The impact of retirement on blood pressure: evidence from a nationwide survey in China.

INTRODUCTION: The health impact of retirement is controversial. Most previous studies have been based on self-reported health indicators or the endpoints of some chronic diseases (e.g., morbidity or mortality), but objective physiological indicators (e.g., blood pressure) have rarely been used. The objective of this study is to elucidate the health effects of retirement on blood pressure, thereby offering empirical evidence to facilitate the health of retirees and to optimize retirement policies. METHODS: From 2012 to 2015, 84,696 participants of the Chinese Hypertension Survey (CHS) were included in this study. We applied the fuzzy regression discontinuity design (FRDD) to identify retirement's causal effect on systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure. We also explored the heterogeneity in the effects of retirement across different sex and education level groups. RESULTS: Based on the fully adjusted model, we estimated that retirement increased SBP by 5.047 mm Hg (95% CI: -2.628-12.723, P value: 0.197), DBP by 0.614 mm Hg (95% CI: -3.879-5.108, P value: 0.789) and pulse pressure by 4.433 mm Hg (95% CI: -0.985-9.851, P value: 0.109). We found that retirement led to a significant increase in male participants' SBP and pulse pressure as well as a possible decrease in female participants' blood pressure. Additionally, the blood pressure levels of low-educated participants were more vulnerable to the shock of retirement. CONCLUSION: Retirement is associated with an increase in blood pressure level. There is a causal relationship between the increase in blood pressure levels of men and retirement. Policy-makers should pay extra attention to the health status of men and less educated people when adjusting retirement policies in the future.

Impact of Using Pre- and Post-Bronchodilator Spirometry Reference Values in a Chinese Population.

RATIONALE: Spirometry reference equations that are derived from a large, nationally representative, general population are warranted in China and the impact of using pre- and post-BD spirometry reference values has yet to be assessed in Chinese populations. OBJECTIVES: To present both the pre-BD and post-BD spirometry reference values for Chinese adults using the China Pulmonary Health (CPH) study. METHODS: A reference population of 17969 healthy, non-smoking participants in the CPH study was used to calculate the pre- and post-BD reference values for the forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC. Both pre- and post-BD reference values were applied to the entire CPH population (50991 individuals) to illustrate the divergence between the use of references in determining the disease prevalence and severity grading. MEASUREMENTS AND MAIN RESULTS: The prevalence of airflow limitation was 5.36% using pre-BD reference and 8.02% using the post-BD reference. Individuals who had post-BD FEV1/FVC below post-BD but higher than pre-BD reference values were found to have significantly higher rates of self-reported respiratory symptoms, and significantly lower values in spirometry indicators than those above post-BD reference values. An additional 3.51% of participants were identified as grade II-IV COPD using the post-BD FEV1 predicted values. CONCLUSION: This study generated and applied pre- and post-bronchodilator spirometry reference values in a nationally representative Chinese adult population. Post-BD reference values may serve as an additional criterion in identifying individuals at risk for obstructive pulmonary diseases, its diagnostic and prognostic values should be further investigated.

Soil organic matter degradation and methylmercury dynamics in Hg-contaminated soils: Relationships and driving factors.

Biodegradation of soil organic matter (SOM), which involves greenhouse gas (GHG) emissions, plays an essential role in the global carbon cycle. Over the past few decades, this has become an important research focus, particularly in natural ecosystems. SOM biodegradation significantly affects contaminants in the environment, such as mercury (Hg) methylation, producing highly toxic methylmercury (MeHg). However, the potential link between GHG production from SOM turnover in contaminated soils and biogeochemical processes involving contaminants remains unclear. In this study, we investigated the dynamics of GHG, MeHg production, and the relationship between biogeochemical processes in soils from two typical Hg mining sites. The two contaminated soils have different pathways, explaining the significant variations in GHG and MeHg production. The divergence of the microbial communities in these two biogeochemical processes is essential. In addition to the microbial role, abiotic factors such as Hg species can significantly affect MeHg production. On the other hand, we found an inverse relationship between CH4 and MeHg, suggesting that carbon emission reduction policies and management could inadvertently increase the MeHg levels. This highlights the need for an eclectic approach to organic carbon sequestration and contaminant containment. These findings suggest that it is difficult to establish a general pattern to describe and explain the SOM degradation and MeHg production in contaminated soils within the specific scenarios. However, this study provides a case study and helpful insights for further understanding the links between environmental risks and carbon turnover in Hg mining areas.

Dandelion polysaccharides improve the emulsifying properties and antioxidant capacities of emulsions stabilized by whey protein isolate.

In this study, the effects of dandelion polysaccharide (DP) and its carboxymethylated derivative (CMDP) on the emulsifying characteristics and antioxidant capacities of emulsions stabilized by whey protein isolate (WPI) were determined. The addition of both DP and CMDP reduced the particle size and zeta potential of the emulsions. Using 1.0 % WPI and 1.0 % CMDP as emulsifier, the emulsifying activity index (EAI) and emulsifying stability index (ESI) were 32.61 ± 0.11 m2/g and 42.58 ± 0.13 min, respectively, which were higher than the corresponding values of 27.19 ± 0.18 m2/g and 36.17 ± 0.15 min with 1.0 % WPI and 1.0 % DP. Fourier-transform infrared spectroscopy (FT-IR), far-ultraviolet circular dichroism (Far-UV CD), and fluorescence (FS) spectra analyses confirmed that the α-helix and ß-sheet structures in WPI-polysaccharide complexes were reduced compared with those in pure WPI, whereas the random-coil content was enhanced by the addition of polysaccharides. Moreover, DP and CMDP effectively improved the antioxidant capacity and inhibited oxidation of the emulsions during storage. Therefore, DP and its carboxymethylated derivative exhibit great potential to be applied in the emulsion-based delivery system.

The Association Between Urbanization and Electrocardiogram Abnormalities in China: a Nationwide Longitudinal Study.

The health effects of urbanization are controversial. The association between urbanization and reversible subclinical risks of cardiovascular diseases (e.g., electrocardiogram (ECG) abnormalities) has rarely been studied. This study aimed to assess the association between urbanization and ECG abnormalities in China based on the China National Stroke Screening Survey (CNSSS). We used changes in the satellite-measured impervious surfaces rate and nighttime light data to assess the level of urbanization. Every interquartile increment in the impervious surfaces rate or nighttime light was related to a decreased risk of ECG abnormalities, with odds ratios of 0.894 (95% CI, 0.869-0.920) or 0.809 (95% CI, 0.772-0.847), respectively. And we observed a U-shaped nonlinear exposure-response relationship curve between the impervious surfaces rate and ECG abnormalities. In conclusion, the current average level of urbanization among the studied Chinese adults remains a beneficial factor for reducing cardiovascular risks.

Ambient temperature anomalies induce electrocardiogram abnormalities: Findings from a nationwide longitudinal study.

Electrocardiogram (ECG) outcomes serve as early manifestations of cardiovascular functional or structural changes. While temperature fluctuation has been demonstrated to be a risk factor for cardiovascular diseases, few epidemiological studies have reported its relationship with ECG outcomes. In this study, we employed temperature anomaly (TA) as an innovative indicator of temperature fluctuation to quantify its detrimental impacts on ECG outcomes. A longitudinal study design was conducted using the repeated ECG records of the China National Stroke Screening Survey from 2013 to 2019. Only individuals undergoing at least two ECG tests were included. The daily temperature was assimilated by combining three kinds of data: in situ observations, satellite remote sensing measurements and weather research forecast simulations. We used generalized estimating equations to control for autocorrelation among repeated records and to estimate the association between TA and the risk of ECG abnormalities. We found 6837 events of ECG abnormalities in 47,286 individuals with 102,030 visits. Each unit increment of TA increased the risk of ECG abnormalities [odds ratio (OR) = 1.009, 95% confidence interval (CI): 1.001-1.017] and the risk of myocardial ischemia (OR = 1.061, 95% CI: 1.012-1.111). Hierarchic analyses presented a similar association of TA with both ECG abnormalities (OR = 1.017, 95% CI: 1.008-1.026) and myocardial ischemia (OR = 1.061, 95%CI: 1.011-1.114) in Northern China, but not in Southern China. The exposure-response relationship was estimated as a U-shaped curve centered at the TA value of zero. Sudden warming tended to increase the risk of ECG abnormalities and myocardial ischemia, and sudden cooling tended to increase the risk of atrial fibrillation. All these detrimental effects of TA could be modified by specific individual characteristics. In summary, ambient temperature fluctuation increased the risk of ECG abnormalities. This result indicated that regular ECG tests could be an early-warning measure for monitoring the adverse health effects of temperature fluctuations.

Middle-term nitrogen dioxide exposure and electrocardiogram abnormalities: A nationwide longitudinal study.

BACKGROUND: Recently, professionals, such as those from the World Health Organization, have recommended a rigorous standard for nitrogen dioxide (NO2), a typical urban air pollutant affected by regular traffic emissions, based on its short-term and long-term cardiorespiratory effects. However, the association between middle-term NO2 exposure and cardiovascular disorders remains unknown. OBJECTIVES: This study was conducted to examine the relationship between NO2 exposure and its middle-term cardiovascular risks indicated by electrocardiogram (ECG) abnormalities. METHOD: We included 61,094 subjects (132,249 visits) with repeated ECG observations based on longitudinal data from the China National Stroke Screening Survey (CNSSS). The NO2 exposure concentration was derived from a predictive model, measured as the monthly average concentration in the 6 months of preceding the ECG measurement. We used the generalized estimation equation to assess the association between NO2 exposure and ECG abnormalities. RESULT: For each 10 µg/m3 increase in monthly average NO2 concentration, the odds ratio of ECG abnormalities was 1.10 (95% confidence interval [CI] 1.09-1.12) after multiple adjustments. Stratified regression analyses of urban and rural residents showed associations between middle-term NO2 exposure and ECG abnormalities in urban (OR 1.09 [95% CI 1.08-1.11]) and rural residents (OR 1.14 [95% CI 1.10-1.19]). The association was robust within different subpopulations. Associations generally remained statistically significant (OR 1.03 [95% CI 1.02-1.05]) after extra adjustment for PM2.5. Exposure-response relationship analysis revealed a nearly linear relationship between NO2 exposure and the risk for ECG abnormalities. CONCLUSION: Using the variation in ECG signals as a potentially reversible indicator for subclinical risk in cardiovascular systems, our study provides additional evidence on the increased risk posed by middle-term NO2 exposure. Our study showed that policies controlling for NO2 concentrations are beneficial to prevent cardiovascular diseases among Chinese adults.

Short-term exposure to ozone and ECG abnormalities in China: A nationwide longitudinal study.

Ambient ozone (O3) pollution has been associated with an increased risk of cardiovascular diseases. However, few studies have addressed the effect of O3 exposure on electrocardiogram (ECG) abnormalities, a subclinical indicator of early damage to the cardiovascular system. This study aimed to examine the association between short-term exposure to O3 and ECG abnormalities. We included 102,027 visits of 47,290 participants over 40 years old who had a normal ECG at baseline and then visited again at least once from the China National Stroke Screening Survey (CNSSS). Short-term ozone exposure concentrations were measured as averages of maximum daily 8-h O3 concentrations over the two weeks prior to ECG measurements. The generalized estimation equations models were used to evaluate the association between O3 exposure and ECG abnormalities. For every 10 µg/m3 increment in short-term O3 concentration, the odds ratio of any ECG abnormality was 1.055 (95% confidence interval [CI] 1.045-1.064). For ECG-diagnosed cardiac arrhythmia, the odds ratio was 1.062 (95% CI 1.052-1.072). A nonlinear analysis showed a sublinear relationship between O3 exposure and risk for ECG abnormalities. The association between O3 exposure and ECG abnormalities varied by subpopulation. Our study provided new epidemiological evidence on the association between short-term O3 exposure and ECG abnormalities. There is an urgent need to control ambient O3 pollution to prevent cardiovascular events.

Association between long-term exposure to PM2.5 constituents and electrocardiographic abnormality: A nationwide longitudinal study in China.

BACKGROUND: Electrocardiogram (ECG) abnormalities are known to have prognostic value for heart conditions, while evidence on the relationship between long-term exposure to PM2.5 constituents and electrocardiographic (ECG) abnormalities is limited. This study aimed to quantify the association between long-term exposure to PM2.5 constituents and changes in ECG diagnoses. METHODS: We designed a longitudinal study among participants with repeated records of ECG examination based on the China National Stroke Screening Survey 2013-2018. Logistic regressions with multiple adjustment, estimated by the generalized estimating equation to incorporate repeated measurements, were used to assess the associations between the occurrence of any physician-diagnosed ECG abnormalities and long-term exposure to PM2.5 constituents. RESULTS: We included 61,094 participants with 132,249 visits. All five constituents (sulfate, nitrate, ammonium, organic matter, and black carbon) were significantly associated with an increased risk of ECG abnormalities. The excess risk of ECG abnormalities per interquartile-range increase in exposure was the highest for sulfate (26%, 95% confidence interval [CI] 23-29%), followed by ammonium (22%, 19-26%), nitrate (21%, 17-24%), black carbon (16%, 13-10%) and organic matter (9%,6%-11%). We also found that atrial fibrillation patients might be susceptible to the adverse effects of PM2.5 constituents on ECG. CONCLUSION: Differential associations between various constituents of PM2.5 and ECG abnormalities were found. The unequal toxicities for different chemical constituents of ambient particles on cardiovascular electrophysiological endpoints should be taken into consideration when considering the biological pathways linking PM2.5 and cardiovascular conditions.