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

Associations between different body mass index and lung function impairment in Chinese people aged over 40 years: a multicenter cross-sectional study

OBJECTIVE

The aim of this study was to explore the associations between different body mass index (BMI) levels and different lung function impairment (LFI) in Chinese people aged over 40 years.

METHODS

We used a multi-stage stratified cluster random sampling method to investigate 3000 residents aged over 40 years from 5 areas in Hubei province of China in 2019-20. The data on questionnaire, physical measurements, and spirometry of the participants were collected. The associations of different BMI levels with different LFI were analyzed using multivariate logistic regressions after complex weighting. The spirometry data were analyzed using one-factor analysis of variance (ANOVA), and post-hoc was performed using the least significance difference (LSD)-t test.

RESULTS

A total of 2860 subjects were included. The prevalence (95%CI) of obstructive lung disease (OLD), restrictive lung disease (RLD), mixed lung disease (MLD), chronic obstructive pulmonary disease (COPD), COPD mild, and COPD moderate/severe/very severe were 24.1% (95% CI: 22.2-26.2), 11.6% (95% CI: 10.3-12.9), 4.0% (95% CI: 3.3-4.8), 12.6% (95% CI: 11.0-14.1), 7.2% (95% CI: 6.0-8.4), and 5.3% (95% CI: 4.3-6.4) respectively. After multivariate adjustment, the risk of OLD, COPD, and COPD mild decreased with the increment of BMI levels (both P for trend < 0.05). When compared to the normal weight group, the overweight group and obese group were at lower risk of experiencing OLD than normal group, the ORs were 0.77 (95% CI: 0.59-0.99) and 0.59 (95% CI: 0.40-0.86) respectively. The obese group was at lower risk for people with COPD mild (OR: 0.42, 95%CI: 0.21-0.85). Participants in underweight group were more likely to experience COPD and COPD moderate/severe/very severe, the ORs were 2.82 (95% CI: 1.07-7.39) and 3.89 (95% CI: 1.28-11.87) respectively.

CONCLUSION

Higher BMI levels were associated with an decreased risk of OLD and COPD. Obesity had a protective effect on lung function in OLD patients and COPD patients. However, there was no significant difference in RLD and MLD prevalence between different BMI groups.

Comorbidities in patients with chronic obstructive pulmonary disease: a comprehensive study

In recent years, there has been an increasing interest in understanding the systemic nature of COPD and its frequently associated comorbidities. COPD is characterized by chronic lung disease involving local and systemic inflammation and non-reversible airway obstruction. The disease course is marked by recurrent exacerbations and is often accompanied by various comorbidities. This study aimed to evaluate the prevalence of comorbidities among Iraqi patients with COPD and their association with disease severity. A case-control study was conducted at Al-Sader Hospital in Annajaf from October 2019 to October 2020, involving 200 participants. The study population comprised 100 patients with COPD (COPD group) and 100 individuals without COPD serving as the control group. Patients with COPD were divided into four groups according to the disease severity. The prevalence of type 2 diabetes mellitus (T2DM), atherosclerotic cardiovascular diseases (ASCVD), hypertension, and dyslipidemia was determined in all groups. Patients with COPD had a significantly higher prevalence of T2DM, ASCVD, hypertension, and dyslipidemia, and, except for T2DM, the prevalence was significantly higher in the more severe groups. It was concluded that T2DM, ASCVD, hypertension, and dyslipidemia were commonly associated with COPD.

Association between lung function and the risk of atrial fibrillation in a nationwide population cohort study

We investigated the association between lung function and atrial fibrillation (AF) in 21,349 adults without AF aged ≥ 40 years who underwent spirometry. The study participants were enrolled from the Korean National Health and Nutritional Examination Survey between 2008 and 2016. The primary outcome was new-onset non-valvular AF identified from the National Health Insurance Service database. During the median follow-up of 6.5 years, 2.15% of participants developed new-onset AF. The incidence rate of AF per 1000 person-years was inversely related to the forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and FEV₁/FVC quartile. After adjustment for multiple variables, the AF risk in the lowest FEV₁ quartile was 1.64-fold higher than that in the highest quartile (hazard ratio (HR) 1.64 (95% confidence interval (CI) 1.26–2.12) for lowest FEV₁ quartile). The lowest quartile of FVC had 1.56-fold higher AF risk than the highest quartile (HR 1.56 (95% CI 1.18–2.08) for lowest FVC quartile). Although the lowest FEV₁/FVC quartile was associated with an increased risk of AF in the unadjusted model, this increased risk was not statistically significant in the multivariable analysis. Compared to those with normal lung function, participants with restrictive or obstructive lung function had 1.49 and 1.42-fold higher AF risks, respectively. In this large nationwide cohort study, both obstructive and restrictive patterns of reduced lung function were significantly associated with increased AF risk.

The Impact of Lung Function on Extra-Pulmonary Diseases and All-Cause Mortality in US Adult Population with and without COPD

Objective

Spirometric lung function is usually used to evaluate respiratory health. However, the impact of lung function on extra-pulmonary diseases and all-cause mortality has not been fully elucidated, especially in people without chronic obstructive pulmonary disease (COPD).

Patients and Methods

Participants aged ≥20 and underwent spirometry test from the US National Health and Nutrition Examination Surveys (NHANES) 2007-2012 were analyzed in this study. Multivariate logistic and Cox regressions were used to evaluate the impact of forced expiratory volume in 1 second percent of predicted (FEV₁% predicted) and forced vital capacity percent of predicted (FVC% predicted) on 14 extra-pulmonary diseases and all-cause morbidity after adjusting for multiple confounders.

Results

During 2007-2012, 1800 COPD patients and 11,437 non-COPD subjects were included. The prevalence of hypertension, diabetes mellitus (DM), dyslipidemia, metabolic syndrome (MS), congestive heart failure (CHF), coronary disease, stroke, chronic kidney disease (CKD), arthritis, cancer, underweight and osteoporosis in COPD patients was higher than that in the non-COPD population. After adjusting for confounders, the decrease of FEV₁% predicted and FVC% predicted was related with higher odds of having hypertension, DM, obesity, MS, CHF, coronary disease and depression (OR > 1, P<0.05) in both the COPD and non-COPD populations. These 2 indices were also related with higher odds of dyslipidemia, CKD, arthritis and osteoporosis in the non-COPD population. The risk of stroke, anemia and cancer was not related with the decrease of lung function. In addition, the decrease of lung function was independent risk factors for the increase of all-cause mortality. These risks were gradually increased with the decrease of lung function.

Conclusion

The decrease of FEV₁% predicted and FVC% predicted was related with higher risk of multiple extra-pulmonary diseases and all-cause mortality in both the COPD and non-COPD population.

Validation of Predictive Metabolic Syndrome Biomarkers of World Trade Center Lung Injury: A 16-Year Longitudinal Study

BACKGROUND

Metabolic syndrome (MetSyn) predicted future development of World Trade Center lung injury (WTC-LI) in a subgroup of firefighters who never smoked and were male. An intracohort validation of MetSyn as a predictor of WTC-LI is examined in the cohort exposed to the World Trade Center (WTC) that has been followed longitudinally for 16 years.

METHODS

Results of pulmonary function tests (n = 98,221) in workers exposed to the WTC (n = 9,566) were evaluated. A baseline cohort of firefighters who had normal FEV1 before 9/11 and who had had serum drawn before site closure on July 24, 2002 (n = 7,487) was investigated. Case subjects with WTC-LI (n = 1,208) were identified if they had at least two measured instances of FEV1 less than the lower limit of normal (LLN). Cox proportional hazards modeled early MetSyn biomarker ability to predict development of FEV1 less than the LLN.

RESULTS

Case subjects were more likely to smoke, be highly exposed, and have MetSyn. There was a significant exposure dose response; the individuals most highly exposed had a 30.1% increased risk of developing WTC-LI, having MetSyn increased risk of developing WTC-LI by 55.7%, and smoking increased risk by 15.2%. There was significant interaction between smoking and exposure.

CONCLUSIONS

We validated the usefulness of MetSyn to predict future WTC-LI in a larger population of individuals who were exposed. MetSyn defined by dyslipidemia, insulin resistance, and cardiovascular disease suggests that systemic inflammation can contribute to future lung function loss.

Mapping analysis to estimate EQ-5D utility values using the COPD assessment test in Korea

Background

There is no research on mapping algorithms between EQ-5D and COPD assessment test (CAT) in Korea. The purpose of this study was to develop mapping algorithms that predict EQ-5D-3 L utility from the CAT in patients with COPD.

Methods

Survey data of 300 COPD patients were collected from three tertiary teaching hospitals in Korea. To predict EQ-5D-3 L utility from the CAT, various models were assessed. Models were developed using randomly split training samples. Subsequently, the models were validated based on root mean square error (RMSE) and mean absolute error (MAE) in validation samples. The models were also validated using the bootstrap method, which involves iterative splitting, training, and validating of the sample data at least 10,000 times. Average RMSEs and MAEs were used as criteria for model selection.

Results

The recommended mapping algorithms were based on ordinary least squares (OLS) regression models, which revealed five CAT items (chest tightness, breathlessness, activity, leaving home, and energy) as statistically significant on the EQ-5D-3 L. The mapping models estimated the overall mean of EQ-5D-3 L utilities effectively, but EQ-5D-3 L utilities for severe (low utility) patients (< 0.6) were overestimated as the observed EQ-5D-3 L utilities were often distributed over 0.6.

Conclusion

Mapping algorithms can be used to predict EQ-5D-3 L utilities from the CAT. However, mapping algorithms should be used cautiously when applied to groups with greater disease severity.

Electronic supplementary material

The online version of this article (10.1186/s12955-019-1148-3) contains supplementary material, which is available to authorized users.

Association between hand grip strength and spirometric parameters: Korean National health and Nutrition Examination Survey (KNHANES)

Background

We investigated the associations between hand grip strength (HGS) and spirometric parameters.

Methods

A total of 5,303 participants over 40 years of age, who underwent spirometry and HGS testing, were selected from the Korean National Health and Nutrition Examination Survey 2014-2015. Outcome measures were forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), FEV₁/FVC, and peak expiratory flow rate (PEFR). Unadjusted and adjusted linear regressions were used for the analyses.

Results

Mean HGS in the obstructive group was: male: 38.9±6.9 kg; female: 24.2±4.8 kg, which was significantly less than that in the normal group (male: 42.2±7.2 kg, P<0.001; female: 26.0±4.6 kg, P<0.001). In a multiple linear regression model, HGS was significantly associated with FEV₁ (male: β=0.18, P<0.001, female: β=0.21, P<0.001), FVC (male: β=0.23, P<0.001, female: β=0.24, P<0.001) and PEFR (male: β=0.13, P<0.001, female: β=0.14, P<0.001) after adjustment.

Conclusions

We found associations between muscle strength as evaluated by HGS and spirometric pulmonary function parameters.

Relationship between obstructive lung disease and non-alcoholic fatty liver disease in the Korean population: Korea National Health and Nutrition Examination Survey, 2007-2010

Purpose

Previous studies have shown that progressive forms of non-alcoholic fatty liver disease (NAFLD) occur frequently in patients with obstructive lung disease (OLD). However, few studies have written about this relationship. This study aimed to investigate the relationship between OLD and NAFLD.

Subjects and methods

The Korea National Health and Nutrition Examination Survey is a national population-based, cross-sectional surveillance program that was initiated to assess the health and nutritional status of the Korean population. From 2007 to 2010, 11,738 subjects were enrolled. The subjects were defined as having NAFLD when they had scores higher than -0.640 in a NAFLD liver fat score prediction model, which was a previously validated prediction score. Individuals with forced expiratory volume in one second/forced vital capacity <0.7 were considered to have OLD. The subjects were divided into non-OLD and OLD groups and non-NAFLD and NAFLD groups. All analyses were performed using sample weighting using the complex samples plan.

Results

The prevalences of NAFLD and OLD were 30.2% and 8.9%, respectively. Although not statistically significant, subjects in the NAFLD group involved a higher tendency of having OLD than did those in the non-NAFLD group (8.5% vs 10.0%, respectively, P=0.060). Subjects with OLD showed a higher tendency to have NAFLD than non-OLD subjects (30.0% vs 33.7%, respectively, P=0.060). NAFLD subjects were at higher odds of OLD (odds ratio=1.334; 95% confidence interval=1.108-1.607, P=0.002) than non-NAFLD subjects, after adjusting for age, sex, and smoking history. OLD subjects were at higher odds of NAFLD (odds ratio=1.556; 95% confidence interval=1.288-1.879, P<0.001) than non-OLD subjects, after adjusting for age, sex, and smoking history.

Conclusion

This study showed that NAFLD is related to OLD. Clinicians should be aware of possible liver comorbidities in OLD patients and that extrahepatic disease in NAFLD patients may vary more than previously thought.

Changes in the Burden of Comorbidities in Patients with COPD and Asthma-COPD Overlap According to the GOLD 2017 Recommendations

PURPOSE

Comorbidities associated with chronic obstructive pulmonary disease (COPD) affect quality of life and increase mortality. Asthma-COPD overlap (ACO) may express a different profile of comorbidities compared to COPD alone. It is unclear how recent changes in GOLD recommendations affect the profile of comorbidities in COPD and ACO.

METHODS

Eight hundred and thirty-four patients with COPD were recruited from 67 Hungarian secondary care outpatient clinics, 469 of them had ACO. Comorbidities were defined by respiratory specialists based on medical history, patient report, and medications. COPD grades were defined according to the old 2016 and the new 2017 GOLD document. Comorbidities were compared along COPD ABCD groups determined by the old and new GOLD.

RESULTS

66 and 72% of the COPD patients in groups C and D (GOLD 2016) were recategorized to groups A and B (GOLD 2017), respectively. There was no difference in the prevalence of disorders along the 2016 GOLD categories except for osteoporosis in ACO (p = 0.01). When the patients were categorized according to the 2017 GOLD criteria, the prevalence of osteoporosis (p = 0.01) was different among the four groups in all COPD patients. Subgroup analysis of non-ACO COPD patients revealed inter-group differences for cardiac arrhythmia (p < 0.01). No alteration was seen in the prevalence of coronary artery disease, hypertension, diabetes, or the total number of comorbidities.

CONCLUSION

A significant number of patients are recategorized according to the GOLD 2017 criteria. This change only marginally affects the profile of comorbidities; still this needs to be considered when assessing the patients in daily practice.

Prevalence of osteoarthritis in individuals with COPD: a systematic review

The objective of this review was to examine the prevalence of osteoarthritis (OA) in individuals with COPD. A computer-based literature search of CINAHL, Medline, PsycINFO and Embase databases was performed. Studies reporting the prevalence of OA among a cohort of individuals with COPD were included. The sample size varied across the studies from 27 to 52,643 with a total number of 101,399 individuals with COPD recruited from different countries. The mean age ranged from 59 to 76 years. The prevalence rates of OA among individuals with COPD were calculated as weighted means. A total of 14 studies met the inclusion criteria with a prevalence ranging from 12% to 74% and an overall weighted mean of 35.5%. Our findings suggest that the prevalence of OA is high among individuals with COPD and should be considered when developing and applying interventions in this population.

Effect of antiretroviral therapy use and adherence on the risk of hyperlipidemia among HIV-infected patients, in the highly active antiretroviral therapy era

HIV-infected patients exposed to antiretroviral therapy (ART) have an increased risk for hyperlipidemia and cardiovascular disease. We performed a longitudinal, comprehensive, and population-based study to investigate the cumulative effect of different types of ART regimens on hyperlipidemia risk in the Taiwanese HIV/ART cohort. A total of 13,370 HIV-infected patients (2,674 hyperlipidemia and 10,696 non-hyperlipidemia patients) were recruited after matching for age, gender, and the first diagnosis date of HIV infection by using the National Health Insurance Research Database in Taiwan. Hyperlipidemia risk associated with cumulative ART use, ART adherence, and their combination was assessed. The matched hyperlipidemia group had a larger number of patients using ART and a higher incidence of comorbidities, specifically, respiratory disease and diabetes. Patients with high ART dosage and dose-dependent manner adherence, respectively, demonstrated an increased risk of hyperlipidemia. For single ART regimens, patients receiving nucleoside reverse-transcriptase inhibitors (NRTI/NRTI)- containing regimen had the highest hyperlipidemia risk, followed by protease inhibitor (PI)- containing and non-NRTI- containing regimens. For combination ART regimens, patients receiving a NRTI/NRTI + PI regimen had the highest hyperlipidemia risk. An increased cumulative drug dose was observed in patients who received the PI, NRTI/NRTI, NRTI, and NNRTI regimens in the hyperlipidemia group, when compared to the non-hyperlipidemia group. In conclusion, ART cumulative use, adherence, and regimen may affect hyperlipidemia risk among HIV-infected patients in a dose-dependent manner.

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.

Pulmonary complications after abdominal surgery in patients with mild-to-moderate chronic obstructive pulmonary disease

Postoperative pulmonary complications (PPCs) are one of the most important causes of postoperative morbidity and mortality after abdominal surgery. Although chronic obstructive pulmonary disease (COPD) has been considered a risk factor for PPCs, it remains unclear whether mild-to-moderate COPD is a risk factor. This retrospective cohort study included 387 subjects who underwent abdominal surgery with general anesthesia in a tertiary referral hospital. PPCs included pneumonia, pulmonary edema, pulmonary thromboembolism, atelectasis, and acute exacerbation of COPD. Among the 387 subjects, PPCs developed in 14 (12.0%) of 117 patients with mild-to-moderate COPD and in 13 (15.1%) of 86 control patients. Multiple logistic regression analysis revealed that mild-to-moderate COPD was not a significant risk factor for PPCs (odds ratio [OR] =0.79; 95% confidence interval [CI] =0.31-2.03; P=0.628). However, previous hospitalization for respiratory problems (OR =4.20; 95% CI =1.52-11.59), emergency surgery (OR =3.93; 95% CI =1.75-8.82), increased amount of red blood cell (RBC) transfusion (OR =1.09; 95% CI =1.05-1.14 for one pack increase of RBC transfusion), and laparoscopic surgery (OR =0.41; 95% CI =0.18-0.93) were independent predictors of PPCs. These findings suggested that mild-to-moderate COPD may not be a significant risk factor for PPCs after abdominal surgery.

Impaired training-induced adaptation of blood pressure in COPD patients: implication of the muscle capillary bed

Background and aims

Targeting the early mechanisms in exercise-induced arterial hypertension (which precedes resting arterial hypertension in its natural history) may improve cardiovascular morbidity and mortality in COPD patients. Capillary rarefaction, an early event in COPD before vascular remodeling, is a potential mechanism of exercise-induced and resting arterial hypertension. Impaired training-induced capillarization was observed earlier in COPD patients; thus, this study compares the changes in blood pressure (BP) during exercise in COPD patients and matches control subjects (CSs) after a similar exercise training program, in relationship with muscle capillarization.

Methods

Resting and maximal exercise diastolic pressure (DP) and systolic pressure (SP) were recorded during a standardized cardiopulmonary exercise test, and a quadriceps muscle biopsy was performed before and after training.

Results

A total of 35 CSs and 49 COPD patients (forced expiratory volume in 1 second =54%±22% predicted) completed a 6-week rehabilitation program and improved their symptom-limited maximal oxygen uptake (VO_2SL: 25.8±6.1 mL/kg per minute vs 27.9 mL/kg per minute and 17.0±4.7 mL/kg per minute vs 18.3 mL/kg per minute; both P<0.001). The improvement in muscle capillary-to-fiber (C/F) ratio was significantly greater in CSs vs COPD patients (+11%±9% vs +23%±21%; P<0.05). Although maximal exercise BP was reduced in CSs (DP: 89±10 mmHg vs 85±9 mmHg; P<0.001/SP: 204±25 mmHg vs 196±27 mmHg; P<0.05), it did not change in COPD patients (DP: 94±14 mmHg vs 97±16 mmHg; P=0.46/SP: 202±27 mmHg vs 208±24 mmHg; P=0.13). The change in muscle C/F ratio was negatively correlated with maximal exercise SP in CSs and COPD patients (r=−0.41; P=0.02).

Conclusion

COPD patients showed impaired training-induced BP adaptation related to a change in muscle capillarization, suggesting the possibility of blunted angiogenesis.

The relationship between the number of natural teeth and airflow obstruction: a cross-sectional study using data from the Korean National Health and Nutrition Examination Survey

Background

Potential associations between oral health and respiratory disease, including chronic obstructive pulmonary disease (COPD), have been suggested in several studies. Among the indicators reflecting oral health, the number of natural teeth is an integrated and simple index to assess in the clinic. In this study, we examined the relationship between the number of natural teeth and airflow obstruction, which is a central feature of COPD.

Methods

A total of 3,089 participants over 40 years, who underwent reliable spirometry and oral health assessments were selected from the Korean National Health and Nutrition Examination Survey 2012, a cross-sectional and nationally representative survey. Spirometry results were classified as normal, restrictive, or obstructive pattern. Total number and pairs of natural teeth were counted after excluding third molars.

Results

After adjusting for other variables, such as age, body mass index, socioeconomic factors, and oral health factors, the group with airflow obstruction showed significantly fewer natural teeth than the other groups in males (P=0.014 and 0.008 for total number and total pairs of natural teeth, respectively). Compared with participants with full dentition, the adjusted odds ratio for airflow obstruction in males with fewer than 20 natural teeth was 4.18 (95% confidence interval: 2.06–8.49) and with fewer than 10 pairs of natural teeth was 4.74 (95% confidence interval: 2.34–9.62). However, there was no significant association between the total number or pairs of natural teeth and airflow obstruction after adjustment in females.

Conclusions

Loss of natural teeth was significantly associated with the presence of airflow obstruction in males. Our finding suggests that the number of natural teeth could be one of the available indices for obstructive lung diseases, including COPD.