Miao-Miao Liu

Association between long-term air pollution and increased blood pressure and hypertension in China.

Several studies have investigated the short-term effects of ambient air pollutants in the development of high blood pressure and hypertension. However, little information exists regarding the health effects of long-term exposure. To investigate the association between residential long-term exposure to air pollution and blood pressure and hypertension, we studied 24 845 Chinese adults in 11 districts of 3 northeastern cities from 2009 to 2010. Three-year average concentration of particles with an aerodynamic diameter ⩽10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxides (NO2), and ozone (O3) were calculated from monitoring stations in the 11 districts. We used generalized additive models and 2-level logistic regressions models to examine the health effects. The results showed that the odds ratio for hypertension increased by 1.12 (95% confidence interval [CI], 1.08–1.16) per 19 &mgr;g/m3 increase in PM10, 1.11 (95% CI, 1.04–1.18) per 20 &mgr;g/m3 increase in SO2, and 1.13 (95% CI, 1.06–1.20) per 22 &mgr;g/m3 increase in O3. The estimated increases in mean systolic and diastolic blood pressure were 0.87 mm Hg (95% CI, 0.48–1.27) and 0.32 mm Hg (95% CI, 0.08–0.56) per 19 &mgr;g/m3 interquartile increase in PM10, 0.80 mm Hg (95% CI, 0.46–1.14) and 0.31 mm Hg (95% CI, 0.10–0.51) per 20 &mgr;g/m3 interquartile increase in SO2, and 0.73 mm Hg (95% CI, 0.35–1.11) and 0.37 mm Hg (95% CI, 0.14–0.61) per 22 &mgr;g/m3 interquartile increase in O3. These associations were only statistically significant in men. In conclusion, long-term exposure to PM10, SO2, and O3 was associated with increased arterial blood pressure and hypertension in the study population.

Prevalence, awareness, treatment, control, and risk factors associated with hypertension in urban adults from 33 communities of China: the Chpsne study

Objective To assess the prevalence, awareness, treatment, and control of hypertension and their associated factors in an urban Chinese population. Methods A cross-sectional study was conducted in three cities in northeast China from 2009 to 2010, using a multistage cluster sampling method to select a representative sample. A total of 25 196 adults, aged 18–74 years, were examined in 33 communities. Hypertension was defined as a mean SBP of at least 140 mmHg, DBP at least 90 mmHg, and/or use of antihypertensive medications. Results Overall, the prevalence of hypertension was 28.7% for urban residents, and 39.1% for middle-aged and elderly residents (aged ≥35 years). Among all the hypertensive patients examined in the study (n = 7237), 42.9% were aware of their condition, 28.2% were receiving treatment, and only 3.7% had their blood pressure adequately controlled. Female hypertensive patients had more effectively controlled blood pressure than their male counterparts. Among the study participants, 37.9% did not think that high blood pressure would endanger their lives. Among hypertensive patients aware of their conditions, the primary reason for not taking antihypertensive medication was a lack of money (34.8%). Age, sex, education, occupation, income, body mass, waist circumference, and family hypertension history significantly correlated with the prevalence of hypertension. Conclusion Hypertension is highly prevalent in the urban population of China, and the effects of being overweight/obesity on hypertension were much larger than any other examined factors. The percentage of hypertensive patients aware of their condition, receiving proper treatment, and keeping their hypertension under control is unacceptably low.

Gender Differences and Effect of Air Pollution on Asthma in Children with and without Allergic Predisposition: Northeast Chinese Children Health Study

Background Males and females exhibit different health responses to air pollution, but little is known about how exposure to air pollution affects juvenile respiratory health after analysis stratified by allergic predisposition. The aim of the present study was to assess the relationship between air pollutants and asthmatic symptoms in Chinese children selected from multiple sites in a heavily industrialized province of China, and investigate whether allergic predisposition modifies this relationship. Methodology/Principal Findings 30139 Chinese children aged 3-to-12 years were selected from 25 districts of seven cities in northeast China in 2009. Information on respiratory health was obtained using a standard questionnaire from the American Thoracic Society. Routine air-pollution monitoring data was used for particles with an aerodynamic diameter ≤10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxides (NO2), ozone (O3) and carbon monoxide (CO). A two-stage regression approach was applied in data analyses. The effect estimates were presented as odds ratios (ORs) per interquartile changes for PM10, SO2, NO2, O3, and CO. The results showed that children with allergic predisposition were more susceptible to air pollutants than children without allergic predisposition. Amongst children without an allergic predisposition, air pollution effects on asthma were stronger in males compared to females; Current asthma prevalence was related to PM10 (ORs = 1.36 per 31 µg/m3; 95% CI, 1.08–1.72), SO2 (ORs = 1.38 per 21 µg/m3; 95%CI, 1.12–1.69) only among males. However, among children with allergic predisposition, more positively associations between air pollutants and respiratory symptoms and diseases were detected in females; An increased prevalence of doctor-diagnosed asthma was significantly associated with SO2 (ORs = 1.48 per 21 µg/m3; 95%CI, 1.21–1.80), NO2 (ORs = 1.26 per 10 µg/m3; 95%CI, 1.01–1.56), and current asthma with O3 (ORs = 1.55 per 23 µg/m3; 95%CI, 1.18–2.04) only among females. Conclusion/Significance Ambient air pollutions were more evident in males without an allergic predisposition and more associations were detected in females with allergic predisposition.

Serum polyfluoroalkyl concentrations, asthma outcomes, and immunological markers in a case-control study of Taiwanese children.

Background: Perfluorinated compounds (PFCs) are ubiquitous pollutants. Experimental data suggest that they may be associated with adverse health outcomes, including asthma. However, there is little supporting epidemiological evidence. Methods: A total of 231 asthmatic children and 225 nonasthmatic controls, all from northern Taiwan, were recruited in the Genetic and Biomarkers study for Childhood Asthma. Structure questionnaires were administered by face-to-face interview. Serum concentrations of 11 PFCs and levels of immunological markers were also measured. Associations of PFC quartiles with concentrations of immunological markers and asthma outcomes were estimated using multivariable regression models. Results: Nine PFCs were detectable in most children (≥ 84.4%), of which perfluorooctane sulfonate (PFOS) was the most abundant (median serum concentrations of 33.9 ng/mL in asthmatics and 28.9 ng/mL in controls). Adjusted odds ratios for asthma among those with the highest versus lowest quartile of PFC exposure ranged from 1.81 (95% CI: 1.02, 3.23) for the perfluorododecanoic acid (PFDoA) to 4.05 (95% CI: 2.21, 7.42) for perfluorooctanic acid (PFOA). PFOS, PFOA, and subsets of the other PFCs were positively associated with serum IgE concentrations, absolute eosinophil counts (AEC), eosinophilic cationic protein (ECP) concentrations, and asthma severity scores among asthmatics. Conclusions: This study suggests an association between PFC exposure and juvenile asthma. Because of widespread exposure to these chemicals, these findings may be of potential public health concern.

Epidemiology of general obesity, abdominal obesity and related risk factors in urban adults from 33 communities of northeast china: the CHPSNE study

BackgroundObesity increases the risk of many diseases. However, there has been little literature about the epidemiology of obesity classified by body mass index (BMI) or waist (abdominal obesity) among urban Chinese adults. This study is to fill the gap by assessing the prevalence of obesity and associated risk factors among urban Chinese adults.MethodsA representative sample of 25,196 urban adults aged 18 to 74 years in Northeast China was selected and measurements of height, weight and waist circumference (WC) were taken from 2009–2010. Definitions of overweight and obesity by the World Health Organization (WHO) were used.ResultsThe overall prevalence rates of general obesity and overweight classified by BMI were 15.0% (15.7% for men and 14.3% for women, p<0.01) and 19.2% (20.8% for men and 17.7% for women, p<0.01), respectively, and the overall prevalence rate of abdominal obesity was 37.6% (31.1% for men and women 43.9% for women, p<0.01). Multivariable logistic regression showed that the elderly and those who had a history of parental obesity, alcohol drinking, or former cigarette smoking were at high risk of obesity classified by BMI or WC, whereas those with a higher level of education, higher family income, or a healthy and balanced diet were at low risk of obesity. Analysis stratified by gender showed that men with a higher level education level, a white-collar job, a cadre job, or higher family income were the high risk group, and women with a higher level of education or higher family income were the low risk group.ConclusionsObesity and overweight have become epidemic in urban populations in China; associations of risk factors with obesity differ between men and women.

Body mass index compared with abdominal obesity indicators in relation to prehypertension and hypertension in adults: the CHPSNE study.

BACKGROUND Debate ensues regarding the stronger indicator of obesity, body mass index (BMI), or waist circumference (WC), in association with hypertension. Furthermore, little research has been done to compare BMI and WC in their associations with prehypertension. METHODS A cross-sectional survey was undertaken in 33 communities randomly selected from 3 cities in Northeastern China during 2009-2010, using a total of 25,196 adults aged 18-74 years with an overall response rate of 87.4%. Diagnoses of prehypertension and hypertension were based on the criteria set by the Seventh Report of the Joint National Committee. Generalized overweight and obesity were defined as BMI 25-29.9 and ≥30 kg/m(2), respectively. Abdominal overweight and obesity were defined as WC 94-102 and >102 cm in men and WC 80-88 and >88 cm in women, respectively. RESULTS Both BMI and WC were positively related to the prevalence rate of elevated blood pressure. Among younger individuals, aged 18-44 years, WC seemed to be associated with a higher odds ratio (OR) than BMI for hypertension (e.g., for men, 17.18 (BMI) vs. 23.28 (WC) for obesity), in contrast, BMI seemed to be associated with a higher OR than WC for prehypertension (e.g., for men, 5.99 (BMI) vs. 1.51 (WC) for obesity). Among older individuals, aged ≥45 years, the adjusted OR for hypertension was modestly higher for WC than for BMI in men. In women, the adjusted OR was modestly higher for BMI than for WC. CONCLUSIONS In this Chinese population, the association of body fat and abdominal fat with hypertension and prehypertension depends on age and sex.

Factors associated with prevalence, awareness, treatment and control of hypertension in urban adults from 33 communities in China: the CHPSNE Study.

Using a randomized multistage cluster sampling, we studied the factors associated with the prevalence, awareness, treatment and control of hypertension (defined as systolic and diastolic blood pressure (BP) measurements ⩾140 and 90 mm Hg, respectively, or current drug treatment for hypertension) in a representative sample of the urban Chinese population. The participants were 18–74 years of age and had lived for at least 5 years in an area comprising 33 communities in three cities (Shenyang, Anshan and Jinzhou) in China. A total of 28 830 people were selected; the overall response rate was 87.4% (25 196/28 830). The overall prevalence of hypertension was 28.7% (7237/25 196). Of those with hypertension, 42.9% (3107/7237) were aware of their condition, 28.2% (2042/7237) were receiving treatment and 3.7% (264/7237) were considered controlled. More than half (57.8%) of the hypertensives did not think that high BP would endanger their lives. Multivariate analysis revealed that age, gender, education, occupation, income, body mass index, waist circumference and a family history of hypertension correlated significantly with the prevalence of hypertension. Among all the hypertensives, higher awareness (determined by odds ratios; 95% confidence intervals) was noted for persons who were white-collar workers (1.29; 1.08, 1.53, respectively), overweight (1.48; 1.30, 1.69), obese (3.37; 2.76, 4.11) or had a family history of hypertension (3.07; 2.76, 3.42). Among the individuals aware of their hypertension, treatment was more common in those with a higher level of education and less common among individuals consuming ⩾2 alcoholic drinks per day (0.65; 0.52, 0.83). Controlled hypertension was much less common among older persons, and participants who were former smokers (0.49; 0.26, 0.91). The results indicate that more attention is needed to improve the awareness of the potentially fatal nature of hypertension in urban China.

Breastfeeding as a modifier of the respiratory effects of air pollution in children.

Background: Breastfeeding and air pollution are both important factors for respiratory symptoms and asthma in children. Few studies have examined possible interaction between them on respiratory outcomes. Methods: We studied 31,049 Chinese children, ages 2–14 years old, from 25 elementary schools and 50 kindergartens in the Seven Northeastern Cities during 2008–2009. Parents or guardians completed questionnaires about the children’s histories of respiratory conditions, risk factors, and feeding methods. Three-year average concentrations of particles with an aerodynamic diameter ⩽10 µm, sulfur dioxide, nitrogen dioxides, and ozone were calculated from monitoring stations in 25 study districts. We used two-level logistic regressions to examine the effects of exposure, controlling for covariates. Results: Association of air pollution with childhood respiratory conditions was modified by breastfeeding. Compared with children who had been breastfed, those who were not exhibited consistently stronger effects of air pollution. Among non-breastfed children, odds ratios (ORs) per 10 µg/m3 increase in nitrogen dioxide were 1.40 (95% confidence interval = 1.19–1.64) for cough, 1.41 (1.16–1.71) for phlegm, 1.17 (1.00–1.36) for current wheeze, and 1.25 (1.07–1.46) for doctor-diagnosed asthma. For breastfed children, the ORs were 1.25 (1.09–1.43) for cough, 1.15 (0.99–1.34) for phlegm, 0.97 (0.87–1.08) for current wheeze, and 1.17 (1.05–1.32) for doctor-diagnosed asthma. Breastfeeding was more protective among younger children. Breastfeeding was also associated with reduced effects of passive smoke exposure in children. Conclusion: Breastfeeding is associated with smaller associations between air pollution and respiratory conditions in children, suggesting that breastfeeding reduces susceptibility to the respiratory effects of pollutants.

Induction of p53-mediated apoptosis in splenocytes and thymocytes of C57BL/6 mice exposed to perfluorooctane sulfonate (PFOS).

Perfluorooctane sulfonate (PFOS) is a persistent environmental contaminant found in human and wildlife tissues. It has been reported that PFOS can cause atrophy of the immune organs and apoptosis of immunocytes in rodents. However, the mechanism behind such cause is still unclear. To understand the model of cell death and its mechanism on lymphoid cells in vivo, we conducted a dose/response experiment in which 4 groups of male adult C57BL/6 mice (12 mice per group) were dosed daily by oral gavage with PFOS at 0, 0.0167, 0.0833, or 0.8333mg/kg/day, yielding targeted Total Administered Dose (TAD) of 0, 1, 5, or 50mg PFOS/kg, respectively, over 60days. The results showed that spleen and thymus weight were significantly reduced in the highest PFOS-dose-group (TAD 50mg PFOS/kg) compared to the control group, whereas liver weight was significantly increased. We analyzed the cell death via apoptosis with an annexin-V/propidium iodide assay by flow cytometry, and observed that both the percentage of apoptosis and the expression of the pro-apoptotic proteins p53 in splenocytes and thymocytes increased in a dose-related manner after PFOS treatment. We also observed that PFOS induced p53-dependent apoptosis through the cooperation between the Bcl-xl down regulation without changing the Bcl-2 and Bax expression. The down regulation of Bcl-xl was strongly indicating mitochondrial involvement in apoptosis. It is confirmed by the release of cytochrome c and activation of caspase-3. All of these findings establish an important role of p53 and mitochondrial function in PFOS induced toxic environment in the host.

Mechanism of perfluorooctanesulfonate (PFOS)-induced apoptosis in the immunocyte

As a new type of persistent organic pollutant, perfluorooctane sulfonate (PFOS) has raised great concern in recent years due to its ubiquitous distribution in the general environment and its long elimination half-life in humans. PFOS has toxic and carcinogenic effects in animals and humans, but the effects of PFOS on apoptosis are still not clear. The present study aimed to determine the mode of cell death and its mechanism in splenocytes and thymocytes from adult male C57BL/6 mice administered 0, 1, 5, or 10 mg PFOS/kg/day by gavage daily for 7 days. The results showed that more apoptotic cells were present in PFOS-treated mice than in control mice. PFOS induced production of reactive oxygen species (ROS), dissipation of mitochondria membrane potential, and apoptosis of splenocytes and thymocytes. Moreover, activities of superoxide dismutase, catalase, and glutathione reductase were increased, whereas activities of glutathione-S-transferase and glutathione peroxidase were decreased, in splenocytes. Glutathione contents were reduced as well. Differential expressions of proteins such as p53, Bax, caspase-3, and caspase-9 were significantly up-regulated in PFOS-exposed hosts, whereas Bcl-2 expression was significantly down-regulated. One possible mechanism for the findings here was that PFOS could overwhelm homeostasis of anti-oxidative systems, boost ROS generation, impact on mitochondria, and affect protein expression of apoptotic regulators, the latter of which resulted in initiation of the apoptosis program. Results from this study may provide a new insight into the potential adverse effects of PFOS exposure on humans, at the cellular level.