The CRP genotype, serum levels and lung function in men: the Caerphilly Prospective Study

Association Between C-Reactive Protein to Lymphocyte Ratio and Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study

Background

The inflammatory response plays a critical role in the progression and prognosis of Chronic Obstructive Pulmonary Disease (COPD). The C-reactive protein to lymphocyte ratio (CLR) has emerged as a potential novel biomarker of systemic inflammation. Nevertheless, the association between CLR and COPD remains unclear. The objective of this study was to explore the possible connection between CLR and COPD.

Methods

We conducted a retrospective study on 22,581 participants from the NHANES dataset (1999-2010). To evaluate the relationship between CLR and COPD, logistic regression analysis, restricted cubic spline analysis, and threshold effect analysis were utilized. Furthermore, subgroup and sensitivity analyses were conducted to assess the robustness of the identified association.

Results

Multivariate logistic regression models indicated that the ln-transformed CLR was significantly associated with an increased risk of COPD (OR: 1.14, 95% CI: 1.04-1.25; P = 0.005). Compared to participants classified with the first tertile of ln-transformed CLR (T1), the risks of COPD for those in T2 and T3 were 1.03 and 1.33 times higher, respectively. An evident upward trend was noted with an increase in the ln-transformed CLR (P for trend =0.032). Furthermore, an inverse L-shaped association was identified between the ln-transformed CLR and the risk of COPD. The robustness and consistency of these findings were further confirmed by subgroup and sensitivity analyses.

Conclusion

Increased CLR correlated with a heightened risk of developing COPD, exhibiting nonlinear patterns and threshold effects.

Interaction study of the effects of environmental exposure and gene polymorphisms of inflammatory and immune-active factors on chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease, influenced by both environmental and genetic factors. Single nucleotide polymorphism (SNP) in the human genome may influence the risk of developing COPD and the response to treatment. We assessed the effects of gene polymorphism of inflammatory and immune-active factors and gene-environment interaction on risk of COPD in middle-aged and older Chinese individuals.

METHODS

In this community-based case-control study, 471 patients with COPD and 485 controls aged 40-76 years in Heilongjiang Province, China were included. Face-to-face interviews, lung function tests, and multiplex polymerase chain reaction were used to obtain data. Logistic regression model, generalized multifactor dimensionality reduction and crossover analysis were used to analyse the effects of SNPs, gene-gene interactions, and gene-environment interactions on COPD.

RESULTS

CRP gene[rs1130864-A allele (OR, 1.77; 95% CI 1.11-2.81); G/A + A/A genotype (OR, 1.75; 95% CI 1.07-2.84)], FCAR gene[rs4806606-G (OR, 0.72; 95% CI 0.53-0.98); rs8112766-G (OR, 0.79; 95% CI 0.64-0.98)] and FCGR2A gene[rs4656308-C (OR, 0.74; 95% CI 0.55-1.00); rs4656309-T (OR, 0.81; 95% CI 0.66-0.99)] are independent influential factors for COPD. Rs1205 [RERI: 0.15 (0.07-1.00)] and rs1130864 [RERI: 2.45 (0.73-4.18)] of CRP gene, rs11084376 [OR: 0.54 (0.29-0.97)] of FCAR gene, rs844 of FCGR2B [SI: 0.30 (0.11-0.77); OR: 0.46 (0.24-0.90)] gene, rs4656308-rs4656309-rs2165088 haplotype [SI: 0.48 (0.26-0.89)] of FCGR2A gene and exposure to smoking index > 200, indoor coal/wood/straw use, and outdoor straw burning play synergistic or antagonistic roles in the development of COPD.

CONCLUSIONS

Alleles and genotypes of the CRP/FCAR/FCGR2A gene can increase the susceptibility to COPD in the northern Chinese population. For the first time, environmental exposure to the CRP/FCAR/FCGR2A/FCGR2B genes has been shown to have synergistic or antagonistic effects on COPD susceptibility on genotypes or haplotypes.

Respiratory complications and sleep disorders in children with chronic kidney disease: A correlation often underestimated

Chronic Kidney Disease (CKD) is characterized by a progressive and irreversible loss of kidney function which gradually leads to end-stage kidney disease (ESKD). Virtually all the organs are damaged by the toxicity of uremic compounds. The lungs may be affected and the impaired pulmonary function may be the direct result of fluid retention and metabolic, endocrine and cardiovascular alterations, as well as systemic activation of the inflammation. An increased prevalence in sleep disorders (SD) is also reported in patients with CKD, leading to a further negative impact on overall health and quality of life. While these complex relationships are well documented in the adult population, these aspects remain relatively little investigated in children. The aim of this review is to provide a brief overview of the pathophysiology between lung and kidney and to summarize how CKD may affect respiratory function and sleep in children.

Global assessment of C-reactive protein and health-related outcomes: an umbrella review of evidence from observational studies and Mendelian randomization studies

C-reactive protein (CRP) has been studied extensively for association with a large number of non-infectious diseases and outcomes. We aimed to evaluate the breadth and validity of associations between CRP and non-infectious, chronic health outcomes and biomarkers. We conducted an umbrella review of systematic reviews and meta-analyses and a systematic review of Mendelian randomization (MR) studies. PubMed, Scopus, and Cochrane Database of Systematic Reviews were systematically searched from inception up to March 2019. Meta-analyses of observational studies and MR studies examining associations between CRP and health outcomes were identified, excluding studies on the diagnostic value of CRP for infections. We found 113 meta-analytic comparisons of observational studies and 196 MR analyses, covering a wide range of outcomes. The overwhelming majority of the meta-analyses of observational studies reported a nominally statistically significant result (95/113, 84.1%); however, the majority of the meta-analyses displayed substantial heterogeneity (47.8%), small study effects (39.8%) or excess significance (41.6%). Only two outcomes, cardiovascular mortality and venous thromboembolism, showed convincing evidence of association with CRP levels. When examining the MR literature, we found MR studies for 53/113 outcomes examined in the observational study meta-analyses but substantial support for a causal association with CRP was not observed for any phenotype. Despite the striking amount of research on CRP, convincing evidence for associations and causal effects is remarkably limited.

Duration of hemodialysis associated with cardio-respiratory dysfunction and breathlessness: a multicenter study

Background

Patients with hemodialysis suffer with protein-energy wasting and uremic myopathy lead to lack of physical activity and poor functional performance. However, ventilation abnormality in patients undergone hemodialysis remains controversial regarding the respiratory impairment. Therefore, the study aimed to determine the effect of duration of dialysis on respiratory function.

Methods

A multicenter study with cross-sectional study was designed in four hemodialysis outpatient clinics. Respiratory muscle strength (i.e., maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP)) pulmonary function test (i.e., forced vital capacity (FVC), forced expiratory volume in one second (FEV₁) and FEV₁/FVC ratio), functional capacity (6-minute walk test) and sensation of breathlessness were assessed prior to dialysis.

Results

A total of 100 hemodialysis patients were recruited with 38 females and 62 males. An average of duration of hemodialysis was 5.93± 4.96 years. Decreased MIP values, FEV₁ values, FVC values, %FEV₁ and %FVC were noted in patients with long duration of dialysis (defined as ≥ 5 years of dialysis) compared to those with short duration of dialysis (p_s < .05). In addition, increased sensation of breathlessness was observed in patients with long duration of dialysis (p < .05). Furthermore, participants with long duration of dialysis had an increased risk of ventilatory restriction (OR 6.093, p = .007).

Associations of C-reactive Protein with 25-hydroxyvitamin D in 24 Specific Diseases: A Cross-sectional Study from NHANES

Most diseases might be associated with acute or chronic inflammation, and the role of vitamin D in diseases has been extensively explored in recent years. Thus, we examined the associations of one of the best markers for inflammation ― C-reactive protein (CRP) with 25-hydroxyvitamin D [25(OH)D] in 24 specific diseases. We performed cross-sectional analyses among 9,809 subjects aged ≥18 years who participated in the U.S. National Health and Nutrition Examination Survey (NHANES) in 2007~2010. The generalized additive model (GAM) was used to explore the associations of CRP with 25(OH)D in different diseases, adjusted for the age, gender, examination period and race. Distributions of CRP were significantly different (P < 0.05) in gender, examination period and race, and distributions of 25(OH)D were different (P < 0.05) in the examination period and race. Generally, CRP was negatively associated with 25(OH)D for majority diseases. 25(OH)D was negatively associated with CRP generally, and the associations were disease-specific and disease category-specific. In respiratory, gastrointestinal and mental diseases, the associations tended to be approximately linear. While in metabolic diseases, the associations were nonlinear, and the slope of the nonlinear curve decreased with 25(OH)D, especially when 25(OH)D < 30 μg/L.

Using genetic data to strengthen causal inference in observational research

Causal inference is essential across the biomedical, behavioural and social sciences.By progressing from confounded statistical associations to evidence of causal relationships, causal inference can reveal complex pathways underlying traits and diseases and help to prioritize targets for intervention. Recent progress in genetic epidemiology - including statistical innovation, massive genotyped data sets and novel computational tools for deep data mining - has fostered the intense development of methods exploiting genetic data and relatedness to strengthen causal inference in observational research. In this Review, we describe how such genetically informed methods differ in their rationale, applicability and inherent limitations and outline how they should be integrated in the future to offer a rich causal inference toolbox.

Gender- and Age-Specific Associations Between Body Fat Composition and C-Reactive Protein with Lung Function: A Cross-Sectional Study

Lung function deterioration is frequently observed in overweight and obese patients. In the current study, we explored the contribution of body fat (BF) composition, particularly visceral and nonvisceral adiposity, to lung function deterioration. In addition, we examined gender- and age-specific differences in the association between the joint effects of BF% and C-reactive protein (CRP) concentrations with lung function. This cross-sectional study involved 17,802 subjects undergoing health check-up. Clinical characteristics, body composition using bioelectrical impedance analysis (BIA), and lung function were evaluated and compared between genders. Subjects were stratified by gender-specific BF% cut-offs for evaluating the association of body composition and the risk of restrictive lung disease (RLD). Gender differences in the joint effects of BF% and CRP on lung function were observed. Visceral obesity increased the risk of RLD in women aged ≥45 years, but nonvisceral obesity reduced the risk of RLD in women aged <45 years. Our findings suggest that visceral fat per se can be used as an effective parameter to assess the association between lung function and obesity.

Lung Dysfunction and Mortality in Patients with Chronic Kidney Disease

BACKGROUND/AIMS

Lung dysfunction associates with increased mortality but the impact of chronic kidney disease (CKD) is less clear. We evaluated lung function and its association with mortality among individuals with normal to severely reduced glomerular filtration rate (GFR).

METHODS

404 individuals representing GFR category G1 (n=31; GFR >90 mL/min/1.73 m2), G2 (n=46), G3 (n=33), G4 (n=49) and G5 (n=245; GFR< 15 mL/min/1.73 m2) underwent spirometry yielding lung function indices forced vital capacity (FVC), forced expiratory volume in the first second (FEV1) and peak expiratory flow (PEF). Associations of lung function indices expressed as percentages of predicted values (%FEV1, %FVC and %PEF) with 5-year mortality were analyzed by competing-risk regression models.

RESULTS

The prevalence of obstructive (6% in G1 and 11% in G5) and especially restrictive (9% in G1 to 36% in G5) lung dysfunction increased with declining GFR and with higher comorbidity burden. In patients (n=22) with protein-energy wasting, inflammation and cardiovascular disease, the prevalence of restrictive lung function was 64%. The highest tertiles of % FEV1 and %FVC associated with lower sub-hazard ratios (sHR) for all-cause mortality, 0.49 (95% CI, 0.27-0.88)) and 0.56 (95% CI, 0.32-0.98), and that of %FEV1 also with lower cardiovascular mortality risk (sHR 0.16; 95%CI 0.04-0.69) after adjusting for multiple confounders. Restrictive lung dysfunction (FEV1/FVC ≥ 0.70, and %FVC < 80) associated with increased mortality risk (sHR 1.80, 95%CI, 1.04-3.13) while the association with obstructive lung impairment was not statistically significant.

CONCLUSION

Lung dysfunction and in particular restrictive lung dysfunction associates with degree of renal function impairment and presence of comorbidities, and is an independent predictor of increased mortality in CKD patients.

Age at menarche and lung function: a Mendelian randomization study

A trend towards earlier menarche in women has been associated with childhood factors (e.g. obesity) and hypothesised environmental exposures (e.g. endocrine disruptors present in household products). Observational evidence has shown detrimental effects of early menarche on various health outcomes including adult lung function, but these might represent spurious associations due to confounding. To address this we used Mendelian randomization where genetic variants are used as proxies for age at menarche, since genetic associations are not affected by classical confounding. We estimated the effects of age at menarche on forced vital capacity (FVC), a proxy for restrictive lung impairment, and ratio of forced expiratory volume in one second to FVC (FEV1/FVC), a measure of airway obstruction, in both adulthood and adolescence. We derived SNP-age at menarche association estimates for 122 variants from a published genome-wide meta-analysis (N = 182,416), with SNP-lung function estimates obtained by meta-analysing three studies of adult women (N = 46,944) and two of adolescent girls (N = 3025). We investigated the impact of departures from the assumption of no pleiotropy through sensitivity analyses. In adult women, in line with previous evidence, we found an effect on restrictive lung impairment with a 24.8 mL increase in FVC per year increase in age at menarche (95% CI 1.8-47.9; p = 0.035); evidence was stronger after excluding potential pleiotropic variants (43.6 mL; 17.2-69.9; p = 0.001). In adolescent girls we found an opposite effect (-56.5 mL; -108.3 to -4.7; p = 0.033), suggesting that the detrimental effect in adulthood may be preceded by a short-term post-pubertal benefit. Our secondary analyses showing results in the same direction in men and boys, in whom age at menarche SNPs have also shown association with sexual development, suggest a role for pubertal timing in general rather than menarche specifically. We found no effect on airway obstruction (FEV1/FVC).

Associations of pulmonary function with serum biomarkers and dialysis adequacy in patients undergoing peritoneal dialysis

BACKGROUND

As lung impairment is an indicator of increased morbidity and mortality in patients receiving continuous ambulatory peritoneal dialysis (CAPD), the risk factors associated with impaired lung function are of great significance. The aim of this study is to elucidate the effects of inflammatory biomarkers and dialysis adequacy on pulmonary function, in CAPD patients.

METHODS

101 patients undergoing CAPD, 30 CKD5 patients and 30 healthy subjects were enrolled. Spirometry and serum biomarkers were evaluated in each subject. Pulmonary function was compared among patients and control groups. Pearson analysis was used to analyze the correlation between serum biomarkers, dialysis adequacy and pulmonary function.

RESULTS

Lower vital capacity, maximal voluntary ventilation (MVV), forced vital capacity (FVC), peak expiratory flow (PEF), maximal mid-expiratory flow rate (MMEF), and diffusing capacity of the lung for carbon monoxide (DLCO) were observed in the CAPD group (all P < 0.05) when compared with control subjects. DLCO % was negatively correlated with CRP (r = -0.349, P = 0.007) and positively correlated with albumin (r = 0.401, P = 0.002). Total Kt/V was associated positively with MMEF % (r = 0.316, P = 0.019), and MVV % (r = 0.362, P = 0.007). nPNA was positively correlated with FVC % (r = 0.295, P = 0.049) and MMEF % (r = 0.381, P = 0.010).

CONCLUSION

The results suggest that lung function decline was directly related to higher CRP level, hypoalbuminemia, and dialysis inadequacy. These findings provide the evidence that inflammation and dialysis adequacy play a role in predicting outcomes of CAPD patients with pulmonary impairment.

Systemic inflammation and lung function: A longitudinal analysis

BACKGROUND

Systemic inflammation is associated with impaired lung function in healthy adults as well as in patients with lung disease. The mechanism for this association is unknown and it is unclear if systemic inflammation leads to impaired lung function or if poor lung function leads to inflammation. We explored the temporal associations between blood C-reactive protein (CRP), fibrinogen, and white blood cells, and lung function in young adults.

METHODS

Spirometry, plethysmography, and diffusion capacity were measured in a population-based cohort at ages 32 and 38 years. High-sensitivity CRP, fibrinogen, and white blood cells were measured at the same ages.

RESULTS

Higher levels of CRP and, to a lesser extent, fibrinogen were associated with lower lung volumes in cross-sectional analyses at both ages 32 and 38 years. Higher CRP and fibrinogen at age 32 were associated with higher FEV1 and FEV1/FVC at age 38, but not other measures of lung function. Lower lung volumes (total lung capacity, functional residual capacity, and residual volume) but not airflow obstruction (FEV1/FVC) at age 32 were associated with higher CRP at age 38. Associations between age 32 lung function and fibrinogen at follow-up were weaker, but consistent. There were no longitudinal associations between white blood cells and lung function.

CONCLUSIONS

We found no evidence that systemic inflammation causes a decline in lung function. However, lower lung volumes were associated with higher CRP and fibrinogen at follow-up indicating that pulmonary restriction may be a risk factor for systemic inflammation. The mechanism for this association remains unclear.

Mendelian randomization studies: a review of the approaches used and the quality of reporting

BACKGROUND

Mendelian randomization (MR) studies investigate the effect of genetic variation in levels of an exposure on an outcome, thereby using genetic variation as an instrumental variable (IV). We provide a meta-epidemiological overview of the methodological approaches used in MR studies, and evaluate the discussion of MR assumptions and reporting of statistical methods.

METHODS

We searched PubMed, Medline, Embase and Web of Science for MR studies up to December 2013. We assessed (i) the MR approach used; (ii) whether the plausibility of MR assumptions was discussed; and (iii) whether the statistical methods used were reported adequately.

RESULTS

Of 99 studies using data from one study population, 32 used genetic information as a proxy for the exposure without further estimation, 44 performed a formal IV analysis, 7 compared the observed with the expected genotype-outcome association, and 1 used both the latter two approaches. The 80 studies using data from multiple study populations used many different approaches to combine the data; 52 of these studies used some form of IV analysis; 44% of studies discussed the plausibility of all three MR assumptions in their study. Statistical methods used for IV analysis were insufficiently described in 14% of studies.

CONCLUSIONS

Most MR studies either use the genotype as a proxy for exposure without further estimation or perform an IV analysis. The discussion of underlying assumptions and reporting of statistical methods for IV analysis are frequently insufficient. Studies using data from multiple study populations are further complicated by the combination of data or estimates. We provide a checklist for the reporting of MR studies.

Air pollution exposure and lung function in highly exposed subjects in Beijing, China: a repeated-measure study

Background

Exposure to ambient particulate matter (PM) has been associated with reduced lung function. Elemental components of PM have been suggested to have critical roles in PM toxicity, but their contribution to respiratory effects remains under-investigated. We evaluated the effects of traffic-related PM_2.5 and its elemental components on lung function in two highly exposed groups of healthy adults in Beijing, China.

Methods

The Beijing Truck Driver Air Pollution Study (BTDAS) included 60 truck drivers and 60 office workers evaluated in 2008. On two days separated by 1-2 weeks, we measured lung function at the end of the work day, personal PM_2.5, and nine elemental components of PM_2.5 during eight hours of work, i.e., elemental carbon (EC), potassium (K), sulfur (S), iron (Fe), silicon (Si), aluminum (Al), zinc (Zn), calcium (Ca), and titanium (Ti). We used covariate-adjusted mixed-effects models including PM_2.5 as a covariate to estimate the percentage change in lung function associated with an inter-quartile range (IQR) exposure increase.

Results

The two groups had high and overlapping exposure distributions with mean personal PM_2.5 of 94.6 μg/m³ (IQR: 48.5-126.6) in office workers and 126.8 μg/m³ (IQR: 73.9-160.5) in truck drivers. The distributions of the nine elements showed group-specific profiles and generally higher levels in truck drivers. In all subjects combined, forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) did not significantly correlate with PM_2.5. However, FEV1 showed negative associations with concentrations of four elements: Si (-3.07%, 95% CI: -5.00; -1.11, IQR: 1.54), Al (-2.88%, 95% CI: -4.91; -0.81, IQR: 0.86), Ca (-1.86%, 95% CI: -2.95; -0.76, IQR: 1.33), and Ti (-2.58%, 95% CI: -4.44; -0.68, IQR: 0.03), and FVC showed negative associations with concentrations of three elements: Si (-3.23%, 95% CI: -5.61; -0.79), Al (-3.26%, 95% CI: -5.73; -0.72), and Ca (-1.86%, 95% CI: -3.23; -0.47). In stratified analysis, Si, Al, Ca, and Ti showed associations with lung function only among truck drivers, and no significant association among office workers.

Conclusion

Selected elemental components of PM_2.5 showed effects on lung function that were not found in analyses of particle levels alone.

Electronic supplementary material

The online version of this article (doi:10.1186/s12989-014-0051-7) contains supplementary material, which is available to authorized users.

Association of serum C-reactive protein levels with lupus disease activity in the absence of measurable interferon-α and a C-reactive protein gene variant

OBJECTIVE

The type I interferon (IFN) system is important in the pathogenesis of systemic lupus erythematosus (SLE). We previously demonstrated an inhibitory effect of IFNα on interleukin-6 (IL-6)-induced C-reactive protein (CRP) in vitro, hypothetically explaining the poor correlation between disease activity and CRP levels in SLE. This study was undertaken to investigate disease activity, IL-6 levels, and CRP levels in relation to a CRP gene polymorphism and IFNα.

METHODS

Sera from 155 SLE patients and 100 controls were analyzed for CRP. Patients were genotyped for a CRP single-nucleotide polymorphism (rs1205) associated with low CRP levels. Serum IFNα and IL-6 levels were quantified by immunoassays. Clinical disease activity was assessed using the SLE Disease Activity Index 2000 (SLEDAI-2K).

RESULTS

CRP levels were increased in SLE patients compared to controls, but were not associated with SLEDAI-2K or IL-6 levels. However, exclusion of patients carrying at least one rs1205 minor allele revealed an association between disease activity and CRP levels (P = 0.005). We found a strong association between disease activity and CRP levels (P < 0.0005) when patients with measurable IFNα levels as well as the minor allele of rs1205 were excluded from the analysis. Similarly, when patients with elevated IFNα levels and/or the rs1205 polymorphism were excluded, IL-6 levels were associated with CRP levels.

CONCLUSION

The present study demonstrates that the serum IFNα level as well as the CRP genotype affect the CRP response in SLE patients. Lack of correlation between serum levels of CRP and disease activity could therefore be explained by activation of the type I IFN system and polymorphisms in the CRP gene.

C-reactive protein and lung diseases

C-reactive protein (CRP), a member of the pentraxin family of plasma proteins, is one of the most distinctive acute phase reactants. In response to inflammation, cell damage or tissue injury, plasma level of CRP rapidly and dramatically increases up to 1000-fold, a phenomenon that has been used for years to monitor infections and many destructive/inflammatory conditions. The magnitude of CRP increase usually correlates with the severity of injury or inflammation and reflects an important physiological role of this interesting but still under-investigated protein. It is now generally accepted that CRP is involved in host defense and inflammation. However, the exact function of this protein in health and disease remains unclear. Many studies have demonstrated that in different pathophysiological conditions CRP might be involved in the regulation of lung function and may participate in the pathogenesis of various pulmonary disorders. The fluctuation of CRP concentrations in both alveolar fluid and serum associated with different pulmonary diseases suggests its important role in lung biology. Discussion of the still controversial functions of CRP in lung physiology and diseases is the main focus of this review.

Longitudinal association of C-reactive protein and lung function over 13 years: The EPIC-Norfolk study

Chronic obstructive pulmonary disease is known to be associated with systemic inflammation. We examined the longitudinal association of C-reactive protein (CRP) and lung function in a cohort of 18,110 men and women from the European Prospective Investigation Into Cancer in Norfolk who were 40-79 years of age at baseline (recruited in 1993-1997) and followed-up through 2011. We assessed lung function by measuring forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) at baseline, 4 years, and 13 years. Serum CRP levels were measured using a high-sensitivity assay at baseline and the 13-year follow up. Cross-sectional and longitudinal associations of loge-CRP and lung function were examined using multivariable linear mixed models. In the cross-sectional analysis, 1-standard-deviation increase in baseline loge-CRP (about 3-fold higher CRP on the original milligrams per liter scale) was associated with a -86.3 mL (95% confidence interval: -93.9, -78.6) reduction in FEV1. In longitudinal analysis, a 1-standard-deviation increase in loge-CRP over 13 years was also associated with a -64.0 mL (95% confidence interval: -72.1, -55.8) decline in FEV1 over the same period. The associations were similar for FVC and persisted among lifetime never-smokers. Baseline CRP levels were not predictive of the rate of change in FEV1 or FVC over time. In the present study, we found longitudinal observational evidence that suggested that increases in systemic inflammation are associated with declines in lung function.

High hsCRP is associated with reduced lung function in structural firefighters

BACKGROUND

To assess the association between markers of systemic inflammation and pulmonary function in a population of structural firefighters.

METHODS

We studied male career members of a large Midwestern fire department with questionnaires, spirometry, and high-sensitivity C-reactive protein (hsCRP) as a biomarker of systemic inflammation. We examined percent predicted forced expiratory volume in 1 s (FEV1 %-predicted) and forced vital capacity (FVC%-predicted).

RESULTS

Complete data were available for 401 firefighters. Higher hsCRP levels were associated with lower lung function values, after adjusting for confounding variables. Specifically, for every twofold increase in log10-hsCRP, FEV1 %-predicted decreased by a mean 1.5% (95% CI: 0.4, 2.6%) and FVC%-predicted decreased by a mean 1.4% (95% CI: 0.4, 2.3%).

CONCLUSION

hsCRP as a biomarker of systemic inflammation may indicate reduced lung function in structural firefighters.

Associations among lung function, arterial elasticity, and circulating endothelial and inflammation markers: the multiethnic study of atherosclerosis

A parallel physiological pathway for elastic changes is hypothesized for declines in arterial elasticity and lung function. Endothelial dysfunction and inflammation could potentially decrease elasticity of both vasculature and lung tissue. We examined biomarkers, large arterial elasticity and small arterial elasticity (SAE), and forced vital capacity (FVC) in a period cross-sectional design in the multiethnic study of atherosclerosis, which recruited 1823 women and 1803 men, age range 45 to 84 years, black, white, Hispanic, and Chinese, free of clinically recognized cardiovascular disease. Radial artery tonometric pulse waveform registration was performed and large arterial elasticity and SAE were derived from diastole. Spirometric data and markers of endothelial dysfunction and inflammation (soluble intracellular adhesion molecule-1, fibrinogen, hs-C-reactive protein, and interleukin-6) were obtained. Mean large arterial elasticity was 13.7 ± 5.5 mL/mm Hg × 10 and SAE was 4.6 ± 2.6 mL/mm Hg × 100. Mean FVC was 3192 ± 956.0 mL and forced expiratory volume in 1 second was 2386 ± 734.5 mL. FVC was about 40 ± 5 mL higher per SD of SAE, stronger in men than women. The association was slightly weaker with large arterial elasticity, with no sex interaction. After regression adjustment for demographic, anthropometric, and cardiovascular risk factors, the biomarkers tended to be related to reduced SAE and FVC, particularly in men. These biomarker associations suggest important cardiovascular disease risk alterations that occur concurrently with lower arterial elasticity and lung function. The observed positive association of SAE with FVC and with forced expiratory volume in 1 second in middle-aged to older free-living people is consistent with the hypothesis of parallel physiological pathways for elastic changes in the vasculature and in lung parenchymal tissue.

Blood biomarkers and measures of pulmonary function--a study from the Swedish twin registry

OBJECTIVE

There is great need of biomarkers for research and clinical purposes in COPD. This study explored the relationships between ten putative plasma biomarkers of COPD and physiological measures of reduced lung function.

METHODS

FEV(1), FVC, residual volume/total lung capacity (RV/TLC) and CO diffusion capacity (D(L)CO) were assessed in 357 subjects from the Swedish Twin Registry. The lung function measures were studied in relation to plasma levels of desmosines, C-reactive protein (CRP), plasminogen inhibitor activator (PAI-1) concentration and activity, tissue inhibitor of metalloproteinase (TIMP-1), clara cell protein 16 (CC16), surfactant protein D (SPD), matrix metalloproteinase 9 (MMP-9), hepatocyte growth factor (HGF) and interleukin (IL)-8.

RESULTS

After adjustments for age, sex, height, BMI and smoking, FEV(1) was significantly associated with PAI-1 activity and desmosines. RV/TLC was significantly associated with CC16, PAI-1 concentration and PAI-1 activity, and D(L)CO was significantly associated with desmosines, TIMP-1 and CRP. When the multivariate analysis was restricted to subjects with COPD (i.e., FEV(1)/FVC < 0.70), CRP and desmosines were inversely associated with lung function.

CONCLUSION

Several biomarkers were associated with lung function in this cross-sectional study. Especially CRP and desmosines could be useful markers to assess disease severity in subjects with COPD.

Comorbidities of chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Defining the nature of the association between chronic obstructive pulmonary disease (COPD) and other chronic conditions is of primary importance to improve the health status of COPD patients through the optimal care of comorbidities. We aimed at providing a reasoned guide to understand, recognize and treat comorbidity of COPD with the perspective of shifting from comorbidity to multimorbidity.

RECENT FINDINGS

Select comorbidities, such as atherosclerotic disease, depression, chronic kidney disease, cognitive impairment, obstructive sleep apnea syndrome, lung cancer, osteoporosis, diabetes, heart failure, sarcopenia, aortic aneurysm, arrhythmias and pulmonary embolism are highly prevalent among older COPD patients. Several concerns may affect the management of older COPD patients with comorbidity (e.g. the use of β-blockers in patients with COPD and cardiovascular diseases or concerns about the cardiovascular safety of inhaled COPD drugs).

SUMMARY

Evidence suggests that systemic inflammation may be the link between COPD and comorbidities, but this issue is still debated. Whatever the mechanism underlying comorbidities in COPD may be, it has an important clinical, prognostic and therapeutic impact. Nevertheless, clinical practice guidelines do not take into account comorbidities in their recommendations. Additionally, clinical trials investigating COPD treatment in the context of multimorbidity and considering geriatric outcomes are also distinctly lacking.