Asthma, body mass index, and C-reactive protein among US adults

Immune-mediated diseases and risk of incident cardiovascular diseases: a prospective cohort study

OBJECTIVES

Disorders of immune system may impact cardiovascular health; however, comprehensive study is lacking. We aimed to analyse the association of total and 20 individual immune-mediated diseases (IMDs) with risk of incident cardiovascular disease (CVD).

METHODS

In this prospective cohort study, 414 495 participants (55.6% women; mean age 55.9 years) from UK Biobank with baseline assessment at 2006-10 were included. Among them, 21 784 participants had prevalent IMDs. Information on IMDs at baseline and incidence of CVDs during follow-up were recorded. Cox proportional hazard models were used to estimate the association between IMDs and CVDs risk.

RESULTS

During the median follow-up of 12.1 years, there were 6506 cases of CVDs in participants with IMDs (29.9%) and 77 699 cases in those without IMDs (19.8%). After multivariable adjustment, participants with IMDs were significantly associated with an increased risk of total CVD [hazard ratio (HR) 1.57; 95% CI 1.52-1.61]. Among the 20 IMDs, 16 showed significant associations with CVD (all P < 0.0025 after Bonferroni correction), with HR ranging from 1.34 (1.16-1.54) for celiac disease to 2.75 (2.10-3.61) for SLE. Participants with any IMD exposure had a higher risk of all individual CVD events, with HR ranging from 1.34 (1.14-1.58) for cerebral hemorrhage to 1.80 (1.54-2.11) for pericardium diseases. IMD duration <5, 5-10 and >10 years was associated with 55%, 59% and 56% increased risk of total CVD, respectively.

CONCLUSION

Total and individual IMDs were associated with an increased risk of overall CVDs. It is important to consider primary prevention of CVD in patients with IMD and dysregulation of immune system in the cardiovascular health.

Associations of symptoms of anxiety and depression with health-status, asthma control, dyspnoea, dysfunction breathing and obesity in people with severe asthma

BACKGROUND

Anxiety and depression are comorbidities of severe asthma. However, clinical characteristics associated with coexisting severe asthma and anxiety/depression are poorly understood. The study objective is to determine clinical characteristics associated with anxiety and depressive symptoms in severe asthma.

METHODS

Severe asthma participants (N = 140) underwent a multidimensional assessment. Categorization of symptoms of anxiety and depression were based on HADS scale sub-scores and divided into four groups (< 8 on both subscales; ≥ 8 on one subscale; ≥ 8 on both subscales). Clinical characteristics were compared between subgroups. Multivariate logistic regression determined associations of clinical characteristics and anxiety and/or depressive symptoms in people with severe asthma.

RESULTS

Participants were (mean ± SD) 59.3 ± 14.7 years old, and 62% female. There were 74 (53%) severe asthma participants without symptoms of anxiety/depression, 11 (7%) with symptoms of anxiety, 37 (26%) with symptoms of depression and 18 (13%) with symptoms of anxiety and depression. Quality of life impairment was greater in participants with symptoms of depression (4.4 ± 1.2) and combined symptoms of anxiety and depression (4.4 ± 1.1). Asthma control was worse in those with symptoms of depression (2.9 ± 1.1) and combined anxiety and depression (2.6 ± 1.0). In multivariate models, dysfunctional breathing was associated with symptoms of anxiety (OR = 1.24 [1.01, 1.53]). Dyspnoea was associated with symptoms of depression (OR = 1.90 [1.10, 3.25]). Dysfunctional breathing (OR 1.16 [1.04, 1.23]) and obesity (OR 1.17 [1.00, 1.35]) were associated with combined symptoms of anxiety and depression.

CONCLUSION

People with severe asthma and anxiety and/or depressive symptoms have poorer QoL and asthma control. Dyspnoea, dysfunctional breathing and obesity are associated with these symptoms. These key clinical characteristics should be targeted in severe asthma management.

Adults with current asthma but not former asthma have higher all-cause and cardiovascular mortality: a population-based prospective cohort study

Higher mortality in asthmatics has been shown previously. However, evidence on different asthma phenotypes on long-term mortality risk is limited. The aim was to evaluate the impact of asthma phenotypes on mortality in general population. Data from the National Health and Nutrition Examination Survey from 2001–2002 to 2013–2014 linked mortality files through December 31, 2015, were used (N = 37,015). Cox proportional hazards regression was used to estimate the risk of all-cause and cause-specific mortality adjusting for sociodemographic characteristics, smoking, body mass index, and chronic conditions. During the mean follow-up time of 7.5 years, 4326 participants died from a variety of causes. Current asthma, but not former asthma was associated with increased all-cause mortality (current asthma: HR = 1.37; 95% CI 1.20–1.58; Former asthma: HR = 0.93; 95% CI 0.73–1.18); as well as mortality from cardiovascular disease (HR_Current = 1.41; 95% CI 1.08–1.85) and chronic lower respiratory diseases (HR_Current = 3.17; 95% CI 1.96–5.14). In addition, we found that the HR for cardiovascular disease (CVD) mortality was slightly greater in people with childhood-onset asthma than those with adult-onset asthma. The HR for chronic lower respiratory diseases (CLRD) mortality was greater in people with adult-onset asthma than those with childhood-onset asthma. However, the differences were not statistically significant. Our study suggested that current asthma but not former asthma was associated with increased all-cause, CLRD and CVD mortality. Future well-designed studies with larger sample are required to demonstrate the association and clarify the potential mechanisms involved.

Sick fat: the good and the bad of old and new circulating markers of adipose tissue inflammation

Adipose tissue (AT) is one of the largest endocrine organs contributing to metabolic homeostasis. The functional pleiotropism of AT depends on its ability to secrete a large number of hormones, cytokines, extracellular matrix proteins and growth factors, all influencing many local and systemic physiological and pathophysiological processes. In condition of chronic positive energy balance, adipocyte expansion, hypoxia, apoptosis and stress all lead to AT inflammation and dysfunction, and it has been demonstrated that this sick fat is a main risk factor for many metabolic disorders, such as type 2 diabetes mellitus, fatty liver, cardiovascular disease and cancer. AT dysfunction is tightly associated with aberrant secretion of bioactive peptides, the adipocytokines, and their blood concentrations often reflect the expression in the AT. Despite the existence of an association between AT dysfunction and systemic pro-inflammatory state, most of the circulating molecules detectable in obese and dysmetabolic individuals do not identify specifically the condition of sick fat. Based on this premise, this review provides a concise overview of "classic" and novel promising adipocytokines associated with AT inflammation and discusses possible critical approaches to their interpretation in clinical practice.

The association between arthritis and depression is intensified by excessive body weight: Findings from a US national survey, 2005-2012

OBJECTIVE

Obesity and arthritis are leading chronic conditions, but comorbidity of these conditions and their interaction leading to depression have not been fully investigated. The purpose of this study is to determine the degree to which excess body weight effect-modifies the relationship between arthritis and depressive symptoms.

METHODS

We used the data of 8677 men and 8820 women aged 20 or older, who completed a depression screening and general medical condition interview as a part of the National Health and Nutrition Examination Survey, 2005-2012. Depression was ascertained using the Patient Health Questionnaire-9 (PHQ-9); a PHQ-9 score of 15 or higher was defined as indicative of depression.

RESULTS

Arthritis was reported in 26.5% (SE=0.9) of men and 36.9% (SE=1.4) of women. The association between depression and arthritis was not significant among healthy weight women, but significant among overweight and obese women. The prevalence ratios (PRs) of depression among arthritis-free women were 1.00 (reference) for healthy weight, 1.43 (0.85-2.42) for overweight, and 1.99 (1.23-3.23) for obese women. For women with arthritis, the PRs were 1.16 (0.63-2.12) for healthy weight, 3.80 (2.24-6.45) for overweight and 3.73 (2.30-6.05) for obese women. The intensifying effect from excessive body weight on the association between arthritis and depression was less salient among men than women.

CONCLUSIONS

The association between arthritis and depression is intensified significantly by increased body weight, in particular, among women.

Inflammation and Nutritional Science for Programs/Policies and Interpretation of Research Evidence (INSPIRE)

An increasing recognition has emerged of the complexities of the global health agenda—specifically, the collision of infections and noncommunicable diseases and the dual burden of over- and undernutrition. Of particular practical concern are both 1) the need for a better understanding of the bidirectional relations between nutritional status and the development and function of the immune and inflammatory response and 2) the specific impact of the inflammatory response on the selection, use, and interpretation of nutrient biomarkers. The goal of the Inflammation and Nutritional Science for Programs/Policies and Interpretation of Research Evidence (INSPIRE) is to provide guidance for those users represented by the global food and nutrition enterprise. These include researchers (bench and clinical), clinicians providing care/treatment, those developing and evaluating programs/interventions at scale, and those responsible for generating evidence-based policy. The INSPIRE process included convening 5 thematic working groups (WGs) charged with developing summary reports around the following issues: 1) basic overview of the interactions between nutrition, immune function, and the inflammatory response; 2) examination of the evidence regarding the impact of nutrition on immune function and inflammation; 3) evaluation of the impact of inflammation and clinical conditions (acute and chronic) on nutrition; 4) examination of existing and potential new approaches to account for the impact of inflammation on biomarker interpretation and use; and 5) the presentation of new approaches to the study of these relations. Each WG was tasked with synthesizing a summary of the evidence for each of these topics and delineating the remaining gaps in our knowledge. This review consists of a summary of the INSPIRE workshop and the WG deliberations.

C-reactive protein as a marker of melanoma progression

PURPOSE

To investigate the association between blood levels of C-reactive protein (CRP) in patients with melanoma and overall survival (OS), melanoma-specific survival (MSS), and disease-free survival.

PATIENTS AND METHODS

Two independent sets of plasma samples from a total of 1,144 patients with melanoma (587 initial and 557 confirmatory) were available for CRP determination. Kaplan-Meier method and Cox regression were used to evaluate the relationship between CRP and clinical outcome. Among 115 patients who underwent sequential blood draws, we evaluated the relationship between change in disease status and change in CRP using nonparametric tests.

RESULTS

Elevated CRP level was associated with poorer OS and MSS in the initial, confirmatory, and combined data sets (combined data set: OS hazard ratio, 1.44 per unit increase of logarithmic CRP; 95% CI, 1.30 to 1.59; P < .001; MSS hazard ratio, 1.51 per unit increase of logarithmic CRP; 95% CI, 1.36 to 1.68; P < .001). These findings persisted after multivariable adjustment. As compared with CRP < 10 mg/L, CRP ≥ 10 mg/L conferred poorer OS in patients with any-stage, stage I/II, or stage III/IV disease and poorer disease-free survival in those with stage I/II disease. In patients who underwent sequential evaluation of CRP, an association was identified between an increase in CRP and melanoma disease progression.

CONCLUSION

CRP is an independent prognostic marker in patients with melanoma. CRP measurement should be considered for incorporation into prospective studies of outcome in patients with melanoma and clinical trials of systemic therapies for those with melanoma.

Chronic disease co-morbidity of asthma and unscheduled asthma care among adults: results of the national telephone health interview survey German Health Update (GEDA) 2009 and 2010

Background:

Co-morbidities may complicate the clinical management of chronic conditions such as asthma.

Aims:

To quantify the strength of the relationship between asthma and other chronic diseases and to analyse whether co-morbidities contribute to unscheduled asthma care.

Methods:

Data from two consecutive national telephone health interview surveys (GEDA 2009 and 2010) including a total of 43,312 adults (≥18 years of age) were analysed. Persons with and without a current diagnosis of asthma were compared with respect to concurrent diagnoses (diabetes mellitus, hypertension, chronic heart failure, depression, osteoarthritis, stroke, coronary heart disease, and cancer). Logistic regression models were applied to assess the strength of the association between asthma and co-morbidities in the total study population and, among persons with asthma, between the number of co-morbidities and unscheduled inpatient (hospital admissions and/or emergency department admissions) or outpatient asthma care in the past 12 months.

Results:

Overall, 5.3% (95% CI 5.0% to 5.6%) of adults reported current physician-diagnosed asthma. Asthma was significantly associated with most of the conditions considered and 18% of persons with asthma had three or more co-morbidities. Adjusted odds ratios (AOR) of unscheduled asthma care increased with numbers of conditions, with AOR 3.40 (95% CI 1.39 to 8.31) for unscheduled inpatient care and AOR 2.32 (95% CI 1.30 to 4.14) for unscheduled outpatient care comparing those with three or more co-morbidities versus those with none.

Conclusions:

The magnitude of chronic disease co-morbidity is substantial in asthma, is related to unscheduled asthma care, and implies a significant number of adults with asthma facing complex healthcare needs.

Prevalence of systemic inflammation and micronutrient imbalance in patients with complex abdominal hernias

OBJECTIVE

To determine the prevalence of low-grade inflammation, micronutrient imbalances and associated clinical profiles in patients being evaluated for complex abdominal hernia repair.

METHODS

Review of 127 consecutive adult patients for evaluation of complex ventral hernias from January 2012 to March 2013. Records were analyzed to determine the prevalence and correlations of clinical risk factors, attributes of hernias identified by computerized tomography, and laboratory indices of metabolism, inflammation and micronutrient imbalances.

RESULTS

Strong correlations (p < 0.001) were established for body mass index (BMI) with volume of hernia content and C-reactive protein (CRP) level. CRP levels correlated strongly with red cell distribution width and inversely with zinc (p < 0.01). Evidence of micronutrient imbalance (abnormal zinc or red cell distribution width [RDW]) was observed in 48%.

CONCLUSIONS

In this comorbidity-rich population with known variability in surgical outcomes, the prevalence of chronic inflammation and micronutrient deficiency are high enough to warrant systemic preoperative evaluation given their possible effect on wound healing and convalescence. Simple repletion is unlikely to improve outcomes without attention to the biological stresses that are associated with micronutrient imbalance.

Relationship of circulating soluble urokinase plasminogen activator receptor (suPAR) levels to disease control in asthma and asthmatic pregnancy

Asthma has a high burden of morbidity if not controlled and may frequently complicate pregnancy, posing a risk for pregnancy outcomes. Elevated plasma level of the inflammatory biomarker soluble urokinase plasminogen activator receptor (suPAR) is related to a worse prognosis in many conditions such as infectious, autoimmune, or pregnancy-related diseases; however the value of suPAR in asthma and asthmatic pregnancy is unknown. The present study aimed to investigate the suPAR, CRP and IL-6 levels in asthma (asthmatic non-pregnant, ANP; N = 38; female N = 27) and asthmatic pregnancy (AP; N = 15), compared to healthy non-pregnant controls (HNP; N = 29; female N = 19) and to healthy pregnant women (HP; N = 58). The relationship between suPAR levels and asthma control was also evaluated. The diagnostic efficacy of suPAR in asthma control was analyzed using ROC analysis. IL-6 and CRP levels were comparable in all study groups. Circulating suPAR levels were lower in HP and AP than in HNP and ANP subjects, respectively (2.01 [1.81–2.38] and 2.39 [2.07–2.69] vs. 2.60 [1.82–3.49] and 2.84 [2.33–3.72] ng/mL, respectively, p = 0.0001). suPAR and airway resistance correlated in ANP (r = 0.47, p = 0.004). ROC analysis of suPAR values in ANP patients with PEF above and below 80% yielded an AUC of 0.75 (95% CI: 0.57–0.92, p = 0.023) and with ACT total score above and below 20 an AUC of 0.80 (95% CI: 0.64–0.95, p = 0.006). The cut-off value of suPAR to discriminate between controlled and not controlled AP and ANP was 4.04 ng/mL. In conclusion, suPAR may help the objective assessment of asthma control, since it correlates with airway resistance and has good sensitivity in the detection of impaired asthma control. Decrease in circulating suPAR levels detected both in healthy and asthmatic pregnant women presumably represents pregnancy induced immune tolerance.

Obesity, Nutrition, and Asthma in Children

Obesity rates have increased dramatically among children in many parts of the world, especially in North America and several other English-speaking countries. The impact of obesity on pediatric health has become a major prevention initiative by the Obama administration and several public health organizations. Children with obesity are at increased risk for developing asthma, which is already one of the most common chronic diseases among children. The cause underlying obesity's impact on asthma risk is unknown. Commonly cited potential etiologies include airway smooth muscle dysfunction from thoracic restriction, obesity-related circulating inflammation priming the lung, and obesity-related comorbidities mediating asthma symptom development. Each of these theories does not fit precisely with all of the data that have accumulated over the last decade. In this review, I will explore other possible causes including: (1) dietary characteristics common in Westernized countries that might lead to both obesity and asthma; (2) reductions in physical activity; and (3) genetic alterations that increase the propensity to both obesity and asthma together. Next, I will review the current data on how obesity affects common characteristics of asthma such as airway inflammation, lung function, risk of exacerbation, atopy, and response to treatment. Obesity in children with asthma appears to be associated with greater airflow obstruction and a mildly diminished response to inhaled corticosteroids. Little objective evidence in children suggests that obesity significantly heightens the risk of exacerbation or worsens disease stability in children. Lastly, I will discuss the current literature that suggests that obese children with asthma generally should receive the same guidelines-based management as lean children. However, interventions that encourage daily physical activity, weight-loss, normalization of nutrient levels, and monitoring of common obesity-related sequelae should be considered by healthcare providers managing obese children with difficult-to-control asthma.

Effect of bariatric surgery on airway response and lung function in obese subjects with asthma

BACKGROUND

Obesity is a risk factor for self-reported asthma and makes asthma management more difficult. The effects of bariatric surgery on asthma in severely obese subjects remain to be documented.

METHODS

In this prospective study, 12 asthmatic patients with severe obesity were evaluated before, 6 and 12 months after bariatric surgery. Each had methacholine inhalation tests, measures of expiratory flows and lung volumes, measurements of C-reactive protein and questionnaires on asthma medication, asthma symptoms and co-morbid conditions. Eleven severely obese patients with asthma (considered as controls) underwent the same evaluations. Primary endpoint was airway responsiveness to methacholine and secondary endpoints were lung volumes and markers of systemic inflammation.

RESULTS

Mean body mass index decreased from 51.2 to 34.4 kg/m(2) twelve months post-surgery. Mean PC(20) methacholine improved from 0.84 to 6.2 mg/ml (P < 0.001); FEV(1), FVC, FRC, FRC/TLC and ERV all improved (P ≤ 0.006). C-reactive protein decreased from 8.6 to 1.7 mg/L (P < 0.001) Asthma symptoms total score was significantly reduced (P = 0.03) and asthma medication needs decreased, ten patients being able to stop all asthma drugs. No significant changes of these parameters from baseline were observed in asthmatic controls. Improvements in airway responsiveness and lung volumes happened in parallel and correlated with reductions of body mass index (r = 0.58, P = 0.049), C-reactive protein levels (r = -0.74, P = 0.004).

CONCLUSION

Airway responsiveness, lung volumes and asthma severity/control markedly improved with weight loss following bariatric surgery in severely obese patients.

High sensitivity C-reactive protein: its correlation with sputum cell counts in bronchial asthma

BACKGROUND

Two major acute-phase proteins were identified in human, C-reactive protein and serum amyloid A. There are 3 types of C-reactive protein assays: conventional C-reactive protein, high sensitivity C-reactive protein and cardiac C-reactive protein. High sensitivity C-reactive protein assays can detect minor inflammatory changes that could be missed by other indices of inflammation. Induced sputum cell counts are relatively non-invasive, safe and reliable method for identifying the presence and type of airway inflammation in asthmatic patients.

PURPOSE OF THE WORK

This study was designed to detect the role of serum levels of high sensitivity C-reactive protein in asthmatic patients with or without inhaled corticosteroids treatment. Also to determine the relationship of serum high sensitivity C-reactive protein levels to clinical indices of asthma and inflammatory cell counts in induced sputum.

SUBJECTS & METHODS

Serum high sensitivity C-reactive protein level, pulmonary function tests, body mass index and induced sputum cell counts were estimated in 50 asthmatic patients (26 steroid inhaled and 24 steroid naïve). Fifteen healthy volunteers, who matched in age and sex with the other groups, were used as a control group.

RESULTS

There was an increase of high sensitivity C-reactive protein in asthmatic patients among both steroid inhaled and steroid naïve patients compared to the healthy controls. Serum high sensitivity C-reactive protein correlated negatively with pulmonary function tests and positively with sputum eosinophil % in both inhaled steroid and steroid naïve groups.

CONCLUSION

High sensitivity C-reactive protein is one of the markers of systemic inflammation that can be indirectly reflecting the degree of severity of airway inflammation in bronchial asthma.

Effect of oral magnesium supplementation on measures of airway resistance and subjective assessment of asthma control and quality of life in men and women with mild to moderate asthma: a randomized placebo controlled trial

BACKGROUND

Epidemiological data shows low dietary magnesium(Mg) may be related to incidence and progression of asthma.

OBJECTIVE

To determine if long term(6.5 month) treatment with oral Mg would improve asthma control and increase serum measures of Mg status in men and women with mild-to-moderate asthma.

SUBJECTS

55 males and females aged 21 to 55 years with mild to moderate asthma according to the 2002 National Heart, Lung, and Blood Institute(NHLBI) and Asthma Education and Prevention Program(NAEPP) guidelines and who used only beta-agonists or inhaled corticosteroids(ICS) as asthma medications were enrolled.

DESIGN

Subjects were randomly assigned to consume 340 mg(170 mg twice a day) of Mg or a placebo for 6.5 months.

MEASUREMENTS

Multiple measures of Mg status including serum, erythrocyte, urine, dietary, ionized and IV Mg were measured.

OBJECTIVE

markers of asthma control were: methacholine challenge test(MCCT) and pulmonary function test(PFT) results. Subjective validated questionnaires on asthma quality of life(AQLQ) and control(ACQ) were completed by participants. Markers of inflammation, including c-reactive protein(CRP) and exhaled nitric oxide(eNO) were determined.

RESULTS

The concentration of methacholine required to cause a 20% drop in forced expiratory volume in in minute(FEV(1)) increased significantly from baseline to month 6 within the Mg group. Peak expiratory flow rate(PEFR) showed a 5.8% predicted improvement over time(P = 0.03) in those consuming the Mg. There was significant improvement in AQLQ mean score units(P < 0.01) and in overall ACQ score only in the Mg group(P = 0.05) after 6.5 months of supplementation. Despite these improvements, there were no significant changes in any of the markers of Mg status.

CONCLUSION

Adults who received oral Mg supplements showed improvement in objective measures of bronchial reactivity to methacholine and PEFR and in subjective measures of asthma control and quality of life.

Obesity, inflammation, and asthma severity in childhood: data from the National Health and Nutrition Examination Survey 2001-2004

BACKGROUND

The prevalences of asthma and obesity in children have increased significantly during the past 2 decades. The basis for the relationship between pediatric asthma and obesity is not well established.

OBJECTIVES

To explore the association between obesity and asthma severity in children and adolescents and to test whether obesity-induced inflammation, as characterized by serum C-reactive protein (CRP), is associated with increased severity of asthma.

METHODS

Retrospective cohort analysis of interview, physical examination, and laboratory test data from participants younger than 20 years in 2 rounds of the National Health and Nutrition Examination Survey (2001-2002 and 2003-2004). We also performed generalized ordered logistic regression to evaluate the effect of body mass index (BMI) z score and CRP level on asthma severity, controlling for the impact of age, sex, race, income, insurance, and tobacco smoke exposure.

RESULTS

Of the 77 million individuals younger than 20 years represented by this weighted sample, 19% met the study-defined criteria for asthma; most cases were defined as mild (11%) or moderate (6%); 2% had severe asthma. In multivariable models, elevated BMI z scores (odds ratio, 1.12; 95% confidence interval, 1.05-1.21) were associated with worse asthma severity. Elevated CRP level was associated with obesity (P < .001) and asthma severity (odds ratio, 1.33; 95% confidence interval, 1.16-1.52).

CONCLUSIONS

Higher BMI z scores and elevated serum CRP levels are associated with increased asthma severity. These findings highlight the importance of controlling for inflammation when considering the role of obesity and provide support for the hypothesis that obesity-induced inflammation may contribute to greater asthma severity.

Pulmonary function correlates with arterial stiffness in asthmatic patients

BACKGROUND

At the population level, asthma has been associated with chronic systemic inflammation as well as adverse cardiovascular outcomes.

OBJECTIVES

The aim of this study was to investigate peripheral vascular hemodynamic variables of arterial stiffness (AS) and their relationship to pulmonary function tests in asthmatic patients.

METHODS

Young asthmatic patients from the tertiary center for pulmonary diseases at the Barzilai Medical Center underwent pulmonary function evaluation and non-invasive radial artery hemodynamic profiling, pre- and post-exercise. Results were compared to age matched, non-asthmatic controls.

RESULTS

23 young asthmatics and 41 controls, completed all evaluation points. Pulmonary flow parameters were significantly reduced in the asthma group at all points. There were no differences between groups in BMI, blood pressure, pulse rate or measurements of AS at baseline or after bronchodilation. The % predicted forced expiratory volume in the first second at baseline (FEV1%) in asthmatics was positively correlated with the small arteries elasticity index (SAEI) and negatively correlated with the systemic vascular resistance (SVR) in these patients. These correlations were not observed in non-asthmatic controls. In multifactorial regression FEV1 remained the major factor associated with measurements of AS in asthmatic patients, while gender was the only significant factor in non-asthmatic controls.

CONCLUSIONS

Significant correlations between measurements of AS and FEV1 in young asthmatics, suggest the presence of a common systemic, most likely inflammatory pathway involving both the cardiovascular and respiratory systems.

Testing protocols: care of biological samples in a rural setting

The purpose of this study is to evaluate collection, transport, and storage protocols of urine and air allergen samples from infants in a rural setting. Infant urine and aeroallergen samples (n = 21) are collected in the home setting in rural areas where time and distance to the central laboratory is a consideration. Urine samples are analyzed using ELISA tests after being transported using three different techniques: (a) ambient temperature, (b) dry ice, and (c) packaged on dry ice and shipped commercially. Following initial ELISA testing for levels of cytokines, urine samples are frozen at -70 degrees Celsius for 6 months. Samples are then reanalyzed for levels of cytokines. Dust samples are analyzed for levels of aeroallergens, stored at 4 degrees for 6 months, and reanalyzed. The integrity of samples varies by biomarker, shipment temperature, and storage time, creating a high degree of variability in results.

Asthma is an independent risk for elevation of plasma C-reactive protein levels

BACKGROUND

Chronic inflammation of the airways plays a major role in the pathogenesis of asthma. Although C-reactive protein (CRP) is now an established circulating marker for cardiovascular diseases, it remains unclear whether asthma is an independent risk for increased plasma CRP.

METHODS

In Study 1, we evaluated CRP levels in 329 asthmatic patients and 1684 non-asthmatic subjects. Inhaled corticosteroids were regularly used by 308 asthmatics. In Study 2, the effects of inhaled corticosteroids on CRP levels were examined in 64 corticosteroid-naive asthmatic patients.

RESULTS

In Study 1, plasma CRP levels were associated with body mass index (R=0.349, P<0.0001) and age (R=0.111, P<0.0001) in all study subjects, but were higher in patients with asthma, hypertension, diabetes and/or dyslipidemia than in those without these disorders. Multivariate regression analysis identified body mass index, age and asthma, but not hypertension, diabetes or dyslipidemia, as independently associated with an elevation of CRP levels. In Study 2, treatment of 64 corticosteroid-naive asthmatic patients with inhaled corticosteroids for 3 months significantly reduced plasma CRP levels.

CONCLUSIONS

Asthma is a disorder associated with increased plasma CRP levels independent of various other factors. Treatment with inhaled corticosteroids was associated with a significant reduction in plasma CRP levels, which may reflect their clinical effect on the inflammatory process within airways.

Associations of circulating C-reactive protein and interleukin-6 with cancer risk: findings from two prospective cohorts and a meta-analysis

OBJECTIVE

We investigated the associations of circulating C-reactive protein (CRP) and interleukin-6 (IL-6) with cancer risk.

METHODS

We examined the associations of CRP and IL-6 with incident cancer in two prospective cohorts, the British Women's Heart and Health Study (4,286 women aged 60-80) and the Caerphilly Cohort (2,398 men aged 45-59) using Cox regression and pooled our findings with previous prospective studies' in fixed and random effects meta-analyses.

RESULTS

CRP and IL-6 were associated with some incident cancers in our cohorts, but the numbers of cancer cases were small. In our meta-analyses elevated CRP was associated with an increased overall risk of cancer (random effects estimate (RE): 1.10, 95% CI: 1.02, 1.18) and lung cancer (RE: 1.32, 95% CI: 1.08, 1.61). Its associations with colorectal (RE: 1.09, 95% CI: 0.98, 1.21) and breast cancer risks (RE: 1.10, 95% CI: 0.97, 1.26) were weaker. CRP appeared unrelated to prostate cancer risk (RE: 1.00 0.88, 1.13). IL-6 was associated with increased lung and breast cancer risks and decreased prostate cancer risk, and was unrelated to colorectal cancer risk.

CONCLUSIONS

Our findings suggest an etiological role for CRP and IL-6 in some cancers. Further large prospective and genetic studies would help to better understand this role.

Prospective study of inhaled corticosteroid use, cardiovascular mortality, and all-cause mortality in asthmatic women

BACKGROUND

Therapy with inhaled corticosteroids (ICSs) decreases the risk of asthma exacerbations. Recent studies have suggested that ICS therapy also may decrease the risk of cardiovascular disease, and perhaps of all-cause mortality. We examined this hypothesis in a large, well-characterized cohort of asthmatic women.

METHODS

In 1976, the Nurses' Health Study enrolled 121,700 registered nurses, who were 30 to 55 years of age. Participants were asked about "physician-diagnosed asthma" on biennial questionnaires. In 1998, asthmatic participants were sent a supplementary questionnaire on asthma diagnosis and management, including ICS use. Mortality was assessed through 2003, without knowledge of the 1998 (baseline) ICS status. The odds ratios (ORs) for death were adjusted for age, asthma severity, smoking, heart disease, cancer, stroke, aspirin, and statin use.

RESULTS

Among 2,671 eligible women (ie, those who responded to the 1998 supplement [85%], met criteria for persistent asthma, and had not received a prior diagnosis of COPD), 54% reported ICS use. Over the next 5 years, 87 women (3.3%) died (cardiovascular deaths, 22; cancer deaths, 31; other, 34 [including 4 from asthma]). Compared to asthmatic women who did not use ICSs, those receiving therapy with ICSs had lower all-cause mortality (OR, 0.58; 95% confidence interval [CI], 0.36 to 0.92). ICS users were at significantly lower risk of cardiovascular death (OR, 0.35; 95% CI, 0.13 to 0.93), but not of death from cancer (OR, 0.66; 95% CI, 0.32 to 1.38) or other causes (OR, 0.62; 95% CI, 0.30 to 1.27).

CONCLUSIONS

ICS use was associated with significantly lower cardiovascular and all-cause mortality in women with asthma. These observational data suggest that ICSs may indeed have antiinflammatory benefits beyond the airway, which is a possibility that merits further study.

Association of obesity and insulin resistance with asthma and aeroallergen sensitization

BACKGROUND

It has been hypothesized that obesity and insulin resistance may play a role in the development of asthma and allergy. The aim of the study was to examine the association of obesity and insulin resistance with asthma and aeroallergen sensitization.

METHODS

Cross-sectional population-based study of 3609 Danish men and women aged 30-60 years. Aeroallergen sensitization was defined as positive levels of specific IgE against a panel of inhalant allergens. Asthma was defined as self-reported physician diagnosed asthma. Allergic asthma was defined as the presence of both asthma and aeroallergen sensitization. The homeostasis model assessment of insulin resistance was used to estimate the degree of insulin resistance. Body mass index, waist-to-hip ratio, and waist circumference were used as measures of obesity. Data were analyzed by multiple logistic regression analyses.

RESULTS

Obesity was associated with increased risk of aeroallergen sensitization as well as allergic and nonallergic asthma. Insulin resistance was asssociated with aeroallergen sensitization and allergic asthma, but not nonallergic asthma. The associations of obesity with aeroallegen sensitization and allergic asthma became nonsignificant after adjustment for insulin resistance, whereas the association of obesity with nonallergic asthma was unaffected. No sex-differences were observed.

CONCLUSION

Obesity may be related to an increased risk of aeroallergen sensitization and allergic asthma through mechanisms also involved in the development of insulin resistance.

Training improves physical fitness and decreases CRP also in asthmatic conscripts

To study the respiratory and physical health of young men, 224 asthmatic and 668 non-asthmatic military conscripts were recruited from the intake groups of July 2004 and January 2005 in Kajaani, Finland. Factors affecting respiratory health were elicited by a questionnaire at the beginning of the service, and results of high sensitive C-reactive protein (hsCRP) determination, peak expiratory flow (PEF), and 12-minute running test were collected at the beginning and the end of the service. Respiratory infections were diagnosed by a study physician. Upon entering military service, asthmatics had frequent exercise- and cold-related asthma symptoms (69.6% and 76.3%), and 48% of them had no medication for asthma. At the beginning, 25.8% of asthmatics and 19.1% of non-asthmatics had a poor result of less than 2,200 m (p = 0.05) in the 12-minute running test, and after 180 to 362 days of service, the corresponding percentages were 11.7% and 9.7% (p = 0.434). The levels of hsCRP, a marker of low-grade systemic inflammation, decreased significantly among both asthmatics, 1.5 (p = 0.001), and non-asthmatics, 1.6 mg/L (p < 0.001). Asthmatic men had 0.2 and non-asthmatics 0.1 respiratory infections per month (p < 0.001). In summary, asthmatic conscripts can enhance their physical fitness by training similarly to non-asthmatic ones. Their levels of hsCRP also decrease.

Association between exhaled nitric oxide and systemic inflammatory markers

BACKGROUND

Asthma is an inflammatory condition of the airways, and there is some evidence to suggest that it is associated with a systemic inflammatory response, as measured by C-reactive protein (CRP) and fibrinogen. Exhaled nitric oxide is a noninvasive measure of asthmatic airway inflammation.

OBJECTIVE

To determine if there is an association between exhaled nitric oxide and these systemic inflammatory markers.

METHODS

The Dunedin Multidisciplinary Health and Development Study is a birth cohort of approximately 1,000 individuals born between April 1, 1972, and March 31, 1973. At the age of 32 years, study members were assessed for diagnosis of asthma, atopy by skin prick testing, smoking, body mass index, exhaled nitric oxide, high-sensitivity serum CRP, and plasma fibrinogen level.

RESULTS

There was no significant association between exhaled nitric oxide and CRP (P = .99). There was a trend to an inverse association between exhaled nitric oxide and fibrinogen (P = .049), but this was not significant after adjusting for smoking and use of corticosteroids or after further adjustment for body mass index and atopy (P = .71).

CONCLUSION

In this population-based sample of young adults, there was no association between airway inflammation, as measured by exhaled nitric oxide, and systemic inflammation, as measured by either CRP or fibrinogen.

BMI and health status among adults with asthma

BACKGROUND

A convincing body of literature links obesity with a higher risk for developing adult-onset asthma. The impact of obesity on asthma severity among adults with pre-existing asthma, however, is less clear.

METHODS AND PROCEDURES

In a prospective cohort study of 843 adults with severe asthma, we studied the impact of BMI on asthma health status.

RESULTS

The prevalence of obesity and overweight were 44% (95% confidence interval (CI) 41-47%) and 28% (95% CI 25-32%). The obese BMI group was associated with a higher risk for daily or near daily asthma symptoms than was the normal BMI group (odds ratio (OR) 1.81; 95% CI 1.10-2.96). Compared to the normal BMI group, generic physical health status was worse in the overweight (mean score decrement -2.42 points; 95% CI -4.39 to -0.45) and the obese groups (-6.31 points; 95% CI -8.14 to -4.49). Asthma-specific quality of life was worse in the underweight (mean score increment 8.66 points; 95% CI 2.53-14.8) and obese groups (4.51 points; 95% CI 2.21-6.81), compared to those with normal BMI. Obese persons also had a higher number of restricted activity days that past month (5.05 days; 95% CI 2.90-7.19 days).

DISCUSSION

It appears that obesity has a substantive negative effect on health status among adults with asthma. Further work is needed to clarify the precise mechanisms. Clinicians should counsel dietary modification and weight loss for their overweight and obese patients with asthma.

Association between asthma, asthma symptoms and C-reactive protein in US adults: data from the National Health and Nutrition Examination Survey, 1999-2002

BACKGROUND AND OBJECTIVES

CRP is elevated in several inflammatory diseases; however, little is known about its association with asthma.

METHODS

The study evaluated the associations between CRP, asthma and asthma symptoms using data on 8020 adults >or=20 years of age from the latest US National Health and Nutrition Examination Survey.

RESULTS

The prevalence estimates of current asthma, wheezing and nocturnal cough were 3.6% (95% CI: 2.9-4.4), 14.7% (95% CI: 13.7-15.8) and 4.6% (95% CI: 3.8-5.3), respectively. Geometric mean of CRP was 0.20 mg/dL (95% CI: 0.19-0.21). The majority of female (69.5%) respondents were in the fourth (highest) quartile of CRP. Mean CRP levels were significantly higher in non-Hispanic blacks as compared with non-Hispanic whites. The adjusted odds of current asthma and past asthma (as compared with no asthma) were 1.60 (95% CI: 1.02-2.53) and 1.43 (95% CI: 1.07-1.91), respectively, greater in the fourth quartile of CRP. The adjusted odds of presence of both wheezing and nocturnal cough were 2.18 and 3.40 in the third and fourth quartile of CRP, respectively.

CONCLUSIONS

This study shows that adults with asthma and asthma symptoms have higher levels of CRP. The potential use of CRP as a clinically useful marker for asthma severity and control should be further explored.

A systematic review of the association between circulating concentrations of C reactive protein and cancer

The objective of this study was to review and summarise the published evidence for an association between circulating concentrations of C reactive protein (CRP) and cancer through a systematic review. 90 discrete studies were identified. 81 (90%) were prevalent case-control or cross-sectional studies, and only 9 studies had a prospective design. In most prevalent studies, CRP concentrations were found to be higher in patients with cancer than in healthy controls or controls with benign conditions. Of the nine large prospective studies identified in this review, four reported no relationship between circulating CRP levels and breast, prostate or colorectal cancers, and five studies found that CRP was associated with colorectal or lung cancers. Most of the studies evaluating CRP as a diagnostic marker of cancer did not present relevant statistical analyses. Furthermore, any association reported in the prevalent studies might reflect reverse causation, survival bias or confounding. The prospective studies provided no strong evidence for a causal role of CRP in cancer. Instead of further prevalent studies, more large prospective studies and CRP gene-cancer association studies would be valuable in investigating the role of CRP in cancer.

Association between exhaled nitric oxide and systemic inflammatory markers

BACKGROUND

Asthma is an inflammatory condition of the airways, and there is some evidence to suggest that it is associated with a systemic inflammatory response, as measured by C-reactive protein (CRP) and fibrinogen. Exhaled nitric oxide is a noninvasive measure of asthmatic airway inflammation.

OBJECTIVE

To determine if there is an association between exhaled nitric oxide and these systemic inflammatory markers.

METHODS

The Dunedin Multidisciplinary Health and Development Study is a birth cohort of approximately 1,000 individuals born between April 1, 1972, and March 31, 1973. At the age of 32 years, study members were assessed for diagnosis of asthma, atopy by skin prick testing, smoking, body mass index, exhaled nitric oxide, high-sensitivity serum CRP, and plasma fibrinogen level.

RESULTS

There was no significant association between exhaled nitric oxide and CRP (P = .99). There was a trend to an inverse association between exhaled nitric oxide and fibrinogen (P = .049), but this was not significant after adjusting for smoking and use of corticosteroids or after further adjustment for body mass index and atopy (P = .71).

CONCLUSION

In this population-based sample of young adults, there was no association between airway inflammation, as measured by exhaled nitric oxide, and systemic inflammation, as measured by either CRP or fibrinogen.

The effect of montelukast and low-dose theophylline on cardiovascular disease risk factors in asthmatics

BACKGROUND

Recent studies have implicated the 5-lipoxygenase/leukotriene (LT) pathway in cardiovascular disease (CVD), which may have important implications for asthmatics because several drugs that target this pathway are currently used to treat asthma. We sought to determine whether montelukast, a cysteinyl LT antagonist, and low-dose theophylline affected serum inflammatory and lipid CVD risk factors in a recently completed clinical trial in asthmatic patients.

METHODS

Patients were randomized to receive either montelukast (10 mg/d), theophylline (300 mg/d), or placebo. A baseline run-in period of 7 to 14 days was followed by treatment for 6 months. Serum levels of C-reactive protein (CRP), interleukin-6, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density cholesterol (HDL-C) were measured 1 month and 6 months after treatment.

RESULTS

Patients with moderate-to-severe asthma receiving montelukast (n = 60) had significantly lower serum CRP compared to placebo (n = 73) after 1 month (1.7 mg/L vs 3.2 mg/L, respectively; p < 0.006) and 6 months of treatment (2.3 mg/L vs 3.5 mg/L, respectively; p < 0.04). At both time points, serum levels of all lipids were also significantly lower in the montelukast and theophylline groups compared to placebo, but these effects were primarily observed in individuals who were also receiving inhaled corticosteroids as monotherapy for asthma.

CONCLUSIONS

Asthmatic patients receiving montelukast and, to some extent, low-dose theophylline have lower levels of CVD-associated inflammatory biomarkers and lipid levels. These observations suggest these asthma medications may have some beneficial value in asthmatics with respect to CVD risk, although the effects on HDL-C levels should also be taken into consideration.

Socioeconomic status and C-reactive protein levels in the US population: NHANES IV

C-reactive protein (CRP), a marker of inflammation, has been identified as a risk factor for cardiovascular disease and mortality. Using data on adults aged 20 and over from the fourth National Health and Nutrition Examination Survey, a nationally representative cross-sectional survey, we examined the association between socioeconomic status and CRP in US adults (N=7634). Socioeconomic variation in CRP occurred only at very high levels of CRP (>10.0 mg/L). There was no significant difference in the prevalence of moderate (1.1-3.0 mg/L) or high values of CRP (3.1-10.0mg/L) by socioeconomic status; however, among those with family income at or below the poverty level, 15.7% had very high levels of CRP (greater than 10.0 mg/L), compared to only 9.1% of those in families above the poverty level. Logistic regression results indicate that acute illness, chronic conditions, and differential health behaviors account for about two-thirds of this association. African Americans, Hispanics, and women were more likely to have high levels of CRP. Obesity was the largest risk factor for every level of CRP above normal. Results suggest that differences in very high CRP may be due to factors beyond acute illness and may also reflect chronic health, behavioral and disease processes associated with low socioeconomic status.

Hypercholesterolemia is a potential risk factor for asthma

INTRODUCTION

The effect of hyperlipidemia on asthma has never been addressed. Recent literature implicates a pro-inflammatory role for hypercholesterolemia. This study evaluates the effect of serum cholesterol level on asthma frequency.

METHODS

Factors associated with asthma risk were examined in a retrospective study design. Study subjects were between the 4 and 20 years of age who presented to a rural pediatric clinic and whose total serum cholesterol level was obtained. Diagnosis of asthma was determined by the treating physician. Multivariable logistic regression was performed to identify variables that were related to the odds of having asthma.

RESULTS

A total of 188 patients were included. Asthma was present in 50 patients. Total serum cholesterol (mean +/- SD) for the asthma group was 176.7 +/- 39.8 compared to 162.9 +/- 12.8 in the non-asthma group (P = 0.028). A total of 21 of the 50 (42%) asthma patients were obese compared to 31 of the 138 (22%) non-asthma patients (p = 0.014). There was no difference between both groups regarding age and gender. Hypercholesterolemia and obesity were identified by logistic regression analysis to increase the probability of asthma independently.

CONCLUSION

Hypercholesterolemia is a potential risk factor for asthma independent of obesity.

Obesity and asthma

Obesity is an important public health problem. An increasing body of data supports the hypothesis that obesity is a risk factor for asthma. These data include numerous large cross-sectional and prospective studies performed in adults, adolescents, and children throughout the world. With few exceptions, these studies indicate an increased relative risk of asthma in the obese and overweight and demonstrate that obesity antedates asthma. Obesity appears to be a particularly important issue for severe asthma. Studies showing improvements in asthma in subjects who lose weight, as well as studies showing that obese mice have innate airway hyperresponsiveness (AHR) as well as increased responses to certain asthma triggers also suggest a causal relationship between obesity and asthma. The mechanistic basis for this relationship has not been established. It may be that obesity and asthma share some common etiology, such as a common genetic predisposition, common effects of in utero conditions, or that obesity and asthma are both the result of some other predisposing factor such as physical activity or diet. However, there are also plausible biological mechanisms whereby obesity could be expected to either cause or worsen asthma. These include co-morbidities such as gastroesophageal reflux, complications from sleep-disordered breathing (SDB), breathing at low lung volume, chronic systemic inflammation, and endocrine factors, including adipokines and reproductive hormones. Understanding the mechanistic basis for the relationship between obesity and asthma may lead to new therapeutic strategies for treatment of this susceptible population.

Obesity and asthma, what are the links?

PURPOSE OF REVIEW

Obesity is a major cause of morbidity accounting for approximately 300 000 deaths each year and about 7% of the health care budget with an economic impact greater than US dollar 100 billion annually in the United States. Obesity and its sequelae such as cardiovascular disease, diabetes, arthritis or cancer have been on the rise over the last decades. The parallel time trend with an increasing prevalence of asthma has induced a lively debate about a potential link between both conditions.

RECENT FINDINGS

A number of prospective studies have shown that weight gain can antedate the development of asthma. Effect modification by sex may occur as some studies have shown effects of body mass index on asthma only among females. However, sex differences are not consistent. Several hypotheses have been proposed to explain the epidemiological associations including alterations in airway mechanics and immune responses, hormonal influences and genetic factors.

SUMMARY

There is evidence that obesity and overweight are associated with the development of asthma. Yet, the mechanisms underlying this relation are unclear. Weight reduction among asthmatic patients can result in improvements of lung function demonstrating the potential clinical impact of the findings.

C reactive protein levels are increased in non-allergic but not allergic asthma: a multicentre epidemiological study

BACKGROUND

High sensitivity C reactive protein (HsCRP) is an inflammatory marker known to be related to smoking, obesity, and cardiovascular disease. A study was undertaken to determine whether HsCRP is related to respiratory symptoms, asthma, atopy, and bronchial hyperresponsiveness in population samples from three countries.

METHODS

HsCRP was measured in 1289 subjects from three centres in ECRHS II: Reykjavik, Uppsala and Tartu. The HsCRP values ranged from <0.01 mg/l to 70.0 mg/l and were divided into four equal groups (< or = 0.45, 0.46-0.96, 0.97-2.21, and >2.21 mg/l).

RESULTS

HsCRP increased with increasing body mass index (r = 0.41; p<0.0001) and was higher in smokers than in never smokers (p = 0.02). A significant relationship was found between increased HsCRP levels and respiratory symptoms such as wheeze, attacks of breathlessness after effort, and nocturnal cough (p<0.0001). The crude odds ratio (95% CI) for the probability of non-allergic asthma was 3.57 (1.83 to 6.96) for subjects in the 4th quartile compared with the 1st quartile of HsCRP. This association remained significant after adjusting for study centre, age, sex, body weight, and smoking history (OR 2.19 (95% CI 1.04 to 4.63)). No significant relationship was observed between HsCRP and allergic asthma or bronchial responsiveness.

CONCLUSIONS

Raised levels of HsCRP are significantly associated with respiratory symptoms and non-allergic asthma but not with allergic asthma.