Prevalence and clinical impact of frailty in COPD: a systematic review and meta-analysis

Frailty and Exacerbation of Chronic Obstructive Pulmonary Disease: Is There Any Association?

Purpose

This study investigated if individuals with chronic obstructive pulmonary disease (COPD) and frailty are more likely to have acute exacerbations of COPD or require hospitalization for exacerbation than those without frailty.

Patients and Methods

Data on 135 outpatients with stable COPD were analyzed with the Cox proportional hazards model to assess the risk of future events. The Kihon Checklist was administered at baseline to classify the participants as robust, pre-frail, or frail. The follow-up period was a maximum of six and a half years.

Results

In all, 76 patients (56.3%) experienced an exacerbation and 46 (34.1%) were hospitalized due to it. Multivariate Cox proportional hazards analysis that accounted for FEV1 and sex showed that the frail group was more likely to face future risks of COPD exacerbations [Hazard ratio 1.762 (95% CI 1.011-3.070), p=0.046] and hospitalizations for exacerbation [2.238 (1.073-4.667), p=0.032] than the robust group. No significant differences were observed when comparing robust patients to those who were pre-frail or pre-frail to frail either in exacerbations or hospitalizations. When comparing the C-indices for frailty and FEV1, the former index (exacerbation 0.591 and hospitalization 0.663) did not exceed the latter (0.663 and 0.769) in either analysis.

Conclusion

Frail COPD patients have a more unfavorable future risk of acute exacerbations of COPD and hospitalizations for exacerbation than robust patients. However, no significant differences were observed when comparing robust patients to those who were pre-frail or pre-frail to frail, suggesting that the future risk for COPD patients with frailty is only higher compared to those who are considered robust. Additionally, FEV1 was found to be a more reliable predictor of future events than measures of frailty.

Association of Frailty with Patient-Report Outcomes and Major Clinical Determinants in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

This study aimed to explore the correlation of frailty status with disease characteristics and patient-reported outcomes (PROs) in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and determine the sensitivity and specificity of modified COPD PRO scale (mCOPD-PRO) for detecting frailty.

Patients and Methods

This cross-sectional study surveyed 315 inpatients with AECOPD from a tertiary hospital in China from August 2022 to June 2023. Patient frailty and PROs were assessed using the validated FRAIL scale and mCOPD-PRO, respectively. Spearman's ρ was used to assess the relevance of lung disease indicators commonly used in clinical practice, and ordinal logistic regression analyses were used to identify the variables associated with frailty status. The validity of mCOPD-PRO in discriminating frail or non-frail individuals was determined using the receiver operating characteristic curve.

Results

The participants (N=302, mean age 72.4±9.1 years) were predominantly males (73.2%). Among them, 43 (14.3%) patients were not frail, whereas 123 (40.7%) and 136 (45.0%) patients were pre-frail and frail, respectively. The FRAIL scale was moderately correlated with the mCOPD-PRO scores (Spearman's rank correlation coefficient [Rs]=0.52, P<0.01) for all dimensions (Rs=0.43-0.49, P<0.01). Patients residing in rural areas (odds ratio [OR], 1.67; 95% confidence interval [95% CI], 1.01-2.76) and with higher mCOPD-PRO scores (OR, 4.78; 95% CI, 2.75-8.32) were more likely to be frail. Physically active patients (OR, 0.42; 95% CI, 0.21-0.84) were less likely to be frail. In addition, mCOPD-PRO had good discriminate validity for detecting frailty (area under the curve=0.78), with a sensitivity and specificity of 84.6% and 60.8%, respectively. The optimal probability threshold for mCOPD-PRO was ≥1.52 points.

Conclusion

In patients with AECOPD, frailty is closely related to PROs and disease characteristics. Additionally, the mCOPD-PRO score can distinguish well between frail and non-frail patients. Our findings provide support for interventions targeting frail populations with AECOPD.

Lung transcriptomics reveals the underlying mechanism by which aerobic training enhances pulmonary function in chronic obstructive pulmonary disease

BACKGROUND

Aerobic training is the primary method of rehabilitation for improving respiratory function in patients with chronic obstructive pulmonary disease (COPD) in remission. However, the mechanism underlying this improvement is not yet fully understood. The use of transcriptomics in rehabilitation medicine offers a promising strategy for uncovering the ways in which exercise training improves respiratory dysfunction in COPD patients. In this study, lung tissue was analyzed using transcriptomics to investigate the relationship between exercise and lung changes.

METHODS

Mice were exposed to cigarette smoke for 24 weeks, followed by nine weeks of moderate-intensity treadmill exercise, with a control group for comparison. Pulmonary function and structure were assessed at the end of the intervention and RNA sequencing was performed on the lung tissue.

RESULTS

Exercise training was found to improve airway resistance and lung ventilation indices in individuals exposed to cigarette smoke. However, the effect of this treatment on damaged alveoli was weak. The pair-to-pair comparison revealed numerous differentially expressed genes, that were closely linked to inflammation and metabolism.

CONCLUSIONS

Further research is necessary to confirm the cause-and-effect relationship between the identified biomarkers and the improvement in pulmonary function, as this was not examined in the present study.

Causal relationship between frailty and chronic obstructive pulmonary disease or asthma: A two sample bidirectional Mendelian randomization study

BACKGROUND

Observational studies have established a strong association between frailty and obstructive lung diseases. However, the causal nature of this association remains unclear. To address this gap, we conducted a bidirectional Mendelian randomization (MR) study to investigate the causal relationship between frailty, as measured by the frailty index (FI), and chronic obstructive pulmonary disease (COPD) or asthma.

METHODS

The latest meta-analysis of genome-wide association studies for FI, which included individuals of European ancestry from UK Biobank and TwinGene (N = 175,226), yielded the genetic instruments for frailty and outcome summary statistics. The genetic instrument for COPD and asthma, as well as the outcome summary data, were derived from the GWAS conducted on individuals of European ancestry from the FinnGen, with a sample size of 16,410 cases and 283,589 controls for COPD, and 37,253 cases and 187,112 controls for asthma. The analysis of MR was conducted employing the inverse-variance weighted (IVW) method, complemented by the weighted median method, MR-Egger regression, and MR pleiotropy residual sum and outlier (MR-PRESSO) test.

RESULTS

Our results showed that genetically predicted higher FI was significantly associated with increased risk of COPD (odds ratio [OR] 1.75, 95 % confidence interval [CI] 1.29-2.36) and asthma (OR 2.10, 95 % CI 1.44-3.16). In the reverse direction analysis, genetic liability to both COPD (beta 0.06, 95 % CI 0.01-0.10) and asthma (beta 0.08, 95 % CI 0.06-0.11) showed significant associations with a higher FI.

CONCLUSIONS

Our research has reinforced the existing evidence supporting a reciprocal causal relationship between frailty and obstructive lung diseases. A deeper comprehension of this interconnection is imperative for the prevention and treatment of obstructive lung diseases.

Association between oxidative balance score and frailty in chronic obstructive pulmonary disease

Background

Oxidative stress is associated with frailty and adverse outcomes in chronic obstructive pulmonary disease (COPD). The oxidative balance score (OBS) assesses oxidative stress from diet and lifestyle, with higher OBS indicating more antioxidants than oxidants. A cross-sectional study was conducted to investigate the potential association between OBS and frailty in US adults with COPD.

Methods

A total of 1201 COPD subjects from the National Health and Nutrition Examination Survey (NHANES 1999-2018) were assessed for frailty using the Frailty Index. OBS, consisting of 20 dietary and lifestyle factors, was the exposure variable. Weighted multiple logistic regression, subgroup analysis, and restricted cubic spline curves were used to assess the association between OBS and frailty.

Results

Compared with the lowest OBS reference group (Q1), the adjusted odds ratios (ORs) for the highest quartile group (Q4) for OBS, dietary OBS, and lifestyle OBS were 0.41 (95% CI: 0.19-0.92), 0.37 (95% CI: 0.20-0.71), and 0.41 (95% CI: 0.24-0.71), respectively. All trend p-values were less than 0.05. Subgroup and RCS analyses revealed a negative linear association between OBS and frailty, with a significant reduction in frailty risk observed in women compared to men.

Conclusions

OBS was negatively associated with frailty in COPD. The higher the OBS, the lower the risk of frailty, especially in women. Identifying at-risk populations with OBS and through antioxidant diet and lifestyle are potential ways to reduce the prevalence of frailty.

Impact of Frailty on Symptom Burden in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD), the sixth leading cause of death in the United States in 2022 and the third leading cause of death in England and Wales in 2022, is associated with high symptom burden, particularly dyspnoea. Frailty is a complex clinical syndrome associated with an increased vulnerability to adverse health outcomes. The aim of this review was to explore the current evidence of the influence of frailty on symptoms in patients with a confirmed diagnosis of COPD according to GOLD guidelines. Fourteen studies report a positive association between frailty and symptoms, including dyspnoea, assessed with the COPD Assessment Test (CAT) and the modified Medical Research Council (mMRC) scale. Data were analysed in a pooled a random-effects meta-analysis of mean differences (MDs). There was an association between COPD patients living with frailty and increased CAT score versus COPD patients without frailty [pooled SMD, 1.79 (95% CI 0.72-2.87); I2 = 99%]. A lower association was found between frailty and dyspnoea measured by the mMRC scale versus COPD patients without frailty [pooled SMD, 1.91 (95% CI 1.15-2.66); I2 = 98%]. The prevalence of frailty ranged from 8.8% to 82% and that of pre-frailty from 30.4% to 73.7% in people living with COPD. The available evidence supports the role of frailty in worsening symptom burden in COPD patients living with frailty. The review shows that frailty is common in patients with COPD. Future research is needed to have further details related to the data from CAT to improve our knowledge of the frailty impact in this population.

Lung function and the risk of frailty in the European population: a mendelian randomization study

BACKGROUND

Epidemiological evidence has suggested a relationship between lung function and frailty, but the precise nature of the causality remains unclear. In this study, we applied a two-sample Mendelian randomization (MR) analysis to determine the causal effects of lung function on frailty.

METHODS

Single nucleotide polymorphisms (SNPs) independently related (P ≤ 5E-08) to lung function, as identified by genome-wide association study (GWAS), were applied as instrumental variables (IV). The association with frailty index (FI) was investigated using summary-level data from the latest GWAS on FI (n = 175,226). Different statistical methods were employed to evaluate the causal estimates between lung function and FI. The pleiotropy, heterogeneity, and leave-one-out analysis were applied to confirm the stability of the MR estimates.

RESULTS

Using the random-effect inverse-variance weighted approach, genetically proxied forced expiratory volume in the first second (FEV1), ratio of FEV1 on forced vital capacity (FVC) [FEV1/FVC], and peak expiratory flow (PEF) were significantly and inversely associated with FI (FEV1, β = -0.08, P = 2.03E-05; FEV1/FVC, β = -0.06, P = 9.51E-06; PEF, β = -0.07, P = 4.09E-04) with good statistical power (99.7-100%). However, no significant association was observed between FVC and FI (β = -0.01, P = 0.681). Leave-one-out analysis showed that there was no single SNP driving the bias of the estimates. There was potential heterogeneity, but no obvious pleiotropy was founded in this MR study.

CONCLUSIONS

Our findings indicate that impaired pulmonary function is closely related to the risk of frailty. Enhancing lung function in the elderly population may contribute to the prevention of frailty to a certain extent.

Cystic Fibrosis in Adults: A Paradigm of Frailty Syndrome? An Observational Study

This study aimed to assess the main clinical and anamnestic characteristics of adult Cystic Fibrosis (CF) patients and to evaluate the association of frailty with the CF genotyping classification. In an observational cross-sectional study, all ambulatory CF patients over 18 years old who received a diagnosis at the Regional Cystic Fibrosis Center for adults were enrolled and assessed by spirometry for respiratory function, by ADL and IADL for functional status, and by the Study of Osteoporotic Fractures (SOF) Index for frailty. The study population consisted of 139 CF patients (mean age 32.89 ± 10.94 years old, 46% women). Most of the subjects were robust (60.4%). The pre-frail/frail group was more frequently females (p = 0.020), had a lower BMI (p = 0.001), worse respiratory function, a higher number of pulmonary exacerbations/years, cycles of antibiotic therapy, and hospitalization (all p < 0.001) with respect to robust patients. The pre-frail/frail subjects used more drugs and were affected by more CF-related diseases (all p < 0.001). In relation to logistic regression, the best predictor of the pre-frail/frail status was a low FEV1 level. The CF patients show similarities to older pre-frail/frail subjects, suggesting that CF might be considered an early expression of this geriatric syndrome. This finding could help to better define the possible progression of CF, but overall, it could also suggest the usefulness employing of some tools used in the management and therapy of frailty subjects to identify the more severe CF subjects.

Impact of chronic obstructive pulmonary disease in patients with atrial fibrillation: an analysis from the GLORIA-AF registry

AIMS

Chronic obstructive pulmonary disease (COPD) may influence management and prognosis of atrial fibrillation (AF), but this relationship has been scarcely explored in contemporary global cohorts. We aimed to investigate the association between AF and COPD, in relation to treatment patterns and major outcomes.

METHODS AND RESULTS

From the prospective, global GLORIA-AF registry, we analysed factors associated with COPD diagnosis, as well as treatment patterns and risk of major outcomes in relation to COPD. The primary outcome was the composite of all-cause death and major adverse cardiovascular events (MACEs). A total of 36 263 patients (mean age 70.1 ± 10.5 years, 45.2% females) were included; 2,261 (6.2%) had COPD. The prevalence of COPD was lower in Asia and higher in North America. Age, female sex, smoking, body mass index, and cardiovascular comorbidities were associated with the presence of COPD. Chronic obstructive pulmonary disease was associated with higher use of oral anticoagulant (OAC) [adjusted odds ratio (aOR) and 95% confidence interval (CI): 1.29 (1.13-1.47)] and higher OAC discontinuation [adjusted hazard ratio (aHR) and 95% CI: 1.12 (1.01-1.25)]. Chronic obstructive pulmonary disease was associated with less use of beta-blocker [aOR (95% CI): 0.79 (0.72-0.87)], amiodarone and propafenone, and higher use of digoxin and verapamil/diltiazem. Patients with COPD had a higher hazard of primary composite outcome [aHR (95% CI): 1.78 (1.58-2.00)]; no interaction was observed regarding beta-blocker use. Chronic obstructive pulmonary disease was also associated with all-cause death [aHR (95% CI): 2.01 (1.77-2.28)], MACEs [aHR (95% CI): 1.41 (1.18-1.68)], and major bleeding [aHR (95% CI): 1.48 (1.16-1.88)].

CONCLUSION

In AF patients, COPD was associated with differences in OAC treatment and use of other drugs; Patients with AF and COPD had worse outcomes, including higher mortality, MACE, and major bleeding.

Prevalence and assessment of frailty in interstitial lung disease - a systematic review and meta-analysis

BACKGROUND

Frailty is a multisystem dysregulation that challenges homeostasis and increases vulnerability towards stressors. In patients with interstitial lung diseases (ILD) frailty is associated with poorer lung function, greater physical impairment, and higher symptom burden. Our understanding of the prevalence of frailty in ILD and consequently its impact on the ILD population is limited.

OBJECTIVE AND METHODS

We aimed to systematically review frailty assessment tools and to determine frailty prevalence across different ILD cohorts. Meta-analyses were used to calculate the pooled prevalence of frailty in the ILD population.

RESULTS

We identified 26 studies (15 full-texts, 11 conference abstracts) including a total of 4614 patients with ILD. The most commonly used frailty assessment tools were the Fried Frailty Phenotype (FFP), the Short Physical Performance Battery (SPPB), and the cumulative Frailty Index (FI). Data allowed for meta-analyses of FFP and SPPB prevalence. The pooled prevalence of frailty was 35% (95% CI 25%-45%) by FFP, and 19% (95% CI 12%-28%) by SPPB.

CONCLUSIONS

Frailty is common in ILD, with considerable variability of frailty prevalence depending on the frailty assessment tool used. These findings highlight the importance of frailty in ILD and the need for a standardized approach to frailty assessment in this population.