Inflammation and cell-to-cell communication, two related aspects in frailty

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.

Immune system-related plasma extracellular vesicles in healthy aging

Objectives

To identify age-related plasma extracellular vehicle (EVs) phenotypes in healthy adults.

Methods

EV proteomics by high-resolution mass spectrometry to evaluate EV protein stability and discover age-associated EV proteins (n=4 with 4 serial freeze-thaws each); validation by high-resolution flow cytometry and EV cytokine quantification by multiplex ELISA (n=28 healthy donors, aged 18-83 years); quantification of WI-38 fibroblast cell proliferation response to co-culture with PKH67-labeled young and old plasma EVs. The EV samples from these plasma specimens were previously characterized for bilayer structure, intra-vesicle mitochondria and cytokines, and hematopoietic cell-related surface markers.

Results

Compared with matched exo-EVs (EV-depleted supernatants), endo-EVs (EV-associated) had higher mean TNF-α and IL-27, lower mean IL-6, IL-11, IFN-γ, and IL-17A/F, and similar mean IL-1β, IL-21, and IL-22 concentrations. Some endo-EV and exo-EV cytokine concentrations were correlated, including TNF-α, IL-27, IL-6, IL-1β, and IFN-γ, but not IL-11, IL-17A/F, IL-21 or IL-22. Endo-EV IFN-γ and exo-EV IL-17A/F and IL-21 declined with age. By proteomics and confirmed by flow cytometry, we identified age-associated decline of fibrinogen (FGA, FGB and FGG) in EVs. Age-related EV proteins indicated predominant origins in the liver and innate immune system. WI-38 cells (>95%) internalized similar amounts of young and old plasma EVs, but cells that internalized PKH67-EVs, particularly young EVs, underwent significantly greater cell proliferation.

Conclusion

Endo-EV and exo-EV cytokines function as different biomarkers. The observed healthy aging EV phenotype reflected a downregulation of EV fibrinogen subpopulations consistent with the absence of a pro-coagulant and pro-inflammatory condition common with age-related disease.

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.

Physical activity, sedentary behavior, and the risk of frailty and falling: A Mendelian randomization study

BACKGROUND

Due to inconclusive evidence from observational studies regarding the impact of physical activity (PA) and sedentary behavior on frailty and falling risk, we conducted a two-sample Mendelian randomization analysis to investigate the causal associations between PA, sedentary behavior, and frailty and falls.

METHODS

We extracted summary data from genome-wide association studies conducted among individuals of European ancestry, encompassing PA (n = 90 667-608 595), sedentary behavior (n = 372 609-526 725), frailty index (n = 175 226), and falling risk (n = 451 179). Single nucleotide polymorphisms associated with accelerometer assessed fraction >425 milligravities, self-reported vigorous activity, moderate to vigorous physical acticity (MVPA), leisure screen time (LST), and sedentary behavior at work were taken as instrumental variables. The causal effects were primarily estimated using inverse variance weighted methods, complemented by several sensitivity and validation analyses.

RESULTS

Genetically predicted higher levels of PA were significantly associated with a reduction in the frailty index (accelerometer assessed fraction >425 milligravities: β = -0.25, 95% CI = -0.36 to -0.14, p = 1.27 × 10-5 ; self-reported vigorous activity: β = -0.13, 95% CI = -0.20 to -0.05, p = 7.9 × 10-4 ; MVPA: β = -0.28, 95% CI = -0.40 to -0.16, p = 9.9 × 10-6 ). Besides, LST was significantly associated with higher frailty index (β = 0.18, 95% CI = 0.14-0.22, p = 5.2 × 10-20 ) and higher odds of falling (OR = 1.13, CI = 1.07-1.19, p = 6.9 × 10-6 ). These findings remained consistent throughout sensitivity and validation analyses.

CONCLUSIONS

Our study offers evidence supporting a causal relationship between PA and a reduced risk of frailty. Furthermore, it underscores the association between prolonged LST and an elevated risk of frailty and falls. Therefore, promoting PA and reducing sedentary behavior may be an effective strategy in primary frailty and falls prevention.

Physical Interventions Restore Physical Frailty and the Expression of CXCL-10 and IL-1β Inflammatory Biomarkers in Old Individuals and Mice

BACKGROUND

Frailty is a geriatric syndrome associated with negative health outcomes that represents a dynamic condition with a potential of reversibility after physical exercise interventions. Typically, inflammatory and senescence markers are increased in frail individuals. However, the impact that physical exercise exerts on inflammatory and senescence biomarkers remains unknown. We assessed the effect of physical intervention in old individuals and mice and determined the expression of inflammatory and senescence markers.

METHODS

Twelve elderly individuals were enrolled from a primary care setting to a 3-month intervention. Frailty was measured by SPPB and the expression of biomarkers by cytokine array and RT-qPCR. In addition, 12 aged C57BL/6 mice completed an intervention, and inflammation and senescence markers were studied.

RESULTS

The physical intervention improved the SPPB score, reducing frail and pre-frail individuals. This was correlated with a reduction in several pro-inflammatory biomarkers such as IL-6, CXCL-1, CXCL-10, IL-1β, IL-7, GM-CSF as well as p16INK4a and p21CIP1 senescence markers. Otherwise, the levels of anti-inflammatory biomarker IL-4 were significantly increased. Moreover, the physical intervention in mice also improved their functional capacity and restored the expression of inflammatory (Il-1β, Cxcl-10, Il-6, and Cxcl-1) and senescence (p21Cip1) markers. Additionally, PLSDA and ROC curve analysis revealed CXCL-10 and IL-1β to be the biomarkers of functional improvement in both cohorts.

CONCLUSIONS

Our results showed that a physical intervention improves physical frailty, and reverses inflammation and senescence biomarkers comprising CXCL-10 and IL-1β.

Inflammatory markers and physical frailty: towards clinical application

Global population aging poses a tremendous burden on the health care system worldwide. Frailty is associated with decreased physical reserve and is considered an important indicator of adverse events in the older population. Therefore, there is growing interest in the early diagnosis and intervention of frailty, but the cellular mechanisms responsible for frailty are still not completely understood. Chronic inflammation is related to decreased physical function and increased disease risk. Additionally, multiple human and animal studies suggest that inflammation probably plays the largest role in contributing to frailty. Some inflammatory markers have been proposed to predict physical frailty. However, there are still large gaps in knowledge related to the clinical application of these markers in frail patients. Therefore, understanding the biological processes and identifying recognized and reliable markers are urgent and pivotal tasks for geriatricians. In the present review, we broadly summarize the inflammatory markers that may have potential diagnostic and therapeutic use, thereby translating them into health care for older people with frailty in the near future.

Huanglian Jiedu Wan intervened with "Shi-Re Shanghuo" syndrome through regulating immune balance mediated by biomarker succinate

With increasing stress in daily life and work, subhealth conditions induced by "Shi-Re Shanghuo" syndrome was gradually universal. "Huanglian Jiedu Wan" (HLJDW) was the first new syndrome Chinese medicine approved for the treatment of "Shi-Re Shanghuo" with promising clinical efficacy. Preliminary small-sample clinical studies have identified some notable biomarkers (succinate, 4-hydroxynonenal, etc.). However, the correlation and underlying mechanism between these biomarkers of HLJDW intervention on "Shi-Re Shanghuo" syndrome remained ambiguous. Therefore, this study was designed as a randomized, double-blind, multicenter, placebo-controlled Phase II clinical trial, employing integrated analysis techniques such as non-targeted and targeted metabolomics, salivary microbiota, proteomics, parallel peaction monitoring, molecular docking and surface plasmon resonance (SPR). The results of the correlation analysis indicated that HLJDW could mediate the balance between inflammation and immunity through succinate produced via host and microbial source to intervene "Shi-Re Shanghuo" syndrome. Further through the HIF1α/MMP9 pathway, succinate regulated downstream arachidonic acid metabolism, particularly the lipid peroxidation product 4-hydroxynonenal. Finally, an animal model of recurrent oral ulcers induced by "Shi-Re Shang Huo" was established and HLJDW was used for intervention, key essential indicators (succinate, glutamine, 4-hydroxynonenal, arachidonic acid metabolism) essential in the potential pathway HIF1α/MMP9 discovered in clinical practice were validated. The results were found to be consistent with our clinical findings. Taken together, succinate was observed as an important signal that triggered immune responses, which might serve as a key regulatory metabolic switch or marker of "Shi-Re Shanghuo" syndrome treated with HLJDW.

The influence of inflammation and frailty in the aging continuum

Inflammaging is a low-grade inflammatory state that can be considered an adaptive process aimed at stimulating appropriate anti-inflammatory response. Frailty is determined by the accumulation of molecular and cellular defects accumulated throughout life; therefore, an appropriate frailty computation could be a valuable tool for measuring biological age. This study aims to analyse the association between inflammatory markers and both chronological age "per se" and frailty. We studied 452 persons aged 43-114 years. A Frailty Index (FI) was computed considering a wide range of age-related signs, symptoms, disabilities, and diseases. Plasma concentrations of inflammatory cytokines and peripheral markers of neuroinflammation were analysed by next-generation ELISA. The mean age of the cohort was 79.7 (from 43 to 114) years and the median FI was 0.19 (from 0.00 to 0.75). The concentrations of most inflammatory markers increased significantly with chronological age, after adjustment for sex and FI. Interferon-γ was significantly affected only by FI, while interleukin (IL)-10 and IL-1β were associated only with chronological age. In conclusion, we described different associations between inflammatory components and chronological vs. biological age. A better characterization of the molecular signature of aging could help to understand the complexity of this process.

Association of triglyceride-glucose index trajectory and frailty in urban older residents: evidence from the 10-year follow-up in a cohort study

BACKGROUND

Frailty is an age-related geriatric syndrome that leads to a series of clinically negative events. A better understanding of the factors associated with frailty assists in preventing its progression. The triglyceride-glucose (TyG) index, a simple alternative index of insulin resistance, has not yet been proven to be associated with frailty. The present study aimed to investigate the association between the TyG index and its trajectory with frailty from a cross-sectional, retrospective and prospective level based on an ongoing cohort.

METHODS

This longitudinal study included 1,866 older residents from the "Fujian prospective aging cohort" (ChiCTR 2,000,032,949). The TyG index was calculated as ln [fasting triglyceride (mg/dL) ╳ fasting plasma glucose (mg/dL)/2] and group-based trajectory model (GBTM) was applied to identify the trajectory of TyG index. The association between different trajectory groups of TyG index with frailty risk were estimated using multinomial logistic regression analysis.

RESULTS

In the cross-sectional analysis, the highest quartile of the TyG index was associated with an increased risk of frailty (TyG index Q4 vs. Q1, OR = 1.50, 95% CI 1.00-2.25, P = 0.048). Restricted cubic splines demonstrated an increasing trend for TyG index and frailty risk. During a follow-up of ten years, three distinct trajectories of the TyG index were identified: low-stable (n = 697, 38.3%), moderate-stable (n = 910, 50.0%) and high-stable (n = 214, 11.7%). Compared with those in the stable-low group of TyG index trajectory, the ORs (95% CI) of prefrailty and frailty risk were 1.79 (95% CI 1.11-2.88) and 2.17 (95% CI 1.01-3.88) for the high-stable group, respectively (P = 0.017 and P = 0.038). In the subgroup analysis, the association of the high-stable trajectory of TyG and frailty status were only observed in subjects with BMI ≥ 24 kg/m2. Prospectively, the highest quartile of the TyG index was associated with a 2.09-fold significantly increased risk of one-year ADL/IADL decline (P = 0.045).

CONCLUSIONS

The present study suggests a potential role for a high and sustainable level of TyG index in the risk of frailty. The trajectories of the TyG index can help to identify older individuals at a higher risk of frailty who deserve primitive preventive and therapeutic approaches.

Application of Multiple Omics to Understand Postoperative Delirium Pathophysiology in Humans

Delirium, an acute change in cognition, is common, morbid, and costly, particularly among hospitalized older adults. Despite growing knowledge of its epidemiology, far less is known about delirium pathophysiology. Initial work understanding delirium pathogenesis has focused on assaying single or a limited subset of molecules or genetic loci. Recent technological advances at the forefront of biomarker and drug target discovery have facilitated application of multiple "omics" approaches aimed to provide a more complete understanding of complex disease processes such as delirium. At its basic level, "omics" involves comparison of genes (genomics, epigenomics), transcripts (transcriptomics), proteins (proteomics), metabolites (metabolomics), or lipids (lipidomics) in biological fluids or tissues obtained from patients who have a certain condition (i.e., delirium) and those who do not. Multi-omics analyses of these various types of molecules combined with machine learning and systems biology enable the discovery of biomarkers, biological pathways, and predictors of delirium, thus elucidating its pathophysiology. This review provides an overview of the most recent omics techniques, their current impact on identifying delirium biomarkers, and future potential in enhancing our understanding of delirium pathogenesis. We summarize challenges in identification of specific biomarkers of delirium and, more importantly, in discovering the mechanisms underlying delirium pathophysiology. Based on mounting evidence, we highlight a heightened inflammatory response as one common pathway in delirium risk and progression, and we suggest other promising biological mechanisms that have recently emerged. Advanced multiple omics approaches coupled with bioinformatics methodologies have great promise to yield important discoveries that will advance delirium research.

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

BACKGROUND

Frailty has been increasingly identified as a risk factor of adverse outcomes in chronic obstructive pulmonary disease (COPD). The prevalence and impact of frailty on health outcomes in people with COPD require clarification.

METHODS

PubMed, Embase, The Cochrane Library and Web of Science (January 1, 2002, to July 1, 2022) were comprehensively searched to identify studies related to frailty and COPD. Comparisons were made between people who did and did not have frailty for pulmonary function, dyspnea severity, 6-minute walking distance, activities of daily life, and mortality.

RESULTS

Twenty studies (9 cross-sectional, 10 cohort studies,1 clinical trial) from Europe (9), Asia (6), and North and South America (4), Oceania (1) involving 11, 620 participants were included. The prevalence of frailty was 32.07% (95% confidence interval (CI) 26.64-37.49) with a range of 6.43-71.70% based on the frailty tool used. People with frailty had lower predicted forced expiratory volume in the first second (mean difference - 5.06%; 95%CI -6.70 to -3.42%), shorter 6-minute walking distance (mean difference - 90.23 m; 95%CI -124.70 to -55.76), poorer activities of daily life (standardized mean difference - 0.99; 95%CI -1.35 to -0.62), higher CAT(COPD Assessment Test) score(mean difference 6.2; 95%CI 4.43 to 7.96) and mMRC (modified Medical Research Council) grade (mean difference 0.93; 95%CI 0.85 to 1.02) compared with those who did not (P < 0.001 for all). Meta-analysis showed that frailty was associated with an increased risk of long-term all-cause mortality (HR 1.68; 95% CI 1.37-2.05; I² = 0%, P < 0.001).

CONCLUSION

Frailty is prevalent in people with COPD and linked with negative clinical outcomes including pulmonary function, dyspnea severity, exercise capacity, quality of life and mortality.

Interaction between sleep quality and dietary inflammation on frailty: NHANES 2005-2008

Aims: The underlying mechanism of both sleep disorders and frailty is chronic inflammation, which can be reflected by the dietary inflammatory index (DII). Therefore, we aimed to explore the association between sleep quality, frailty, and dietary inflammation. Methods: 9007 participants aged over 20 years from the National Health and Nutrition Examination Survey (NHANES) in 2005-2008 were involved in the study. Dietary inflammation was assessed by DII, sleep quality was assessed by the Pittsburgh sleep quality index (PSQI), and frailty was assessed by the 36-item frailty index (FI). Logistic regression, stratified analysis of sub-groups, and forest plots were used in this study. Results: Both pro-inflammatory diet and poor sleep quality were risk factors for frailty. There was an interaction between dietary inflammation and sleep quality (P-interaction = 0.003). Pro-inflammatory diet was associated with increased risk of frailty among the population with poor sleep quality. Compared with the anti-inflammatory diet and good sleep quality group, the OR of frailty was 1.44 (1.21, 1.73) and 2.16 (1.64, 2.80) for the anti-inflammatory diet and poor sleep quality and pro-inflammatory diet and poor sleep quality groups, respectively. Conclusion: There was an interaction between dietary inflammation and sleep quality on frailty. Anti-inflammatory diet may attenuate the detrimental impacts of poor sleep quality on frailty.