Comorbidities of chronic obstructive pulmonary disease in Koreans: a population-based study

Association between COPD and CKD: a systematic review and meta-analysis

Objective

Chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD) are significant global health issues with a well-established association between the two. This study aims to assess the risk of developing CKD in patients with COPD through systematic review and meta-analysis, and to explore the impact of CKD on the prognosis of COPD patients.

Methods

A total of 23 studies were included in the analysis, comprising 11 studies on the risk of CKD in patients with COPD, 6 studies on the impact of CKD on the short-term all-cause mortality risk of patients with acute exacerbation of COPD (AECOPD), and 6 studies on the impact of CKD on the long-term all-cause mortality risk of COPD patients. The meta-analysis showed that the risk of developing CKD in COPD patients was significantly increased (OR 1.54, 95% CI: 1.28-1.84), and CKD significantly increased the short-term all-cause mortality risk in AECOPD patients (OR 1.53, 95% CI: 1.44-1.63) as well as the long-term all-cause mortality risk in COPD patients (OR 1.70, 95% CI: 1.35-2.15).

Results

We searched the PubMed, EMBASE, and Cochrane Library databases in accordance with the PRISMA guidelines, including studies from the inception of the databases through December 31, 2023, to identify research assessing the relationship between COPD and CKD. The quality of the studies was assessed using the Newcastle-Ottawa Scale (NOS). Data were analyzed using either a random effects model or a fixed effects model for the meta-analysis.

Conclusion

This study establishes a significant association between COPD and CKD and reveals the adverse impact of CKD on the prognosis of COPD patients, which may provide important guidance for clinical practice.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/.

Practical Guidelines by the Andalusian Group for Nutrition Reflection and Investigation (GARIN) on Nutritional Management of Patients with Chronic Obstructive Pulmonary Disease: A Review

Malnutrition is common in chronic obstructive pulmonary disease (COPD) patients and is associated with worse lung function and greater severity. This review by the Andalusian Group for Nutrition Reflection and Investigation (GARIN) addresses the nutritional management of adult COPD patients, focusing on Morphofunctional Nutritional Assessment and intervention in clinical practice. A systematic literature search was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology, followed by critical appraisal based on Scottish Intercollegiate Guidelines Network (SIGN) guidelines. Recommendations were graded according to the European Society for Clinical Nutrition and Metabolism (ESPEN) system. The results were discussed among GARIN members, with consensus determined using a Likert scale. A total of 24 recommendations were made: 2(A), 6(B), 2(O), and 14(GPP). Consensus exceeded 90% for 17 recommendations and was 75-90% for 7. The care of COPD patients is approached from a nutritional perspective, emphasizing nutritional screening, morphofunctional assessment, and food intake in early disease stages. Nutritional interventions include dietary advice, recommendations on food group intake, and the impact of specialized nutritional treatment, particularly oral nutritional supplements. Other critical aspects, such as physical activity and quality of life, are also analyzed. These recommendations provide practical guidance for managing COPD patients nutritionally in clinical practice.

COPD and T2DM: a Mendelian randomization study

Introduction

Type 2 diabetes (T2DM) stands as a global chronic illness, exerting a profound impact on health due to its complications and generating a significant economic burden. Recently, observational studies have pointed toward a potential link between Chronic Obstructive Pulmonary Disease (COPD) and T2DM. To elucidate this causal connection, we employed the Mendelian randomization analysis.

Method

Our study involved a two-sample Mendelian randomization (MR) analysis on COPD and T2DM. Additionally, tests for heterogeneity and horizontal pleiotropy were performed.

Results

For the MR analysis, 26 independent single nucleotides polymorphisms (SNPs) with strong associations to COPD were chosen as instrumental variables. Our findings suggest a pronounced causal relationship between COPD and T2DM. Specifically, COPD emerges as a risk factor for T2DM, with an odds ratio (OR) of 1.06 and a 95% confidence interval ranging from 1.01 to 1.11 (P = 0.006). Notably, all results were devoid of any heterogeneity or pleiotropy.

Conclusion

The MR analysis underscores a significant causal relationship between COPD and T2DM, highlighting COPD as a prominent risk factor for T2DM.

Prevalence of pre-existing lung diseases and their association with income level among patients with lung cancer: a nationwide population-based case-control study in South Korea

BACKGROUND

This study aimed to estimate the prevalence of pre-existing lung diseases in patients with lung cancer compared to people without lung cancer and examine the association between income levels and pre-existing lung diseases.

METHODS

Data on patients with lung cancer (case) and the general population without lung cancer (non-cancer controls) matched by age, sex and region were obtained from the Korea National Health Insurance Service-National Health Information Database (n=51 586). Insurance premiums were divided into quintiles and medicaid patients. Conditional logistic regression models were used to examine the association between pre-existing lung diseases and the risk of lung cancer. The relationship between income level and the prevalence of pre-existing lung disease among patients with lung cancer was analysed using logistic regression models.

RESULTS

The prevalence of asthma (17.3%), chronic obstructive lung disease (COPD) (9.3%), pneumonia (9.1%) and pulmonary tuberculosis (1.6%) in patients with lung cancer were approximately 1.6-3.2 times higher compared with the general population without lung cancer. A significantly higher risk for lung cancer was observed in individuals with pre-existing lung diseases (asthma: OR=1.36, 95% CI 1.29 to 1.44; COPD: 2.11, 95% CI 1.94 to 2.31; pneumonia: 1.49, 95% CI 1.38 to 1.61; pulmonary tuberculosis: 2.16, 95% CI 1.75 to 2.66). Patients with lung cancer enrolled in medicaid exhibited higher odds of having pre-existing lung diseases compared with those in the top 20% income level (asthma: OR=1.75, 95% CI 1.56 to 1.96; COPD: 1.91, 95% CI 1.65 to 2.21; pneumonia: 1.73, 95% CI 1.50 to 2.01; pulmonary tuberculosis: 2.45, 95% CI 1.78 to 3.36).

CONCLUSIONS

Pre-existing lung diseases were substantially higher in patients with lung cancer than in the general population. The high prevalence odds of pre-existing lung diseases in medicaid patients suggests the health disparity arising from the lowest income group, underscoring a need for specialised lung cancer surveillance.

Relationships Between Pulmonary Function and Composite Indices of Femoral Neck Strength in Korean Men (KNHANES IV)

BACKGROUND

Despite the close relationship between osteoporosis and chronic pulmonary diseases, few studies have evaluated relationships between pulmonary functions and bone quality. We investigated associations between pulmonary function test results and femoral neck strength indices (SIs) in Korean men.

METHODS

This population-based, cross-sectional study was conducted using data from the Korea National Health and Nutrition Examination Survey IV on 936 men aged ≥ 19 years. Pulmonary functions (forced vital capacity [FVC] and forced expiratory volume in one second [FEV₁]) were measured using a dry rolling seal spirometer. Femoral neck SIs, relative to load, were calculated by hip dual-energy X-ray absorptiometry for compression strength index (CSI), bending strength index (BSI), and impact strength index (ISI).

RESULTS

The 443 (47.3%) of the 936 men were current smokers. FVC, FVC percentage with respect to the expected normal value, FEV₁, and FEV₁ percentage with respect to the expected normal value (FEV₁p) were positively associated with CSI and BSI after adjusting for confounders, including smoking history (β = 0.003-0.223, P = 0.005-0.036). FEV₁ and FEV₁p were positively associated with ISI (β = 0.000-0.014, P = 0.010-0.025). Of components of femoral neck SIs, bone mineral density was correlated with FEV₁ and FEV₁p (β = 0.001-0.037, P = 0.017-0.019). After adjusting for all confounders, all femoral neck SIs increased with FVC quintiles (P for trends = 0.001-0.012), and CSI and BSI increased with FEV₁ quintiles (P for trends = 0.034-0.043).

CONCLUSION

Reduced pulmonary function was correlated with reduced femoral neck strength, even after adjusting for smoking history in Korean men. Femoral neck SIs might be useful tools for evaluating bone health in men with reduced pulmonary function.

Word Embedding Reveals Cyfra 21-1 as a Biomarker for Chronic Obstructive Pulmonary Disease

BACKGROUND

Although patients with chronic obstructive pulmonary disease (COPD) experience high morbidity and mortality worldwide, few biomarkers are available for COPD. Here, we analyzed potential biomarkers for the diagnosis of COPD by using word embedding.

METHODS

To determine which biomarkers are likely to be associated with COPD, we selected respiratory disease-related biomarkers. Degrees of similarity between the 26 selected biomarkers and COPD were measured by word embedding. And we infer the similarity with COPD through the word embedding model trained in the large-capacity medical corpus, and search for biomarkers with high similarity among them. We used Word2Vec, Canonical Correlation Analysis, and Global Vector for word embedding. We evaluated the associations of selected biomarkers with COPD parameters in a cohort of patients with COPD.

RESULTS

Cytokeratin 19 fragment (Cyfra 21-1) was selected because of its high similarity and its significant correlation with the COPD phenotype. Serum Cyfra 21-1 levels were determined in patients with COPD and controls (4.3 ± 5.9 vs. 3.9 ± 3.6 ng/mL, P = 0.611). The emphysema index was significantly correlated with the serum Cyfra 21-1 level (correlation coefficient = 0.219, P = 0.015).

CONCLUSION

Word embedding may be used for the discovery of biomarkers for COPD and Cyfra 21-1 may be used as a biomarker for emphysema. Additional studies are needed to validate Cyfra 21-1 as a biomarker for COPD.

Impact of the spirometric definition on comorbidities in chronic obstructive pulmonary disease

BACKGROUND

Little is known about how the spirometric definition of airway obstruction affects the association between COPD and comorbidities and whether these associations might be due to genetic predisposition.

AIM

1) To examine the impact of the spirometric definition on the associations between COPD and its comorbidities and 2) To examine whether these associations can be explained by shared genetic or environmental factors.

METHODS

11,458 twins, aged 40-80 years, from the Danish Twin Registry were recruited who completed a questionnaire on medical history, life style factors and had a clinical examination. COPD was defined by respiratory symptoms (RS) plus airway obstruction according to either GOLD (FR-COPD) or ERS/ATS guidelines (LLN-COPD). Self-reported physician diagnoses were used to identify comorbidities.

RESULTS

The mean age of participants was 58.4 years ±SD 9.7, mean BMI was 26.6 kg/m² ± SD 4.4, 52% were female and the prevalence of LLN2.5-COPD and FR-COPD was 2.5% and 6.3%, respectively. Among eight major comorbidities, multivariate logistic regression showed COPD was only associated with heart failure, whereas RS alone were associated with 6 out of 8 comorbidities after Bonferroni-correction. There was an increased risk of heart failure, ischemic heart disease, depression and pulmonary embolism in twin individuals with RS compared with the co-twin without RS.

CONCLUSIONS

COPD was only associated with an increased risk of heart failure. Discordant COPD-individuals (FR-COPD+/LLN5-COPD-) were at increased risk of heart failure. Sub-analyses showed that RS, but not airway obstruction were associated with an increased risk of comorbidities.

Chronic obstructive pulmonary disease, lung function and risk of type 2 diabetes: a systematic review and meta-analysis of cohort studies

Background

The association between chronic obstructive pulmonary disease (COPD), lung function and risk of type 2 diabetes mellitus (T2DM) remains controversial. We performed a meta-analysis to clarify this issue.

Methods

The PubMed and EMBASE databases were searched. Cohort studies on COPD, lung function and risk of T2DM in adults were included. A random effects model was adopted to calculate the summary risk ratio (RR) and 95% confidence interval (CI). Dose-response analysis was conducted where possible.

Results

A total of 13 eligible cohort studies involving 307,335 incident T2DM cases and 7,683,784 individuals were included. The risk of T2DM was significantly higher in patients with COPD than those without COPD (RR = 1.25, 95% CI 1.16–1.34). Compared to the highest category of percentage forced vital capacity (FVC%), the lowest category of FVC% was associated with a higher risk of T2DM (RR = 1.43, 95% CI 1.33–1.53). Similarly, the summary RR of T2DM for the lowest versus highest category of percentage forced expiratory volume in 1 s (FEV1%) was 1.49 (95% CI 1.39–1.60). Significant linear associations of FVC% and FEV1% with risk of T2DM were found (P_{non-linearity} > 0.05); the RR of T2DM was 0.88 (95% CI 0.82–0.95) and 0.87 (95% CI 0.81–0.94) per 10% increase in FVC% and FEV1%, respectively. There was a non-significant relationship between the FEV1/FVC ratio and the risk of T2DM.

Conclusions

Both COPD and impaired lung function, especially restricted ventilation dysfunction, could increase the risk of T2DM. However, these findings should be interpreted with caution due to the limited number of studies, and need to be validated by future studies.

Diabetic lung disease: fact or fiction?

Diabetes mellitus is a chronic, progressive, incompletely understood metabolic disorder whose prevalence has been increasing steadily worldwide. Even though little attention has been paid to lung disorders in the context of diabetes, its prevalence has recently been challenged by newer studies of disease development. In this review, we summarize and discuss the role of diabetes mellitus involved in the progression of pulmonary diseases, with the main focus on pulmonary fibrosis, which represents a chronic and progressive disease with high mortality and limited therapeutic options.

Clinical Phenotypes, Comorbidities, and Exacerbations according to Serum 25-OH Vitamin D and Plasma Fibrinogen Levels in Chronic Obstructive Pulmonary Disease

BACKGROUND

Although vitamin D deficiency is prevalent in patients with chronic obstructive pulmonary disease (COPD), the influence of vitamin D deficiency on COPD has not been fully established. Moreover, the inflammation process is associated with vitamin D deficiency in the general population. Therefore, this study aimed to determine whether clinical phenotypes, comorbidities, and exacerbation rates are affected by the level of plasma fibrinogen, well studied by an inflammatory marker in COPD patients, and 25-hydroxy (25-OH) vitamin D.

METHODS

This retrospective study analyzed patients with COPD whose inflammatory marker levels, especially plasma fibrinogen and 25-OH vitamin D levels, had been examined. A correlation analysis was conducted for inflammatory markers and 25-OH vitamin D. Clinical characteristics, comorbidities and exacerbation rates were compared among four groups based on plasma fibrinogen concentrations (threshold, 350 mg/dL) and 25-OH vitamin D levels (threshold, 20 ng/mL).

RESULTS

Among 611 patients with COPD, 236 were included in the study. The levels of inflammatory markers had no statistical correlation with the serum 25-OH vitamin D levels. The four groups showed no statistically significant differences in age, sex, smoking history, inhaler use, and severity of comorbidities. Patients with high plasma fibrinogen concentrations and low 25-OH vitamin D levels had lower lung function, higher severity index, and higher annual rate of severe exacerbations 12 months before (0.23/year) and after (0.41/year) the measurement of 25-OH vitamin D levels than did the other patients.

CONCLUSION

Our findings suggested an interaction between vitamin D deficiency and COPD. The measurement of plasma fibrinogen concentrations could help identify a severe phenotypic group among patients with vitamin D deficiency.

Different impacts of respiratory symptoms and comorbidities on COPD-specific health-related quality of life by COPD severity

Background

Patients with chronic obstructive pulmonary disease (COPD) often have poor health-related quality of life (HRQoL) that is disproportionate to their degree of airflow limitation. This study evaluated the association between St George's Respiratory Questionnaire for COPD (SGRQ-C) score and forced expiratory volume in one second and investigated the factors responsible for high SGRQ-C score according to severity of airflow limitation.

Methods

Data from 1,264 COPD patients were obtained from the Korean COPD Subgroup Study (KOCOSS) cohort. Patients were categorized into two groups according to severity of airflow limitation: mild-to-moderate and severe-to-very severe COPD groups. We evaluated the clinical factors associated with high SGRQ-C score (≥25) in each COPD patient group.

Results

Of the 1,264 COPD patients, 902 (71.4%) had mild-to-moderate airflow limitation and 362 (28.6%) had severe-to-very severe airflow limitation. Of the mild-to-moderate COPD patients, 59.2% (534/902) had high SGRQ-C score, while 80.4% (291/362) of the severe-to-very severe COPD patients had high SGRQ-C score. The association between SGRQ-C score and post-bronchodilator forced expiratory volume in one second (% predicted) was very weak in the mild-to-moderate COPD patients (r=-0.103, p=0.002) and weak in the severe-to-very severe COPD patients (r=-0.219, p<0.001). Multiple logistic regression analysis revealed that age, being an ex- or current smoker, lower level of education, cough, dyspnea, and number of comorbidities with congestive heart failure, hyperlipidemia, and depression were significantly associated with high SGRQ-C score in mild-to-moderate COPD patients. In comparison, being an ex-smoker and having respiratory symptoms including sputum and dyspnea were significant factors associated with high SGRQ-C score in severe-to-very severe COPD patients.

Conclusions

In addition to the respiratory symptoms of dyspnea and cough, high SGRQ-C score was associated with extra-pulmonary comorbidities in mild-to-moderate COPD patients. However, only respiratory symptoms such as sputum and dyspnea were significantly associated with high SGRQ-C score in severe-to-very severe COPD patients. This indicates the need for an improved management strategy for relieving respiratory symptoms in COPD patients with poor HRQoL. In addition, attention should be paid to extra-pulmonary comorbidities, especially in mild-to-moderate COPD patients with poor HRQoL.

Inflammatory biomarkers and radiologic measurements in never-smokers with COPD: A cross-sectional study from the CODA cohort

Various biomarkers have emerged as potential surrogates to represent various subgroups of chronic obstructive pulmonary disease (COPD), which manifest with different phenotypes. However, the biomarkers representing never-smokers with COPD have not yet been well elucidated. The aim of this study was to evaluate the associations of certain serum and radiological biomarkers with the presence of COPD in never-smokers. To explore the associations of serum and radiological biomarkers with the presence of COPD in never-smokers, we conducted a cross-sectional patient cohort study composed of never-smokers from the COPD in Dusty Areas (CODA) cohort, consisting of subjects living in dusty areas near cement plants in South Korea. Of the 131 never-smokers in the cohort, 77 (58.8%) had COPD. There were no significant differences in the number of subjects with high levels of inflammatory biomarkers (>90th percentile of never-smokers without COPD), including white blood cell count, total bilirubin, interleukin (IL)-6, IL-8, and C-reactive protein, or radiologic measurements (including emphysema index and mean wall area percentage) between never-smokers with COPD and those without COPD. However, the number of subjects with high uric acid was significantly higher in never-smokers with COPD than never-smokers without COPD (31.2% (24/77) vs. 11.1% (6/54); p = 0.013). In addition, multivariate analysis revealed that high uric acid was significantly associated with the presence of COPD in never-smokers (adjusted relative risk: 1.63; 95% confidence interval: 1.21, 2.18; p = 0.001). Our study suggests that high serum levels of uric acid might be a potential biomarker for assessing the presence of COPD in never-smokers.

Diabetes risks and outcomes in chronic obstructive pulmonary disease patients: Two nationwide population-based retrospective cohort studies

OBJECTIVE

The relationship between chronic obstructive pulmonary disease (COPD) and diabetes remains incompletely understood. This study evaluated diabetes risk and post-diabetes outcomes in COPD patients with and without exacerbations.

METHODS

We identified 4671 adults newly diagnosed with COPD exacerbations and 9342 adults newly diagnosed with COPD without exacerbations during 2000-2008 using Taiwan's National Health Insurance Research Database. A comparison cohort of 18684 adults without COPD, matched by age and sex, was randomly selected from the same dataset for the control group. Diabetes events during 2000-2013 were ascertained from medical claims during the follow-up period. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of diabetes associated with COPD with or without exacerbations were calculated. We conducted another nested cohort study of 395516 patients with diabetes hospitalization during 2002-2013 and calculated adjusted odds ratios (ORs) and 95% CIs of histories of COPD and COPD exacerbations associated with adverse events after diabetes admission.

RESULTS

During the follow-up period, the incidences of diabetes for patients without COPD and for patients with COPD without or with exacerbations were 3.4, 4.1 and 7.4 per 1000 person-years, respectively (P < 0.0001). Increased risk of diabetes for patients with COPD without exacerbations (HR 1.09, 95% CI 1.02-1.17) and COPD with exacerbations (HR 2.18, 95% CI 1.88-2.52) was noted. Post-diabetes pneumonia (OR 3.28, 95% CI 3.13-3.43), intensive care admission (OR 1.32, 95% CI 1.26-1.39) and mortality (OR 2.06, 95% CI 1.88-2.25) were associated with COPD exacerbations.

CONCLUSION

Prevention and intervention strategies for diabetes and post-diabetes outcomes are needed for this susceptible population.

The impact of anaemia and iron deficiency in chronic obstructive pulmonary disease: A clinical overview

INTRODUCTION

Anaemia is increasingly recognised as an important comorbidity in the context of chronic obstructive pulmonary disease (COPD), but remains undervalued in clinical practice. This review aims to characterise the impact of anaemia and iron deficiency in COPD.

METHODS

Literature review of studies exploring the relationship between anaemia/iron deficiency and COPD, based on targeted MEDLINE and Google Scholar queries.

RESULTS

The reported prevalence of anaemia in COPD patients, ranging from 4.9% to 38.0%, has been highly variable, due to different characteristics of study populations and lack of a consensus on the definition of anaemia. Inflammatory processes seem to play an important role in the development of anaemia, but other causes (including nutritional deficiencies) should not be excluded from consideration. Anaemia in COPD has been associated with increased morbidity, mortality, and overall reduced quality of life. The impact of iron deficiency, irrespective of anaemia, is not as well studied, but it might have important implications, since it impacts production of red blood cells and respiratory enzymes. Treatment of anaemia/iron deficiency in COPD remains poorly studied, but it appears reasonable to assume that COPD patients should at least receive the same type of treatment as other patients.

CONCLUSIONS

Anaemia and iron deficiency continue to be undervalued in most COPD clinical settings, despite affecting up to one-third of patients and having negative impact on prognosis. Special efforts should be made to improve clinical management of anaemia and iron deficiency in COPD patients as a means of achieving better patient care.

Prevalence of chronic kidney disease in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

Background

The incidence and prevalence of chronic kidney disease (CKD) continue to rise worldwide. Increasing age, diabetes, hypertension, and cigarette smoking are well-recognized risk factors for CKD. Chronic obstructive pulmonary disease (COPD) is characterized by chronic airway inflammation leading to airway obstruction and parenchymal lung destruction. Due to some of the common pathogenic mechanisms, COPD has been associated with increased prevalence of CKD.

Methods

Systematic review of medical literature reporting the incidence and prevalence of CKD in patients with COPD using the Cochrane Collaboration Methodology, and conduct meta-analysis to study the cumulative effect of the eligible studies. We searched Medline via Ovid, PubMed, EMBASE and ISI Web of Science databases from 1950 through May, 2016. We included prospective and retrospective observational studies that reported the prevalence of CKD in patients with COPD.

Results

Our search resulted in 19 eligible studies of which 9 have been included in the meta-analysis. The definition of CKD was uniform across all the studies included in analysis. COPD was found to be associated with CKD in the included epidemiological studies conducted in many countries. Our meta-analysis showed that COPD was found to be associated with a significantly increased prevalence of CKD (Odds Ratio [OR] = 2.20; 95% Confidence Interval [CI] 1.83, 2.65). Study limitations: Studies included are observational studies. However, given the nature of our research question there is no possibility to perform a randomized control trial.

Conclusions

Patients with COPD have increased odds of developing CKD. Future research should investigate the pathophysiological mechanism behind this association, which may lead to better outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0315-0) contains supplementary material, which is available to authorized users.

Hyperlipidemia in COPD is associated with decreased incidence of pneumonia and mortality: a nationwide health insurance data-based retrospective cohort study

PURPOSE

COPD is often associated with various comorbidities that may influence its outcomes. Pneumonia, cardiovascular disease (CVD), and cancer are the major causes of death in COPD patients. The objective of this study is to investigate the influence of comorbidities on COPD by using the Taiwan National Health Insurance database.

PATIENTS AND METHODS

We retrospectively analyzed the database in 2006 of one million sampling cohort. Newly diagnosed patients with COPD with a controlled cohort that was matched by age, sex, and Charlson comorbidity index (CCI) were included for analysis.

RESULTS

In total, 1,491 patients with COPD were included for analysis (61.8% male). Patients with COPD had higher incidences of pneumonia (25.7% vs 10.4%; P<0.0001), CVD (15.1% vs 10.5%; P<0.0001), and mortality rate (26.6% vs 15.8%; P<0.001) compared with the control group in the 4-year follow-up. In patients with COPD, CCI ≥3 have a higher incidence of pneumonia (hazard ratio [HR] 1.61; 95% confidence interval [CI] 1.23-2.09; P<0.0001), CVD (HR 1.73; 95% CI 1.24-2.41; P=0.001), and mortality (HR 1.12; 95% CI 1.12-1.83; P=0.004). Among the major comorbidities of COPD, hyperlipidemia was associated with decreased incidence of pneumonia (HR 0.68; 95% CI 0.5-0.93; P=0.016) and mortality (HR 0.64; 95% CI 0.46-0.90; P=0.009), but was not associated with increased risk of CVD (HR 1.10; 95% CI 0.78-1.55; P=0.588).

CONCLUSION

Our results demonstrate that COPD is associated with increased incidence of pneumonia, CVD, and mortality. In patients with COPD, higher CCI is associated with increased incidence of pneumonia, CVD, and mortality. However, COPD with hyperlipidemia is associated with decreased incidence of pneumonia and mortality.

Comorbidities in obstructive lung disease in Korea: data from the fourth and fifth Korean National Health and Nutrition Examination Survey

BACKGROUND

Comorbidities can occur frequently in patients with chronic obstructive pulmonary disease (COPD) and can influence mortality and morbidity independently. It is increasingly recognized that many patients with COPD have comorbidities that have a major impact on their quality of life and survival. Therefore, we investigated the prevalence of comorbidities in Korean COPD populations.

METHODS

We used data obtained in the 6 years of the fourth and fifth Korean National Health and Nutrition Examination Survey (KNHANES) IV and V. Among 50,405 subjects, 16,151 subjects aged ≥40 years who performed spirometry adequately were included in this study. Airway obstruction was defined as forced expiratory volume in 1 second/forced vital capacity <0.7, and the Global Initiative For Chronic Obstructive Lung Disease stage was used to evaluate the severity of airway obstruction. Statistical analyses were performed using SAS 9.2.

RESULTS

Among the 16,151 subjects (43.2% male, 56.8% female; mean age: 57.1 years for men and 57.2 years for women), 13.1% had obstructive lung function; 11.3%, restrictive lung function; and 75.6%, normal lung function. Among individuals with obstructive lung function, 45.3%, 49.4%, and 5.3% had mild, moderate, and severe and very severe airflow limitation. The prevalence of hypertension, diabetes mellitus (DM), underweight, and hypertriglyceridemia was higher in the obstructive lung function group than in the normal lung function group (49.6% vs 35.2%; 16.8% vs 10.5%; 3.3% vs 1.3%; 19.7% vs 17.0%). According to the severity of airway obstruction, hypertension and underweight were more common as severity increased, although the prevalence of DM and hypertriglyceridemia was lower in subjects with severe airway obstruction. The prevalence of hypercholesterolemia, overweight, and osteoarthritis was lower in the obstructive lung function group, especially in the severe airway obstruction groups.

CONCLUSIONS

Overall, our analysis is similar to research that was conducted earlier. Our study showed that hypertension and underweight are common comorbidities in COPD patients, and are higher as the severity of airflow obstruction increased in both men and women. DM, hypertriglyceridemia, and low high-density lipoprotein cholesterol are more common in subjects with airway obstruction, although their incidence is lower in the severe group.

Chronic obstructive pulmonary disease and diabetes mellitus: a systematic review of the literature

The objective of this systematic review was to discuss our current understanding of the complex relationship between chronic obstructive pulmonary disease (COPD) and type-2 diabetes mellitus (T2DM). We performed a systematic search of the literature related to both COPD and diabetes using PubMed. Relevant data connecting both diseases were compiled and discussed. Recent evidence suggests that diabetes can worsen the progression and prognosis of COPD; this may result from the direct effects of hyperglycemia on lung physiology, inflammation or susceptibility to bacterial infection. Conversely, it has also been suggested that COPD increases the risk of developing T2DM as a consequence of inflammatory processes and/or therapeutic side effects related to the use of high-dose corticosteroids. In conclusion, although there is evidence to support a connection between COPD and diabetes, additional research is needed to better understand these relationships and their possible implications.

Diabetes mellitus among outpatients with COPD attending a university hospital

Type 2 diabetes mellitus is a common comorbidity of COPD, but there are still many doubts about the relation among diabetes and COPD. We retrospectively collected data from patients afferent to our Respiratory Diseases outpatient clinic at the Tor Vergata University Hospital between 2010 and 2012. The study population was analyzed by clusters of age, gender, body mass index (BMI), smoking status, lung function, concomitant pharmacologic therapies and comorbidities. The values of the association between variables were expressed as odds ratio. Data were adjusted for gender, age and possible confounding variables by Mantel-Haenszel method. We identified 493 patients with COPD. Ninety-two (18.7 %) patients were affected by type 2 diabetes mellitus, with no significant gender differences. The prevalence distribution was similar among the different age clusters, but the association was stronger in patients younger than 65 years. The association was present only in obese subjects in whom it was significant only in patients with moderate-to-severe COPD, but not mild COPD. The presence of cardiovascular diseases was significantly associated with diabetes mellitus in patients with COPD. There was a slight association of inhaled corticosteroid (ICS) use with the presence of diabetes mellitus in COPD, but the combination of an ICS with a β2-agonist apparently reduced this association. The association with type 2 diabetes mellitus was greater in patients with COPD respect to general population, and correlated with the increase in BMI and the presence of other comorbidities, suggesting that both diseases may be targets of systemic inflammation.

Clinical characteristics and survival of Korean idiopathic pulmonary arterial hypertension patients based on vasoreactivity

We aimed to identify a vasoreactive subset of patients with idiopathic pulmonary arterial hypertension (IPAH) in Korea and to show their clinical characteristics and prognosis. Data on patients who were diagnosed with IPAH at Asan Medical Center between January 1994 and March 2013 were retrospectively collected. Acute vasodilator testing was performed with inhaled nitric oxide during diagnostic right heart catheterization. A positive acute response was defined as a reduction in mean pulmonary arterial pressure (PAP) ≥10 mmHg to an absolute level of mean PAP <40 mmHg without a decrease in cardiac output. Among a total of 60 IPAH patients included for analysis, 9 (15%) showed a positive acute response to acute vasodilator testing. Acute responders showed significantly lower peak velocity of a tricuspid regurgitation jet on echocardiography (4.1±0.3 m/s vs. 4.6±0.6 m/s; P=0.01) and significantly lower mean PAP hemodynamically (47±10 mmHg vs. 63±17 mmHg; P=0.003) than non-responders at baseline. The survival rate of acute responders was 88% at 1, 3, 5, and 10 yr, respectively, which was significantly higher than that of non-responders (85%, 71%, 55%, and 40%, respectively; P=0.029). In conclusion, Korean IPAH patients with vasoreactivity showed better baseline hemodynamic features and survival than those without vasoreactivity.

The relationship between chronic obstructive pulmonary disease and comorbidities: a cross-sectional study using data from KNHANES 2010-2012

BACKGROUND

Multiple comorbidities related to chronic obstructive pulmonary disease (COPD) make it a difficult disease to treat. The relationship between these comorbidities and COPD has not been fully investigated. We aimed to determine whether COPD was independently associated with various comorbidities.

METHODS

This was a cross-sectional study, which used data from the Korean National Health and Nutrition Examination Survey (KNHANES) V conducted between 2010 and 2012. Survey design analysis was employed to determine the association between COPD and 15 comorbidities. A COPD patient was defined as a smoker with forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < 0.7 and comorbidities were defined based on objective laboratory findings and questionnaires.

RESULTS

Of a total of 9488 patient who underwent spirometry, 744 (7.84%) COPD cases and 3313 non-COPD controls were included in the analyses. Although the prevalence rates of the majority of the comorbidities were high among the COPD patients, only hypertension (adjusted odds ratio [aOR], 1.63; 95% CI, 1.13-2.33 in Stage 1 COPD group; aOR, 1.92; 95% CI, 1.36-2.72 in Stage 2-4 COPD group) and a history of pulmonary tuberculosis (aOR, 3.38; 95% CI, 1.90-5.99 in Stage 2-4 COPD group) were independently associated with COPD after adjustment for age, smoking status, and confounders.

CONCLUSIONS

Only hypertension and a history of pulmonary tuberculosis were independently associated with COPD after adjustment for confounders among 15 comorbidities. The results suggest that majority of COPD patients might have similar risk factors with its comorbidities, including age and smoking status.

Anaemia in chronic obstructive pulmonary disease: an insight into its prevalence and pathophysiology

Chronic obstructive pulmonary disease (COPD) is a major health problem, with increasing morbidity and mortality. There is a growing literature regarding the extra-pulmonary manifestations of COPD, which can have a significant impact on symptom burden and disease progression. Anaemia is one of the more recently identified co-morbidities, with a prevalence that varies between 4.9% and 38% depending on patient characteristics and the diagnostic criteria used. Systemic inflammation seems to be an important factor for its establishment and repeated bursts of inflammatory mediators during COPD exacerbations could further inhibit erythropoiesis. However, renal impairment, malnutrition, low testosterone levels, growth hormone level abnormalities, oxygen supplementation, theophylline treatment, inhibition of angiotensin-converting enzyme and aging itself are additional factors that could be associated with the development of anaemia. The present review evaluates the published literature on the prevalence and significance of anaemia in COPD. Moreover, it attempts to elucidate the reasons for the high variability reported and investigates the complex pathophysiology underlying the development of anaemia in these patients.

Quantifying comorbidity in individuals with COPD: a population study

Chronic obstructive pulmonary disease (COPD) has been associated with many types of comorbidity. We aimed to quantify the real world impact of COPD on lower respiratory tract infection, cardiovascular disease, diabetes, psychiatric disease, musculoskeletal disease and cancer, and their impact on COPD through health services.

A population study using health administrative data from Ontario, Canada, in 2008–2012 was conducted. Absolute and adjusted relative rates of ambulatory care visits, emergency department visits and hospitalisations for the comorbidities of interest in people with and without COPD were determined and compared.

Among 7 241 591 adults, 909 948 (12.6%) had COPD. Over half of all lung cancer, a third of all lower respiratory tract infection and cardiovascular disease, a quarter of all low trauma fracture, and a fifth of all psychiatric, musculoskeletal, non-lung cancer and diabetes ambulatory care visits, emergency department visits and hospitalisations in Ontario were used by people with COPD. Individuals with COPD used about five times more health services for lung cancer, and two times more health services for lower respiratory tract infections and cardiovascular disease than people without COPD.

Individuals with COPD use a disproportionate amount of health services for comorbid disease, placing significant burden on the healthcare system.

The prevalence of COPD co-morbidities in Serbia: results of a national survey

BACKGROUND

Research studies have found different prevalence rates for co-morbidities in patients with chronic obstructive pulmonary disease (COPD).

AIMS

The aim of our study was to investigate the prevalence of co-morbidities as well as functional limitations in subjects with COPD.

METHODS

The study was based on a nationally representative sample of the population of Serbia. Information on the health of the population was obtained from interviews and anthropometric measurements. In this study we analysed a total of 10,013 respondents aged 40 years or older. There were 653 subjects with COPD and 9,360 respondents without COPD.

RESULTS

Out of the 10,013 respondents, 5,377 were aged 40-59 years and 4,636 were 60 years or older. The prevalence of COPD was 5.0% in respondents aged 40-59 years and 8.3% in those aged 60 years or older; the total prevalence was 6.5%. The most prevalent co-morbidities among respondents with COPD were hypertension (54.5%) and dyslipidaemia (26.5%). The prevalence of all analysed co-morbidities was higher in respondents with COPD and the difference was highly statistically significant, except for stroke and malignancies, for which the difference was significant. Analysis showed that respondents with COPD had a higher prevalence of all analysed clinical factors (dizziness, obesity, anaemia and frailty) and functional impairments (mobility and hearing and visual impairment) compared with respondents without COPD. For those aged 40-59 years the difference was highest for mobility difficulty (four times higher prevalence in COPD patients) and anaemia (three times higher in COPD patients).

CONCLUSION

Our analysis showed that the most prevalent co-morbidities in COPD were hypertension, dyslipidaemia, chronic renal disease and anxiety/depression. The finding suggests that health professionals should actively assess co-morbidities in patients with COPD.

Prevalence of chronic sputum and associated factors in Korean adults

Chronic sputum is a troublesome symptom in many respiratory diseases. The prevalence of chronic sputum varies from 1.2% to 13% according to the country. The purpose of this study was to estimate the prevalence of chronic sputum and to find its associated factors in a general Korean population. We analyzed the data of the Korea National Health and Nutrition Examination Survey 2010 and 2011. A total number of 6,783 subjects aged 40 yr or more were enrolled in this study with 3,002 men and 3,781 women. As a result, the prevalence of chronic sputum was 6.3% (n=430). Significant risk factors for chronic sputum by multivariate analysis were: age (≥ 70 yr) (odds ratio [OR], 1.954; 95% confidence interval [CI], 1.308-2.917), current smoking (OR, 4.496; 95% CI, 3.001-6.734), chronic obstructive pulmonary disease (COPD) (OR, 1.483; 95% CI, 1.090-2.018), and tuberculosis (OR, 1.959; 95% CI, 1.307-2.938). In conclusion, the prevalence of chronic sputum in Korea was in the intermediate range compared with other countries. Smoking is a preventable risk factor identified in this study, and major respiratory diseases, such as COPD and tuberculosis, should be considered in subjects with chronic sputum.

Chronic obstructive pulmonary disease: a risk factor for type 2 diabetes: a nationwide population-based study

BACKGROUND

Type 2 diabetes mellitus (DM) is a common medical disorder and a leading cause of morbidity and mortality worldwide. We investigated whether chronic obstructive pulmonary disease (COPD) was the risk factor for type 2 diabetes in an Asian population.

MATERIALS AND METHODS

From Taiwan's National Health Insurance Research Database, we collected data from 16,088 patients, including 8044 COPD patients and 8044 age- and gender- matched control subjects. Cox proportional hazard regression was performed to evaluate independent risk factors for type 2 diabetes in all patients and identify risk factors in patients with COPD.

RESULTS

During the 5.5-year follow-up, patients with COPD were found to have a significantly higher rate of incident type 2 diabetes than the control group (P < 0.001). COPD was significantly associated with type 2 diabetes hazard ratio (HR : 1.41, 1.23-1.63, P < 0.001) after adjusting sex, age, residential area, insurance premium, steroid use, hypertriglycemia, hypertension, coronary artery disease (CAD) and cerebrovascular disease. Cox regression analysis showed that hypertension (HR : 1.55, 1.33-1.80, P < 0.001) and hypertriglycemia (HR : 1.48, 1.15-1.90, P = 0.002) were important risk factors for type 2 diabetes in patients with COPD.

CONCLUSIONS

Patients with COPD have a higher risk of type 2 diabetes compared with control subjects after adjusting for confounding factors such as sex, age, residential area, insurance premium, steroid use, hypertriglycemia, hypertension, CAD and cerebrovascular disease. Continuous surveillance of signals of dysglycemia may be incorporated into care programmes for patients with COPD.

Obesity in Bulgarian patients with chronic obstructive pulmonary disease

It has been well defined that obesity is strongly linked with several respiratory symptoms and diseases, but no convincing evidence has been provided for chronic obstructive pulmonary disease (COPD). In the current study, we aim to assess the possible prevalence of obesity in patients with COPD in a cross-sectional case–control study of individuals from the region of Stara Zagora, Bulgaria, and to explore whether the body mass has some effect on the lung function of COPD patients. The study included 158 patients with COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) II, III, and IV stages) and 123 individuals unaffected by the disease (control). A higher frequency of obesity compared to the controls (20.3%) was observed in patients with COPD (29.1%, p = 0.093), especially in those with GOLD II stage (37.7%, p = 0.009). Prevalence of obesity was highest in COPD GOLD II, followed by GOLD III and IV stages ( p = 0.068). When diabetes was considered as confounding factor, we found a significant prevalence of obesity in COPD patients than the controls with diabetes ( p = 0.031). Interestingly, there was a statistically significant moderate positive correlation between the body mass index and forced expiratory volume in one second as a percentage of predicted value in the whole patients’ group ( R = 0.295, p = 0.0002) as well as in the subgroups of GOLD II ( R = 0.257, p = 0.024) and GOLD III COPD ( R = 0.259, p = 0.031).The results of our study propose that the increased body mass, particularly obesity is frequent comorbidity to COPD, especially to less severe diseases. Moreover, the results suggest that the higher body weight may provide some protection against the impairment of lung functions in patients with stable COPD.

Chronic obstructive pulmonary disease and glucose metabolism: a bitter sweet symphony

Chronic obstructive pulmonary disease, metabolic syndrome and diabetes mellitus are common and underdiagnosed medical conditions. It was predicted that chronic obstructive pulmonary disease will be the third leading cause of death worldwide by 2020. The healthcare burden of this disease is even greater if we consider the significant impact of chronic obstructive pulmonary disease on the cardiovascular morbidity and mortality. Chronic obstructive pulmonary disease may be considered as a novel risk factor for new onset type 2 diabetes mellitus via multiple pathophysiological alterations such as: inflammation and oxidative stress, insulin resistance, weight gain and alterations in metabolism of adipokines. On the other hand, diabetes may act as an independent factor, negatively affecting pulmonary structure and function. Diabetes is associated with an increased risk of pulmonary infections, disease exacerbations and worsened COPD outcomes. On the top of that, coexistent OSA may increase the risk for type 2 DM in some individuals. The current scientific data necessitate a greater outlook on chronic obstructive pulmonary disease and chronic obstructive pulmonary disease may be viewed as a risk factor for the new onset type 2 diabetes mellitus. Conversely, both types of diabetes mellitus should be viewed as strong contributing factors for the development of obstructive lung disease. Such approach can potentially improve the outcomes and medical control for both conditions, and, thus, decrease the healthcare burden of these major medical problems.