Global health impacts of ambient fine particulate pollution associated with climate variability.

Air pollution is a key global environmental problem raising human health concern. It is essential to comprehensively assess the long-term characteristics of air pollution and the resultant health impacts. We first assessed the global trends of fine particulate matter (PM2.5) during 1980-2020 using a monthly global PM2.5 reanalysis dataset, and evaluated their association with three types of climate variability including El Niño-Southern Oscillation, Indian Ocean Dipole and North Atlantic Oscillation. We then estimated PM2.5-attributable premature deaths using integrated exposure-response functions. Results show a significant increasing trend of ambient PM2.5 during 1980-2020 due to increases in anthropogenic emissions. Ambient PM2.5 caused a total of âˆ¼ 135 million premature deaths globally during the four decades. Occurrence of air pollution episodes was strongly associated with climate variability, which were associated with up to 14 % increase in annual global PM2.5-attributable premature deaths.

[Studies on clinicopathological features of duodenal-type follicular lymphoma of 18 patients].

To investigate the clinical and pathological characteristics of duodenal-type follicular lymphoma (D-FL), and to deepen the understanding of Duodenal-type follicular lymphoma. The clinical symptoms, endoscopic features, pathologic features, immunophenotype, molecular pathological features and treatment follow-up of 18 D-FL patients diagnosed in Department of Pathology, Beijing Tiantan Hospital affiliated to Capital Medical University between January 2020 and July 2023 were summarized. A total of 18 patients with D-FL were included, including 10 males and 8 females. The median age was 49 (32-69) years respectively. Most of the patients were found during gastroenteroscopy or presented with the common gastrointestinal symptoms of stomach pain, acid reflux, vomiting and diarrhea. Most endoscopic findings were multiple small gray and white polyposis. In the pathological morphology, the mucous layer and submucous layer showed lymphoid follicular structures with full and strained follicles. The immunophenotype showed that the tumor cells strongly expressed CD20 and BCL2 and had low proliferation activity. Immunoglobulin clonal analysis of 1 case showed IgK monoclonal rearrangement (1/1). FISH showed 1 case of BCL2 gene rearrangement (1/3). All patients did not receive targeted chemotherapy and adopted a wait-and-see strategy. Median follow-up was 12 (2-34) months. This study shows that D-FL is an indolent lymphoma, which tends to occur in the duodenum and has a good prognosis.

[Imaging and cerebrospinal fluid features of two cases with lymphomatosis cerebri].

This article reported the clinical experience of diagnosis and treatment for two patients with lymphomatosis cerebri. Case 1 was female and aged 53 years old, while case 2 was male and aged 69 years old. Progressive cognitive impairment was the main clinical manifestation in both patients. Brain magnetic resonance imaging (MRI) suggested leukoencephalopathy with patchy or mass enhancement. Cerebral blood flow was reduced on perfusion imaging in one patient. Brain biopsy confirmed diffuse large B-cell lymphoma in both cases. The concentration of interleukin-10 in cerebrospinal fluid (CSF) of two patients was significantly increased, however, the result of CSF flow cytology was negative. The current study suggests that interleukin-10 in CSF is an important biological indicator for the diagnosis of lymphomatosis cerebri, but CSF flow cytometry may not be helpful. Moreover, cerebral hypoperfusion can be present in patients with lymphomatosis cerebri.

[The outcomes of Tiantan first-aid protocol on critically ill patients with primary central nervous system lymphoma].

Objective: To examine the outcomes of Tiantan first-aid protocol on critically ill patients with primary central nervous system lymphoma (PCNSL). Methods: The clinical data of 18 patients with PCNSL who were treated according to Tiantan first-aid protocol at Department of Neurosurgery,Beijing Tiantan Hospital, Capital Medical University from November 2019 to December 2021 were retrospectively analyzed. There were 9 males and 9 females, aged (56.9±11.1)years (range: 29 to 77 years). The median Karnofsky performance status(KPS) score at admission was 40 (range: 20 to 60). Three patients were mild coma, 3 were lethargy and 12 were conscious. The mean midline shift was 0.7 cm (range: 0 to 1.8 cm). After admission, all patients were treated according to the plan of rapid biopsy, rapid routine pathology and rapid salvage chemotherapy. The treatment procedures, clinical and radiographic outcomes, KPS score and adverse reactions of patients after chemotherapy were collected. Results: All of the 18 patients completed the first-aid treatment. The median duration from admission to the biopsy was 1 day (range: 0 to 5 days), from biopsy to routine pathological diagnosis was 1 day (range: 1 to 4 days) and from routine pathology to salvage chemotherapy was 1 day (range: 0 to 4 days). All the patients were pathologically confirmed with diffuse large B cell lymphoma, 1 patient was double-hit lymphoma. Seventeen patients underwent clinical remission and 1 died of cardiac dysfunction. The successful salvage rate was 17/18. Radiologically, complete remission was observed in 1 case, partial remission in 16 cases, and stable disease in 1 case. The median KPS score at discharge was 60 (range: 30 to 80). The mild gastrointestinal, hematological and hepatic adverse effects were observed after chemotherapy. Conclusion: Tiantan first-aid protocol is effective for critically ill patients with PCNSL, which has the merit to be popularly used and improved.

[Relationship between binaural high-frequency mean hearing threshold and hypertension in female worker exposed to noise].

Objective: To explore the relationship between the binaural high-frequency mean hearing threshold and the hypertension of female workers exposed to noise, and to understand the application significance of the binaural high-frequency mean hearing threshold as an internal effect indicator of the risk of hypertension in female workers exposed to noise. Methods: From January to December 2018, a total of 20882 female workers exposed to noise in Guangzhou were selected by cluster sampling. Pure tone audiometry, blood pressure, age and length of service were collected. Trend test was used to evaluate the effects of exposure to noise and binaural high-frequency mean hearing threshold on blood pressure. Binary logistic regression model was used to evaluate the risk of hypertension associated with exposure to noise and binaural high-frequency mean hearing threshold. Results: The detection rate of normal hearing threshold, mild hearing loss and severe hearing loss was 80.73% (16858/20882) , 16.21% (3384/20882) and 3.06% (640/20882) respectively. The prevalence of hypertension was 6.04% (1018/16858) in normal hearing group, 10.28% (348/3384) in patients with high frequency mild hearing loss, and 11.25% (72/640) in patients with high frequency severe hearing loss. There was a linear relationship between the increase of working age and high-frequency mean hearing threshold and the increase of systolic and diastolic blood pressure (P< 0.05) . Compared with those exposed to noise for less than 1 year, the risk of hypertension in female workers with 7-9 years and more than 9 years was decreased (OR= 0.79, 0.75, P<0.05) . Compared with normal hearing group, the risk of hypertension in high frequency mild hearing loss group was increased (OR=1.31, P<0.05) . Conclusion: The increase in the binaural high-frequency mean hearing threshold of female workers exposed to noise can increase the blood pressure level and the risk of hypertension, and attention should be paid to female workers with high-frequency mild hearing loss.

Mapping ozone source-receptor relationship and apportioning the health impact in the Pearl River Delta region using adjoint sensitivity analysis.

While fine particulate matters are decreasing in the Pearl River Delta (PRD) region, the regional ozone (O3) shows an increasing trend that affects human health, leading to an urgent need for scientific understanding of source-receptor relationship between O3 and its precursor emissions given the changing background composition. We advanced and applied an adjoint air quality model to map contributions of individual O3 precursor emission sources [nitrogen oxides (NOx) and volatile organic compound (VOC)] at each location to annual regional O3 concentrations and to identify the possible dominant influential pathways of emission sources to O3 at different spatiotemporal scales. Additionally, we introduced the novel adjoint sensitivity approach to assess the relationship between precursor emissions and O3-induced premature mortality. Adjoint results show that Shenzhen was a major source contributor to regional O3 throughout all seasons, of which 49.4% (3.8%) were from its NOx (VOC) emissions. Local emissions (within PRD) contributed to 83% of the regional O3 whereas only ~54% of the estimated ~4000 regional O3-induced premature mortalities. The discrepancy between these two contributions was because O3-induced mortalities are dependent on not only O3 concentration, but incident rate and population density. We also found that a city with low O3-induced mortalities could have significant emission contributions to health impact in the region since the transport pathways could be through transport of local O3 or through transport of O3 precursors that form regional O3 thereafter. It is therefore necessary to formulate emission control policies from both air quality and public health perspectives, and it is also critical to have better understanding of influential pathways of emission sources to O3.

Suppression of αvß6 downregulates P-glycoprotein and sensitizes multidrug-resistant breast cancer cells to anticancer drugs.

Multidrug resistance (MDR) in breast cancer treatment is the major cause leading to the failure of chemotherapy. P-glycoprotein (P-gp), the product of the human MDR1 gene, plays a key role in resistance to chemotherapy and confers cross-resistance to many structurally unrelated anticancer drugs. We have previously reported that integrin αvß6 plays a critical role in breast cancer invasion and metastasis. However, whether and how αvß6 is associated with P-gp and regulated by potential genetic mechanisms in breast cancer remains unclear. In the present study, we further investigated the reversal effect and underlying mechanisms of MDR in breast cancer. Two small interfering RNA constructs (pSUPER-ß6shRNAs) targeting two different regions of the ß6 gene have been designed to inhibit αvß6 expression by transfecting them into adriamycin-resistant MCF-7/ADR cell lines. Suppression of αvß6 dramatically downregulated the levels of MDR1 gene mRNA and P-gp. In particular, ß6shRNA-mediated silencing of αvß6 gene increased significantly the cellular accumulation of Rhodamine 123 and markedly decreased drug efflux ability, suggesting that ß6shRNAs indeed inhibit P-gp mediated drug efflux and effectively overcome drug resistance. In addition, inhibition of integrin αvß6 suppressed the expression of ERK1/2. Interestingly, our data demonstrate that suppression of integrin αvß6 caused significant downregulation of Bcl-2, Bcl-xL and upregulation of caspase 3, Bad, accompanied by increasing activity of cytochrome C. A possible connection between αvß6 and P-gp in drug resistance biology is suggested. Taken together, ß6shRNA could efficiently inhibit αvß6 and MDR1 expression in vitro and these findings may offer specifically useful means to reverse MDR in breast cancer therapy.

[A retrospective cohort study of long-term nitrogen dioxide exposure and incident hypertension].

Objective: To investigate the effect of long-term exposure of nitrogen dioxide on the incidence of hypertension. Methods: From March to December 2009, 37 386 eligible residents from four cities in northern China (Tianjin, Shenyang, Taiyuan, and Rizhao) were enrolled in a follow-up study by using the random cluster sampling method. Demographic characteristics, lifestyle, history of diseases, and self-report situation of hypertension were collected by using questionnaire. Based on the average annual concentration of NO2 during the period from the cohort to the onset of hypertension as an estimate of exposure, the effect of NO2 exposure on hypertension was analyzed by employing Cox proportional hazards model. The interactions between NO2 exposure and different characteristics (age, sex, body mass index, smoking, alcohol consumption, education, economy, exercise, and fruit intake) were also examined. Results: The baseline age of residents was (43.74±13.78) years, and the body mass index (BMI) was (22.56±2.92) kg/m(2). During an average follow-up time of 11.40 years, 2 619 (7.0%) new cases of hypertension were reported. The overall mean environmental pollution levels during the study period for the entire cohort was (40.74±17.07) µg/m(3). After adjusting for age, sex, BMI, family history of hypertension, socio-economic information, and lifestyle, the hazard ratio (HR) of incident hypertension with a 10 µg/m(3) increase of NO2 was 1.21 (95%CI: 1.18-1.25). Compared with residents aged 60 years and over (HR=1.19, 95%CI: 1.14-1.26), former and current smoking (HR=1.20, 95%CI: 1.14-1.25), and high-frequency fruit consumption (HR=1.17, 95%CI: 1.13-1.21), residents younger than 60 years (HR=1.28, 95%CI: 1.25-1.32), non-smoker (HR=1.23, 95%CI: 1.19-1.27), and low-frequency fruit consumption (HR=1.27, 95%CI: 1.20-1.35) had stronger interaction effect with NO2 (all P values for interaction<0.05). Conclusion: NO2 exposure may lead to the onset of hypertension, which has a stronger effect on people younger than 60 years old, without smoking history and with low-frequency fruit consumption.

[The study on the association of long-term ambient fine particulate matters exposure and elevated blood pressure in children].

Objective: To evaluate the association of long-term ambient fine particulate matters (PM(2.5)) exposure with elevated blood pressure in children. Methods: From April 2012 to June 2013, we used cluster randomized sampling method to investigate 9 354 children aged 5-17 years old from 68 primary and middle schools in the seven Northeastern Cities (Shenyang, Dalian, Fushun, Anshan, Benxi, Liaoyang and Dandong) in Liaoning Province, and measured their blood pressure (BP). A spatial statistical model nested by aerosol optical depth (AOD) was used to inverse PM(2.5) concentrations. Generalized additive model was used to quantify the association between PM(2.5) exposure and blood pressure in children. To examine the associations, two-level regression model was used to evaluate individual characteristics' modifying effect on the health influence of PM(2.5). Results: The prevalence of hypertension in children was 13.78% (1 289/9 354). The results showed that there was an associations between hypertension and pollutants, and the multivariable regression analysis indicated that the increase in mean systolic blood pressure (SBP), diastolic blood pressure (DBP), and the OR of hypertension associated with a 10 µg/m(3) increase for PM(2).5 were 3.12 (95%CI: 2.71-3.54) mmHg (1 mmHg=0.133 kPa), 1.45 (95%CI:1.12-1.78) mmHg, and 1.55 (95%CI: 1.10-2.19), respectively. Compared with non-breastfeeding children (OR=2.10, 95%CI: 1.39-3.17), children who were breastfeeding (OR=1.49, 95%CI: 1.00-2.20) exhibited consistently weaker effects, and the interaction effect of P value was 0.002. Conclusion: Study findings indicate that long-term exposure to PM(2.5) is associated with increased arterial BP and hypertension among the children. Breastfeeding may reduce this association.

[Value of PET/CT in the prognosis of extranodal NK/T cell lymphoma].

Objective: To explore the value of Positron-Emission Tomography/Computed Tomography (PET/CT) in the prognosis of extranodal NK/T cell lymphoma. Methods: The patients of NK/T cell lymphoma diagnosed from January 2007 to July 2016 in Department of Pathology of Beijing Tongren Hospital were enrolled in this study. Seventy-two in-hospital patients were examined on the invasion of adjecent tissue or organ by PET/CT. The PET/CT results were analyzed retrospectively. Kaplan-Meier method was used to analyze the prognostic value of the positive results by PET/CT on overall survival (OS). Results: There were 54 males and 18 females with median age of 44.5 years (13-75 years). According to Ann Arbor staging system, there were 16 cases (22.2%) in stage Ⅰ, 29 cases (40.3%) in stage Ⅱ, 6 cases (8.3%) in stage Ⅲ and 21 cases (29.2%) in stage Ⅳ. According to the IPI scoring system, there were 34 cases (47.2%) in the low risk group (0-1 point), 21 cases (29.2%) in the low-middle risk group (2 points), 16 cases (22.2%) in the middle-high risk group (3 points), and 1 case (1.4%) in the high risk group (4-5 points) . The median follow-up time was 29.2 months (1-118 months). The disease occured in unilateral nasal cavity in 26 cases (36.1%), bilateral nasal cavities in 36 cases (50.0%), nasopharynx, oropharynx and pharynx in 10 cases (13.9%). The tumors of 51 cases involved the surrounding tissue, including nasal wings in 29 cases (40.3%), nasal sinus in 29 cases (40.3%), maxillofacial soft tissue in 18 cases (25.0%), orbital in 12 cases (16.7%), maxilla and skull base in 8 cases (11.1%), eyelid in 6 cases (8.3%), brain tissue in 3 cases (4.2%), eyeball in 2 cases (2.8%). In addition, cervical and inguinal lymphadenopathy were found in 54 cases (75.0%) . Splenomegaly and hepatomegaly were found in 10 cases (13.9%) and 2 cases (2.8%), respectively. Survival analysis showed that the clinical stage and IPI were significantly associated the clinical prognosis (P=0.000, 0.001, respectively). Involvement of the maxillofacial soft tissue, eyelid, orbital, maxilla and skull base and brain tissue were significantly related to reduced the overall survival time (P=0.006, 0.000, 0.024, 0.001 and 0.015, respectively). Involvement of palate or tonsil, the nosewingand nasal sinus did not show significant shorter overall survival (P=0.091, 0.063, and 0.139, respectively). Cox regression multivariate analysis showed maxilla and skull base involvement was independent adverse prognostic factor (P=0.047). Conclusions: The PET/CT examination can accurately detect the extent of adjacent and distant tissues of tumor involvement of NK/T cell lymphoma by showing the tumor structure and metabolic status, thus has important value in the clinical staging and prognosis predication.

Vector Form of Symmetry Degree.

ABSRACT: Symmetry degree is utilized to characterize the asymmetry of a physical system with respect to a symmetry group. The scalar form of symmetry degree (SSD) based on Frobenius-norm has been introduced recently to present a quantitative description of symmetry. Here we present the vector form of the symmetry degree (VSD) which possesses more advantages than the SSD. Mathematically, the dimension of VSD is defined as the conjugacy class number of the symmetry group, the square length of the VSD gives rise to the SSD and the direction of VSD is determined by the orders of the conjugacy classes. The merits of applying VSD both for finite and infinite symmetry groups include the additional information of broken symmetry operators with single symmetry breaking perturbation, and the capability of distinguishing distinct symmetry breaking perturbations which exactly give rise to degenerate SSD. Additionally, the VSD for physical systems under symmetry breaking perturbations can be regarded as a projection of the initial VSD without any symmetry breaking perturbations, which can be described by an evolution equation. There are the same advantages by applying VSD for the accidental degeneracy and spontaneous symmetry breaking.

Pre-natal and post-natal exposure to pet ownership and lung function in children: The Seven Northeastern Cities Study.

To evaluate the association between pre-natal and post-natal exposure to pet ownership and lung function in children, a cross-sectional study named Seven Northeastern Cities (SNEC) study was conducted. In this study, children's lung function including the forced expiratory volume in 1 second (FEV1 ), forced vital capacity (FVC), maximal mid-expiratory flow (MMEF), and peak expiratory flow (PEF) were measured by spirometers, and pet ownership situations were collected by questionnaire. Analyzed by multiple logistic regression and generalized linear modeling, we found that for all subjects, pet exposure in the first 2 years of life was significantly associated with lung function impairment of FVC<85% predicted (adjusted odds ratio [aOR]=1.28; 95% confidence interval [CI]: 1.01, 1.63). For current pet exposure, the increased odds of lung function impairment ranged from 35% (aOR=1.35; 95%CI: 1.12, 1.62) for FVC<85% predicted to 57% (aOR=1.57; 95%CI: 1.29, 1.93) for FEV1 <85% predicted. The in utero exposure was not related to lung function impairment. Compared with other pets, higher odds were observed among children with dogs. When stratified by gender, girls with current pet exposure were more likely to have lung function impairment than boys. It implies self-reported exposures to pets were negatively associated with lung function among the children under study.

Frobenius-norm-based measures of quantum coherence and asymmetry.

We formulate the Frobenius-norm-based measures for quantum coherence and asymmetry respectively. In contrast to the resource theory of coherence and asymmetry, we construct a natural measure of quantum coherence inspired from optical coherence theory while the group theoretical approach is employed to quantify the asymmetry of quantum states. Besides their simple structures and explicit physical meanings, we observe that these quantities are intimately related to the purity (or linear entropy) of the corresponding quantum states. Remarkably, we demonstrate that the proposed coherence quantifier is not only a measure of mixedness, but also an intrinsic (basis-independent) quantification of quantum coherence contained in quantum states, which can also be viewed as a normalized version of Brukner-Zeilinger invariant information. In our context, the asymmetry of N-qubit quantum systems is considered under local independent and collective transformations. In- triguingly, it is illustrated that the collective effect has a significant impact on the asymmetry measure, and quantum correlation between subsystems plays a non-negligible role in this circumstance.

Breastfeeding modifies the effects of environment tobacco smoke exposure on respiratory diseases and symptoms in Chinese children: the Seven Northeast Cities Study.

To evaluate the potential effect of interaction between breastfeeding and environmental tobacco smoke (ETS) exposure on respiratory health, we studied 31 049 children (aged 2-14 years) from 25 districts of seven cities in northeast China. Parents of the children completed standardized questionnaires that characterized the children's histories of respiratory symptoms and illness, feeding methods, ETS exposure, and other associated risk factors. Breastfeeding was defined as having been mainly breastfed for 3 months or more. The results showed that the association of ETS exposure with childhood respiratory conditions/diseases was modified by breastfeeding, and the association for nonbreastfed children was stronger than that for breastfed children. In particular, for nonbreastfed children, the odds ratios (ORs) for the effect of current ETS exposure asthma was 1.71 (95% CI: 1.43-2.05); however, the OR for breastfed children was 1.33 (95% CI: 1.20-1.48), indicating that the interactions between breastfeeding and current ETS exposure on asthma were statistically significant (P = 0.019). When stratified by school (kindergarten vs. elementary school), breastfeeding was more protective for asthma-related symptoms among children from kindergarten. In conclusion, this study shows that breastfeeding is associated with smaller associations between ETS exposure and respiratory conditions in children, suggesting that breastfeeding reduces susceptibility to the respiratory effects of ETS.

Epidemiology of elevated blood pressure and associated risk factors in Chinese children: the SNEC study.

Despite the association of childhood blood pressure (BP) with hypertension later in the life course, there remains dearth of information regarding the prevalence and emergence of hypertension in children, especially in China. To investigate the current status of BP, prevalence of elevated BP and related factors in Chinese children, a cross-sectional survey in a representative sample of 9354 Chinese children 5-17 years old was conducted in seven cities in Northeastern China during 2011 and 2012. BP measurements were taken by mercury sphygmomanometer. Elevated BP in children was defined as an average diastolic BP or systolic BP that is in the 95th percentile or higher for their gender, age and height. Overall, total prevalence of elevated BP was 13.8%, and no significant difference between males and females was identified. Multivariate analyses revealed that children having a higher area of residence had a lower of elevated BP. Increased odds for elevated BP were found for individuals who were lean (odds ratio (OR)=2.12; 95% confidence interval (CI): 1.67-2.69), overweight (OR=2.05; 95% CI: 1.74-2.42), obese (OR=3.15; 95% CI: 2.70-3.68), were born with low birth weight (OR=1.26; 95%CI: 1.01-1.63), premature birth (OR=1.46; 95%CI: 1.13-1.88), and were with home coal use (OR=1.24; 95%CI: 1.02-1.52). In conclusion, elevated BP was found to be prevalent in children in urban areas of Northeast China. These results underscore the importance of implementing a package of measures aimed at reducing malleable risk for this cardiovascular condition in school-aged children in Northeast China.

Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 B.P.

Our understanding of when and how humans adapted to living on the Tibetan Plateau at altitudes above 2000 to 3000 meters has been constrained by a paucity of archaeological data. Here we report data sets from the northeastern Tibetan Plateau indicating that the first villages were established only by 5200 calendar years before the present (cal yr B.P.). Using these data, we tested the hypothesis that a novel agropastoral economy facilitated year-round living at higher altitudes since 3600 cal yr B.P. This successful subsistence strategy facilitated the adaptation of farmers-herders to the challenges of global temperature decline during the late Holocene.

Environmental tobacco smoke exposure, urine CC-16 levels, and asthma outcomes among Chinese children.

BACKGROUND: Previous studies have shown the relationship between club cell secretory protein (Clara) (CC-16) and respiratory diseases. However, few studies have explored the associations between urine CC-16 levels and environmental tobacco smoke (ETS) exposure in children. The objective of this study was to evaluate whether ETS exposure is associated with CC-16 when stratified by asthma status. METHODS: In our study, CC-16 was measured on 537 children aged 9-15 from northeast China in 2011-2012 using the Human Clara Cell Protein ELISA kits. Doctor-diagnosed asthma was defined as having ever been diagnosed with asthma by a physician. The relationship between ETS exposure and urine CC-16 level was assessed using linear regression. RESULTS: When stratified by asthma status, a negative association between ETS exposure and urine CC-16 was observed after adjusting for the effects of the related covariates, with an adjusted ß coefficient [P value] = -0.31 [0.006] in the first 2 years of life and with an adjusted ß coefficient [P value] = -0.68 [0.004] in the first 2 years of life and current. CONCLUSIONS: Our study shows long-term exposure to ETS was associated with urinary CC-16 among children without asthma.

Obesity enhanced respiratory health effects of ambient air pollution in Chinese children: the Seven Northeastern Cities study.

OBJECTIVE: Experimental data suggest that obesity enhances the effects of ambient air pollutants on exacerbation of asthma; however, there is little supporting epidemiological evidence. The aim of present study is to evaluate whether obesity modifies the association between ambient air pollution and respiratory symptoms and asthma in children. METHODS: In Northeast China, 30 056 children aged 2-14 years were selected from 25 districts of seven cities. Parents of the children completed questionnaires that characterized the children's histories of respiratory symptoms and illness, and associated risk factors. Overweight and obesity were calculated with an age and sex-specific body mass index (BMI, kg m(-2)), with BMIs of greater than the 85th and 95th percentiles defining overweight and obesity, respectively. Average annual ambient exposure to particulate matter with an aerodynamic diameter 10 µm (PM(10)), sulfur dioxide (SO(2)), nitrogen dioxides (NO(2)) and ozone (O(3)) was estimated from data collected at monitoring stations in each of the 25 study districts. RESULTS: We observed consistent and significant interactions between exposure and obesity on respiratory symptoms and asthma. The associations between each pollutant's yearly concentrations and respiratory symptoms and asthma were consistently larger for overweight/obese children than for normal-weight children, with odds ratios (ORs) ranging from 1.17 per 31 µg m(-3) for PM(10) on wheeze (95% confidence interval (CI): 1.01, 1.36) to 1.50 per 10 µg m(-3) for NO(2) on phlegm (95% CI: 1.21, 1.87) and cough (95% CI: 1.24, 1.81). CONCLUSION: These results showed that overweight/obesity enhanced respiratory health effects of air pollution in the study children.

Gender difference of childhood overweight and obesity in predicting the risk of incident asthma: a systematic review and meta-analysis.

The aims of our meta-analysis were (i) to quantify the predictability of childhood overweight and obesity on the risk of incident asthma; and (ii) to evaluate the gender difference on this relationship. The selection criteria included prospective cohort paediatric studies which use age- and sex-specific body mass index (BMI) as a measure of childhood overweight and the primary outcome of incident asthma. A total of 1,027 studies were initially identified through online database searches, and finally 6 studies met the inclusion criteria. The combined result of reported relative risk from the 6 included studies revealed that overweight children conferred increased risks of incident asthma as compared with non-overweight children (relative risk, 1.19; 95% confidence interval [CI], 1.03-1.37). The relationship was further elevated for obesity vs. non-obesity (relative risk, 2.02; 95% CI, 1.16-3.50). A dose-responsiveness of elevated BMI on asthma incidence was observed (P for trend, 0.004). Obese boys had a significantly larger effect than obese girls (relative risk, boys: 2.47; 95% CI, 1.57-3.87; girls: 1.25; 95% CI, 0.51-3.03), with significant dose-dependent effect. Proposed mechanisms of gender difference could be through pulmonary mechanics, sleep disordered breathing and leptin. Further research might be needed to better understand the exact mechanism of gender difference on the obesity-asthma relationship.