Effects of occupational exposure to dust, gas, vapor and fumes on chronic bronchitis and lung function.

Background: Chronic obstructive pulmonary disease (COPD) is one of the leading causes of mortality worldwide, and therefore the identification of the modifiable risk factors [such as exposure to vapors, gases, dust and fumes (VGDF)] for accelerate disease progression has important significance. Methods: We conducted COPD surveillance in six cities of southern China between 2014 and 2019. We recorded the diagnosis of chronic bronchitis, respiratory symptoms, occupational exposure to VGDF and other covariates by using a structured questionnaire. Logistic regression and multivariate linear regression model were adopted for analysis. We performed sensitivity analyses based on two methods of propensity score (PS) methods to evaluate the robustness of our results. Results: A total of 7,418 participants were included. Cough [odds ratios (ORs): 1.60, 95% confidence interval (CI): 1.22 to 2.08] and phlegm (OR: 1.49, 95% CI: 1.19 to 1.85) correlated significantly with exposure to dust. There was an increased risk of cough (OR: 1.53, 95% CI: 1.11 to 2.07) for occupational exposure to gas/vapor/fume. Dual exposure to dust and gas/vapor/fume was associated with a significantly increased risk of chronic bronchitis (OR: 1.74, 95% CI: 1.20 to 2.52), cough (OR: 1.43, 95% CI: 1.15 to 1.79) and phlegm (OR: 1.49, 95% CI: 1.24 to 1.79). In 5,249 participants with complete data of spirometry, gas/vapor/fume was associated with a decreased ratio of forced expiratory volume in one second and forced vital capacity (FEV1/FVC) (ß: -1.05, 95% CI: -1.85 to -0.26) and maximal mid-expiratory flow (MMEF) (ß: -0.15, 95% CI: -0.23 to -0.07). Dual exposure to dust and gas/vapor/fume was significantly associated with decreased FEV1/FVC (ß: -0.74, 95% CI: -1.28 to -0.20) and MMEF (ß: -0.06, 95% CI: -0.12 to -0.01). Results of sensitivity analysis were not materially changed. Conclusions: VGDF exposure is associated with chronic bronchitis, respiratory symptoms and decreased lung function, suggesting that VGDF contributes to the pathogenesis and progression of COPD.

[Association between early-life factors and pubertal timing in girls]. / ç”Ÿå‘½æ—©æœŸå› ç´ ä¸Žå¥³ç”Ÿé’æ˜¥å‘åŠ¨æ—¶ç›¸çš„å ³è”åˆ†æž.

OBJECTIVES: To study the association between early-life factors (including birth weight, method of birth, gestational age, and history of gestational metabolic disorders) and pubertal timing in girls. METHODS: The stratified cluster sampling method was used to select the girls in grades 2-3 and 7-8 from three primary schools and three middle schools in Guangzhou, China from March to December, 2019, and breast development was examined for all girls. A questionnaire survey was performed to collect the information on early-life factors. The multivariate logistic regression model was used to evaluate the association of gestational metabolic disorders, birth weight, method of birth, and gestational age with pubertal timing in girls. The Bootstrap method was used to assess the mediation effect of body mass index (BMI) (Z score) between high birth weight (≥4 000 g) and pubertal timing. RESULTS: A total of 1 665 girls were enrolled, among whom 280 (16.82%) were judged to have early pubertal timing. The multivariate logistic regression analysis showed that high birth weight was associated with the increased risk of early pubertal timing (OR=2.12, 95%CI: 1.19-3.66, P=0.008). Nevertheless, no significant association was observed between other early-life factors and pubertal timing (P>0.05). The OR for the mediation effect of BMI (Z score) between high birth weight and early pubertal timing was 1.25 (95%CI: 1.09-1.47), accounting for 29.33% of the total effect of high birth weight on early pubertal timing. CONCLUSIONS: High birth weight is associated with the increased risk of early pubertal timing in girls, and overweight/obesity may play a partial mediating role in the association between high birth weight and early pubertal timing in girls.

Impact of polluting fuels for cooking on diabetes mellitus and glucose metabolism in south urban China.

We hypothesized that exposure to polluting fuels for cooking was associated with abnormality of glucose metabolism and diabetes mellitus (DM) in south urban China. 3414 residents were surveyed in 14 urban areas of Guangdong Province in 2018. We recorded polluting fuels for cooking exposure, different DM status (DM, prediabetes), fasting blood glucose (FBG), oral glucose tolerance test (OGTT), glycated hemoglobin (HbA1c ), and other covariates by using a structured questionnaire. We conducted logistic regression model and multivariate linear regression model based on propensity-score method (inverse probability of weighting) to examine the effect of polluting fuels for cooking exposure on DM and glucose metabolism. Exposure to polluting fuels for cooking was associated with DM (odds ratio: 2.57, 95% confidence interval: 1.71 to 3.86) and prediabetes (odds ratio: 1.98, 95% confidence interval: 1.52 to 2.58) in both the adjusted and unadjusted models (all p < 0.05). Exposure to polluting fuels for cooking was significantly associated with an increase of FBG (ß: 0.30 mmol/L, 95% confidence interval: 0.22 to 0.38 mmol/L). Sensitivity analysis showed that the results were not substantially changed. There was an increased risk of DM, prediabetes and high levels of FBG, OGTT, and HbA1c among participants aged ≥ 40 years with exposure to polluting fuels for cooking. We demonstrated that exposure to polluting fuels for cooking was associated with higher levels of FBG, which contributed to the increased risk of DM and prediabetes in middle-aged elderly Chinese population living in urban areas.