Quantile regression to examine the association of air pollution with subclinical atherosclerosis in an adolescent population

Quantile regression to explore association of sleep duration with depression among adults in NHANES and KNHANES

BACKGROUND

Sleep duration has been associated with depression. However, mean regression, such as linear regression or logistic regression, may not capture relationships that occur mainly in the tails of outcome distribution. This study aimed to evaluate the associations between sleep duration and depression along the entire distribution of depression using quantile regression approach.

METHODS

This study included 55,954 adults aged 18 to 80 years from the National Health and Nutrition Examination Survey (N = 34,156) and the Korea National Health and Nutrition Examination Survey (N = 21,798). The coefficients corresponding to cross-group differences in PHQ-9 scores were estimated when comparing short or long sleep duration with normal sleep duration on deciles of PHQ-9 score distribution.

RESULTS

At lower quantiles, either short or long sleep duration was not associated with depression. At higher quantiles, the association of both short and long sleep duration with depression became much more pronounced. Compared with normal sleep duration, short and long sleep duration were associated with increases of 1.34 (95 % CI: 1.16, 1.51) and 0.28 (95 % CI: 0.04, 0.52) in PHQ-9 scores at the 50th quantile, while the corresponding increases were 3.27 (95 % CI: 2.83, 3.72) and 1.65 (95 % CI: 0.86, 2.45) at the 90th quantile, respectively. We also found that the magnitude of association between short sleep duration and depression was stronger among females and individuals with chronic diseases.

CONCLUSIONS

The beneficial effect of sufficient sleep in decreasing depression severity may be more evident among individuals with severe depression. Further studies could explore whether these heterogeneous associations can be generalized to populations with different characteristics.

Air Pollution, Built Environment, and Early Cardiovascular Disease

As the world's population becomes increasingly urbanized, there is growing concern about the impact of urban environments on cardiovascular health. Urban residents are exposed to a variety of adverse environmental exposures throughout their lives, including air pollution, built environment, and lack of green space, which may contribute to the development of early cardiovascular disease and related risk factors. While epidemiological studies have examined the role of a few environmental factors with early cardiovascular disease, the relationship with the broader environment remains poorly defined. In this article, we provide a brief overview of studies that have examined the impact of the environment including the built physical environment, discuss current challenges in the field, and suggest potential directions for future research. Additionally, we highlight the clinical implications of these findings and propose multilevel interventions to promote cardiovascular health among children and young adults.

Associations of time-weighted individual exposure to ambient particulate matter with carotid atherosclerosis in Beijing, China

BACKGROUND

Time-location information (time spent on commuting, indoors and outdoors around residential and work places and physical activity) and infiltrated outdoor pollution was less considered estimating individual exposure to ambient air pollution. Studies investigating the association between individual exposure to particulate matter (PM) with aerodynamic diameter < 10 μm (PM₁₀) and < 2.5 μm (PM_2.5) and carotid atherosclerosis presented inconsistent results. Moreover, combined effect of pollutants on carotid atherosclerosis was not fully explored. We aimed to investigate the association between long-term individual time-weighted average exposure to PM_2.5 and PM₁₀ and the risk of carotid atherosclerosis, and further explore the overall effect of co-exposure to pollutants on carotid atherosclerosis.

METHODS

The study population included 3069 participants derived from the Beijing Health Management Cohort (BHMC) study. Daily concentration of ambient air pollutants was estimated by land-use regression model at both residential and work addresses, and one- and two-year time-weighted average individual exposure was calculated by further considering personal activity pattern and infiltration of ambient air pollution indoors. We explored the association of PM_2.5 and PM₁₀ with carotid atherosclerosis and pooled the overall effect of co-exposure to ambient air pollutants by quantile g-computation.

RESULTS

A significant association between time-weighted average exposure to PM_2.5 and PM₁₀ and carotid atherosclerosis was observed. Per interquartile range increase in two-year exposure to PM_2.5 (Hazard ratio (HR): 1.322, 95% confidence interval (CI): 1.219-1.434) and PM₁₀ (HR:1.213, 95% CI: 1.116-1.319) showed the strongest association with carotid atherosclerosis, respectively. Individuals in higher quartiles of pollutants were at higher risk for carotid atherosclerosis compared with those in the lowest quartile group. Concentration response functions documented the nearly linear and nonlinear relationship and interpreted the upward trends of the risk for carotid atherosclerosis with increasing level of pollutant concentrations. Moreover, effect estimates for the mixture of pollutants and carotid atherosclerosis were larger than any of the individual pollutants (HR (95% CI) was 1.510 (1.338-1.704) and 1.613 (1.428-1.822) per quartile increase for one-year and two-year time-weighted average exposure, respectively).

CONCLUSIONS

Individual time-weighted average exposure to PM_2.5 and PM₁₀ was associated with carotid atherosclerosis. Co-exposure to ambient air pollution was also positively associated with carotid atherosclerosis.

Pollution from fine particulate matter and atherosclerosis: A narrative review

According to the WHO, the entire global population is exposed to air pollution levels higher than recommended for health preservation. Air pollution is a complex mixture of nano- to micro-sized particles and gaseous components that poses a major global threat to public health. Among the most important air pollutants, causal associations have been established between particulate matter (PM), mainly < 2.5 μm, and cardiovascular diseases (CVD), i.e., hypertension, coronary artery disease, ischemic stroke, congestive heart failure, arrhythmias as well as total cardiovascular mortality. Aim of this narrative review is to describe and critically discuss the proatherogenic effects of PM_2.5 that have been attributed to many direct or indirect effects comprising endothelial dysfunction, a chronic low-grade inflammatory state, increased production of reactive oxygen species, mitochondrial dysfunction and activation of metalloproteases, all leading to unstable arterial plaques. Higher concentrations of air pollutants are associated with the presence of vulnerable plaques and plaque ruptures witnessing coronary artery instability. Air pollution is often disregarded as a CVD risk factor, in spite of the fact that it is one of the main modifiable factors relevant for prevention and management of CVD. Thus, not only structural actions should be taken in order to mitigate emissions, but health professionals should also take care to counsel patients on the risks of air pollution.

A review of cardiovascular effects and underlying mechanisms of legacy and emerging per- and polyfluoroalkyl substances (PFAS)

Cardiovascular disease (CVD) poses the leading threats to human health and life, and their occurrence and severity are associated with exposure to environmental pollutants. Per- and polyfluoroalkyl substances (PFAS), a group of widely used industrial chemicals, are characterized by persistence, long-distance migration, bioaccumulation, and toxicity. Some PFAS, particularly perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexanesulfonic acid (PFHxS), have been banned, leaving only legacy exposure to the environment and human body, while a number of novel PFAS alternatives have emerged and raised concerns, such as polyfluoroalkyl ether sulfonic and carboxylic acid (PFESA and PFECA) and sodium p-perfluorous nonenoxybenzene sulfonate (OBS). Overall, this review systematically elucidated the adverse cardiovascular (CV) effects of legacy and emerging PFAS, emphasized the dose/concentration-dependent, time-dependent, carbon chain length-dependent, sex-specific, and coexposure effects, and discussed the underlying mechanisms and possible prevention and treatment. Extensive epidemiological and laboratory evidence suggests that accumulated serum levels of legacy PFAS possibly contribute to an increased risk of CVD and its subclinical course, such as cardiac toxicity, vascular disorder, hypertension, and dyslipidemia. The underlying biological mechanisms may include oxidative stress, signaling pathway disturbance, lipid metabolism disturbance, and so on. Various emerging alternatives to PFAS also play increasingly prominent toxic roles in CV outcomes that are milder, similar to, or more severe than legacy PFAS. Future research is recommended to conduct more in-depth CV toxicity assessments of legacy and emerging PFAS and explore more effective surveillance, prevention, and treatment strategies, accordingly.