European Respiratory Society statement on frailty in adults with chronic lung disease

Pulmonary rehabilitation and functional independence: Impact on survival in patients with fibrotic interstitial lung disease or chronic obstructive pulmonary disease

BACKGROUND

Pulmonary rehabilitation (PR) aims to improve patients' functioning in interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD). The impact of change in functional independence during PR on subsequent survival has not been established. We aimed to determine functional independence during PR and its association with survival over three years post-PR.

METHODS

This retrospective cohort study included patients with fibrotic ILD or COPD who participated in a 3-week inpatient PR program. The Functional Independence Measure (FIM) was assessed at PR entry and discharge. Correlations between FIM and demographics, clinical/functional parameters were analyzed. Time from PR to death/lung transplantation/censoring was assessed, stratified by baseline/changes in FIM above/below the median. Multivariable Cox proportional hazard models were used to determine the impact of FIM on mortality risk.

RESULTS

223 patients (76 ILD/147 COPD) were included. Mean ± standard deviation (SD) age was 69 ± 10 for ILD and 67 ± 10 for COPD. FIM total and motor scores improved significantly in both groups. Baseline FIM showed a strong negative and change in 6-min walk distance (6MWD) a strong positive correlation with change in FIM during PR. Each 1-point increase in FIM motor score was associated with a 3 % lower risk of mortality (HR 0.97, 95%CI 0.94-1, p = 0.03).

CONCLUSIONS

Inpatient PR improves functional independence in patients with fibrotic ILD or COPD, and baseline and change in FIM are associated with survival up to three years post-PR. This emphasizes the importance of PR for all patients with chronic lung disease regardless of their initial level of independence.

Clinical significance of the preoperative prognostic nutritional index in patients with resectable non-small cell lung cancer: a multicenter study

PURPOSE

To validate the clinical impacts of the prognostic nutritional index (PNI), an immune-nutritional blood marker, in patients with resectable non-small cell lung cancer (NSCLC) using multicenter cohort data.

METHODS

The subjects of this retrospective multicenter study, involving 11 hospitals, were patients who underwent curative lung resection for pathological stage IA-IIIA NSCLC. We analyzed the relationship between the preoperative PNI and postoperative outcomes. Patients were divided into a high PNI group and a low PNI group (cutoff: 45). We also performed exact matching and three propensity score-based methods to validate the results.

RESULTS

Among the total 2,770 patients, 2,272 (82.0%) had a high PNI (>45) and 498 (18.0%) had a low PNI (≤45). A low preoperative PNI was a predictor of increased overall postoperative complications (relative risk 1.49; 95% confidence interval (CI) 1.31-1.69) and an independent adverse prognostic factor for overall survival (hazard ratio 1.77; 95% CI 1.45-2.17) and recurrence-free survival (1.34; 95% CI 1.14-1.59). All the methods we used (whole cohort, exact matching, and three propensity score methods) showed consistent results.

CONCLUSIONS

The findings of this multicenter study suggest that immune-nutritional assessment using the PNI will provide useful prognostic information for patients with resectable NSCLC.

Integrated Lung, Diaphragm and Lower Limb Muscular Ultrasound: Clinical Correlations in Geriatric Patients with Acute Respiratory Illness

Background/Objectives: Point-of-care lung ultrasonography (LUS) represents an accurate diagnostic tool in older patients with respiratory failure. The integration of LUS with ultrasonographic assessment of diaphragm thickness and excursion, right vastus lateralis (RVL) muscle thickness and cross-sectional area (CSA) could provide real-time information on frailty and sarcopenia. The primary aim of this proof-of-concept prospective study was to evaluate clinical correlates of thoracic, diaphragmatic, and muscular ultrasound to characterize the associations between frailty, respiratory failure, and sarcopenia in older patients hospitalized for acute respiratory complaints. Methods: Each of 52 participants (age median 84, IQR 80-89 years old) underwent integrated LUS, diaphragm and RVL ultrasound examination upon admission (T0) and after 72 h of hospitalization (T1). LUS score was used to estimate lung interstitial syndrome severity. Diaphragm excursion, thickness, RVL thickness and CSA were measured following a standardized protocol. Frailty was assessed with the PC-FI (Primary Care-Frailty Index). Results: All patients exhibited multifactorial causes of respiratory symptoms. The LUS score on T0 predicted 3-month rehospitalization. Frail patients exhibited higher LUS scores on T1. Diaphragm excursion on T0 was reduced in patients with COPD and heart failure and in those developing delirium during hospitalization. Diaphragm excursion on T1 was negatively associated with PC-FI. Diaphragm thickness, RVL thickness, and CSA exhibited a positive association with obesity. Right vastus lateralis CSA on T1, however, was also negatively associated with PC-FI. Conclusions: Integrated lung, diaphragm, and RVL ultrasound shows clinical correlations with several aspects of frailty that may help to improve the management of geriatric patients with respiratory illness.

Diagnosis and management of comorbid disease in COPD

COPD is one of the most common chronic respiratory conditions and is associated with high healthcare use, morbidity and mortality. Multimorbidity in COPD is common and confers a worse prognosis. Despite this, there is delayed and often under-diagnosis of comorbid diseases in COPD. Knowledge of the respiratory and non-respiratory pathologies that can coexist with COPD is essential to ensure early detection and appropriate management. This review provides an overview of the comorbidities that have been described in COPD. We discuss their pathogenesis, pitfalls in their diagnosis, and strategies for their prevention and treatment.

The Association Between Dietary Magnesium Intake and Frailty in Patients with Chronic Obstructive Pulmonary Disease: National Health and Nutrition Examination Survey

Background

Patients with chronic obstructive pulmonary disease (COPD) are at high risk of developing frailty and need to be prevented and managed. This study aims to investigate the relationship between dietary magnesium (Mg) intake and the risk of frailty in patients with COPD.

Methods

We conducted a cross-sectional study from the National Health and Nutrition Examination Survey (NHANES) in the United States, focusing on patients with COPD. We used logistic regression to determine the adjusted odds ratios (OR) and 95% confidence interval (CI). Curve fitting, subgroup analysis, and sensitivity analysis were performed to further assess the relationship between dietary Mg intake and frailty in patients with COPD.

Results

There were 1696 participants in this study, and the mean age was 60.4 ± 0.4 years. Weighted logistic regression and curve fitting showed a linear relationship between dietary Mg intake and frailty in patients with COPD. The risk of frailty decreased by 15% for each 100-unit increase in Mg intake (OR: 0.85, 95% CI: 0.76-0.96). Participants in the highest quartile Q4 of Mg intake had a lower risk of frailty than those in the lowest quartile Q1 (OR: 0.48, 95% CI: 0.32-0.72).

Conclusion

There is a linear relationship between dietary Mg intake and frailty in patients with COPD. Increasing dietary Mg intake is associated with a decreased risk of frailty in COPD.

Breathlessness, Frailty, and Sarcopenia in Older Adults

BACKGROUND

Breathlessness shares aging mechanisms with frailty and sarcopenia.

RESEARCH QUESTION

Are frailty and sarcopenia associated with breathlessness itself?

STUDY DESIGN AND METHODS

We analyzed data from a population-based, prospective cohort study of 780 community-dwelling older adults. Breathlessness was defined using the modified Medical Research Council dyspnea scale (≥ 2 points) and the COPD Assessment Test (≥ 10 points). Frailty was defined by frailty index (FI); frailty phenotype; and fatigue, resistance, ambulation, illness, and weight loss (FRAIL) questionnaire results. Sarcopenia was defined by the Asian Working Group for Sarcopenia in 2019. Sarcopenia phenotype score quantified the number of criteria met. The associations of frailty and sarcopenia with breathlessness were evaluated by logistic regression analyses. Adjusted ORs (aORs) were calculated, accounting for age, sex, chronic airway disease, smoking status, BMI, lung functions, socioeconomic status (living alone, income, education), comorbid conditions (hypertension, diabetes, malignancy, myocardial infarction, heart failure), and other geriatric contributors (cognitive dysfunction, depression, malnutrition, polypharmacy, fall history in the past year). Institutionalization-free survival was compared by log-rank test.

RESULTS

The prevalence of frailty was higher in the breathlessness group compared with the group without breathlessness (42.6% vs 10.5% by FI, 26.1% vs 8.9% by frailty phenotype, and 23.0% vs 4.2% by FRAIL questionnaire) and sarcopenia (38.3% vs 26.9%), with P < .01 for all comparisons. The multivariable logistic regression analyses showed that frailty (FI [aOR, 9.29], FRAIL questionnaire [aOR, 5.21], and frailty phenotype [aOR, 3.09]) and sarcopenia phenotype score (2 [aOR, 2.00] and 3 [aOR, 2.04] compared with 0) were associated with breathlessness. The cumulative incidence of institutionalization-free survival was higher in the breathlessness group than its counterparts (P = .02).

INTERPRETATION

These findings suggest that frailty and sarcopenia strongly contribute to breathlessness in community-dwelling older adults. Measuring sarcopenia and frailty in older adults may offer opportunities to prevent age-related breathlessness.

Assessment of bidirectional relationships between frailty and acute respiratory distress syndrome: a bidirectional Mendelian Randomization study

BACKGROUND

While previous observational studies have suggested a link between frailty and acute respiratory distress syndrome (ARDS), the causality of this connection remains unclear. The objective of this study was to explore the potential bidirectional causal links between frailty and ARDS.

METHODS

A two-sample univariable Mendelian randomization (MR) was performed to assess the causal relationship between frailty, as defined by frailty index (FI, n = 175,226) and fried frailty score (FFS, n = 386,565), and ARDS. The genome-wide association study (GWAS) data of frailty was from the UK Biobank and the ARDS data was from the FinnGen Database. Univariable MR analyses were conducted using inverse-variance weighted (IVW), weighted median, MR-Egger regression, and robust adjusted profile score (MR. RAPS). We also performed multivariable Mendelian randomization (MVMR) analysis including smoking initiation, alcohol consumption, body mass index (BMI), and cognitive performance.

RESULTS

This bidirectional MR analysis demonstrated no causal effect of FI (OR = 0.96, 95% CI 0.14-6.88) and FFS (OR = 1.95, 95%CI 0.14-28.16) on increased susceptibility of ARDS. Also, no evidence was found for an effect of ARDS on the risk of frailty. The MVMR analysis indicated higher BMI and poorer cognitive performance were associated with increased risk of ARDS.

CONCLUSIONS

The outcomes of our analysis imply a probable absence of a direct causal relationship between frailty and susceptibility to ARDS. To reinforce and expand upon these preliminary findings, it is imperative to conduct larger-scale genome-wide association studies.

Association of Physical Activity with Asthma and Chronic Obstructive Pulmonary Disease and Mediation of Frailty: Mendelian Randomization Analyses

Background

The existence of an association between physical activity (PA) and asthma and chronic obstructive pulmonary disease (COPD) has been confirmed in observational studies. Therefore, it is necessary to reveal whether there is a risk-effect relationship between physical activity and asthma and COPD through Mendelian randomization (MR) analysis.

Materials and Methods

Univariate Mendelian randomization (UVMR) analyses were performed to examine the associations between moderate to vigorous physical activity (MVPA), vigorous physical activity (VPA), accelerometer-assessed physical activity (AA), and strenuous exercise or other exercise (SSOE) with asthma and COPD. The methods of analysis were dominated by Inverse Variance-Weighted (IVW), Weighted median (WM), and MR-Egger methods. In addition, multivariate Mendelian randomization (MVMR) analyses were performed to correct the effects of four types of physical activity on asthma and COPD. Finally, potential mediating effect relationships were identified through mediation analyses.

Results

The results of Univariate Mendelian randomization analysis showed that SSOE could reduce the risk of asthma and COPD(asthma: OR=0.15,95% CI=0.04-0.58, P=0.006; COPD: OR=0.05, 95% CI=0.01-0.33, P=0.002). The results of the Multivariate Mendelian randomization analysis showed that SSOE was still able to reduce the risk of asthma and COPD after adjusting for the effects of different types of physical activity(asthma: 95% CI=-2.77--0.31, P=0.014; COPD: 95% CI=-4.00--0.50, P=0.012). Mediation analyses showed that frailty intervened in the causal relationship between physical activity and asthma and chronic obstructive pulmonary disease.

Conclusion

SSOE is a protective factor for asthma and COPD in the European population, while frailty plays a mediating role.

Sarcopenia in interstitial lung disease

BACKGROUND

Interstitial lung disease (ILD) encompasses a heterogeneous group of chronic lung conditions with considerable variability in prognosis and response to treatment. People with reduced muscle mass and function, known as sarcopenia, have a higher risk of mortality and adverse clinical outcomes both in the general population and in other chronic disease states. The importance of sarcopenia across the spectrum of patients with ILD is not well established.

OBJECTIVES

In this narrative review, we explore the prevalence and clinical implications of sarcopenia in patients with ILD, evaluate the optimal methods to diagnose sarcopenia in this patient population and review treatment interventions.

FINDINGS

Almost one third of patients with chronic forms of ILD have evidence of sarcopenia. Sarcopenia is associated with adverse clinical outcomes and increased risk of mortality in select populations with ILD. Screening tests such as the SARC-F (strength, assistance walking, rise from a chair, climb stairs, falls) questionnaire and clinical assessment tools (including grip strength dynamometry) are well validated. Medical imaging modalities, including computed tomography, are hampered by lack of a gold standard and normative values, but have been used in patients with ILD in acute care and research settings. If sarcopenia is identified, multidimensional interventions such as pulmonary rehabilitation are beneficial.

CONCLUSION

Sarcopenia is common in patients with ILD and is associated with poorer outcomes. Accordingly, if identified, targeted interventions should be considered. Validated diagnostic criteria exist, but the optimal use of medical imaging techniques in this patient cohort remains an area of uncertainty.

Advance care planning in patients with respiratory failure

Advance care planning (ACP) is a complex and iterative communication process between patients, surrogates and clinicians that defines goals of care that may include, but is not limited to, documentation of advance directives. The aim of ACP is to promote patient-centred care tailored to the patient's clinical situation through informed preparation for the future and improved communication between patient, clinicians and surrogates, if the latter need to make decisions on patient's behalf.The aim of this article is to review research related to ACP in acute and chronic respiratory failure, regarding the process, communication, shared decision-making, implementation and outcomes.Research has produced controversial results on ACP interventions due to the heterogeneity of measures and outcomes, but positive outcomes have been described regarding the quality of patient-physician communication, preference for comfort care, decisional conflict and patient-caregiver congruence of preferences and improved documentation of ACP or advance directives.The main barriers to ACP in chronic respiratory failure are the uncertainty of prognosis (particularly in the organ failure trajectory), the choice of the best timing for initiation and the lack of training of healthcare workers. In acute respiratory failure, the ACP process can be very short, should include the patient whenever possible, and is based on a discussion of treatments appropriate to the patient's functional status prior to the event (e.g. assessment of frailty) and clear communication of the likely consequences of possible options.All healthcare worker dealing with patients with serious illnesses should have training in communication skills to promote engagement in ACP discussions.

The ageing of people living with cystic fibrosis: what to expect now?

The prognosis of people with cystic fibrosis (pwCF) has improved dramatically with the introduction of cystic fibrosis transmembrane conductance regulator (CFTR) modulators (CFTRm). The ageing of the cystic fibrosis (CF) population is changing the disease landscape with the emergence of different needs and increasing comorbidities related to both age and long-term exposure to multiple treatments including CFTRm. Although the number of pwCF eligible for this treatment is expected to increase, major disparities in care and outcomes still exist in this population. Moreover, the long-term impact of the use of CFTRm is still partly unknown due to the current short follow-up and experience with their use, thus generating some uncertainties. The future spread and initiation of these drugs at an earlier stage of the disease is expected to reduce the systemic burden of systemic inflammation and its consequences on health. However, the prolonged life expectancy is accompanied by an increasing burden of age-related comorbidities, especially in the context of chronic disease. The clinical manifestations of the comorbidities directly or indirectly associated with CFTR dysfunction are changing, along with the disease dynamics and outcomes. Current protocols used to monitor slow disease progression will need continuous updates, including the composition of the multidisciplinary team for CF care, with a greater focus on the needs of the adult population.

The Clinical Frailty Scale for Risk Stratification in Patients With Fibrotic Interstitial Lung Disease

BACKGROUND

Previous studies have shown the importance of frailty in patients with fibrotic interstitial lung disease (ILD).

RESEARCH QUESTION

Is the Clinical Frailty Scale (CFS) a valid tool to improve risk stratification in patients with fibrotic ILD?

STUDY DESIGN AND METHODS

Patients with fibrotic ILD were included from the prospective multicenter Canadian Registry for Pulmonary Fibrosis. The CFS was assessed using available information from initial ILD clinic visits. Patients were stratified into fit (CFS score 1-3), vulnerable (CFS score 4), and frail (CFS score 5-9) subgroups. Cox proportional hazards and logistic regression models with mixed effects were used to estimate time to death or lung transplantation. A derivation and validation cohort was used to establish prognostic performance. Trajectories of functional tests were compared using joint models.

RESULTS

Of the 1,587 patients with fibrotic ILD, 858 (54%) were fit, 400 (25%) were vulnerable, and 329 (21%) were frail. Frailty was a risk factor for early mortality (hazard ratio, 5.58; 95% CI, 3.64-5.76, P < .001) in the entire cohort, in individual ILD diagnoses, and after adjustment for potential confounders. Adding frailty to established risk prediction parameters improved the prognostic performance in derivation and validation cohorts. Patients in the frail subgroup had larger annual declines in FVC % predicted than patients in the fit subgroup (-2.32; 95% CI, -3.39 to -1.17 vs -1.55; 95% CI, -2.04 to -1.15, respectively; P = .02).

INTERPRETATION

The simple and practical CFS is associated with pulmonary and physical function decline in patients with fibrotic ILD and provides additional prognostic accuracy in clinical practice.

The effect of frailty on mortality and hospital admission in patients with benign pleural disease in Wales: a cohort study

BACKGROUND

Pleural disease is common, representing 5% of the acute medical workload, and its incidence is rising, partly due to the ageing population. Frailty is an important feature and little is known about disease progression in patients with frailty and pleural disease. We aimed to examine the effect of frailty on mortality and other relevant outcomes in patients diagnosed with pleural disease.

METHODS

In this cohort study in Wales, the national Secure Anonymised Information Linkage databank was used to identify a cohort of individuals diagnosed with non-malignant pleural disease between Jan 1, 2005, and March 1, 2023, who were not known to have left Wales. Frailty was assessed at diagnosis of pleural disease using an electronic Frailty Index. The primary outcome was time from diagnosis to all-cause mortality for all patients. Data were analysed using multilevel mixed-effects Cox proportional hazards regression adjusting for the prespecified covariates of age, sex, Welsh Index of Multiple Deprivation quintile, smoking status, comorbidity, and subtype of pleural disease.

FINDINGS

54 566 individuals were included in the final sample (median age 66 years [IQR 47-77]; 26 477 [48·5%] were female and 28 089 [51·5%] were male). By the end of the study period, 25 698 (47·1%) participants had died, with a median follow-up of 1·0 years (IQR 0·2-3·6). There was an association between frailty and all-cause mortality, which increased as frailty worsened. Compared with fit individuals, there was increasing mortality for those with mild frailty (adjusted hazard ratio 1·11 [95% CI 1·08-1·15]; p<0·0001), moderate frailty (1·25 [1·20-1·31]; p<0·0001), and severe frailty (1·36 [1·28-1·44]; p<0·0001).

INTERPRETATION

Independent of age and comorbidities, frailty status at diagnosis of pleural disease appeared to be useful as a prognostic indicator. Patients with moderate or severe frailty had a rapid decline in health. Future patients should be assessed for frailty at the time of diagnosis of pleural disease and might benefit from optimised care and advance care planning.

FUNDING

Cardiff University's Wellcome Trust iTPA funding award.

Peeping at COPD through the keyhole: time to broaden the view to the complexity of the disease by the heterogeneity of symptoms

The assessment of co-occurring nonrespiratory symptoms in COPD allow us to explore the true complexity of the disease and to plan specific integrated, multidimensional care strategies https://bit.ly/4dwdnBQ.

Diaphragm Ultrasound in Different Clinical Scenarios: A Review with a Focus on Older Patients

Diaphragm muscle dysfunction is increasingly recognized as a fundamental marker of several age-related diseases and conditions including chronic obstructive pulmonary disease, heart failure and critical illness with respiratory failure. In older individuals with physical frailty and sarcopenia, the loss of muscle mass and function may also involve the diaphragm, contributing to respiratory dysfunction. Ultrasound has recently emerged as a feasible and reliable strategy to visualize diaphragm structure and function. In particular, it can help to predict the timing of extubation in patients undergoing mechanical ventilation in intensive care units (ICUs). Ultrasonographic evaluation of diaphragmatic function is relatively cheap, safe and quick and can provide useful information for real-time monitoring of respiratory function. In this review, we aim to present the current state of scientific evidence on the usefulness of ultrasound in the assessment of diaphragm dysfunction in different clinical settings, with a particular focus on older patients. We highlight the importance of the qualitative information gathered by ultrasound to assess the integrity, excursion, thickness and thickening of the diaphragm. The implementation of bedside diaphragm ultrasound could be useful for improving the quality and appropriateness of care, especially in older subjects with sarcopenia who experience acute respiratory failure, not only in the ICU setting.

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.

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.