Higher serum levels of systemic inflammatory markers are linked to greater inspiratory muscle dysfunction in COPD

Predictive and therapeutic value of lipoprotein-associated phospholipaseA2 in sarcopenia in chronic obstructive pulmonary disease

BACKGROUND

Sarcopenia, characterized by progressive muscle dysfunction, is a common complication of chronic obstructive pulmonary disease (COPD). Our previous study revealed serum Lipoprotein-associated phospholipaseA2 (Lp-PLA2) level significantly increased in COPD and associated with exercise tolerance. This study further investigated the functions and target potential of Lp-PLA2 for sarcopenia in COPD.

METHODS

The circulating Lp-PLA2 level/enzyme activity in COPD patients and age-matched healthy volunteers were measured. Clinical parameters on skeletal muscle were measured and their correlations with Lp-PLA2 were analyzed. We explored the involvement of Lp-PLA2 in vivo and treatment effectiveness of darapladib (a specific Lp-PLA2 inhibitor) in CS-induced muscle dysfunction models.

RESULTS

Circulating Lp-PLA2 level/enzyme activity was elevated in COPD patients compared with healthy controls, negatively associated with skeletal muscle mass and function. In CS-induced muscle dysfunction murine models, up-regulated serum Lp-PLA2 level/enzyme activity was verified again. In CS-exposed mouse models, darapladib treatment reversed muscle mass loss and muscle dysfunction, meanwhile rescued upregulation of MuRF1 and atrogin-1, and activation of inflammatory factors, oxidant enzymes and NF-κB signaling.

CONCLUSIONS

Lp-PLA2 could be a potential indicator for sarcopenia in COPD. Darapladib, a Lp-PLA2 inhibitor, can alleviate CS-induced skeletal muscle dysfunction and represents a potential therapeutic for sarcopenia in COPD.

Comparison of High-Sensitive CRP, RDW, PLR and NLR between Patients with Chronic Obstructive Pulmonary Disease and Chronic Heart Failure

Background:

Chronic obstructive pulmonary disease (COPD) is a chronic systemic inflammation, which has similar signs and symptoms to chronic heart failure (CHF).

Objective:

To compare high-sensitive C-reactive protein (hsCRP) level and selected blood indices in patients with COPD and CHF.

Methods:

This prospective cross-sectional study (July 2019-July 2020) was conducted on patients aged 40-70 years old with a previous diagnosis of COPD, CHF, and cor pulmonale. They were divided into four groups: 1) patients with COPD, who were hospitalized due to exacerbation of dyspnea, 2) patients with CHF without a history of COPD, 3) patients with CHF and history of COPD (COPD+CHF), and finally 4) patients who had concomitant COPD and cor pulmonale condition. Spirometry, echocardiography, and six-minute walking test were performed. The hsCRP level was assessed at the beginning and end of hospital admission. Finally, RDW, neutrophil, lymphocyte, platelet counts, neutrophil to lymphocyte ratio (NLR), and platelet to lymphocyte ratio (PLR) were measured. Data were analyzed by SPSS software (α = 0.05).

Results:

In total, 140 patients were enrolled. The highest hsCRP level was observed in patients in the COPD+CHF group, and the lowest level was found in patients with CHF. Overall, a significant difference was observed in the hsCRP level at the beginning and the end of admission (P =0.0001). HsCRP had a positive correlation with the duration of hospital stay and a negative correlation with the results of the six-minute walking test. The lymphocyte counts and PLR had significant positive correlations with the six-minute walking test (R =0.38, P =0.0001 vs. R =0.325, P =0.001, respectively), and significant negative correlations with duration of hospital stay (R =-0.317, P =0.0001 vs. R =-0.380, P =0.001, respectively). At the admission, a significant difference in hsCRP was only observed comparing the COPD and cor pulmonale groups (OR =1.097, P =0.002). There were significant differences in the six-minute walking test comparing the COPD group with either of CHF or COPD+CHF groups. Significant differences were noted in the hospital stay duration comparing the COPD group with all other groups.

Determinants of dynamic inspiratory muscle strength in healthy trained elderly

BACKGROUND

The S-Index assessed by means of electronic devices is a measure of Inspiratory Muscle Strength (IMS) that highly correlates with the maximal inspiratory pressure (MIP). The variables involved when using regression models for the prediction of IMS/MIP depend on both the sample characteristics and the device or protocol used. In light of the scarce information on the influence of physical activity (PA) on IMS in healthy older adults (OA), together with the incorporation of new assessment devices, the objectives of this research are: 1) to determine which factors influence the IMS in a group of trained OA, using a portable electronic device; and 2) to propose a regression model to improve its assessment and training.

METHODS

One hundred and fifty-nine individuals were assessed for body composition, lung capacity, IMS, and PA. A total of 92 individuals (72.73 ± 4.99 years) were considered for the final sample.

RESULTS

Using age, sex, and weight as control variables, forced expiratory volume in the first second (FEV₁) is the variable which is most likely to be included in the model (80%), without physical fitness appearing to be decisive. In the absence of spirometric variables, cardiorespiratory fitness (6MWT) takes on this role in a predictive model (16%).

CONCLUSIONS

This is the first study proposing IMS predictive formulas considering spirometry and/or physical fitness results for a Spanish, healthy, and trained OAs population. A predictive formula including also the spirometric variables (mainly the FEV₁) might better predict the inspiratory muscle strength. In addition, physical and respiratory functions confirm to be different, so it is necessary for the inspiratory muscles to be trained in a specific way.

Serum Amyloid A in Stable COPD Patients is Associated with the Frequent Exacerbator Phenotype

Background

We sought to determine whether circulating inflammatory biomarkers were associated with the frequent exacerbator phenotype in stable COPD patients ie, those with two or more exacerbations in the previous year.

Methods

Eighty-eight stable, severe, COPD patients (4 females) were assessed for exacerbation frequency, pulmonary function, fraction of expired nitric oxide (F_ENO); inflammatory variables were measured in venous blood. Logistic regression assessed associations between the frequent exacerbator phenotype and systemic inflammation.

Results

Compared with infrequent exacerbators, frequent exacerbators (n=10; 11.4%) had greater serum concentration (median (25th-75th quartile)) of serum amyloid A (SAA; 134 (84–178) vs 71 (38–116) ng/mL; P=0.024), surfactant protein D (SP-D; 15.6 (9.0–19.3) vs 8.5 (3.6–14.9) ng/mL; P=0.049) and interleukin-4 (IL-4; 0.12 (0.08–1.44) vs 0.03 (0.01–0.10) pg/mL; P=0.001). SAA, SP-D and IL-4 were not significantly correlated with FEV₁%predicted or FVC %predicted. After adjusting for sex, age, BMI, FEV₁/FVC and smoking pack-years, only SAA remained independently associated with the frequent exacerbator phenotype (OR 1.49[1.09–2.04]; P=0.012). The odds of being a frequent exacerbator was 18-times greater in the highest SAA quartile (≥124.1 ng/mL) than the lowest SAA quartile (≤44.1 ng/mL) (OR 18.34[1.30–258.81]; P=0.031), and there was a significant positive trend of increasing OR with increasing SAA quartile (P=0.008). For SAA, the area under the receiver operating characteristic curve was 0.721 for identification of frequent exacerbators; an SAA cut-off of 87.0 ng/mL yielded an 80% sensitivity and 61.5% specificity.

Conclusion

In stable COPD patients, SAA was independently associated with the frequent exacerbator phenotype, suggesting that SAA may be a useful serum biomarker to inform progression or management in COPD.

The association between cystatin C and COPD: a meta-analysis and systematic review

BACKGROUND

In recent years, many studies have discovered that cystatin C (Cys C) may play an important role in respiratory diseases, especially in chronic obstructive pulmonary disease (COPD). However, the findings of these studies were inconsistent. This systematic review and meta-analysis aimed to assess the relationship between serum Cys C and COPD.

METHODS

We conducted a systematic literature search in PubMed, Embase, Web of Science, Wanfang databases, and the China National Knowledge Infrastructure. The standardized mean difference (SMD), Fisher's Z-value and 95% confidence interval (CI) were calculated to investigate the effect sizes. Subgroup analyses were performed on disease status, ethnicity, assay method, and study design. Sensitivity was performed, and publication bias was assessed.

RESULTS

A total of 15 studies, including 4079 COPD patients and 5949 controls, were included in this meta-analysis. The results showed that serum Cys C levels in patients with COPD were significantly higher than those in controls (SMD = 0.99, 95% CI =0.62-1.37, P < 0.001), especially in AECOPD (SMD = 1.59, 95% CI =1.05-2.13, P < 0.001), and there were statistically different among AECOPD and SCOPD (SMD = 0.35, 95% CI =0.10-0.59, P = 0.005). The serum Cys C levels were negatively correlated with FEV1%pre (Z = - 0.45, 95%CI = -0.58--0.32, P = 0.011) and FEV1/FVC (Z = - 0.32, 95%CI = -0.50--0.14, P = 0.006). The serum Cys C levels were independent of ethnicity, assay method, and study design.

CONCLUSION

Serum Cys C levels were associated with COPD and COPD exacerbation, and they were inversely correlated with FEV1%pre and FEV1/FVC.

Novel versus Traditional Inspiratory Muscle Training Regimens as Home-Based, Stand-Alone Therapies in COPD: Protocol for a Randomized Controlled Trial

BACKGROUND

Subjects with COPD frequently develop considerable weakness and deconditioning of the inspiratory musculature, which can be corrected with inspiratory muscle training (IMT). While rehabilitation centers may be able to provide IMT as part of the rather complex management of COPD, there is currently a lack of rehabilitation services in the Czech Republic. Remote IMT may then benefit subjects with COPD who are unable to attend or do not have access to rehabilitation programs. We aim at evaluating the utility of the test of incremental respiratory endurance (TIRE) as an at-home IMT method in subjects with COPD, while comparing the effectiveness of this novel training approach to the outcomes of traditional, threshold loading IMT protocols.

METHODS/DESIGN

This prospective, randomized controlled trial will comprise 8 weeks of at-home IMT sessions with remote supervision followed by 4 months of unsupervised, independent IMT. Eligible subjects will be randomly assigned to one of the following three distinct home-based IMT protocols: (1) TIRE, (2) Threshold loading, and (3) Sham training. Subjects allocated to the TIRE group will train once daily using an advanced IMT electronic system (PrO2), while the other two groups will receive threshold devices. Study outcomes will include measures of inspiratory muscle strength and endurance, pulmonary function, COPD-specific symptomatology, functional exercise capacity, surrogate markers of mortality risk, mental health status and health-related quality of life.

DISCUSSION

While we acknowledge the value of threshold loading IMT protocols, we believe that the TIRE training method has the potential to provide additional clinical benefits in COPD given its sophisticated remote tracking system and ability to modulate all aspects of muscular performance, including not only strength but also endurance, power and work capacity, allowing users to achieve considerably higher inspiratory pressures throughout the full range of inspiration when compared to other more traditionally used IMT methods.