Elevated plasma adiponectin levels in patients with chronic obstructive pulmonary disease

BACKGROUND: Adiponectin is an anti-inflammatory adipokine that may play a role in chronic obstructive pulmonary disease (COPD) pathogenesis. OBJECTIVE: To investigate the relationship between adiponectin, interleukin (IL) 6, IL-8 and C-reactive protein (CRP) and COPD by evaluating these biomarkers in ever-smokers with or without the disease. METHOD: Plasma levels of adiponectin, IL-6, IL-8 and CRP were measured using commercially available kits in COPD patients (n = 71), healthy ever-smokers (n = 62) and non-smokers (n = 51). RESULTS: There were significant increases in plasma adiponectin, IL-6 and CRP in COPD patients (median [IQR] 4.39 μg/ml [2.68-6.98], 4.19 pg/ml [<2.40-6.40], 8.75 mg/l [4.26-40.63], respectively) compared to healthy ever-smokers (1.90 μg/ml [0.86-2.86], <2.40 pg/ml [<2.40-2.77], 3.71 mg/l [1.97-10.37 mg/l], respectively, P < 0.001) and non-smokers (1.76 μg/ml [1.34-2.52], <2.40 pg/ml [<2.40-2.78], 3.12 mg/l [2.11-5.71], respectively, P < 0.001). COPD patients had lower plasma IL-8 levels than healthy ever-smokers. Among ever-smokers with or without COPD, plasma adiponectin, IL-6 and CRP levels were inversely correlated with forced expiratory volume in 1 second (% predicted) after adjustment for age, body mass index, smoking status and pack-years. CONCLUSION: Our findings suggest that in COPD patients, adiponectin might be associated with COPD pathogenesis. © 2010 The Union.postprin

Reactive oxidant species in asthma

PURPOSE OF REVIEW: This overview summarizes some recent studies on the balance of oxidants to antioxidants in patients with asthma. The aim of the review is to compare studies on the changes in oxidants/antioxidants in stable asthma or in acute exacerbation of asthma. RECENT FINDINGS: Our review of the recent literature in this field seems to indicate conflicting findings. Increased release of reactive oxygen species such as superoxide anion and hydrogen peroxide has been reported in exhaled breath condensates and from circulating granulocytes, and from the bronchoalveolar lavage cells of patients with asthma. In asthma, bronchial obstruction is associated with an increased spontaneous and stimulus-induced production of oxygen free radicals. The primary defense against reactive oxygen species is endogenous antioxidants, which are found to be altered in asthma. A marked decrease in plasma antioxidant capacity occurs. Superoxide dismutase activity is higher in erythrocytes and serum of asthmatic than in normal subjects and is diminished in cells from lavage and brushing samples of patients with asthma. Higher level of erythrocyte catalase activity has only been found in Chinese asthmatic patients while decreased glutathione peroxidase activity has been well documented. SUMMARY: Since there are considerable discrepancies in erythrocyte or plasma antioxidant enzyme activity in patients with asthma, the problem at this time is attempting to sort out these conflicting results and to find their roles in the pathogenesis of asthma. There is good evidence that antioxidant compounds may have a potential role in the treatment of asthma, especially of asthma exacerbation. © 2006 Lippincott Williams & Wilkins.link_to_subscribed_fulltex

Use of a food frequency questionnaire on Chinese diet to assess antioxidant status in individuals with asthma

It has been suggested that dietary antioxidants have a protective role in asthma. However, validated dietary questionnaires have mostly been carried out in the western populations. In this study we investigated: 1) the relationship between dietary intake of carotene and vitamin E as well as their plasma levels in asthmatic patients and healthy subjects; and 2) the validity of a food frequency questionnaire (FFQ) by comparing dietary intake with plasma levels in the Chinese population. A case-control study was carried out on 39 asthmatic patients and 33 healthy subjects. Dietary data of carotene and vitamin E were obtained by a FFQ. β-Carotene and α-tocopherol in plasma were also measured. Significant positive correlations were found between plasma β-carotene levels and carotene intake as well as between plasma α-tocopherol levels and vitamin E intake. No differences in antioxidant intake and their plasma levels were seen between asthmatic patients and controls. Our study supports the validity of FFQs use in nutrient assessments in the Chinese population. © 2004 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex

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Polymorphisms in manganese superoxide dismutase and catalase genes: Functional study in Hong Kong Chinese asthma patients

Background: Reactive oxygen species may contribute to the pathogenesis of asthma. Functional genetic polymorphisms of antioxidant enzymes, superoxide dismutase (SOD) and catalase are good candidates for asthma susceptibility. Objective: To investigate the association of the manganese-containing form of SOD (MnSOD) gene at amino acid position 16 (Val16Ala) and catalase gene in the promoter at A-21T and C-262T polymorphisms and asthma in a Hong Kong Chinese population. Methods: The association study was conducted in a case-control design in asthma patients (n=251) and healthy controls (n=316) by genotyping. The functional significance was assessed by determining erythrocyte SOD and catalase activity. Results: The Val allele of MnSOD at Val16Ala and the A allele of catalase gene at A-21T were not different between patients and controls, while the C allele of catalase gene at C-262T was found to be significantly different between patients and controls (P=0.033). The less frequent variant of catalase gene (-262T) was found to be protective from the development of asthma in a Hong Kong Chinese non-smoking population (adjusted odds ratio=0.35, 0.15-0.85; P=0.017). Asthma patients had elevated erythrocyte SOD and catalase activities in comparison with healthy controls (P<0.01). However, their activities were not associated with different genotypes within healthy controls or asthma patients. Conclusion: This is the first report showing that SOD and catalase functional activities are not associated with their respective genetic polymorphisms but related to the presence of asthma in a Hong Kong Chinese population. © 2006 Blackwell Publishing Ltd.link_to_subscribed_fulltex

Reference values of diffusing capacity of non-smoking Chinese in Hong Kong

Background and objective: This study was conducted to define normal reference values and lower limits of normal (LLN) for single-breath carbon monoxide diffusing capacity (DLco) and DLco per unit of alveolar volume (Kco) for Chinese adults in Hong Kong. Methods: Healthy non-smoking men and women aged 18-80 years were recruited by random digit dialling. DLco and Kco were measured according to American Thoracic Society standards. Reference equations were obtained by multiple linear regression; LLN were derived by distribution-free method for estimation of age-related centiles. Results: Tests from 568 subjects (259 men, 309 women) were analysed. DLco declined with age in both genders, and increased with height and the interaction term of height and age in men and women, respectively. Considering Hb values did not improve the reference equations. Kco declined with age and increased with weight in both genders, while height and its interaction term with age were additional determinants in women. The reference DLco was lower than some Caucasian values, and was only explained partially by a smaller body size and alveolar volume in Chinese. The distribution-free method yielded better overall approximation to the fifth percentile compared with the traditional method of determining LLN. Conclusions: The equations for reference values and LLN of diffusing capacity derived in this study are of clinical relevance to Chinese subjects. © 2007 The Authors.link_to_subscribed_fulltex

Analysis of TGF-β1 gene polymorphisms in Hong Kong Chinese patients with asthma

Background: The C-509T polymorphism of TGF-β1 gene has been associated with asthma and atopy in white populations. Objective: We investigated the association between asthma and previously identified polymorphisms at C-509T and T869C of the TGF-β1 gene among 250 Chinese patients with asthma and 308 healthy controls in Hong Kong. Methods: Genotyping was performed on peripheral blood genomic DNA by using PCR-RFLP. Results: There were no differences in the frequencies of genotypes and alleles between patients and controls. The C-509T and T869C polymorphisms were in tight linkage disequilibrium (P < .01). Among atopic subjects, significant differences were found in genotype and allele frequencies for T869C polymorphism between patients and controls (P = .014 and P = .019, respectively), and individuals bearing the CC genotype were associated with increased risk for the development of asthma (odds ratio, 2.58; 95% CI, 1.17-5.66; P = .018) after adjusting for age, sex, and smoking status. Individuals with asthma bearing the CT genotype of the C-509T polymorphism had significantly increased risk for severe airflow obstruction compared with individuals who had mild obstruction (odds ratio, 4.00; 95% CI, 1.06-15.08; P = .035). Conclusion: Our results indicate that the polymorphisms at C-509T and T869C of the TGF- β1 gene are associated with asthma susceptibility in atopic subjects of the Hong Kong Chinese population, and the C-509T polymorphism may play a role in the pathogenesis of airflow obstruction. © 2005 American Academy of Allergy, Asthma and Immunology.link_to_subscribed_fulltex

FEV 3, FEV 6 and their derivatives for detecting airflow obstruction in adult Chinese

BACKGROUND: Forced expiratory volume in 3 seconds (FEV 3) and 6 seconds (FEV 6) could complement FEV 1and forced vital capacity (FVC) for detecting airflow obstruction. OBJECTIVE: To compare FEV 1/FEV 6 and FEV 3/FVC with FEV 1/FVC in the detection of airflow obstruction. METHOD: Previous lung function data were re-analysed to establish reference values for FEV 3 and FEV 6. Data from a separate cohort of male smokers were used as test set. FEV 1, FEV 3, FEV 6, FVC, FEV 1/FVC, FEV 1/FEV 6 and FEV 3/FVC were regressed against age, standing height, weight and body mass index, and the mean and 95% confidence intervals for the lower limit of normal (LLN) values for these parameters were determined. RESULTS: The percentage of smokers with airflow obstruction in the test population using FEV 1/FVC < LLN was 15.0%, while using FEV 1/FEV 6 < LLN and FEV 3/FVC < LLN they were respectively 18.5% and 18.1%. Using FEV 1/FVC < LLN as reference, the sensitivity and specificity of FEV 1/FEV 6 < LLN in identifying airflow obstruction were 82.3% and 92.8%, while those for FEV 3/FVC < LLN were 78.5% and 92.6%; the positive and negative predictive values were 67% and 96.7% for FEV 1/FEV 6 < LLN and 65.3% and 96% for FEV 3/FVC < LLN. CONCLUSION: FEV 3/FVC < LLN and FEV 1/FEV 6 < LLN are comparable to FEV 1/FVC < LLN for detecting airflow obstruction. FEV 3/FVC < LLN could be useful in screening for airflow obstruction, while FEV 1/FEV 6 < LLN is useful in detecting airflow limitation in the elderly or in subjects with severe airflow obstruction. © 2012 The Union.link_to_OA_fulltex