Ambient Air Pollution and 16-Year Weight Change in African-American Women

Associations of long-term exposure to air pollution and noise with body composition in children and adults: Results from the LEAD general population study

BACKGROUND

While long-term air pollution and noise exposure has been linked to increasing cardiometabolic disease risk, potential effects on body composition remains unclear. This study aimed to investigate the associations of long-term air pollution, noise and body composition.

METHODS

We used repeated data from the LEAD (Lung, hEart, sociAl, boDy) study conducted in Vienna, Austria. Body mass index (BMI; kg/m2), fat mass index (FMI; z-score), and lean mass index (LMI; z-score) were measured using dual-energy x-ray absorptiometry at the first (t0; 2011-ongoing) and second (t1; 2017-ongoing) examinations. Annual particulate matter (PM10) and nitrogen dioxide (NO2) concentrations were estimated with the GRAMM/GRAL model (2015-2021). Day-evening-night (Lden) and night-time (Lnight) noise levels from transportation were modeled for 2017 following the European Union Directive 2002/49/EC. Exposures were assigned to residential addresses. We performed analyses separately in children/adolescents and adults, using linear mixed-effects models with random participant intercepts and linear regression models for cross-sectional and longitudinal associations, respectively. Models were adjusted for co-exposure, lifestyle and sociodemographics.

RESULTS

A total of 19,202 observations (nt0 = 12,717, nt1 = 6,485) from participants aged 6-86 years (mean age at t0 = 41.0 years; 52.9 % female; mean PM10 = 21 µg/m3; mean follow-up time = 4.1 years) were analyzed. Among children and adolescents (age ≤ 18 years at first visit), higher PM10exposure was cross-sectionally associated with higher FMI z-scores (0.09 [95 % Confidence Interval (CI): 0.03, 0.16]) and lower LMI z-scores (-0.05 [95 % CI: -0.10, -0.002]) per 1.8 µg/m3. Adults showed similar trends in cross-sectional associations as children, though not reaching statistical significance. We observed no associations for noise exposures. Longitudinal analyses on body composition changes over time yielded positive associations for PM10, but not for other exposures.

CONCLUSION

Air pollution exposure, mainly PM10, was cross-sectionally and longitudinally associated with body composition in children/adolescents and adults. Railway/road-traffic noise exposures showed no associations in both cross-sectional and longitudinal analyses.

The association between chemical constituents of ambient fine particulate matter and obesity in adults: A large population-based cohort study

OBJECTIVES

Current evidence demonstrated that ambient fine particulate matter with an aerodynamic diameter ≤2.5 μm (PM2.5) and its constituents may be obesogenic in children, but evidence from adults is lacking. Our aim was to characterize the association between PM2.5 and its constituents and obesity in adults.

METHODS

We included 68,914 participants from the China Multi-Ethnic Cohort (CMEC) baseline survey. Three-year average concentrations of PM2.5 and its constituents were evaluated by linking pollutant estimates to the geocoded residential addresses. Obesity was defined as body mass index (BMI) ≥ 28 kg/m2. Logistic regression was used to examine the relationship between PM2.5 and its constituents and obesity. We performed weighed quantile sum (WQS) regression to get the overall effect of PM2.5 and its constituents and the relative contribution of each constituent.

RESULTS

Per-SD increase in PM2.5 (odds ratio [OR] = 1.43, 95% confidence interval [CI]: 1.37-1.49), black carbon (BC) (1.42, 1.36-1.48), ammonium (1.43, 1.37-1.49), nitrate (1.44, 1.38-1.50), organic matter (OM) (1.45, 1.39-1.51), sulfate (1.42, 1.35-1.48), and soil particles (SOIL) (1.31, 1.27-1.36) were positively associated with obesity, and SS (0.60, 0.55-0.65) was negatively associated with obesity. The overall effect (OR = 1.34, 95% CI: 1.29-1.41) of the PM2.5 and its constituents was positively associated with obesity, and ammonium made the most contribution to this relationship. Participants who were older, female, never smoked, lived in urban areas, had lower income or higher levels of physical activity were more significantly adversely affected by PM2.5, BC, ammonium, nitrate, OM, sulfate and SOIL compared to other individuals.

CONCLUSION

Our study revealed that PM2.5 constituents except SS were positively associated with obesity, and ammonium played the most important role. These findings provided new evidence for public health interventions, especially the precise prevention and control of obesity.

Exposure to air pollution and gains in body weight and waist circumference among middle-aged and older adults

INTRODUCTION

Emerging research suggested a nexus between air pollution exposure and risks of overweight and obesity, while existing longitudinal evidence was extensively sparse, particularly in densely populated regions. This study aimed to quantify concentration-response associations of changes in weight and waist circumference (WC) related to air pollution in Chinese adults.

METHODS

We conceived a nationally representative longitudinal study from 2011 to 2015, by collecting 34,854 observations from 13,757 middle-aged and older adults in 28 provincial regions of China. Participants' height, weight and WC were measured by interviewers using standardized devices. Concentrations of major air pollutants including fine particulate matter (PM_2.5), nitrogen dioxide (NO₂) and ozone (O₃) predicted by well-validated spatiotemporal models were assigned to participants according to their residential cities. Possible exposure biases were checked through 1000 random simulated exposure at individual level, using a Monte Carlo simulation approach. Linear mixed-effects models were applied to estimate the relationships of air pollution with weight and WC changes, and restricted cubic spline functions were adopted to smooth concentration-response (C-R) curves.

RESULTS

Each 10-μg/m³ rise in PM_2.5, NO₂ and O₃ was associated with an increase of 0.825 (95% confidence interval: 0.740, 0.910), 0.921 (0.811, 1.032) and 1.379 (1.141, 1.616) kg in weight, respectively, corresponding to WC gains of 0.688 (0.592, 0.784), 1.189 (1.040, 1.337) and 0.740 (0.478, 1.002) cm. Non-significant violation for linear C-R relationships was observed with exception of NO₂-weight and PM_2.5/NO₂-WC associations. Sex-stratified analyses revealed elevated vulnerability in women to gain of weight in exposure to PM_2.5 and NO₂. Sensitive analyses largely supported our primary findings via assessing exposure estimates from 1000 random simulations, and performing reanalysis based on non-imputed covariates and non-obese participants, as well as alternative indicators (i.e., body mass index and waist-to-height ratio).

CONCLUSIONS

We found positively robust associations of later-life exposure to air pollutants with gains in weight and WC based on a national sample of Chinese adult men and women. Our findings suggested that mitigation of air pollution may be an efficient intervention to relieve obesity burden.

Regional urbanicity levels modify the association between ambient air pollution and prevalence of obesity: A nationwide cross-sectional survey

Ambient air pollution exposure may increase the risk of obesity, but the population susceptibility associated with urbanicity has been insufficiently investigated. Based on a nationwide representative cross-sectional survey on 44,544 adults, high-resolution night light satellite remote sensing products, and multi-source ambient air pollution inversion data, the present study evaluated the associations of fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) concentrations with the prevalence of obesity and abdominal obesity. We further calculated the associations in regions with different urbanicity levels characterized by both administrative classification of urban/rural regions and night light index (NLI). We found that 10 μg/m³ increments in PM_2.5 at 1-year moving average and in NO₂ at 5-year moving average were associated with increased prevalence of obesity [odds ratios (OR) = 1.16 (1.14, 1.19); 1.12 (1.09, 1.15), respectively] and abdominal obesity [OR = 1.08 (1.07, 1.10); 1.07 (1.05, 1.09), respectively]. People in rural regions experienced stronger adverse effects than those in urban regions. For instance, a 10 μg/m³ increment in PM_2.5 was associated with stronger odds of obesity in rural regions than in urban regions [OR = 1.27 (1.23, 1.31) vs 1.10 (1.05, 1.14), P for interaction <0.001]. In addition, lower NLI values were associated with constantly amplified associations of PM_2.5 and NO₂ with obesity and abdominal obesity (all P for interaction <0.001). In summary, people in less urbanized regions are more susceptible to the adverse effects of ambient air pollution on obesity, suggesting the significance of collaborative planning of urbanization development and air pollution control, especially in less urbanized regions.

Air pollution, greenness and risk of overweight among middle-aged and older adults: A cohort study in China

BACKGROUND

Exposure to air pollution may increase the risk of obesity, but living in greener space may reduce this risk. Epidemiological evidence, however, is inconsistent.

METHODS

Using data from the China Health and Retirement Longitudinal Study (2011-2015), we conducted a nationwide cohort study of 7424 adults. We measured overweight/obesity according to body mass index. We used annual average ground-level air pollutants, including ozone (O₃), nitrogen dioxide (NO2), and particulate matter with aerodynamic diameters ≤2.5 μm (PM_2.5), to demonstrate air pollution levels. We used the Normalized difference vegetation index (NDVI) to measure greenness exposure. We used time-varying Cox proportional hazard regression models to analyze the connections among air pollution, greenness, and the development of overweight/obesity in middle-aged and older adults in China. We also conducted mediation analyses to examine the mediating effects of air pollution.

RESULTS

We found that lower risk of overweight/obesity was associated with more greenness exposure and lower levels of air pollution. We identified that an interquartile increment in NDVI was correlated with a lower hazard ratio (HR) of becoming overweight or obese (HR = 0.806, 95% confidence interval [CI]: 0.754-0.862). Although a 10 μg/m³ increase in PM_2.5 and NO₂ was correlated with higher risks (HR = 1.049, 95% CI = 1.022-1.075, HR = 1.376, 95% CI = 1.264-1.499). Effects of PM_2.5 on being overweight or obese were stronger in men than in women. According to the mediation analysis, PM_2.5 and NO₂ mediated 8.85% and 19.22% of the association between greenness and being overweight or obese.

CONCLUSIONS

An increased risk of being overweight or obese in middle-aged and older adults in China was associated with long-term exposure to higher levels of PM_2.5 and NO₂. This risk was reduced through NDVI exposure, and the associations were partially mediated by air pollutants. To verify these findings, fine-scale studies are needed.

Effects of physical activity intensity on adulthood obesity as a function of long-term exposure to ambient PM2.5: Observations from a Chinese nationwide representative sample

Long-term exposure to PM_2.5 has been associated with increased obesity risk, while physical activity (PA) is a suggested protective factor. This raises a dilemma whether the increased dose of PM_2.5 due to PA-intensified ventilation would offset the benefits of PA. Using a national representative sample, we aim to (1) ascertain inclusive findings of the association between PA and obesity, and (2) examine whether PM_2.5 exposure modifies the PA-obesity relationship. We recruited 91,121 Chinese adults from 31 provinces using a multi-stage stratified-clustering random sampling method. PM_2.5 was estimated using a validated machine learning method with a spatial resolution of 0.1° × 0.1°. PA intensity was calculated as metabolic equivalent (MET)-hour/week by summing all activities. Body weight, height, and waist circumference (WC) were measured after overnight fasting. Obesity-related traits included continuous outcomes (Body mass index [BMI], WC, and waist-to-height ratio (WHtR)) and binomial outcomes (general obesity, abdominal obesity, and WHtR obesity). Generalized linear regression models were used to estimate the interaction effects between PM_2.5 and PA on obesity, controlling for covariates. The results indicated that each IQR increase in PA was associated with 0.078 (95% CI: -0.096 to -0.061) kg/m², 0.342 (-0.389 to -0.294) cm, and 0.0022 (-0.0025 to -0.0019) decrease in BMI, WC, and WHtR, respectively. The joint association showed that benefits of PA on obesity were attenuated as PM_2.5 increased. Risk of abdominal obesity decreased 11.3% (OR = 0.887, 95% CI: 0.866, 0.908) per IQR increase in PA among the low-PM_2.5 (≤55.9 μg/m³) exposure group, but only 5.5% (OR = 0.945, 95% CI: 0.930, 0.960) among the high-PM_2.5 (>55.9 μg/m³) exposure group. We concluded the increase in PA intensity was significantly associated with lower risk of obesity in adults living across mainland China, where annual level of PM_2.5 were mostly exceeding the standard. Reducing PM_2.5 exposure would enhance the PA benefits as a risk reduction strategy.

Positive Association between Indoor Gaseous Air Pollution and Obesity: An Observational Study in 60 Households

This study aims to analyze whether exposure to indoor air pollution affects obesity. In our research, we recruited 127 participants, with an average age of 43.30 ± 15.38 years old, residing in 60 households. We monitored indoor air quality for 24 h, and conducted both questionnaire surveys and collected serum samples for analysis, to assess the relationship between indoor air pollutant exposure and obesity. After adjusting for demographic characteristics, the results showed that CO₂ exposure is positively associated with being overweight and with a higher risk of being abdominally obese. Exposures to CO and formaldehyde were also positively associated with being overweight. IQR increase in TVOC was positively associated with increases in the risk of a high BMI, being abdominally obese and having a high body fat percentage. Two-pollutant models demonstrate that TVOCs presented the strongest risks associated with overweightness. We concluded that persistent exposure to indoor gaseous pollutants increases the risk of overweightness and obesity, as indicated by the positive association with BMI, abdominal obesity, and percentage body fat. TVOCs display the strongest contribution to obesity.

Long-term impacts of ambient fine particulate matter exposure on overweight or obesity in Chinese adults: The China-PAR project

Although emerging researches have linked ambient fine particulate matter (PM2.5) to obesity, evidence from high-polluted regions is still lacking. We thus assessed the long-term impacts of PM2.5 on body mass index (BMI) and the risk of the prevalence of overweight/obesity (BMI≥25 kg/m2), by incorporating the well-established Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR) project comprising 77,609 participants with satellite-based PM2.5 estimates at 1-km spatial resolution. The average of long-term PM2.5 level was 70.4 μg/m3, with the range of 32.1-94.2 μg/m3. Each 10 μg/m3 increment of PM2.5 was associated with 0.421 kg/m2 (95% confidence interval [CI]: 0.402, 0.439) and 13.5% (95% CI: 12.8%, 14.3%) increased BMI and overweight/obesity risk, respectively. Moreover, compared with the lowest quartile of PM2.5 (≤57.5 μg/m3), the relative risk of the prevalence of overweight/obesity from the highest quartile (>85.9 μg/m3) was 1.611 (95% CI: 1.566, 1.657). The exposure-response curve suggested a non-linear relationship between PM2.5 exposure and overweight/obesity. Besides, the association was modified by age, diabetes mellitus, hypertension and dyslipidemia status. Our study provides the evidence for the adverse impacts of long-term PM2.5 on BMI and overweight/obesity in China, and the findings are important for policy development on air quality, especially in severely polluted areas.

Does ozone inhalation cause adverse metabolic effects in humans? A systematic review

We utilized a practical, transparent approach for systematically reviewing a chemical-specific evidence base. This approach was used for a case study of ozone inhalation exposure and adverse metabolic effects (overweight/obesity, Type 1 diabetes [T1D], Type 2 diabetes [T2D], and metabolic syndrome). We followed the basic principles of systematic review. Studies were defined as "Suitable" or "Supplemental." The evidence for Suitable studies was characterized as strong or weak. An overall causality judgment for each outcome was then determined as either causal, suggestive, insufficient, or not likely. Fifteen epidemiologic and 33 toxicologic studies were Suitable for evidence synthesis. The strength of the human evidence was weak for all outcomes. The toxicologic evidence was weak for all outcomes except two: body weight, and impaired glucose tolerance/homeostasis and fasting/baseline hyperglycemia. The combined epidemiologic and toxicologic evidence was categorized as weak for overweight/obesity, T1D, and metabolic syndrome,. The association between ozone exposure and T2D was determined to be insufficient or suggestive. The streamlined approach described in this paper is transparent and focuses on key elements. As systematic review guidelines are becoming increasingly complex, it is worth exploring the extent to which related health outcomes should be combined or kept distinct, and the merits of focusing on critical elements to select studies suitable for causal inference. We recommend that systematic review results be used to target discussions around specific research needs for advancing causal determinations.

Long-term exposure to ambient PM2.5 increase obesity risk in Chinese adults: A cross-sectional study based on a nationwide survey in China

Certain studies suggest that air pollution could be a risk factor for obesity, but the evidence on the association between air pollution exposure and obesity in adults is limited. This study aims to examine the association between long-term exposure to fine particulate matter (PM_2.5) and obesity-related traits in Chinese adults. Thus, a cross-sectional study was conducted based on a nationally representative sample of 91, 121 adults from 31 provinces in China. Integrated the data from satellites, chemical transport model, and ground observations, annual average concentrations of PM_2.5 was obtained at the township level using a machine learning method. The information on body weight, height, and waist circumference (WC) were obtained from a questionnaire survey. The general obesity and abdominal obesity status were classified based on body mass index (BMI) and WC, respectively. Logistic and multivariate linear regression models were used to examine the association between PM_2.5 and obesity-related traits, along with the examination of potential effect modifications. After adjustment for covariates, a 10 μg/m³ increase in PM_2.5 concentration was associated with 8.0% [95% confidence interval (CI): 1.0%, 10.0%] and 10% (95% CI: 9.0%, 11.0%) increases in odds for general obesity and abdominal obesity, respectively. The odds ratios associated with per 10 μg/m³ PM_2.5 increase were significantly greater in individuals of older age (≥60 years), of Han ethnicity, with lower socioeconomic status (SES), cooking without using a ventilation device, using unclean household fuels, having near-home pollution sources, and doing no physical exercise. These findings suggest that long-term exposure to ambient PM_2.5 increase obesity risk in Chinese adults. It has significant significance to reduce air pollution to reducing the burden of obesity, particularly for the susceptible populations.

Air pollution and breast cancer risk in the Black Women's Health Study

BACKGROUND

Air pollution contains numerous carcinogens and endocrine disruptors which may be relevant for breast cancer. Previous research has predominantly been conducted in White women; however, Black women may have higher air pollution exposure due to geographic and residential factors.

OBJECTIVE

We evaluated the association between air pollution and breast cancer risk in a large prospective population of Black women.

METHODS

We estimated annual average ambient levels of particulate matter <2.5 μm (PM_2.5), nitrogen dioxide (NO₂) and ozone (O₃) at the 1995 residence of 41,317 participants in the Black Women's Health Study who resided in 56 metropolitan areas across the United States. Cox proportional hazards regression was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for an interquartile range (IQR) increase in each pollutant. We evaluated whether the association varied by menopausal status, estrogen receptor (ER) status of the tumor and geographic region of residence.

RESULTS

With follow-up through 2015 (mean = 18.3 years), 2146 incident cases of breast cancer were confirmed. Higher exposure to NO₂ or O₃ was not associated with a higher risk of breast cancer. For PM_2.5, although we observed no association overall, there was evidence of modification by geographic region for both ER- (p for heterogeneity = 0.01) and premenopausal breast cancer (p for heterogeneity = 0.01). Among women living in the Midwest, an IQR increase in PM_2.5 (2.87 μg/m³), was associated with a higher risk of ER- (HR = 1.53, 95% CI: 1.07-2.19) and premenopausal breast cancer (HR = 1.32, 95% CI: 1.03-1.71). In contrast, among women living in the South, PM_2.5 was inversely associated with both ER- (HR = 0.74, 95% CI: 0.56-0.97) and premenopausal breast cancer risk (HR = 0.75, 95% CI: 0.62-0.91).

DISCUSSION

Overall, we observed no association between air pollution and increased breast cancer risk among Black women, except perhaps among women living in the Midwestern US.

Ambient air pollution and body weight status in adults: A systematic review and meta-analysis

Overweight and obesity have become a global epidemic and concern, and contributed to at least 4.0 million deaths each year worldwide. However, current evidence regarding the impact of air pollution on body weight status remains inconsistent. We therefore conducted a systematic review and meta-analysis to evaluate the effect of long-term exposure to ambient air pollutants on body weight status in adults. Three databases were searched up to Dec 31, 2019 for articles investigating the association of gaseous (sulfur dioxide, nitrogen dioxide, ozone) and particulate (diameter ≤ 10 μm or ≤ 2.5 μm) air pollutants with body weight status. Random effect models were used to estimate the pooled odds ratios (ORs), regression coefficients (β) and their 95% confidence intervals (95% CIs) associated with air pollution. Among twelve studies that were eligible in the systematic review, ten were used to estimate the pooled effect size, and most of them were cross-sectional studies. We identified that ambient air pollution had adverse effects on body weight status. For example, elevated PM_2.5 and O₃ were associated with higher level of body mass index, with the pooled β (95% CIs) of 0.34 (0.30-0.38) and 0.21 (0.17-0.24) per 10 μg/m³ increment, respectively. In addition, increased NO₂, SO₂ and O₃ were associated with higher risk of having overweight/obesity, with the corresponding pooled OR (95% CI) of 1.13 (1.01-1.26), 1.04 (1.01-1.06) and 1.07 (1.02-1.13) per 10 μg/m³ increment. Overall, air pollution is a potential risk factor for body weight status in adults, and more high-quality studies, especially prospective studies from severely polluted regions, are warranted for comprehensive understanding of its health effects.

Association between exposure to fine particulate matter and obesity in children: A national representative cross-sectional study in China

BACKGROUND

Childhood obesity is a global health issue, and limited evidence suggests that air pollution may be a contributing factor. This study aims to examine whether exposure to fine particulate matter (PM_2.5) is associated with obesity status in a nationally representative sample of schoolchildren in China.

METHODS

The study population consisted of 41,439 schoolchildren of 6-17 years old, recruited from 30 provinces in China using a multi-stage stratified sampling method. Weights and heights were measured for all the participants, and sociodemographic information was collected using a questionnaire. The obesity status was classified following the Chinese national standards. The PM_2.5 exposure was estimated as the 5-year average concentration at the school location for each participant. The association between obesity status and PM_2.5 exposure was examined using weighted logistic regressions adjusted for potential confounders.

RESULTS

The prevalence of normal weight, overweight, and obesity were 78.5%, 12.4%, and 9.0%, respectively. PM_2.5 exposure averaged 59.8 ± 17.6 μg/m³ with a range of 30.5-115.2 μg/m³ among all the participants. The risk of obesity increased by 10.0% (95% confidence interval: 3.0-16.0%) per 10 μg/m³ increase in PM_2.5 exposure. The PM_2.5-associated risk was significantly elevated in older age groups and children living in urban areas (interaction p-values < 0.05).

CONCLUSIONS

This national survey revealed that approximately 1 in 5 Chinese schoolchildren were overweight or obese. Exposure to PM_2.5 in the ambient air was significantly associated with childhood obesity. The findings suggest the need for further research to uncover the roles of PM_2.5 exposure in childhood obesity development.

Associations of air pollution with obesity and body fat percentage, and modification by polygenic risk score for BMI in the UK Biobank

Air pollution has consistently been associated with cardiometabolic outcomes, although associations with obesity have only been recently reported. Studies of air pollution and adiposity have mostly relied on body mass index (BMI) rather than body fat percentage (BF%), and most have not accounted for noise as a possible confounder. Additionally, it is unknown whether genetic predisposition for obesity increases susceptibility to the obesogenic effects of air pollution. To help fill these gaps, we used the UK Biobank, a large, prospective cohort study in the United Kingdom, to explore the relationship between air pollution and adiposity, and modification by a polygenic risk score for BMI. We used 2010 annual averages of air pollution estimates from land use regression (NO₂, NO_X, PM_2.5, PM_{2.5absorbance}, PM_2.5-10, PM₁₀), traffic intensity (TI), inverse distance to road (IDTR), along with examiner-measured BMI, waist-hip-ratio (WHR), and impedance measures of BF%, which were collected at enrollment (2006-2010, n = 473,026) and at follow-up (2012-2013, n = 19,518). We estimated associations of air pollution with BMI, WHR, and BF% at enrollment and follow-up, and with obesity, abdominal obesity, and BF%-obesity at enrollment and follow-up. We used linear and logistic regression and controlled for noise and other covariates. We also assessed interactions of air pollution with a polygenic risk score for BMI. On average, participants at enrollment were 56 years of age, 54% were female, and 32% had completed college or a higher degree. Almost all participants (~95%) were white. All air pollution measures except IDTR were positively associated with at least one continuous measure of adiposity at enrollment. However, NO₂ was negatively associated with BMI but positively associated with WHR at enrollment, and IDTR was also negatively associated with BMI. At follow-up (controlling for enrollment adiposity), we observed positive associations for PM_2.5-10 with BMI, PM₁₀ with BF%, and TI with BF% and BMI. Associations were similar for binary measures of adiposity, with minor differences for some pollutants. Associations of NO_X, NO₂, PM_{2.5absorbance}, PM_2.5 and PM₁₀, with BMI at enrollment, but not at follow-up, were stronger among individuals with higher BMI polygenic risk scores (interaction p <0.05). In this large, prospective cohort, air pollution was associated with several measures of adiposity at enrollment and follow-up, and associations with adiposity at enrollment were modified by a polygenic risk score for obesity.

Ambient air pollution exposure and obesity-related traits in Korean adults

PURPOSE

Although some studies have tried to determine the impact of long-term air pollution exposure on obesity, they have mainly focused on body mass index (BMI) and the results are inconsistent. Therefore, we investigated the association of annual ambient air pollution exposure with various obesity traits, including computed tomography-measured abdominal fatness, in a large Korean adult population.

PATIENTS AND METHODS

A total of 5,114 participants who underwent routine health check-ups at Seoul National University Hospital were included in the analysis. We calculated the annual average concentrations of ambient air pollutants, such as particulate matter ≤10 μm in diameter (PM₁₀) and nitrogen dioxide (NO₂), using the individual's zip code. Obesity-related indicators included the BMI, waist circumference (WC), percent body fat (PBF), total adipose tissue (TAT), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT).

RESULTS

The mean age of the population was 53.5 and 70.9% were men. The mean annual concentrations of PM₁₀ and NO₂ were 49.4 μg/m³ and 30.3 ppb, respectively. In the full covariates model, adjusted for demographic and clinical variables, interquartile range increase in annual average concentration of PM₁₀ and NO₂ was not associated with any obesity-related phenotypes including BMI, WC, PBF, TAT, VAT, and SAT (all P>0.05). Likewise, no significant association between air pollutants and obesity-related traits was observed in any subgroups, stratified by sex and age (all P>0.05).

CONCLUSION

Annual exposure to ambient air pollution is not associated with any obesity-related traits in Korean adults.