Prevalence and risk factors of chronic obstructive pulmonary diseases in a Hlai community in Hainan Island of China.

OBJECTIVES: We investigated prevalence and risk factors of chronic obstructive pulmonary disease (COPD) in a population of Hlai (the Li) ethnicity, a major minority, in Qicha Town, Changjiang County, Hainan Province, PRC, during 2014. METHODS: All residents at the age of 40 years or older were interviewed with standardized questionnaires. Spirometry was performed to measure the possible airflow limitation. According to the GOLD criteria, post bronchodilator FEV1/FVC < 70% was defined as COPD. Case-control study was used to screen the risk factors by analyzing COPD group (212 cases) and non-COPD control group (236 cases). Single factor analysis and multiple factor logistic regression analysis were used as statistical methods. RESULTS: The prevalence of COPD in the residents at the age of 40 years or older of Hlai community was 5.07% (286/5637) (95% CI = 0.045-0.057). In the logistic regression analysis, the COPD prevalence was 5.07% (147/2901) in men and 5.08% (139/2736) in women, respectively, with odds ratio (OR) 1.003, 95% CI 0.790-1.272 and P > 0.05, suggesting that the sex did not affect the COPD prevalence in the investigated samples, but age (OR = 1.096), expectoration (OR = 87.917), locomotor activity limitation (OR = 3.908) and frequency of respiration (OR = 2.512) were risk factors and associated with the development of COPD. Notably, although the tobacco smoker in male and female COPD patients were 48.6% (54/111) and 4.0% (4/101), respectively, passive smokers in female with COPD were 45.6% (46/101). CONCLUSION: In the Hlai population aged ≥40 years, the COPD prevalence was 5.07%. Smoking, age, expectoration, locomotor activity limitation and frequency of respiration were risk factors of COPD in Hlai ethnicity.

Association between RTEL1 gene polymorphisms and COPD susceptibility in a Chinese Han population.

OBJECTIVE: We investigated the association between single-nucleotide polymorphisms in regulation of telomere elongation helicase 1 (RTEL1), which has been associated with telomere length in several brain cancers and age-related diseases, and the risk of chronic obstructive pulmonary disease (COPD) in a Chinese Han population. METHODS: In a case-control study that included 279 COPD cases and 290 healthy controls, five single-nucleotide polymorphisms in RTEL1 were selected and genotyped using the Sequenom MassARRAY platform. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression after adjusting for age and gender. RESULTS: In the genotype model analysis, we determined that rs4809324 polymorphism had a decreased effect on the risk of COPD (CC versus TT: OR =0.28; 95% CI =0.10-0.82; P=0.02). In the genetic model analysis, we found that the "C/C" genotype of rs4809324 was associated with a decreased risk of COPD based on the codominant model (OR =0.33; 95% CI =0.13-0.86; P=0.022) and recessive model (OR =0.32; 95% CI =0.12-0.80; P=0.009). CONCLUSION: Our data shed new light on the association between genetic polymorphisms of RTEL1 and COPD susceptibility in the Chinese Han population.

The analyses of risk factors for COPD in the Li ethnic group in Hainan, People's Republic of China.

OBJECTIVE: To study the risk factors for chronic obstructive pulmonary disease (COPD) in Li population in Hainan province, People's Republic of China. METHODS: Li people above 40 years of age from Hainan were chosen by stratified random cluster sampling between 2012 and 2014. All participants were interviewed with a home-visiting questionnaire, and spirometry was performed on all eligible participants. Patients with airflow limitation (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] <0.70) were further examined by postbronchodilator spirometry, and those with a postbronchodilator FEV1/FVC <0.70 was diagnosed with COPD. The information of physical condition and history, smoking intensity, smoking duration, second-hand smoking, education, job category, monthly household income, working years, residential environment, primary fuel for cooking and heating (biomass fuel including wood, crop residues, dung, and charcoal, or modern fuel such as natural gas, liquefied petroleum gas, electricity, and solar energy), ventilated kitchen, heating methods, air pollution, recurrent respiratory infections, family history of respiratory diseases, cough incentives, and allergies of COPD and non-COPD subjects was analyzed by univariate and multivariate logistic regression models to identify correlated risk factors for COPD. RESULTS: Out of the 5,463 Li participants, a total of 277 COPD cases were identified by spirometry, and 307 healthy subjects were randomly selected as controls. Univariate logistic regression analyses showed that older people (65 years and above), low body mass index (BMI), biomass smoke, 11-20 and >20 cigarettes/day, smoking for 40 years or more, second-hand smoking, recurrent respiratory infections, and induced cough were risk factors for COPD, whereas high BMI, high education level, and presence of ventilated kitchen were protective factors. Subsequent multivariate logistic regression model further demonstrated that aging, low BMI, biomass smoke, >20 cigarettes/day, and recurrent respiratory tract infections were high-risk factors for COPD in the Li population. CONCLUSION: The incidence of COPD has a strong correlation with age, BMI, biomass smoke, >20 cigarettes/day, and recurrent respiratory infections, suggesting they were high-risk factors for COPD in Li population.