D were identified; group A n = 37, group B n = 29, group C n = 41, and group D n = 55. Fifteen subjects were recruited from groups C and D, while this goal was not reached in the groups A (n = 12) and B (n = 10). The most common reasons for excluding individuals identified as A or B were comorbidities contraindicating bronchoscopy, or inflammatory diseases/immune suppressive medication expected to affect the outcome. Conclusion: The study is expected to generate important results regarding pathophysiological mechanisms associated with rate of decline in lung function among subjects with COPD and the in-detail described recruitment process, including reasons for non-participation, is a strength when interpreting the results in forthcoming studies.

Echo intensity of the rectus femoris in stable COPD patients

Objective

The aim of this study was to investigate whether echo intensity of the rectus femoris when measured using ultrasound can distinguish muscles affected by COPD compared with healthy non-COPD affected muscles and whether the severity of ultrasonic abnormalities was associated with health-related quality of life (HRQoL).

Methods

Echo intensity, areas of the rectus femoris, and the thickness of quadriceps muscles were measured using ultrasound in 50 COPD outpatients and 21 age-matched non-COPD controls. The results of the 8-Item Short-Form Health Survey and the functional assessment of chronic illness therapy fatigue scales were used to evaluate HRQoL.

Results

There was a significantly higher echo intensity of the rectus femoris in all stages of COPD patients than in age-matched non-COPD subjects; the quadriceps muscle thickness and cross-sectional area of the rectus femoris significantly decreased in COPD GOLD III–IV only. Furthermore, in our stable COPD patients, echo intensity of the rectus femoris was associated with HRQoL independently.

Conclusion

Quantitative ultrasound distinguishes healthy muscles from those affected by COPD grade I–IV, and quality and quantity of muscles are associated with HRQoL and forced expiratory volume in 1 second. Ultrasonic echo intensity of the rectus femoris may be a useful instrument for assessing disease severity and monitoring the changes of skeletal muscle resulting from disease progression or clinical intervention in patients with COPD.

Ischemic ECG abnormalities are associated with an increased risk for death among subjects with COPD, also among those without known heart disease

Abstract presentation

An abstract, including parts of the results, has been presented at an oral session at the European Respiratory Society International Conference, London, UK, September 2016.

Background

Cardiovascular comorbidity contributes to increased mortality among subjects with COPD. However, the prognostic value of ECG abnormalities in COPD has rarely been studied in population-based surveys.

Aim

To assess the impact of ischemic ECG abnormalities (I-ECG) on mortality among individuals with COPD, compared to subjects with normal lung function (NLF), in a population-based study.

Methods

During 2002–2004, all subjects with FEV₁/VC <0.70 (COPD, n=993) were identified from population-based cohorts, together with age- and sex-matched referents without COPD. Re-examination in 2005 included interview, spirometry, and 12-lead ECG in COPD (n=635) and referents [n=991, whereof 786 had NLF]. All ECGs were Minnesota-coded. Mortality data were collected until December 31, 2010.

Results

I-ECG was equally common in COPD and NLF. The 5-year cumulative mortality was higher among subjects with I-ECG in both groups (29.6% vs 10.6%, P<0.001 and 17.1% vs 6.6%, P<0.001). COPD, but not NLF, with I-ECG had increased risk for death assessed as the mortality risk ratio [95% confidence interval (CI)] when compared with NLF without I-ECG, 2.36 (1.45–3.85) and 1.65 (0.94–2.90) when adjusted for common confounders. When analyzed separately among the COPD cohort, the increased risk for death associated with I-ECG persisted after adjustment for FEV₁ % predicted, 1.89 (1.20–2.99). A majority of those with I-ECG had no previously reported heart disease (74.2% in NLF and 67.3% in COPD) and the pattern was similar among them.

Conclusion

I-ECG was associated with an increased risk for death in COPD, independent of common confounders and disease severity. I-ECG was of prognostic value also among those without previously known heart disease.

Pre- and post-bronchodilator airway obstruction are associated with similar clinical characteristics but different prognosis - report from a population-based study

INTRODUCTION

According to guidelines, the diagnosis of COPD should be confirmed by post-bronchodilator (post-BD) airway obstruction on spirometry; however, in clinical practice, this is not always performed. The aim of this population-based study was to compare clinical characteristics and prognosis, assessed as mortality, between subjects with airway obstruction divided into pre- but not post-BD obstruction, post-BD airway obstruction (COPD), and subjects without airway obstruction.

MATERIALS AND METHODS

In 2002-2004, four adult population-based cohorts were reexamined with spirometry and structured interview. Subjects with airway obstruction, with a ratio of forced expiratory volume in 1 s to (forced) vital capacity <0.70 (n=993), were identified together with sex- and age-matched referents (n=993). These subjects were further divided into subjects with pre- but not post-BD airway obstruction (pre- not post-BD obstruction) and subjects with post-BD airway obstruction (COPD). Mortality data were collected until December 31, 2014.

RESULTS

Out of 993 subjects with airway obstruction, 736 (74%) had COPD and 257 (26%) pre- not post-BD obstruction. Any respiratory symptoms, allergic rhinitis, asthma, exacerbations, and comorbidities were equally common among subjects with COPD and pre- not post-BD obstruction, but less common among nonobstructive subjects. Mortality was highest among subjects with COPD and higher in men than in women. In both sexes, COPD, but not pre- not post-BD obstruction, was associated with an increased risk for death compared to those without airway obstruction. When COPD was divided into Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages, GOLD 2 and 3-4 had an increased risk for death when compared to the nonobstructive group, also when adjusted for common confounders and comorbidities such as heart disease, diabetes, and anxiety/depression.

CONCLUSION

Even though subjects with COPD and pre- not post-BD obstruction had fairly similar presentation of clinical characteristics, only those with COPD, specifically GOLD stage ≥2, had increased risk for death when compared with nonobstructive subjects.

Targeted high-throughput sequencing of candidate genes for chronic obstructive pulmonary disease

Background

Reduced lung function in patients with chronic obstructive pulmonary disease (COPD) is likely due to both environmental and genetic factors. We report here a targeted high-throughput DNA sequencing approach to identify new and previously known genetic variants in a set of candidate genes for COPD.

Methods

Exons in 22 genes implicated in lung development as well as 61 genes and 10 genomic regions previously associated with COPD were sequenced using individual DNA samples from 68 cases with moderate or severe COPD and 66 controls matched for age, gender and smoking. Cases and controls were selected from the Obstructive Lung Disease in Northern Sweden (OLIN) studies.

Results

In total, 37 genetic variants showed association with COPD (p < 0.05, uncorrected). Several variants previously discovered to be associated with COPD from genetic genome-wide analysis studies were replicated using our sample. Two high-risk variants were followed-up for functional characterization in a large eQTL mapping study of 1,111 human lung specimens. The C allele of a synonymous variant, rs8040868, predicting a p.(S45=) in the gene for cholinergic receptor nicotinic alpha 3 (CHRNA3) was associated with COPD (p = 8.8 x 10⁻³). This association remained (p = 0.003 and OR = 1.4, 95 % CI 1.1-1.7) when analysing all available cases and controls in OLIN (n = 1,534). The rs8040868 variant is in linkage disequilibrium with rs16969968 previously associated with COPD and altered expression of the CHRNA5 gene. A follow-up analysis for detection of expression quantitative trait loci revealed that rs8040868-C was found to be significantly associated with a decreased expression of the nearby gene cholinergic receptor, nicotinic, alpha 5 (CHRNA5) in lung tissue.

Conclusion

Our data replicate previous result suggesting CHRNA5 as a candidate gene for COPD and rs8040868 as a risk variant for the development of COPD in the Swedish population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0309-y) contains supplementary material, which is available to authorized users.

Hand grip strength is associated with forced expiratory volume in 1 second among subjects with COPD: report from a population-based cohort study

Background

Cardiovascular diseases and skeletal muscle dysfunction are common comorbidities in COPD. Hand grip strength (HGS) is related to general muscle strength and is associated with cardiovascular disease and all-cause mortality, while the results from small selected COPD populations are contradictory. The aim of this population-based study was to compare HGS among the subjects with and without COPD, to evaluate HGS in relation to COPD severity, and to evaluate the impact of heart disease.

Subjects and methods

Data were collected from the Obstructive Lung disease in Northern Sweden COPD study, where the subjects with and without COPD have been invited to annual examinations since 2005. In 2009–2010, 441 subjects with COPD (postbronchodilator forced expiratory volume in 1 second [FEV₁]/vital capacity <0.70) and 570 without COPD participated in structured interviews, spirometry, and measurements of HGS.

Results

The mean HGS was similar when comparing subjects with and without COPD, but those with heart disease had lower HGS than those without. When compared by Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades, the subjects with GOLD 3–4 had lower HGS than those without COPD in both sexes (females 21.4 kg vs 26.9 kg, P=0.010; males 41.5 kg vs 46.3 kg, P=0.038), and the difference persisted also when adjusted for confounders. Among the subjects with COPD, HGS was associated with FEV₁% of predicted value but not heart disease when adjusted for height, age, sex, and smoking habits, and the pattern was similar among males and females.

Conclusion

In this population-based study, the subjects with GOLD 3–4 had lower HGS than the subjects without COPD. Among those with COPD, HGS was associated with FEV₁% of predicted value but not heart disease, and the pattern was similar in both sexes.

Hospitalization Due to Co-Morbid Conditions is the Main Cost Driver Among Subjects With COPD-A Report From the Population-Based OLIN COPD Study

BACKGROUND

Co-morbidities are common in COPD; however, there is a lack of population-based studies evaluating the health economic impact of co-morbid diseases for subjects with COPD. The main objective of this study was to estimate annual direct health-care costs, divided into costs due to non-respiratory and respiratory conditions, comparing subjects with and without COPD.

METHODS

Subjects with and without COPD derived from population-based cohorts in northern Sweden have been invited to annual examinations involving spirometry and structured interviews since 2005. This paper is based on data from 1472 subjects examined in 2006. COPD classification was based on spirometry.

RESULTS

Mean annual costs for both respiratory and non-respiratory conditions were significantly higher for subjects with COPD than non-COPD subjects, in total USD 2139 vs. USD 1276 (p = 0.026), and COPD remained significantly associated with higher costs also after adjustment for common confounders as age, smoking habits, BMI and sex. The mean total cost increased with COPD disease severity and was higher for all severity stages (GOLD) than for non-COPD subjects. Hospitalization due to non-respiratory diseases was the main cost driver in COPD, after adjustment for common confounders amounting to about 46% (unadjusted 62%) of the total COPD-costs.

CONCLUSIONS

Costs were higher for COPD than non-COPD. In COPD, costs for co-morbid conditions were higher than those for respiratory conditions, and hospitalization due to co-morbid conditions was the main cost driver also when adjusted for common confounders.

Ischemic heart disease among subjects with and without chronic obstructive pulmonary disease--ECG-findings in a population-based cohort study

Background

Cardiovascular comorbidity in COPD is common and contributes to increased mortality. A few population-based studies indicate that ischemic electrocardiogram (ECG)-changes are more prevalent in COPD, while others do not. The aim of the present study was to estimate the presence of ischemic heart disease (IHD) in a population-based COPD-cohort in comparison with subjects without COPD.

Methods

All subjects with obstructive lung function (COPD, n = 993) were identified together with age- and sex-matched controls (non-COPD, n = 993) from population-based cohorts examined in 2002–04. In 2005, data from structured interview, spirometry and ECG were collected from 1625 subjects. COPD was classified into GOLD 1–4 after post-bronchodilator spirometry. Ischemic ECG-changes, based on Minnesota-coding, were classified according to the Whitehall criteria into probable and possible IHD.

Results

Self-reported IHD was equally common in COPD and non-COPD, and so were probable and possible ischemic ECG-changes according to Whitehall. After excluding subjects with restrictive spirometric pattern from the non-COPD-group, similar comparison with regard to presence of IHD performed between those with COPD and those with normal lung-function did neither show any differences. There was a significant association between self-reported IHD (p = 0.007) as well as probable ischemic ECG-changes (p = 0.042), and increasing GOLD stage. In COPD there was a significant association between level of FEV₁ percent of predicted and self-reported as well as probable ischemic ECG-changes, and this association persisted for self-reported IHD also after adjustment for sex and age.

Conclusion

In this population-based study, self-reported IHD and probable ischemic ECG-changes were associated with COPD disease severity assessed by spirometry.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0149-1) contains supplementary material, which is available to authorized users.

Public Awareness of Sepsis Is Low in Sweden

Background. Sepsis is a serious and common condition with high mortality and morbidity. The public awareness, knowledge, and perception of sepsis in Sweden are unknown.

Methods. A survey was performed using an online interview distributed to adults, aged 18–74, between March 6 and 9, 2015.

Results. A total of 1001 people responded to the survey. Twenty-one percent of participants had heard of sepsis, whereas more than 86% had heard of each of the other conditions listed; for example, stroke (95%), chronic obstructive pulmonary disease (COPD) (95%), and leukemia (92%). Of those who had heard of sepsis, 93% responded that it is an infection or blood poisoning in an open question. The respondents who had heard of each disease estimated its mortality. For sepsis, the mortality was estimated at an average of 30%, which was at the same level as estimated mortalities for prostate and breast cancer but lower than for stroke, COPD, and leukemia.

Conclusions. The awareness and knowledge of sepsis is low. The mortality for sepsis is not as overestimated as for many other diseases. The lack of awareness of sepsis might be a target to improve the outcome for sepsis patients by reducing the prehospital delay and hence enable early interventions. An increased general awareness might also raise interest for funding for research in this area and for its priority in healthcare support.

Low nicotine dependence and high self-efficacy can predict smoking cessation independent of the presence of chronic obstructive pulmonary disease: a three year follow up of a population-based study

BACKGROUND

Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD), and smoking cessation is the only intervention that slows disease progression. It is important to know whether current factors related to smoking and smoking cessation are different among subjects with and without COPD in order to support smoking cessation. The aim of this study was to evaluate factors related to smoking cessation and to compare characteristics and nicotine dependence among smokers with and without COPD.

METHODS

In 2005, 1614 subjects in a population-based longitudinal study of subjects with COPD and controls were examined. The Fagerström Test for Nicotine Dependence (FTND) and motivation for smoking cessation were assessed for current smokers (n = 299 total, 194 with COPD). Data on smoking cessation were collected in a follow-up in 2008 (n = 240).

RESULTS

Smokers with COPD had more pack-years and respiratory symptoms than smokers without COPD, whereas higher FTND scores were associated with anxiety/depression and respiratory symptoms in both groups. Nineteen percent of the smokers had quit smoking by the follow-up 3 years later, and they had significantly lower FTND scores (2.54 vs. 3.75, p < 0.001) and higher self-efficacy scores (10.0 vs. 6.0, p = 0.020) at baseline than the sustained smokers. Smoking cessation was related to low FTND scores and high self-efficacy independent of the presence of COPD, respiratory symptoms, anxiety/depression, and heart disease.

CONCLUSIONS

The FTND score and a simple visual analog scale for assessing self-efficacy seem to be valuable instruments for predicting smoking cessation over several years, independent of COPD, respiratory symptoms, presence of anxiety/depression, and heart disease.

Physical activity and fatigue in chronic obstructive pulmonary disease - A population based study

BACKGROUND

In subjects with chronic obstructive pulmonary disease (COPD), symptoms of fatigue, concomitant heart disease and low physical activity levels are more frequently described than in subjects without COPD. However, there are no population-based studies addressing the relationship between physical activity, fatigue and heart disease in COPD. The aim was to compare physical activity levels among subjects with and without COPD in a population based study, and to evaluate if concomitant heart disease and fatigue was associated to physical activity.

METHODS

In this, 470 subjects with COPD and 659 subjects without COPD (non-COPD) participated in examinations including structured interview and spirometry. A ratio of the forced expiratory volume in one second (FEV1)/best of forced vital capacity (FVC) and vital capacity (VC) < 0.7 was used to define COPD. Physical activity was assessed with the International Physical Activity Questionnaire (IPAQ), and fatigue with the Functional Assessment of Chronic Illness Therapy - Fatigue scale (FACIT-F).

RESULTS

The prevalence of low physical activity was higher among subjects with FEV1 < 80% predicted compared to non-COPD subjects (22.4% vs. 14.6%, p = 0.041). The factors most strongly associated with low physical activity in subjects with COPD were older age, OR 1.52, (95% CI 1.12-2.06), a history of heart disease, OR 2.11 (1.10-4.08), and clinically significant fatigue, OR 2.33 (1.31-4.13); while obesity was the only significant factor among non-COPD subjects, OR 2.26 (1.17-4.35).

CONCLUSION

Physical activity levels are reduced when lung function is decreased below 80% of predicted, and the factors associated with low physical activity are different among subject with and without COPD. We propose that the presence of fatigue and heart disease are useful to evaluate when identifying subjects for pulmonary rehabilitation.

Central arterial stiffness is increased among subjects with severe and very severe COPD: report from a population-based cohort study

Introduction

Cardiovascular disease (CVD) is common in chronic obstructive pulmonary disease (COPD) and is, as productive cough, related to poorer prognosis in COPD. Central arterial stiffness is a marker of early atherosclerosis, but the association between COPD, productive cough, and arterial stiffness as a possible indicator of CVD is unclear.

Objectives

To compare both arterial stiffness among subjects with and without COPD and the impact of productive cough in a population-based cohort.

Methods

A population-based cohort, including 993 COPD and 993 non-COPD subjects, has been invited to annual examination since 2005. In 2010, 947 subjects, of which 416 had COPD (according to the GOLD spirometric criteria), participated in examinations including structured interview, spirometry, and measurements of central arterial stiffness as pulse wave velocity (PWV).

Results

PWV was higher in GOLD 3–4 compared to non-COPD (10.52 vs. 9.13 m/s, p=0.042). CVD and age ≥60 were both associated with significantly higher PWV in COPD as well as in non-COPD. In COPD, those with productive cough had higher PWV than those without, significantly so in GOLD 1 (9.59 vs. 8.92 m/s, p=0.024). In a multivariate model, GOLD 3–4 but not productive cough was associated with higher PWV, when adjusted for sex, age group, smoking habits, blood pressure, CVD, and pulse rate.

Conclusions

GOLD 3–4, age ≥60, and CVD were associated with increased arterial stiffness, and also increased in COPD subjects with productive cough compared to those without. Of importance, GOLD 3–4 but not productive cough remained associated with increased central arterial stiffness when adjusted for confounders.

Serum metalloproteinase-9 is related to COPD severity and symptoms - cross-sectional data from a population based cohort-study

BACKGROUND

Chronic obstructive pulmonary disease, COPD, is an increasing cause of morbidity and mortality worldwide, and an imbalance between proteases and antiproteases has been implicated to play a role in COPD pathogenesis. Matrix metalloproteinases (MMP) are important proteases that along with their inhibitors, tissue inhibitors of metalloproteinases (TIMP), affect homeostasis of elastin and collagen, of importance for the structural integrity of human airways. Small observational studies indicate that these biomarkers are involved in the pathogenesis of COPD. The aim of this study was to investigate serum levels of MMP-9 and TIMP-1 in a large Swedish population-based cohort, and their association with disease severity and important clinical symptoms of COPD such as productive cough.

METHODS

Spirometry was performed and peripheral blood samples were collected in a populations-based cohort (median age 67 years) comprising subjects with COPD (n = 594) and without COPD (n = 948), in total 1542 individuals. Serum MMP-9 and TIMP-1 concentrations were measured with enzyme linked immunosorbant assay (ELISA) and related to lung function data and symptoms.

RESULTS

Median serum MMP-9 values were significantly higher in COPD compared with non-COPD 535 vs. 505 ng/ml (P = 0.017), without any significant differences in serum TIMP-1-levels or MMP-9/TIMP-1-ratio. In univariate analysis, productive cough and decreasing FEV1% predicted correlated significantly with increased MMP-9 among subjects with COPD (P = 0.004 and P = 0.001 respectively), and FEV1% predicted remained significantly associated to MMP-9 in a multivariate model adjusting for age, sex, pack years and productive cough (P = 0.033).

CONCLUSION

Productive cough and decreasing FEV1 were each associated with MMP-9 in COPD, and decreasing FEV1 remained significantly associated with MMP-9 also after adjustment for common confounders in this population-based COPD cohort. The increased serum MMP-9 concentrations in COPD indicate an enhanced proteolytic activity that is related to disease severity, and further longitudinal studies are important for the understanding of MMP-9 in relation to the disease process and the pathogenesis of different COPD phenotypes.

Subjects with COPD and productive cough have an increased risk for exacerbations and death

BACKGROUND

Chronic bronchitis is related to worse general health status, exacerbations and mortality among subjects with COPD. Also less longstanding cough and phlegm may be related to worse prognosis in COPD but this has rarely been evaluated in population-based studies.

AIM

To evaluate the relationship between productive cough, exacerbations and mortality among subjects with and without COPD.

METHOD

All subjects with COPD (n = 993) were identified together with sex- and age matched reference subjects without obstructive lung function impairment from four population-based cohorts in 2002-04. Baseline spirometry and structured interview including data on exacerbations last 12 months were used in this study (n = 1986) together with mortality data collected until February 2012.

RESULTS

Productive cough was more common in COPD than non-COPD (42.8 vs. 23.5%, p < 0.001), more common in men than women, but associated to exacerbations in both sexes. COPD-subjects with productive cough had the highest risk for exacerbations in both sexes and they had a significantly increased risk for death (HR 1.48, 95% CI 1.13-1.94) also when adjusted for sex, age, BMI, smoking habits and heart disease.

CONCLUSION

Productive cough was common and increased the risk for exacerbations in both sexes, in both COPD and non-COPD. COPD-subjects with productive cough had the highest risk for exacerbations and a significantly higher risk for death also after adjustment for common risk factors.

Fatigue Affects Health Status and Predicts Mortality Among Subjects with COPD: Report from the Population-Based OLIN COPD Study

BACKGROUND

COPD is associated to increased fatigue, decreased health status and mortality. However, these relationships are rarely evaluated in population-based studies.

AIMS

To describe the relationship between health status, respiratory symptoms and fatigue among subjects with and without COPD. Further, to evaluate whether fatigue and/or health status predicts mortality in these groups.

METHODS

Data were collected in 2007 from the population-based OLIN COPD study. Subjects participated in lung function tests and structured interviews, and 434 subjects with and 655 subjects without COPD were identified. Fatigue was assessed by FACIT-Fatigue and health status by the generic SF-36 questionnaire including physical (PCS) and mental (MCS) components. Mortality data until February 2012 were collected.

RESULTS

Fatigue greatly impacts the physical and mental dimensions of health status, both among subjects with and without COPD. Among subjects with clinically significant fatigue, COPD subjects had significantly lower PCS-scores compared to non-COPD subjects. Fairly strong correlations were found between FACIT-F, SF-36 PCS and MCS, respectively. In multivariate models adjusting for covariates, increased fatigue, decreased physical and mental dimensions of health status were all associated to mortality in subjects with COPD (OR 1.06, CI 1.02-1.10, OR 1.04, CI 1.01-1.08 and OR 1.06, CI 1.02-1.10), but not in non-COPD.

CONCLUSIONS

Fatigue and decreased health status were closely related among subjects with and without COPD. Not only physical health status, but also fatigue and mental health predicted mortality among subjects with COPD. Fatigue assessed by FACIT-F, can be a useful instrument of prognostic value in the care of subjects with COPD.

Health economic costs of COPD in Sweden by disease severity--has it changed during a ten years period?

OBJECTIVES

The objectives of the presented study were to estimate societal costs of COPD in Sweden, the relationship between costs and disease severity, and possible changes in the costs during the last decade.

METHODS

Subjects with COPD derived from the general population in Northern Sweden were interviewed by telephone regarding their resource utilisation and productivity losses four times quarterly during 2009-10. Mean annual costs were estimated for each severity stage of COPD.

RESULTS

A strong relationship was found between disease severity and costs. Estimated mean annual costs per subject of mild, moderate, severe and very severe COPD amounted to 596 (SEK 5686), 3245 (SEK 30,957), 5686 (SEK 54,242), and 17,355 euros (SEK 165,569), respectively. The main cost drivers for direct costs were hospitalisations (for very severe COPD) and drugs (all other severity stages). The main cost driver for indirect costs was productivity loss due to sick-leave (for mild COPD) and early retirement (all other severity stages). Costs appeared to be lower in 2010 than in 1999 for subjects with severe and very severe COPD, but higher for those with mild and moderate COPD.

CONCLUSION

Our results show that costs of COPD are strongly related to disease severity, and scaling the data to the whole Swedish population indicates that the total costs in Sweden amounted to 1.5 billion euros (SEK 13.9 bn) in 2010. In addition, costs have decreased since 1999 for subjects with severe and very severe COPD, but increased for those with mild and moderate COPD.

Why do smokers diagnosed with COPD not quit smoking? - a qualitative study

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is currently one of the most widespread chronic lung diseases and a growing cause of suffering and mortality worldwide. It is predicted to become the third leading cause of death in the near future. Smoking is the most important risk factor, and about 50% of smokers develop COPD. Smoking cessation is the most important way to improve prognosis. The aim of the study was to describe difficulties of smoking cessation experienced by individuals with COPD who are unable to stop smoking.

METHODS

Ten smokers (five women) with COPD, GOLD stage II, participated in semi-structured interviews in 2010. The data were analyzed using qualitative content analysis. The participants were recruited from the Obstructive Lung Disease in Northern Sweden (OLIN) studies.

RESULTS

The participants lives were governed by a lifelong smoking habit that was difficult to break although they had knowledge about the harmful effects and the consequences of COPD. The participants described incidents in their lives as reasons for never finding the time to quit smoking. Demands to quit smoking from other people could lead to continued smoking or get them started again after cessation as they did not want to be patronized. They wanted to receive support from relatives and care providers but they wanted to make the decision to quit on their own.

CONCLUSION

For successful smoking cessation, it is important to understand the difficulties smokers are experiencing that influence their efforts to quit smoking. To achieve a successful lasting smoking cessation it might be more effective to first ensure that the smoker has the right internal motivation to make the decision to quit, then assist with smoking cessation.

Epidemiology of chronic obstructive pulmonary disease: a literature review

The aim of this study is to quantify the burden of chronic obstructive pulmonary disease (COPD) – incidence, prevalence, and mortality – and identify trends in Australia, Canada, France, Germany, Italy, Japan, The Netherlands, Spain, Sweden, the United Kingdom, and the United States of America. A structured literature search was performed (January 2000 to September 2010) of PubMed and EMBASE, identifying English-language articles reporting COPD prevalence, incidence, or mortality. Of 2838 articles identified, 299 full-text articles were reviewed, and data were extracted from 133 publications. Prevalence data were extracted from 80 articles, incidence data from 15 articles, and mortality data from 58 articles. Prevalence ranged from 0.2%–37%, but varied widely across countries and populations, and by COPD diagnosis and classification methods. Prevalence and incidence were greatest in men and those aged 75 years and older. Mortality ranged from 3–111 deaths per 100,000 population. Mortality increased in the last 30–40 years; more recently, mortality decreased in men in several countries, while increasing or stabilizing in women. Although COPD mortality increased over time, rates declined more recently, likely indicating improvements in COPD management. In many countries, COPD mortality has increased in women but decreased in men. This may be explained by differences in smoking patterns and a greater vulnerability in women to the adverse effects of smoking.

Co-morbidity in mild-to-moderate COPD: comparison to normal and restrictive lung function

BACKGROUND

A relationship between local and systemic inflammation and different co-morbidities, such as cardiovascular, has been discussed in relation to disease process and prognosis in COPD.

AIM

To evaluate if conditions as cardiovascular diseases, diabetes, chronic rhinitis and gastroesophageal reflux are overrepresented in COPD.

METHODS

All subjects with COPD according to GOLD, FEV(1)/FVC<0.70, were identified (n = 993) from the clinical follow-up in 2002-04 of the OLIN (Obstructive Lung Disease in Northern Sweden) studies' cohorts together with 993 gender- and age-matched reference subjects without COPD (non-COPD, further divided into normal and restrictive lung function). Interview data on co-morbidity and symptoms were used.

RESULTS

Cardiovascular co-morbidity, taken together heart disease, hypertension, stroke and intermittent claudication, was the most common and higher in COPD compared to in normal lung function (Nlf) 50.1% vs 41.0% (p<0.001). The prevalence of chronic rhinitis and gastroesophageal reflux (GERD) was higher in COPD compared to in Nlf (43.1% vs 32.3%, p<0.001 and 16.7% vs 12.0%, p = 0.011). In restrictive lung function the prevalence of chronic rhinitis, cardiovascular disease, hyperlipemia and diabetes was higher compared to in Nlf (41.0% vs 32.3%, p = 0.017, 59.0% vs 41.0%, p<0.001, 29.2% vs.12.9%, p = 0.033, 20.9% vs 8.6%, p <0.001). In COPD and heart disease, 62.5% had chronic rhinitis and/or GERD, while in Nlf the corresponding proportion was 42.5%.

CONCLUSION

Co-morbid conditions such as cardiovascular disease, chronic rhinitis and gastroesophageal reflux were common in COPD. The overlap between heart disease, chronic rhinitis and GERD was large in COPD. Restrictive lung function did also identify a population with increased disease burden.

Up-to-date on mortality in COPD - report from the OLIN COPD study

BACKGROUND

The poor recognition and related underdiagnosis of COPD contributes to an underestimation of mortality in subjects with COPD. Data derived from population studies can advance our understanding of the true burden of COPD. The objective of this report was to evaluate the impact of COPD on mortality and its predictors in a cohort of subjects with and without COPD recruited during the twenty first century.

METHODS

All subjects with COPD (n = 993) defined according to the GOLD spirometric criteria, FEV1/FVC < 0.70, and gender- and age-matched subjects without airway obstruction, non-COPD (n = 993), were identified in a clinical follow-up survey of the Obstructive Lung Disease in Northern Sweden (OLIN) Studies cohorts in 2002-2004. Mortality was observed until the end of year 2007. Baseline data from examination at recruitment were used in the risk factor analyses; age, smoking status, lung function (FEV1 % predicted) and reported heart disease.

RESULTS

The mortality was significantly higher among subjects with COPD, 10.9%, compared to subjects without COPD, 5.8% (p < 0.001). Mortality was associated with higher age, being a current smoker, male gender, and COPD. Replacing COPD with FEV1 % predicted in the multivariate model resulted in the decreasing level of FEV1 being a significant risk factor for death, while heart disease was not a significant risk factor for death in any of the models.

CONCLUSIONS

In this cohort COPD and decreased FEV1 were significant risk factors for death when adjusted for age, gender, smoking habits and reported heart disease.